25
26 #include "precompiled.hpp"
27 #include "classfile/classLoaderData.inline.hpp"
28 #include "classfile/classLoaderDataGraph.hpp"
29 #include "classfile/javaClasses.inline.hpp"
30 #include "classfile/symbolTable.hpp"
31 #include "classfile/vmClasses.hpp"
32 #include "classfile/vmSymbols.hpp"
33 #include "gc/shared/gcLocker.hpp"
34 #include "gc/shared/gcVMOperations.hpp"
35 #include "gc/shared/workerThread.hpp"
36 #include "jfr/jfrEvents.hpp"
37 #include "jvm.h"
38 #include "memory/allocation.inline.hpp"
39 #include "memory/resourceArea.hpp"
40 #include "memory/universe.hpp"
41 #include "oops/fieldStreams.inline.hpp"
42 #include "oops/klass.inline.hpp"
43 #include "oops/objArrayKlass.hpp"
44 #include "oops/objArrayOop.inline.hpp"
45 #include "oops/oop.inline.hpp"
46 #include "oops/typeArrayOop.inline.hpp"
47 #include "runtime/continuationWrapper.inline.hpp"
48 #include "runtime/frame.inline.hpp"
49 #include "runtime/handles.inline.hpp"
50 #include "runtime/javaCalls.hpp"
51 #include "runtime/javaThread.inline.hpp"
52 #include "runtime/jniHandles.hpp"
53 #include "runtime/os.hpp"
54 #include "runtime/threads.hpp"
55 #include "runtime/threadSMR.hpp"
56 #include "runtime/vframe.hpp"
57 #include "runtime/vmOperations.hpp"
58 #include "runtime/vmThread.hpp"
59 #include "runtime/timerTrace.hpp"
60 #include "services/heapDumper.hpp"
61 #include "services/heapDumperCompression.hpp"
62 #include "services/threadService.hpp"
63 #include "utilities/checkedCast.hpp"
64 #include "utilities/macros.hpp"
65 #include "utilities/ostream.hpp"
66 #ifdef LINUX
67 #include "os_linux.hpp"
299 * 7: double array
300 * 8: byte array
301 * 9: short array
302 * 10: int array
303 * 11: long array
304 * [u1]* elements
305 *
306 * HPROF_CPU_SAMPLES a set of sample traces of running threads
307 *
308 * u4 total number of samples
309 * u4 # of traces
310 * [u4 # of samples
311 * u4]* stack trace serial number
312 *
313 * HPROF_CONTROL_SETTINGS the settings of on/off switches
314 *
315 * u4 0x00000001: alloc traces on/off
316 * 0x00000002: cpu sampling on/off
317 * u2 stack trace depth
318 *
319 *
320 * When the header is "JAVA PROFILE 1.0.2" a heap dump can optionally
321 * be generated as a sequence of heap dump segments. This sequence is
322 * terminated by an end record. The additional tags allowed by format
323 * "JAVA PROFILE 1.0.2" are:
324 *
325 * HPROF_HEAP_DUMP_SEGMENT denote a heap dump segment
326 *
327 * [heap dump sub-records]*
328 * The same sub-record types allowed by HPROF_HEAP_DUMP
329 *
330 * HPROF_HEAP_DUMP_END denotes the end of a heap dump
331 *
332 */
333
334
335 // HPROF tags
336
337 enum hprofTag : u1 {
338 // top-level records
339 HPROF_UTF8 = 0x01,
340 HPROF_LOAD_CLASS = 0x02,
341 HPROF_UNLOAD_CLASS = 0x03,
342 HPROF_FRAME = 0x04,
343 HPROF_TRACE = 0x05,
344 HPROF_ALLOC_SITES = 0x06,
345 HPROF_HEAP_SUMMARY = 0x07,
346 HPROF_START_THREAD = 0x0A,
347 HPROF_END_THREAD = 0x0B,
348 HPROF_HEAP_DUMP = 0x0C,
349 HPROF_CPU_SAMPLES = 0x0D,
350 HPROF_CONTROL_SETTINGS = 0x0E,
351
352 // 1.0.2 record types
353 HPROF_HEAP_DUMP_SEGMENT = 0x1C,
354 HPROF_HEAP_DUMP_END = 0x2C,
355
356 // field types
357 HPROF_ARRAY_OBJECT = 0x01,
358 HPROF_NORMAL_OBJECT = 0x02,
359 HPROF_BOOLEAN = 0x04,
360 HPROF_CHAR = 0x05,
361 HPROF_FLOAT = 0x06,
362 HPROF_DOUBLE = 0x07,
363 HPROF_BYTE = 0x08,
364 HPROF_SHORT = 0x09,
365 HPROF_INT = 0x0A,
366 HPROF_LONG = 0x0B,
367
368 // data-dump sub-records
369 HPROF_GC_ROOT_UNKNOWN = 0xFF,
370 HPROF_GC_ROOT_JNI_GLOBAL = 0x01,
371 HPROF_GC_ROOT_JNI_LOCAL = 0x02,
372 HPROF_GC_ROOT_JAVA_FRAME = 0x03,
373 HPROF_GC_ROOT_NATIVE_STACK = 0x04,
374 HPROF_GC_ROOT_STICKY_CLASS = 0x05,
375 HPROF_GC_ROOT_THREAD_BLOCK = 0x06,
376 HPROF_GC_ROOT_MONITOR_USED = 0x07,
377 HPROF_GC_ROOT_THREAD_OBJ = 0x08,
378 HPROF_GC_CLASS_DUMP = 0x20,
379 HPROF_GC_INSTANCE_DUMP = 0x21,
380 HPROF_GC_OBJ_ARRAY_DUMP = 0x22,
381 HPROF_GC_PRIM_ARRAY_DUMP = 0x23
382 };
383
384 // Default stack trace ID (used for dummy HPROF_TRACE record)
385 enum {
386 STACK_TRACE_ID = 1,
387 INITIAL_CLASS_COUNT = 200
388 };
389
390 // Supports I/O operations for a dump
391 // Base class for dump and parallel dump
392 class AbstractDumpWriter : public CHeapObj<mtInternal> {
393 protected:
394 enum {
395 io_buffer_max_size = 1*M,
396 dump_segment_header_size = 9
397 };
398
399 char* _buffer; // internal buffer
400 size_t _size;
401 size_t _pos;
402
403 bool _in_dump_segment; // Are we currently in a dump segment?
404 bool _is_huge_sub_record; // Are we writing a sub-record larger than the buffer size?
405 DEBUG_ONLY(size_t _sub_record_left;) // The bytes not written for the current sub-record.
406 DEBUG_ONLY(bool _sub_record_ended;) // True if we have called the end_sub_record().
407
408 char* buffer() const { return _buffer; }
409 size_t buffer_size() const { return _size; }
722 }
723 }
724
725 class DumperClassCacheTable;
726 class DumperClassCacheTableEntry;
727
728 // Support class with a collection of functions used when dumping the heap
729 class DumperSupport : AllStatic {
730 public:
731
732 // write a header of the given type
733 static void write_header(AbstractDumpWriter* writer, hprofTag tag, u4 len);
734
735 // returns hprof tag for the given type signature
736 static hprofTag sig2tag(Symbol* sig);
737 // returns hprof tag for the given basic type
738 static hprofTag type2tag(BasicType type);
739 // Returns the size of the data to write.
740 static u4 sig2size(Symbol* sig);
741
742 // returns the size of the instance of the given class
743 static u4 instance_size(InstanceKlass* ik, DumperClassCacheTableEntry* class_cache_entry = nullptr);
744
745 // dump a jfloat
746 static void dump_float(AbstractDumpWriter* writer, jfloat f);
747 // dump a jdouble
748 static void dump_double(AbstractDumpWriter* writer, jdouble d);
749 // dumps the raw value of the given field
750 static void dump_field_value(AbstractDumpWriter* writer, char type, oop obj, int offset);
751 // returns the size of the static fields; also counts the static fields
752 static u4 get_static_fields_size(InstanceKlass* ik, u2& field_count);
753 // dumps static fields of the given class
754 static void dump_static_fields(AbstractDumpWriter* writer, Klass* k);
755 // dump the raw values of the instance fields of the given object
756 static void dump_instance_fields(AbstractDumpWriter* writer, oop o, DumperClassCacheTableEntry* class_cache_entry);
757 // get the count of the instance fields for a given class
758 static u2 get_instance_fields_count(InstanceKlass* ik);
759 // dumps the definition of the instance fields for a given class
760 static void dump_instance_field_descriptors(AbstractDumpWriter* writer, Klass* k);
761 // creates HPROF_GC_INSTANCE_DUMP record for the given object
762 static void dump_instance(AbstractDumpWriter* writer, oop o, DumperClassCacheTable* class_cache);
763 // creates HPROF_GC_CLASS_DUMP record for the given instance class
764 static void dump_instance_class(AbstractDumpWriter* writer, Klass* k);
765 // creates HPROF_GC_CLASS_DUMP record for a given array class
766 static void dump_array_class(AbstractDumpWriter* writer, Klass* k);
767
768 // creates HPROF_GC_OBJ_ARRAY_DUMP record for the given object array
769 static void dump_object_array(AbstractDumpWriter* writer, objArrayOop array);
770 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given type array
771 static void dump_prim_array(AbstractDumpWriter* writer, typeArrayOop array);
772 // create HPROF_FRAME record for the given method and bci
773 static void dump_stack_frame(AbstractDumpWriter* writer, int frame_serial_num, int class_serial_num, Method* m, int bci);
774
775 // check if we need to truncate an array
776 static int calculate_array_max_length(AbstractDumpWriter* writer, arrayOop array, short header_size);
777
778 // fixes up the current dump record and writes HPROF_HEAP_DUMP_END record
779 static void end_of_dump(AbstractDumpWriter* writer);
780
781 static oop mask_dormant_archived_object(oop o) {
782 if (o != nullptr && o->klass()->java_mirror() == nullptr) {
783 // Ignore this object since the corresponding java mirror is not loaded.
784 // Might be a dormant archive object.
785 return nullptr;
786 } else {
787 return o;
788 }
789 }
790 };
791
792 // Hash table of klasses to the klass metadata. This should greatly improve the
793 // hash dumping performance. This hash table is supposed to be used by a single
794 // thread only.
795 //
796 class DumperClassCacheTableEntry : public CHeapObj<mtServiceability> {
797 friend class DumperClassCacheTable;
798 private:
799 GrowableArray<char> _sigs_start;
800 GrowableArray<int> _offsets;
801 u4 _instance_size;
802 int _entries;
803
804 public:
805 DumperClassCacheTableEntry() : _instance_size(0), _entries(0) {};
806
807 int field_count() { return _entries; }
808 char sig_start(int field_idx) { return _sigs_start.at(field_idx); }
809 int offset(int field_idx) { return _offsets.at(field_idx); }
810 u4 instance_size() { return _instance_size; }
811 };
812
813 class DumperClassCacheTable {
814 private:
815 // ResourceHashtable SIZE is specified at compile time so we
816 // use 1031 which is the first prime after 1024.
817 static constexpr size_t TABLE_SIZE = 1031;
818
819 // Maintain the cache for N classes. This limits memory footprint
820 // impact, regardless of how many classes we have in the dump.
821 // This also improves look up performance by keeping the statically
822 // sized table from overloading.
823 static constexpr int CACHE_TOP = 256;
824
825 typedef ResourceHashtable<InstanceKlass*, DumperClassCacheTableEntry*,
826 TABLE_SIZE, AnyObj::C_HEAP, mtServiceability> PtrTable;
827 PtrTable* _ptrs;
828
837 bool do_entry(InstanceKlass*& key, DumperClassCacheTableEntry*& entry) {
838 delete entry;
839 return true;
840 }
841 } cleanup;
842 table->unlink(&cleanup);
843 }
844
845 public:
846 DumperClassCacheTableEntry* lookup_or_create(InstanceKlass* ik) {
847 if (_last_ik == ik) {
848 return _last_entry;
849 }
850
851 DumperClassCacheTableEntry* entry;
852 DumperClassCacheTableEntry** from_cache = _ptrs->get(ik);
853 if (from_cache == nullptr) {
854 entry = new DumperClassCacheTableEntry();
855 for (HierarchicalFieldStream<JavaFieldStream> fld(ik); !fld.done(); fld.next()) {
856 if (!fld.access_flags().is_static()) {
857 Symbol* sig = fld.signature();
858 entry->_sigs_start.push(sig->char_at(0));
859 entry->_offsets.push(fld.offset());
860 entry->_entries++;
861 entry->_instance_size += DumperSupport::sig2size(sig);
862 }
863 }
864
865 if (_ptrs->number_of_entries() >= CACHE_TOP) {
866 // We do not track the individual hit rates for table entries.
867 // Purge the entire table, and let the cache catch up with new
868 // distribution.
869 unlink_all(_ptrs);
870 }
871
872 _ptrs->put(ik, entry);
873 } else {
874 entry = *from_cache;
875 }
876
877 // Remember for single-slot cache.
878 _last_ik = ik;
879 _last_entry = entry;
880
881 return entry;
951 }
952
953 // dump a jfloat
954 void DumperSupport::dump_float(AbstractDumpWriter* writer, jfloat f) {
955 if (g_isnan(f)) {
956 writer->write_u4(0x7fc00000); // collapsing NaNs
957 } else {
958 writer->write_u4(bit_cast<u4>(f));
959 }
960 }
961
962 // dump a jdouble
963 void DumperSupport::dump_double(AbstractDumpWriter* writer, jdouble d) {
964 if (g_isnan(d)) {
965 writer->write_u8(0x7ff80000ull << 32); // collapsing NaNs
966 } else {
967 writer->write_u8(bit_cast<u8>(d));
968 }
969 }
970
971 // dumps the raw value of the given field
972 void DumperSupport::dump_field_value(AbstractDumpWriter* writer, char type, oop obj, int offset) {
973 switch (type) {
974 case JVM_SIGNATURE_CLASS :
975 case JVM_SIGNATURE_ARRAY : {
976 oop o = obj->obj_field_access<ON_UNKNOWN_OOP_REF | AS_NO_KEEPALIVE>(offset);
977 if (o != nullptr && log_is_enabled(Debug, cds, heap) && mask_dormant_archived_object(o) == nullptr) {
978 ResourceMark rm;
979 log_debug(cds, heap)("skipped dormant archived object " INTPTR_FORMAT " (%s) referenced by " INTPTR_FORMAT " (%s)",
980 p2i(o), o->klass()->external_name(),
981 p2i(obj), obj->klass()->external_name());
982 }
983 o = mask_dormant_archived_object(o);
984 assert(oopDesc::is_oop_or_null(o), "Expected an oop or nullptr at " PTR_FORMAT, p2i(o));
985 writer->write_objectID(o);
986 break;
987 }
988 case JVM_SIGNATURE_BYTE : {
989 jbyte b = obj->byte_field(offset);
990 writer->write_u1(b);
1015 writer->write_u4(i);
1016 break;
1017 }
1018 case JVM_SIGNATURE_LONG : {
1019 jlong l = obj->long_field(offset);
1020 writer->write_u8(l);
1021 break;
1022 }
1023 case JVM_SIGNATURE_BOOLEAN : {
1024 jboolean b = obj->bool_field(offset);
1025 writer->write_u1(b);
1026 break;
1027 }
1028 default : {
1029 ShouldNotReachHere();
1030 break;
1031 }
1032 }
1033 }
1034
1035 // returns the size of the instance of the given class
1036 u4 DumperSupport::instance_size(InstanceKlass* ik, DumperClassCacheTableEntry* class_cache_entry) {
1037 if (class_cache_entry != nullptr) {
1038 return class_cache_entry->instance_size();
1039 } else {
1040 u4 size = 0;
1041 for (HierarchicalFieldStream<JavaFieldStream> fld(ik); !fld.done(); fld.next()) {
1042 if (!fld.access_flags().is_static()) {
1043 size += sig2size(fld.signature());
1044 }
1045 }
1046 return size;
1047 }
1048 }
1049
1050 u4 DumperSupport::get_static_fields_size(InstanceKlass* ik, u2& field_count) {
1051 field_count = 0;
1052 u4 size = 0;
1053
1054 for (JavaFieldStream fldc(ik); !fldc.done(); fldc.next()) {
1055 if (fldc.access_flags().is_static()) {
1056 field_count++;
1057 size += sig2size(fldc.signature());
1058 }
1059 }
1060
1061 // Add in resolved_references which is referenced by the cpCache
1062 // The resolved_references is an array per InstanceKlass holding the
1063 // strings and other oops resolved from the constant pool.
1064 oop resolved_references = ik->constants()->resolved_references_or_null();
1065 if (resolved_references != nullptr) {
1066 field_count++;
1067 size += sizeof(address);
1068
1069 // Add in the resolved_references of the used previous versions of the class
1070 // in the case of RedefineClasses
1071 InstanceKlass* prev = ik->previous_versions();
1072 while (prev != nullptr && prev->constants()->resolved_references_or_null() != nullptr) {
1073 field_count++;
1074 size += sizeof(address);
1075 prev = prev->previous_versions();
1076 }
1077 }
1078
1079 // We write the value itself plus a name and a one byte type tag per field.
1080 return checked_cast<u4>(size + field_count * (sizeof(address) + 1));
1081 }
1082
1083 // dumps static fields of the given class
1084 void DumperSupport::dump_static_fields(AbstractDumpWriter* writer, Klass* k) {
1085 InstanceKlass* ik = InstanceKlass::cast(k);
1086
1087 // dump the field descriptors and raw values
1088 for (JavaFieldStream fld(ik); !fld.done(); fld.next()) {
1089 if (fld.access_flags().is_static()) {
1090 Symbol* sig = fld.signature();
1091
1092 writer->write_symbolID(fld.name()); // name
1093 writer->write_u1(sig2tag(sig)); // type
1094
1095 // value
1096 dump_field_value(writer, sig->char_at(0), ik->java_mirror(), fld.offset());
1097 }
1098 }
1099
1100 // Add resolved_references for each class that has them
1101 oop resolved_references = ik->constants()->resolved_references_or_null();
1102 if (resolved_references != nullptr) {
1103 writer->write_symbolID(vmSymbols::resolved_references_name()); // name
1104 writer->write_u1(sig2tag(vmSymbols::object_array_signature())); // type
1105 writer->write_objectID(resolved_references);
1106
1107 // Also write any previous versions
1108 InstanceKlass* prev = ik->previous_versions();
1109 while (prev != nullptr && prev->constants()->resolved_references_or_null() != nullptr) {
1110 writer->write_symbolID(vmSymbols::resolved_references_name()); // name
1111 writer->write_u1(sig2tag(vmSymbols::object_array_signature())); // type
1112 writer->write_objectID(prev->constants()->resolved_references());
1113 prev = prev->previous_versions();
1114 }
1115 }
1116 }
1117
1118 // dump the raw values of the instance fields of the given object
1119 void DumperSupport::dump_instance_fields(AbstractDumpWriter* writer, oop o, DumperClassCacheTableEntry* class_cache_entry) {
1120 assert(class_cache_entry != nullptr, "Pre-condition: must be provided");
1121 for (int idx = 0; idx < class_cache_entry->field_count(); idx++) {
1122 dump_field_value(writer, class_cache_entry->sig_start(idx), o, class_cache_entry->offset(idx));
1123 }
1124 }
1125
1126 // dumps the definition of the instance fields for a given class
1127 u2 DumperSupport::get_instance_fields_count(InstanceKlass* ik) {
1128 u2 field_count = 0;
1129
1130 for (JavaFieldStream fldc(ik); !fldc.done(); fldc.next()) {
1131 if (!fldc.access_flags().is_static()) field_count++;
1132 }
1133
1134 return field_count;
1135 }
1136
1137 // dumps the definition of the instance fields for a given class
1138 void DumperSupport::dump_instance_field_descriptors(AbstractDumpWriter* writer, Klass* k) {
1139 InstanceKlass* ik = InstanceKlass::cast(k);
1140
1141 // dump the field descriptors
1142 for (JavaFieldStream fld(ik); !fld.done(); fld.next()) {
1143 if (!fld.access_flags().is_static()) {
1144 Symbol* sig = fld.signature();
1145
1146 writer->write_symbolID(fld.name()); // name
1147 writer->write_u1(sig2tag(sig)); // type
1148 }
1149 }
1150 }
1151
1152 // creates HPROF_GC_INSTANCE_DUMP record for the given object
1153 void DumperSupport::dump_instance(AbstractDumpWriter* writer, oop o, DumperClassCacheTable* class_cache) {
1154 InstanceKlass* ik = InstanceKlass::cast(o->klass());
1155
1156 DumperClassCacheTableEntry* cache_entry = class_cache->lookup_or_create(ik);
1157
1158 u4 is = instance_size(ik, cache_entry);
1159 u4 size = 1 + sizeof(address) + 4 + sizeof(address) + 4 + is;
1160
1161 writer->start_sub_record(HPROF_GC_INSTANCE_DUMP, size);
1162 writer->write_objectID(o);
1163 writer->write_u4(STACK_TRACE_ID);
1164
1165 // class ID
1166 writer->write_classID(ik);
1167
1168 // number of bytes that follow
1169 writer->write_u4(is);
1170
1171 // field values
1172 dump_instance_fields(writer, o, cache_entry);
1173
1174 writer->end_sub_record();
1175 }
1176
1177 // creates HPROF_GC_CLASS_DUMP record for the given instance class
1178 void DumperSupport::dump_instance_class(AbstractDumpWriter* writer, Klass* k) {
1179 InstanceKlass* ik = InstanceKlass::cast(k);
1180
1181 // We can safepoint and do a heap dump at a point where we have a Klass,
1182 // but no java mirror class has been setup for it. So we need to check
1183 // that the class is at least loaded, to avoid crash from a null mirror.
1184 if (!ik->is_loaded()) {
1185 return;
1186 }
1187
1188 u2 static_fields_count = 0;
1189 u4 static_size = get_static_fields_size(ik, static_fields_count);
1190 u2 instance_fields_count = get_instance_fields_count(ik);
1191 u4 instance_fields_size = instance_fields_count * (sizeof(address) + 1);
1192 u4 size = checked_cast<u4>(1 + sizeof(address) + 4 + 6 * sizeof(address) + 4 + 2 + 2 + static_size + 2 + instance_fields_size);
1197 writer->write_classID(ik);
1198 writer->write_u4(STACK_TRACE_ID);
1199
1200 // super class ID
1201 InstanceKlass* java_super = ik->java_super();
1202 if (java_super == nullptr) {
1203 writer->write_objectID(oop(nullptr));
1204 } else {
1205 writer->write_classID(java_super);
1206 }
1207
1208 writer->write_objectID(ik->class_loader());
1209 writer->write_objectID(ik->signers());
1210 writer->write_objectID(ik->protection_domain());
1211
1212 // reserved
1213 writer->write_objectID(oop(nullptr));
1214 writer->write_objectID(oop(nullptr));
1215
1216 // instance size
1217 writer->write_u4(DumperSupport::instance_size(ik));
1218
1219 // size of constant pool - ignored by HAT 1.1
1220 writer->write_u2(0);
1221
1222 // static fields
1223 writer->write_u2(static_fields_count);
1224 dump_static_fields(writer, ik);
1225
1226 // description of instance fields
1227 writer->write_u2(instance_fields_count);
1228 dump_instance_field_descriptors(writer, ik);
1229
1230 writer->end_sub_record();
1231 }
1232
1233 // creates HPROF_GC_CLASS_DUMP record for the given array class
1234 void DumperSupport::dump_array_class(AbstractDumpWriter* writer, Klass* k) {
1235 InstanceKlass* ik = nullptr; // bottom class for object arrays, null for primitive type arrays
1236 if (k->is_objArray_klass()) {
1237 Klass *bk = ObjArrayKlass::cast(k)->bottom_klass();
1251 assert(java_super != nullptr, "checking");
1252 writer->write_classID(java_super);
1253
1254 writer->write_objectID(ik == nullptr ? oop(nullptr) : ik->class_loader());
1255 writer->write_objectID(ik == nullptr ? oop(nullptr) : ik->signers());
1256 writer->write_objectID(ik == nullptr ? oop(nullptr) : ik->protection_domain());
1257
1258 writer->write_objectID(oop(nullptr)); // reserved
1259 writer->write_objectID(oop(nullptr));
1260 writer->write_u4(0); // instance size
1261 writer->write_u2(0); // constant pool
1262 writer->write_u2(0); // static fields
1263 writer->write_u2(0); // instance fields
1264
1265 writer->end_sub_record();
1266
1267 }
1268
1269 // Hprof uses an u4 as record length field,
1270 // which means we need to truncate arrays that are too long.
1271 int DumperSupport::calculate_array_max_length(AbstractDumpWriter* writer, arrayOop array, short header_size) {
1272 BasicType type = ArrayKlass::cast(array->klass())->element_type();
1273 assert(type >= T_BOOLEAN && type <= T_OBJECT, "invalid array element type");
1274
1275 int length = array->length();
1276
1277 int type_size;
1278 if (type == T_OBJECT) {
1279 type_size = sizeof(address);
1280 } else {
1281 type_size = type2aelembytes(type);
1282 }
1283
1284 size_t length_in_bytes = (size_t)length * type_size;
1285 uint max_bytes = max_juint - header_size;
1286
1287 if (length_in_bytes > max_bytes) {
1288 length = max_bytes / type_size;
1289 length_in_bytes = (size_t)length * type_size;
1290
1291 warning("cannot dump array of type %s[] with length %d; truncating to length %d",
1292 type2name_tab[type], array->length(), length);
1293 }
1294 return length;
1295 }
1296
1297 // creates HPROF_GC_OBJ_ARRAY_DUMP record for the given object array
1298 void DumperSupport::dump_object_array(AbstractDumpWriter* writer, objArrayOop array) {
1299 // sizeof(u1) + 2 * sizeof(u4) + sizeof(objectID) + sizeof(classID)
1300 short header_size = 1 + 2 * 4 + 2 * sizeof(address);
1301 int length = calculate_array_max_length(writer, array, header_size);
1302 u4 size = checked_cast<u4>(header_size + length * sizeof(address));
1303
1304 writer->start_sub_record(HPROF_GC_OBJ_ARRAY_DUMP, size);
1305 writer->write_objectID(array);
1306 writer->write_u4(STACK_TRACE_ID);
1307 writer->write_u4(length);
1308
1309 // array class ID
1310 writer->write_classID(array->klass());
1311
1312 // [id]* elements
1313 for (int index = 0; index < length; index++) {
1314 oop o = array->obj_at(index);
1315 if (o != nullptr && log_is_enabled(Debug, cds, heap) && mask_dormant_archived_object(o) == nullptr) {
1316 ResourceMark rm;
1317 log_debug(cds, heap)("skipped dormant archived object " INTPTR_FORMAT " (%s) referenced by " INTPTR_FORMAT " (%s)",
1318 p2i(o), o->klass()->external_name(),
1319 p2i(array), array->klass()->external_name());
1320 }
1321 o = mask_dormant_archived_object(o);
1322 writer->write_objectID(o);
1323 }
1324
1325 writer->end_sub_record();
1326 }
1327
1328 #define WRITE_ARRAY(Array, Type, Size, Length) \
1329 for (int i = 0; i < Length; i++) { writer->write_##Size((Size)Array->Type##_at(i)); }
1330
1331 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given type array
1332 void DumperSupport::dump_prim_array(AbstractDumpWriter* writer, typeArrayOop array) {
1333 BasicType type = TypeArrayKlass::cast(array->klass())->element_type();
1334 // 2 * sizeof(u1) + 2 * sizeof(u4) + sizeof(objectID)
1335 short header_size = 2 * 1 + 2 * 4 + sizeof(address);
1336
1337 int length = calculate_array_max_length(writer, array, header_size);
1338 int type_size = type2aelembytes(type);
1339 u4 length_in_bytes = (u4)length * type_size;
1340 u4 size = header_size + length_in_bytes;
1341
1342 writer->start_sub_record(HPROF_GC_PRIM_ARRAY_DUMP, size);
1343 writer->write_objectID(array);
1344 writer->write_u4(STACK_TRACE_ID);
1345 writer->write_u4(length);
1346 writer->write_u1(type2tag(type));
1347
1429 int bci) {
1430 int line_number;
1431 if (m->is_native()) {
1432 line_number = -3; // native frame
1433 } else {
1434 line_number = m->line_number_from_bci(bci);
1435 }
1436
1437 write_header(writer, HPROF_FRAME, 4*oopSize + 2*sizeof(u4));
1438 writer->write_id(frame_serial_num); // frame serial number
1439 writer->write_symbolID(m->name()); // method's name
1440 writer->write_symbolID(m->signature()); // method's signature
1441
1442 assert(m->method_holder()->is_instance_klass(), "not InstanceKlass");
1443 writer->write_symbolID(m->method_holder()->source_file_name()); // source file name
1444 writer->write_u4(class_serial_num); // class serial number
1445 writer->write_u4((u4) line_number); // line number
1446 }
1447
1448
1449 // Support class used to generate HPROF_UTF8 records from the entries in the
1450 // SymbolTable.
1451
1452 class SymbolTableDumper : public SymbolClosure {
1453 private:
1454 AbstractDumpWriter* _writer;
1455 AbstractDumpWriter* writer() const { return _writer; }
1456 public:
1457 SymbolTableDumper(AbstractDumpWriter* writer) { _writer = writer; }
1458 void do_symbol(Symbol** p);
1459 };
1460
1461 void SymbolTableDumper::do_symbol(Symbol** p) {
1462 ResourceMark rm;
1463 Symbol* sym = *p;
1464 int len = sym->utf8_length();
1465 if (len > 0) {
1466 char* s = sym->as_utf8();
1467 DumperSupport::write_header(writer(), HPROF_UTF8, oopSize + len);
1468 writer()->write_symbolID(sym);
1879
1880 void HeapObjectDumper::do_object(oop o) {
1881 // skip classes as these emitted as HPROF_GC_CLASS_DUMP records
1882 if (o->klass() == vmClasses::Class_klass()) {
1883 if (!java_lang_Class::is_primitive(o)) {
1884 return;
1885 }
1886 }
1887
1888 if (DumperSupport::mask_dormant_archived_object(o) == nullptr) {
1889 log_debug(cds, heap)("skipped dormant archived object " INTPTR_FORMAT " (%s)", p2i(o), o->klass()->external_name());
1890 return;
1891 }
1892
1893 if (o->is_instance()) {
1894 // create a HPROF_GC_INSTANCE record for each object
1895 DumperSupport::dump_instance(writer(), o, &_class_cache);
1896 } else if (o->is_objArray()) {
1897 // create a HPROF_GC_OBJ_ARRAY_DUMP record for each object array
1898 DumperSupport::dump_object_array(writer(), objArrayOop(o));
1899 } else if (o->is_typeArray()) {
1900 // create a HPROF_GC_PRIM_ARRAY_DUMP record for each type array
1901 DumperSupport::dump_prim_array(writer(), typeArrayOop(o));
1902 }
1903 }
1904
1905 // The dumper controller for parallel heap dump
1906 class DumperController : public CHeapObj<mtInternal> {
1907 private:
1908 Monitor* _lock;
1909 const uint _dumper_number;
1910 uint _complete_number;
1911
1912 public:
1913 DumperController(uint number) :
1914 _lock(new (std::nothrow) PaddedMonitor(Mutex::safepoint, "DumperController_lock")),
1915 _dumper_number(number),
1916 _complete_number(0) { }
1917
1918 ~DumperController() { delete _lock; }
1922 _complete_number++;
1923 // propagate local error to global if any
1924 if (local_writer->has_error()) {
1925 global_writer->set_error(local_writer->error());
1926 }
1927 ml.notify();
1928 }
1929
1930 void wait_all_dumpers_complete() {
1931 MonitorLocker ml(_lock, Mutex::_no_safepoint_check_flag);
1932 while (_complete_number != _dumper_number) {
1933 ml.wait();
1934 }
1935 }
1936 };
1937
1938 // DumpMerger merges separate dump files into a complete one
1939 class DumpMerger : public StackObj {
1940 private:
1941 DumpWriter* _writer;
1942 const char* _path;
1943 bool _has_error;
1944 int _dump_seq;
1945
1946 private:
1947 void merge_file(char* path);
1948 void merge_done();
1949 void set_error(const char* msg);
1950
1951 public:
1952 DumpMerger(const char* path, DumpWriter* writer, int dump_seq) :
1953 _writer(writer),
1954 _path(path),
1955 _has_error(_writer->has_error()),
1956 _dump_seq(dump_seq) {}
1957
1958 void do_merge();
1959 };
1960
1961 void DumpMerger::merge_done() {
1962 // Writes the HPROF_HEAP_DUMP_END record.
1963 if (!_has_error) {
1964 DumperSupport::end_of_dump(_writer);
1965 _writer->flush();
1966 }
1967 _dump_seq = 0; //reset
1968 }
1969
1970 void DumpMerger::set_error(const char* msg) {
1971 assert(msg != nullptr, "sanity check");
1972 log_error(heapdump)("%s (file: %s)", msg, _path);
1973 _writer->set_error(msg);
1974 _has_error = true;
1975 }
1976
1977 #ifdef LINUX
1978 // Merge segmented heap files via sendfile, it's more efficient than the
1979 // read+write combination, which would require transferring data to and from
1980 // user space.
1981 void DumpMerger::merge_file(char* path) {
1982 assert(!SafepointSynchronize::is_at_safepoint(), "merging happens outside safepoint");
1983 TraceTime timer("Merge segmented heap file directly", TRACETIME_LOG(Info, heapdump));
1984
1985 int segment_fd = os::open(path, O_RDONLY, 0);
2084 }
2085 };
2086
2087 // The VM operation that performs the heap dump
2088 class VM_HeapDumper : public VM_GC_Operation, public WorkerTask {
2089 private:
2090 static VM_HeapDumper* _global_dumper;
2091 static DumpWriter* _global_writer;
2092 DumpWriter* _local_writer;
2093 JavaThread* _oome_thread;
2094 Method* _oome_constructor;
2095 bool _gc_before_heap_dump;
2096 GrowableArray<Klass*>* _klass_map;
2097
2098 ThreadDumper** _thread_dumpers; // platform, carrier and mounted virtual threads
2099 int _thread_dumpers_count;
2100 volatile int _thread_serial_num;
2101 volatile int _frame_serial_num;
2102
2103 volatile int _dump_seq;
2104 // parallel heap dump support
2105 uint _num_dumper_threads;
2106 DumperController* _dumper_controller;
2107 ParallelObjectIterator* _poi;
2108 // worker id of VMDumper thread.
2109 static const size_t VMDumperWorkerId = 0;
2110 // VM dumper dumps both heap and non-heap data, other dumpers dump heap-only data.
2111 static bool is_vm_dumper(uint worker_id) { return worker_id == VMDumperWorkerId; }
2112
2113 // accessors and setters
2114 static VM_HeapDumper* dumper() { assert(_global_dumper != nullptr, "Error"); return _global_dumper; }
2115 static DumpWriter* writer() { assert(_global_writer != nullptr, "Error"); return _global_writer; }
2116
2117 void set_global_dumper() {
2118 assert(_global_dumper == nullptr, "Error");
2119 _global_dumper = this;
2120 }
2121 void set_global_writer() {
2122 assert(_global_writer == nullptr, "Error");
2123 _global_writer = _local_writer;
2185 }
2186
2187 ~VM_HeapDumper() {
2188 if (_thread_dumpers != nullptr) {
2189 for (int i = 0; i < _thread_dumpers_count; i++) {
2190 delete _thread_dumpers[i];
2191 }
2192 FREE_C_HEAP_ARRAY(ThreadDumper*, _thread_dumpers);
2193 }
2194
2195 if (_dumper_controller != nullptr) {
2196 delete _dumper_controller;
2197 _dumper_controller = nullptr;
2198 }
2199 delete _klass_map;
2200 }
2201 int dump_seq() { return _dump_seq; }
2202 bool is_parallel_dump() { return _num_dumper_threads > 1; }
2203 bool can_parallel_dump(WorkerThreads* workers);
2204
2205 VMOp_Type type() const { return VMOp_HeapDumper; }
2206 virtual bool doit_prologue();
2207 void doit();
2208 void work(uint worker_id);
2209 };
2210
2211 VM_HeapDumper* VM_HeapDumper::_global_dumper = nullptr;
2212 DumpWriter* VM_HeapDumper::_global_writer = nullptr;
2213
2214 bool VM_HeapDumper::skip_operation() const {
2215 return false;
2216 }
2217
2218 // fixes up the current dump record and writes HPROF_HEAP_DUMP_END record
2219 void DumperSupport::end_of_dump(AbstractDumpWriter* writer) {
2220 writer->finish_dump_segment();
2221
2222 writer->write_u1(HPROF_HEAP_DUMP_END);
2223 writer->write_u4(0);
2224 writer->write_u4(0);
2382 DumpWriter* local_writer = new DumpWriter(path, writer()->is_overwrite(), compressor);
2383 return local_writer;
2384 }
2385
2386 void VM_HeapDumper::work(uint worker_id) {
2387 // VM Dumper works on all non-heap data dumping and part of heap iteration.
2388 if (is_vm_dumper(worker_id)) {
2389 TraceTime timer("Dump non-objects", TRACETIME_LOG(Info, heapdump));
2390 // Write the file header - we always use 1.0.2
2391 const char* header = "JAVA PROFILE 1.0.2";
2392
2393 // header is few bytes long - no chance to overflow int
2394 writer()->write_raw(header, strlen(header) + 1); // NUL terminated
2395 writer()->write_u4(oopSize);
2396 // timestamp is current time in ms
2397 writer()->write_u8(os::javaTimeMillis());
2398 // HPROF_UTF8 records
2399 SymbolTableDumper sym_dumper(writer());
2400 SymbolTable::symbols_do(&sym_dumper);
2401
2402 // write HPROF_LOAD_CLASS records
2403 {
2404 LockedClassesDo locked_load_classes(&do_load_class);
2405 ClassLoaderDataGraph::classes_do(&locked_load_classes);
2406 }
2407
2408 // write HPROF_FRAME and HPROF_TRACE records
2409 // this must be called after _klass_map is built when iterating the classes above.
2410 dump_stack_traces();
2411
2412 // HPROF_HEAP_DUMP/HPROF_HEAP_DUMP_SEGMENT starts here
2413
2414 // Writes HPROF_GC_CLASS_DUMP records
2415 {
2416 LockedClassesDo locked_dump_class(&do_class_dump);
2417 ClassLoaderDataGraph::classes_do(&locked_dump_class);
2418 }
2419
2420 // HPROF_GC_ROOT_THREAD_OBJ + frames + jni locals
2421 dump_threads();
2433 ClassLoaderData::the_null_class_loader_data()->classes_do(&class_dumper);
2434 }
2435
2436 // Heap iteration.
2437 // writes HPROF_GC_INSTANCE_DUMP records.
2438 // After each sub-record is written check_segment_length will be invoked
2439 // to check if the current segment exceeds a threshold. If so, a new
2440 // segment is started.
2441 // The HPROF_GC_CLASS_DUMP and HPROF_GC_INSTANCE_DUMP are the vast bulk
2442 // of the heap dump.
2443 if (!is_parallel_dump()) {
2444 assert(is_vm_dumper(worker_id), "must be");
2445 // == Serial dump
2446 ResourceMark rm;
2447 TraceTime timer("Dump heap objects", TRACETIME_LOG(Info, heapdump));
2448 HeapObjectDumper obj_dumper(writer());
2449 Universe::heap()->object_iterate(&obj_dumper);
2450 writer()->finish_dump_segment();
2451 // Writes the HPROF_HEAP_DUMP_END record because merge does not happen in serial dump
2452 DumperSupport::end_of_dump(writer());
2453 writer()->flush();
2454 } else {
2455 // == Parallel dump
2456 ResourceMark rm;
2457 TraceTime timer("Dump heap objects in parallel", TRACETIME_LOG(Info, heapdump));
2458 DumpWriter* local_writer = is_vm_dumper(worker_id) ? writer() : create_local_writer();
2459 if (!local_writer->has_error()) {
2460 HeapObjectDumper obj_dumper(local_writer);
2461 _poi->object_iterate(&obj_dumper, worker_id);
2462 local_writer->finish_dump_segment();
2463 local_writer->flush();
2464 }
2465 if (is_vm_dumper(worker_id)) {
2466 _dumper_controller->wait_all_dumpers_complete();
2467 } else {
2468 _dumper_controller->dumper_complete(local_writer, writer());
2469 delete local_writer;
2470 return;
2471 }
2472 }
2473 // At this point, all fragments of the heapdump have been written to separate files.
2552 return -1;
2553 }
2554
2555 // generate the segmented heap dump into separate files
2556 VM_HeapDumper dumper(&writer, _gc_before_heap_dump, _oome, num_dump_threads);
2557 VMThread::execute(&dumper);
2558
2559 // record any error that the writer may have encountered
2560 set_error(writer.error());
2561
2562 // For serial dump, once VM_HeapDumper completes, the whole heap dump process
2563 // is done, no further phases needed. For parallel dump, the whole heap dump
2564 // process is done in two phases
2565 //
2566 // Phase 1: Concurrent threads directly write heap data to multiple heap files.
2567 // This is done by VM_HeapDumper, which is performed within safepoint.
2568 //
2569 // Phase 2: Merge multiple heap files into one complete heap dump file.
2570 // This is done by DumpMerger, which is performed outside safepoint
2571 if (dumper.is_parallel_dump()) {
2572 DumpMerger merger(path, &writer, dumper.dump_seq());
2573 Thread* current_thread = Thread::current();
2574 if (current_thread->is_AttachListener_thread()) {
2575 // perform heapdump file merge operation in the current thread prevents us
2576 // from occupying the VM Thread, which in turn affects the occurrence of
2577 // GC and other VM operations.
2578 merger.do_merge();
2579 } else {
2580 // otherwise, performs it by VM thread
2581 VM_HeapDumpMerge op(&merger);
2582 VMThread::execute(&op);
2583 }
2584 set_error(writer.error());
2585 }
2586
2587 // emit JFR event
2588 if (error() == nullptr) {
2589 event.set_destination(path);
2590 event.set_gcBeforeDump(_gc_before_heap_dump);
2591 event.set_size(writer.bytes_written());
2592 event.set_onOutOfMemoryError(_oome);
|
25
26 #include "precompiled.hpp"
27 #include "classfile/classLoaderData.inline.hpp"
28 #include "classfile/classLoaderDataGraph.hpp"
29 #include "classfile/javaClasses.inline.hpp"
30 #include "classfile/symbolTable.hpp"
31 #include "classfile/vmClasses.hpp"
32 #include "classfile/vmSymbols.hpp"
33 #include "gc/shared/gcLocker.hpp"
34 #include "gc/shared/gcVMOperations.hpp"
35 #include "gc/shared/workerThread.hpp"
36 #include "jfr/jfrEvents.hpp"
37 #include "jvm.h"
38 #include "memory/allocation.inline.hpp"
39 #include "memory/resourceArea.hpp"
40 #include "memory/universe.hpp"
41 #include "oops/fieldStreams.inline.hpp"
42 #include "oops/klass.inline.hpp"
43 #include "oops/objArrayKlass.hpp"
44 #include "oops/objArrayOop.inline.hpp"
45 #include "oops/flatArrayKlass.hpp"
46 #include "oops/flatArrayOop.inline.hpp"
47 #include "oops/oop.inline.hpp"
48 #include "oops/typeArrayOop.inline.hpp"
49 #include "runtime/continuationWrapper.inline.hpp"
50 #include "runtime/fieldDescriptor.inline.hpp"
51 #include "runtime/frame.inline.hpp"
52 #include "runtime/handles.inline.hpp"
53 #include "runtime/javaCalls.hpp"
54 #include "runtime/javaThread.inline.hpp"
55 #include "runtime/jniHandles.hpp"
56 #include "runtime/os.hpp"
57 #include "runtime/threads.hpp"
58 #include "runtime/threadSMR.hpp"
59 #include "runtime/vframe.hpp"
60 #include "runtime/vmOperations.hpp"
61 #include "runtime/vmThread.hpp"
62 #include "runtime/timerTrace.hpp"
63 #include "services/heapDumper.hpp"
64 #include "services/heapDumperCompression.hpp"
65 #include "services/threadService.hpp"
66 #include "utilities/checkedCast.hpp"
67 #include "utilities/macros.hpp"
68 #include "utilities/ostream.hpp"
69 #ifdef LINUX
70 #include "os_linux.hpp"
302 * 7: double array
303 * 8: byte array
304 * 9: short array
305 * 10: int array
306 * 11: long array
307 * [u1]* elements
308 *
309 * HPROF_CPU_SAMPLES a set of sample traces of running threads
310 *
311 * u4 total number of samples
312 * u4 # of traces
313 * [u4 # of samples
314 * u4]* stack trace serial number
315 *
316 * HPROF_CONTROL_SETTINGS the settings of on/off switches
317 *
318 * u4 0x00000001: alloc traces on/off
319 * 0x00000002: cpu sampling on/off
320 * u2 stack trace depth
321 *
322 * HPROF_FLAT_ARRAYS list of flat arrays
323 *
324 * [flat array sub-records]*
325 *
326 * HPROF_FLAT_ARRAY flat array
327 *
328 * id array object ID (dumped as HPROF_GC_PRIM_ARRAY_DUMP)
329 * id element class ID (dumped by HPROF_GC_CLASS_DUMP)
330 *
331 * HPROF_INLINED_FIELDS decribes inlined fields
332 *
333 * [class with inlined fields sub-records]*
334 *
335 * HPROF_CLASS_WITH_INLINED_FIELDS
336 *
337 * id class ID (dumped as HPROF_GC_CLASS_DUMP)
338 *
339 * u2 number of instance inlined fields (not including super)
340 * [u2, inlined field index,
341 * u2, synthetic field count,
342 * id, original field name,
343 * id]* inlined field class ID (dumped by HPROF_GC_CLASS_DUMP)
344 *
345 * When the header is "JAVA PROFILE 1.0.2" a heap dump can optionally
346 * be generated as a sequence of heap dump segments. This sequence is
347 * terminated by an end record. The additional tags allowed by format
348 * "JAVA PROFILE 1.0.2" are:
349 *
350 * HPROF_HEAP_DUMP_SEGMENT denote a heap dump segment
351 *
352 * [heap dump sub-records]*
353 * The same sub-record types allowed by HPROF_HEAP_DUMP
354 *
355 * HPROF_HEAP_DUMP_END denotes the end of a heap dump
356 *
357 */
358
359
360 // HPROF tags
361
362 enum hprofTag : u1 {
363 // top-level records
364 HPROF_UTF8 = 0x01,
365 HPROF_LOAD_CLASS = 0x02,
366 HPROF_UNLOAD_CLASS = 0x03,
367 HPROF_FRAME = 0x04,
368 HPROF_TRACE = 0x05,
369 HPROF_ALLOC_SITES = 0x06,
370 HPROF_HEAP_SUMMARY = 0x07,
371 HPROF_START_THREAD = 0x0A,
372 HPROF_END_THREAD = 0x0B,
373 HPROF_HEAP_DUMP = 0x0C,
374 HPROF_CPU_SAMPLES = 0x0D,
375 HPROF_CONTROL_SETTINGS = 0x0E,
376
377 // 1.0.2 record types
378 HPROF_HEAP_DUMP_SEGMENT = 0x1C,
379 HPROF_HEAP_DUMP_END = 0x2C,
380
381 // inlined object support
382 HPROF_FLAT_ARRAYS = 0x12,
383 HPROF_INLINED_FIELDS = 0x13,
384 // inlined object subrecords
385 HPROF_FLAT_ARRAY = 0x01,
386 HPROF_CLASS_WITH_INLINED_FIELDS = 0x01,
387
388 // field types
389 HPROF_ARRAY_OBJECT = 0x01,
390 HPROF_NORMAL_OBJECT = 0x02,
391 HPROF_BOOLEAN = 0x04,
392 HPROF_CHAR = 0x05,
393 HPROF_FLOAT = 0x06,
394 HPROF_DOUBLE = 0x07,
395 HPROF_BYTE = 0x08,
396 HPROF_SHORT = 0x09,
397 HPROF_INT = 0x0A,
398 HPROF_LONG = 0x0B,
399
400 // data-dump sub-records
401 HPROF_GC_ROOT_UNKNOWN = 0xFF,
402 HPROF_GC_ROOT_JNI_GLOBAL = 0x01,
403 HPROF_GC_ROOT_JNI_LOCAL = 0x02,
404 HPROF_GC_ROOT_JAVA_FRAME = 0x03,
405 HPROF_GC_ROOT_NATIVE_STACK = 0x04,
406 HPROF_GC_ROOT_STICKY_CLASS = 0x05,
407 HPROF_GC_ROOT_THREAD_BLOCK = 0x06,
408 HPROF_GC_ROOT_MONITOR_USED = 0x07,
409 HPROF_GC_ROOT_THREAD_OBJ = 0x08,
410 HPROF_GC_CLASS_DUMP = 0x20,
411 HPROF_GC_INSTANCE_DUMP = 0x21,
412 HPROF_GC_OBJ_ARRAY_DUMP = 0x22,
413 HPROF_GC_PRIM_ARRAY_DUMP = 0x23
414 };
415
416 // Default stack trace ID (used for dummy HPROF_TRACE record)
417 enum {
418 STACK_TRACE_ID = 1,
419 INITIAL_CLASS_COUNT = 200
420 };
421
422
423 class AbstractDumpWriter;
424
425 class InlinedObjects {
426
427 struct ClassInlinedFields {
428 const Klass *klass;
429 uintx base_index; // base index of the inlined field names (1st field has index base_index+1).
430 ClassInlinedFields(const Klass *klass = nullptr, uintx base_index = 0) : klass(klass), base_index(base_index) {}
431
432 // For GrowableArray::find_sorted().
433 static int compare(const ClassInlinedFields& a, const ClassInlinedFields& b) {
434 return a.klass - b.klass;
435 }
436 // For GrowableArray::sort().
437 static int compare(ClassInlinedFields* a, ClassInlinedFields* b) {
438 return compare(*a, *b);
439 }
440 };
441
442 uintx _min_string_id;
443 uintx _max_string_id;
444
445 GrowableArray<ClassInlinedFields> *_inlined_field_map;
446
447 // counters for classes with inlined fields and for the fields
448 int _classes_count;
449 int _inlined_fields_count;
450
451 static InlinedObjects *_instance;
452
453 static void inlined_field_names_callback(InlinedObjects* _this, const Klass *klass, uintx base_index, int count);
454
455 GrowableArray<oop> *_flat_arrays;
456
457 public:
458 InlinedObjects()
459 : _min_string_id(0), _max_string_id(0),
460 _inlined_field_map(nullptr),
461 _classes_count(0), _inlined_fields_count(0),
462 _flat_arrays(nullptr) {
463 }
464
465 static InlinedObjects* get_instance() {
466 return _instance;
467 }
468
469 void init();
470 void release();
471
472 void dump_inlined_field_names(AbstractDumpWriter *writer);
473
474 uintx get_base_index_for(Klass* k);
475 uintx get_next_string_id(uintx id);
476
477 void dump_classed_with_inlined_fields(AbstractDumpWriter* writer);
478
479 void add_flat_array(oop array);
480 void dump_flat_arrays(AbstractDumpWriter* writer);
481
482 };
483
484 InlinedObjects *InlinedObjects::_instance = nullptr;
485
486
487 // Supports I/O operations for a dump
488 // Base class for dump and parallel dump
489 class AbstractDumpWriter : public CHeapObj<mtInternal> {
490 protected:
491 enum {
492 io_buffer_max_size = 1*M,
493 dump_segment_header_size = 9
494 };
495
496 char* _buffer; // internal buffer
497 size_t _size;
498 size_t _pos;
499
500 bool _in_dump_segment; // Are we currently in a dump segment?
501 bool _is_huge_sub_record; // Are we writing a sub-record larger than the buffer size?
502 DEBUG_ONLY(size_t _sub_record_left;) // The bytes not written for the current sub-record.
503 DEBUG_ONLY(bool _sub_record_ended;) // True if we have called the end_sub_record().
504
505 char* buffer() const { return _buffer; }
506 size_t buffer_size() const { return _size; }
819 }
820 }
821
822 class DumperClassCacheTable;
823 class DumperClassCacheTableEntry;
824
825 // Support class with a collection of functions used when dumping the heap
826 class DumperSupport : AllStatic {
827 public:
828
829 // write a header of the given type
830 static void write_header(AbstractDumpWriter* writer, hprofTag tag, u4 len);
831
832 // returns hprof tag for the given type signature
833 static hprofTag sig2tag(Symbol* sig);
834 // returns hprof tag for the given basic type
835 static hprofTag type2tag(BasicType type);
836 // Returns the size of the data to write.
837 static u4 sig2size(Symbol* sig);
838
839 // calculates the total size of the all fields of the given class.
840 static u4 instance_size(InstanceKlass* ik, DumperClassCacheTableEntry* class_cache_entry = nullptr);
841
842 // dump a jfloat
843 static void dump_float(AbstractDumpWriter* writer, jfloat f);
844 // dump a jdouble
845 static void dump_double(AbstractDumpWriter* writer, jdouble d);
846 // dumps the raw value of the given field
847 static void dump_field_value(AbstractDumpWriter* writer, char type, oop obj, int offset);
848 // returns the size of the static fields; also counts the static fields
849 static u4 get_static_fields_size(InstanceKlass* ik, u2& field_count);
850 // dumps static fields of the given class
851 static void dump_static_fields(AbstractDumpWriter* writer, Klass* k);
852 // dump the raw values of the instance fields of the given identity or inlined object;
853 // for identity objects offset is 0 and 'klass' is o->klass(),
854 // for inlined objects offset is the offset in the holder object, 'klass' is inlined object class
855 static void dump_instance_fields(AbstractDumpWriter* writer, oop o, int offset, DumperClassCacheTable* class_cache, DumperClassCacheTableEntry* class_cache_entry);
856 // dump the raw values of the instance fields of the given inlined object;
857 // dump_instance_fields wrapper for inlined objects
858 static void dump_inlined_object_fields(AbstractDumpWriter* writer, oop o, int offset, DumperClassCacheTable* class_cache, DumperClassCacheTableEntry* class_cache_entry);
859
860 // get the count of the instance fields for a given class
861 static u2 get_instance_fields_count(InstanceKlass* ik);
862 // dumps the definition of the instance fields for a given class
863 static void dump_instance_field_descriptors(AbstractDumpWriter* writer, InstanceKlass* k, uintx *inlined_fields_index = nullptr);
864 // creates HPROF_GC_INSTANCE_DUMP record for the given object
865 static void dump_instance(AbstractDumpWriter* writer, oop o, DumperClassCacheTable* class_cache);
866 // creates HPROF_GC_CLASS_DUMP record for the given instance class
867 static void dump_instance_class(AbstractDumpWriter* writer, Klass* k);
868 // creates HPROF_GC_CLASS_DUMP record for a given array class
869 static void dump_array_class(AbstractDumpWriter* writer, Klass* k);
870
871 // creates HPROF_GC_OBJ_ARRAY_DUMP record for the given object array
872 static void dump_object_array(AbstractDumpWriter* writer, objArrayOop array);
873 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given flat array
874 static void dump_flat_array(AbstractDumpWriter* writer, flatArrayOop array, DumperClassCacheTable* class_cache);
875 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given type array
876 static void dump_prim_array(AbstractDumpWriter* writer, typeArrayOop array);
877 // create HPROF_FRAME record for the given method and bci
878 static void dump_stack_frame(AbstractDumpWriter* writer, int frame_serial_num, int class_serial_num, Method* m, int bci);
879
880 // check if we need to truncate an array
881 static int calculate_array_max_length(AbstractDumpWriter* writer, arrayOop array, short header_size);
882 // extended version to dump flat arrays as primitive arrays;
883 // type_size specifies size of the inlined objects.
884 static int calculate_array_max_length(AbstractDumpWriter* writer, arrayOop array, int type_size, short header_size);
885
886 // fixes up the current dump record and writes HPROF_HEAP_DUMP_END record
887 static void end_of_dump(AbstractDumpWriter* writer);
888
889 static oop mask_dormant_archived_object(oop o) {
890 if (o != nullptr && o->klass()->java_mirror() == nullptr) {
891 // Ignore this object since the corresponding java mirror is not loaded.
892 // Might be a dormant archive object.
893 return nullptr;
894 } else {
895 return o;
896 }
897 }
898
899 // helper methods for inlined fields.
900 static bool is_inlined_field(const fieldDescriptor& fld) {
901 return fld.is_flat();
902 }
903 static InlineKlass* get_inlined_field_klass(const fieldDescriptor& fld) {
904 assert(is_inlined_field(fld), "must be inlined field");
905 InstanceKlass* holder_klass = fld.field_holder();
906 return InlineKlass::cast(holder_klass->get_inline_type_field_klass(fld.index()));
907 }
908 };
909
910 // Hash table of klasses to the klass metadata. This should greatly improve the
911 // hash dumping performance. This hash table is supposed to be used by a single
912 // thread only.
913 //
914 class DumperClassCacheTableEntry : public CHeapObj<mtServiceability> {
915 friend class DumperClassCacheTable;
916 private:
917 GrowableArray<char> _sigs_start;
918 GrowableArray<int> _offsets;
919 GrowableArray<InlineKlass*> _inline_klasses;
920 u4 _instance_size;
921 int _entries;
922
923 public:
924 DumperClassCacheTableEntry() : _instance_size(0), _entries(0) {};
925
926 int field_count() { return _entries; }
927 char sig_start(int field_idx) { return _sigs_start.at(field_idx); }
928 void push_sig_start_inlined() { _sigs_start.push('Q'); }
929 bool is_inlined(int field_idx){ return _sigs_start.at(field_idx) == 'Q'; }
930 InlineKlass* inline_klass(int field_idx) { assert(is_inlined(field_idx), "Not inlined"); return _inline_klasses.at(field_idx); }
931 int offset(int field_idx) { return _offsets.at(field_idx); }
932 u4 instance_size() { return _instance_size; }
933 };
934
935 class DumperClassCacheTable {
936 private:
937 // ResourceHashtable SIZE is specified at compile time so we
938 // use 1031 which is the first prime after 1024.
939 static constexpr size_t TABLE_SIZE = 1031;
940
941 // Maintain the cache for N classes. This limits memory footprint
942 // impact, regardless of how many classes we have in the dump.
943 // This also improves look up performance by keeping the statically
944 // sized table from overloading.
945 static constexpr int CACHE_TOP = 256;
946
947 typedef ResourceHashtable<InstanceKlass*, DumperClassCacheTableEntry*,
948 TABLE_SIZE, AnyObj::C_HEAP, mtServiceability> PtrTable;
949 PtrTable* _ptrs;
950
959 bool do_entry(InstanceKlass*& key, DumperClassCacheTableEntry*& entry) {
960 delete entry;
961 return true;
962 }
963 } cleanup;
964 table->unlink(&cleanup);
965 }
966
967 public:
968 DumperClassCacheTableEntry* lookup_or_create(InstanceKlass* ik) {
969 if (_last_ik == ik) {
970 return _last_entry;
971 }
972
973 DumperClassCacheTableEntry* entry;
974 DumperClassCacheTableEntry** from_cache = _ptrs->get(ik);
975 if (from_cache == nullptr) {
976 entry = new DumperClassCacheTableEntry();
977 for (HierarchicalFieldStream<JavaFieldStream> fld(ik); !fld.done(); fld.next()) {
978 if (!fld.access_flags().is_static()) {
979 InlineKlass* inlineKlass = nullptr;
980 if (DumperSupport::is_inlined_field(fld.field_descriptor())) {
981 inlineKlass = DumperSupport::get_inlined_field_klass(fld.field_descriptor());
982 entry->push_sig_start_inlined();
983 entry->_instance_size += DumperSupport::instance_size(inlineKlass);
984 } else {
985 Symbol* sig = fld.signature();
986 entry->_sigs_start.push(sig->char_at(0));
987 entry->_instance_size += DumperSupport::sig2size(sig);
988 }
989 entry->_inline_klasses.push(inlineKlass);
990 entry->_offsets.push(fld.offset());
991 entry->_entries++;
992 }
993 }
994
995 if (_ptrs->number_of_entries() >= CACHE_TOP) {
996 // We do not track the individual hit rates for table entries.
997 // Purge the entire table, and let the cache catch up with new
998 // distribution.
999 unlink_all(_ptrs);
1000 }
1001
1002 _ptrs->put(ik, entry);
1003 } else {
1004 entry = *from_cache;
1005 }
1006
1007 // Remember for single-slot cache.
1008 _last_ik = ik;
1009 _last_entry = entry;
1010
1011 return entry;
1081 }
1082
1083 // dump a jfloat
1084 void DumperSupport::dump_float(AbstractDumpWriter* writer, jfloat f) {
1085 if (g_isnan(f)) {
1086 writer->write_u4(0x7fc00000); // collapsing NaNs
1087 } else {
1088 writer->write_u4(bit_cast<u4>(f));
1089 }
1090 }
1091
1092 // dump a jdouble
1093 void DumperSupport::dump_double(AbstractDumpWriter* writer, jdouble d) {
1094 if (g_isnan(d)) {
1095 writer->write_u8(0x7ff80000ull << 32); // collapsing NaNs
1096 } else {
1097 writer->write_u8(bit_cast<u8>(d));
1098 }
1099 }
1100
1101
1102 // dumps the raw value of the given field
1103 void DumperSupport::dump_field_value(AbstractDumpWriter* writer, char type, oop obj, int offset) {
1104 switch (type) {
1105 case JVM_SIGNATURE_CLASS :
1106 case JVM_SIGNATURE_ARRAY : {
1107 oop o = obj->obj_field_access<ON_UNKNOWN_OOP_REF | AS_NO_KEEPALIVE>(offset);
1108 if (o != nullptr && log_is_enabled(Debug, cds, heap) && mask_dormant_archived_object(o) == nullptr) {
1109 ResourceMark rm;
1110 log_debug(cds, heap)("skipped dormant archived object " INTPTR_FORMAT " (%s) referenced by " INTPTR_FORMAT " (%s)",
1111 p2i(o), o->klass()->external_name(),
1112 p2i(obj), obj->klass()->external_name());
1113 }
1114 o = mask_dormant_archived_object(o);
1115 assert(oopDesc::is_oop_or_null(o), "Expected an oop or nullptr at " PTR_FORMAT, p2i(o));
1116 writer->write_objectID(o);
1117 break;
1118 }
1119 case JVM_SIGNATURE_BYTE : {
1120 jbyte b = obj->byte_field(offset);
1121 writer->write_u1(b);
1146 writer->write_u4(i);
1147 break;
1148 }
1149 case JVM_SIGNATURE_LONG : {
1150 jlong l = obj->long_field(offset);
1151 writer->write_u8(l);
1152 break;
1153 }
1154 case JVM_SIGNATURE_BOOLEAN : {
1155 jboolean b = obj->bool_field(offset);
1156 writer->write_u1(b);
1157 break;
1158 }
1159 default : {
1160 ShouldNotReachHere();
1161 break;
1162 }
1163 }
1164 }
1165
1166 // calculates the total size of the all fields of the given class.
1167 u4 DumperSupport::instance_size(InstanceKlass* ik, DumperClassCacheTableEntry* class_cache_entry) {
1168 if (class_cache_entry != nullptr) {
1169 return class_cache_entry->instance_size();
1170 } else {
1171 u4 size = 0;
1172 for (HierarchicalFieldStream<JavaFieldStream> fld(ik); !fld.done(); fld.next()) {
1173 if (!fld.access_flags().is_static()) {
1174 if (is_inlined_field(fld.field_descriptor())) {
1175 size += instance_size(get_inlined_field_klass(fld.field_descriptor()));
1176 } else {
1177 size += sig2size(fld.signature());
1178 }
1179 }
1180 }
1181 return size;
1182 }
1183 }
1184
1185 u4 DumperSupport::get_static_fields_size(InstanceKlass* ik, u2& field_count) {
1186 field_count = 0;
1187 u4 size = 0;
1188
1189 for (JavaFieldStream fldc(ik); !fldc.done(); fldc.next()) {
1190 if (fldc.access_flags().is_static()) {
1191 assert(!is_inlined_field(fldc.field_descriptor()), "static fields cannot be inlined");
1192
1193 field_count++;
1194 size += sig2size(fldc.signature());
1195 }
1196 }
1197
1198 // Add in resolved_references which is referenced by the cpCache
1199 // The resolved_references is an array per InstanceKlass holding the
1200 // strings and other oops resolved from the constant pool.
1201 oop resolved_references = ik->constants()->resolved_references_or_null();
1202 if (resolved_references != nullptr) {
1203 field_count++;
1204 size += sizeof(address);
1205
1206 // Add in the resolved_references of the used previous versions of the class
1207 // in the case of RedefineClasses
1208 InstanceKlass* prev = ik->previous_versions();
1209 while (prev != nullptr && prev->constants()->resolved_references_or_null() != nullptr) {
1210 field_count++;
1211 size += sizeof(address);
1212 prev = prev->previous_versions();
1213 }
1214 }
1215
1216 // We write the value itself plus a name and a one byte type tag per field.
1217 return checked_cast<u4>(size + field_count * (sizeof(address) + 1));
1218 }
1219
1220 // dumps static fields of the given class
1221 void DumperSupport::dump_static_fields(AbstractDumpWriter* writer, Klass* k) {
1222 InstanceKlass* ik = InstanceKlass::cast(k);
1223
1224 // dump the field descriptors and raw values
1225 for (JavaFieldStream fld(ik); !fld.done(); fld.next()) {
1226 if (fld.access_flags().is_static()) {
1227 assert(!is_inlined_field(fld.field_descriptor()), "static fields cannot be inlined");
1228
1229 Symbol* sig = fld.signature();
1230
1231 writer->write_symbolID(fld.name()); // name
1232 writer->write_u1(sig2tag(sig)); // type
1233
1234 // value
1235 dump_field_value(writer, sig->char_at(0), ik->java_mirror(), fld.offset());
1236 }
1237 }
1238
1239 // Add resolved_references for each class that has them
1240 oop resolved_references = ik->constants()->resolved_references_or_null();
1241 if (resolved_references != nullptr) {
1242 writer->write_symbolID(vmSymbols::resolved_references_name()); // name
1243 writer->write_u1(sig2tag(vmSymbols::object_array_signature())); // type
1244 writer->write_objectID(resolved_references);
1245
1246 // Also write any previous versions
1247 InstanceKlass* prev = ik->previous_versions();
1248 while (prev != nullptr && prev->constants()->resolved_references_or_null() != nullptr) {
1249 writer->write_symbolID(vmSymbols::resolved_references_name()); // name
1250 writer->write_u1(sig2tag(vmSymbols::object_array_signature())); // type
1251 writer->write_objectID(prev->constants()->resolved_references());
1252 prev = prev->previous_versions();
1253 }
1254 }
1255 }
1256
1257 // dump the raw values of the instance fields of the given identity or inlined object;
1258 // for identity objects offset is 0 and 'klass' is o->klass(),
1259 // for inlined objects offset is the offset in the holder object, 'klass' is inlined object class.
1260 void DumperSupport::dump_instance_fields(AbstractDumpWriter* writer, oop o, int offset, DumperClassCacheTable* class_cache, DumperClassCacheTableEntry* class_cache_entry) {
1261 assert(class_cache_entry != nullptr, "Pre-condition: must be provided");
1262 for (int idx = 0; idx < class_cache_entry->field_count(); idx++) {
1263 if (class_cache_entry->is_inlined(idx)) {
1264 InlineKlass* field_klass = class_cache_entry->inline_klass(idx);
1265 int fields_offset = offset + (class_cache_entry->offset(idx) - field_klass->first_field_offset());
1266 DumperClassCacheTableEntry* inline_class_cache_entry = class_cache->lookup_or_create(field_klass);
1267 dump_inlined_object_fields(writer, o, fields_offset, class_cache, inline_class_cache_entry);
1268 } else {
1269 dump_field_value(writer, class_cache_entry->sig_start(idx), o, class_cache_entry->offset(idx));
1270 }
1271 }
1272 }
1273
1274 void DumperSupport::dump_inlined_object_fields(AbstractDumpWriter* writer, oop o, int offset, DumperClassCacheTable* class_cache, DumperClassCacheTableEntry* class_cache_entry) {
1275 // the object is inlined, so all its fields are stored without headers.
1276 dump_instance_fields(writer, o, offset, class_cache, class_cache_entry);
1277 }
1278
1279 // gets the count of the instance fields for a given class
1280 u2 DumperSupport::get_instance_fields_count(InstanceKlass* ik) {
1281 u2 field_count = 0;
1282
1283 for (JavaFieldStream fldc(ik); !fldc.done(); fldc.next()) {
1284 if (!fldc.access_flags().is_static()) {
1285 if (is_inlined_field(fldc.field_descriptor())) {
1286 // add "synthetic" fields for inlined fields.
1287 field_count += get_instance_fields_count(get_inlined_field_klass(fldc.field_descriptor()));
1288 } else {
1289 field_count++;
1290 }
1291 }
1292 }
1293
1294 return field_count;
1295 }
1296
1297 // dumps the definition of the instance fields for a given class
1298 // inlined_fields_id is not-nullptr for inlined fields (to get synthetic field name IDs
1299 // by using InlinedObjects::get_next_string_id()).
1300 void DumperSupport::dump_instance_field_descriptors(AbstractDumpWriter* writer, InstanceKlass* ik, uintx* inlined_fields_id) {
1301 // inlined_fields_id != nullptr means ik is a class of inlined field.
1302 // Inlined field id pointer for this class; lazyly initialized
1303 // if the class has inlined field(s) and the caller didn't provide inlined_fields_id.
1304 uintx *this_klass_inlined_fields_id = inlined_fields_id;
1305 uintx inlined_id = 0;
1306
1307 // dump the field descriptors
1308 for (JavaFieldStream fld(ik); !fld.done(); fld.next()) {
1309 if (!fld.access_flags().is_static()) {
1310 if (is_inlined_field(fld.field_descriptor())) {
1311 // dump "synthetic" fields for inlined fields.
1312 if (this_klass_inlined_fields_id == nullptr) {
1313 inlined_id = InlinedObjects::get_instance()->get_base_index_for(ik);
1314 this_klass_inlined_fields_id = &inlined_id;
1315 }
1316 dump_instance_field_descriptors(writer, get_inlined_field_klass(fld.field_descriptor()), this_klass_inlined_fields_id);
1317 } else {
1318 Symbol* sig = fld.signature();
1319 Symbol* name = nullptr;
1320 // Use inlined_fields_id provided by caller.
1321 if (inlined_fields_id != nullptr) {
1322 uintx name_id = InlinedObjects::get_instance()->get_next_string_id(*inlined_fields_id);
1323
1324 // name_id == 0 is returned on error. use original field signature.
1325 if (name_id != 0) {
1326 *inlined_fields_id = name_id;
1327 name = reinterpret_cast<Symbol*>(name_id);
1328 }
1329 }
1330 if (name == nullptr) {
1331 name = fld.name();
1332 }
1333
1334 writer->write_symbolID(name); // name
1335 writer->write_u1(sig2tag(sig)); // type
1336 }
1337 }
1338 }
1339 }
1340
1341 // creates HPROF_GC_INSTANCE_DUMP record for the given object
1342 void DumperSupport::dump_instance(AbstractDumpWriter* writer, oop o, DumperClassCacheTable* class_cache) {
1343 InstanceKlass* ik = InstanceKlass::cast(o->klass());
1344
1345 DumperClassCacheTableEntry* cache_entry = class_cache->lookup_or_create(ik);
1346
1347 u4 is = instance_size(ik, cache_entry);
1348 u4 size = 1 + sizeof(address) + 4 + sizeof(address) + 4 + is;
1349
1350 writer->start_sub_record(HPROF_GC_INSTANCE_DUMP, size);
1351 writer->write_objectID(o);
1352 writer->write_u4(STACK_TRACE_ID);
1353
1354 // class ID
1355 writer->write_classID(ik);
1356
1357 // number of bytes that follow
1358 writer->write_u4(is);
1359
1360 // field values
1361 dump_instance_fields(writer, o, 0, class_cache, cache_entry);
1362
1363 writer->end_sub_record();
1364 }
1365
1366 // creates HPROF_GC_CLASS_DUMP record for the given instance class
1367 void DumperSupport::dump_instance_class(AbstractDumpWriter* writer, Klass* k) {
1368 InstanceKlass* ik = InstanceKlass::cast(k);
1369
1370 // We can safepoint and do a heap dump at a point where we have a Klass,
1371 // but no java mirror class has been setup for it. So we need to check
1372 // that the class is at least loaded, to avoid crash from a null mirror.
1373 if (!ik->is_loaded()) {
1374 return;
1375 }
1376
1377 u2 static_fields_count = 0;
1378 u4 static_size = get_static_fields_size(ik, static_fields_count);
1379 u2 instance_fields_count = get_instance_fields_count(ik);
1380 u4 instance_fields_size = instance_fields_count * (sizeof(address) + 1);
1381 u4 size = checked_cast<u4>(1 + sizeof(address) + 4 + 6 * sizeof(address) + 4 + 2 + 2 + static_size + 2 + instance_fields_size);
1386 writer->write_classID(ik);
1387 writer->write_u4(STACK_TRACE_ID);
1388
1389 // super class ID
1390 InstanceKlass* java_super = ik->java_super();
1391 if (java_super == nullptr) {
1392 writer->write_objectID(oop(nullptr));
1393 } else {
1394 writer->write_classID(java_super);
1395 }
1396
1397 writer->write_objectID(ik->class_loader());
1398 writer->write_objectID(ik->signers());
1399 writer->write_objectID(ik->protection_domain());
1400
1401 // reserved
1402 writer->write_objectID(oop(nullptr));
1403 writer->write_objectID(oop(nullptr));
1404
1405 // instance size
1406 writer->write_u4(HeapWordSize * ik->size_helper());
1407
1408 // size of constant pool - ignored by HAT 1.1
1409 writer->write_u2(0);
1410
1411 // static fields
1412 writer->write_u2(static_fields_count);
1413 dump_static_fields(writer, ik);
1414
1415 // description of instance fields
1416 writer->write_u2(instance_fields_count);
1417 dump_instance_field_descriptors(writer, ik);
1418
1419 writer->end_sub_record();
1420 }
1421
1422 // creates HPROF_GC_CLASS_DUMP record for the given array class
1423 void DumperSupport::dump_array_class(AbstractDumpWriter* writer, Klass* k) {
1424 InstanceKlass* ik = nullptr; // bottom class for object arrays, null for primitive type arrays
1425 if (k->is_objArray_klass()) {
1426 Klass *bk = ObjArrayKlass::cast(k)->bottom_klass();
1440 assert(java_super != nullptr, "checking");
1441 writer->write_classID(java_super);
1442
1443 writer->write_objectID(ik == nullptr ? oop(nullptr) : ik->class_loader());
1444 writer->write_objectID(ik == nullptr ? oop(nullptr) : ik->signers());
1445 writer->write_objectID(ik == nullptr ? oop(nullptr) : ik->protection_domain());
1446
1447 writer->write_objectID(oop(nullptr)); // reserved
1448 writer->write_objectID(oop(nullptr));
1449 writer->write_u4(0); // instance size
1450 writer->write_u2(0); // constant pool
1451 writer->write_u2(0); // static fields
1452 writer->write_u2(0); // instance fields
1453
1454 writer->end_sub_record();
1455
1456 }
1457
1458 // Hprof uses an u4 as record length field,
1459 // which means we need to truncate arrays that are too long.
1460 int DumperSupport::calculate_array_max_length(AbstractDumpWriter* writer, arrayOop array, int type_size, short header_size) {
1461 int length = array->length();
1462
1463 size_t length_in_bytes = (size_t)length * type_size;
1464 uint max_bytes = max_juint - header_size;
1465
1466 if (length_in_bytes > max_bytes) {
1467 length = max_bytes / type_size;
1468 length_in_bytes = (size_t)length * type_size;
1469
1470 BasicType type = ArrayKlass::cast(array->klass())->element_type();
1471 warning("cannot dump array of type %s[] with length %d; truncating to length %d",
1472 type2name_tab[type], array->length(), length);
1473 }
1474 return length;
1475 }
1476
1477 int DumperSupport::calculate_array_max_length(AbstractDumpWriter* writer, arrayOop array, short header_size) {
1478 BasicType type = ArrayKlass::cast(array->klass())->element_type();
1479 assert((type >= T_BOOLEAN && type <= T_OBJECT) || type == T_PRIMITIVE_OBJECT, "invalid array element type");
1480 int type_size;
1481 if (type == T_OBJECT) {
1482 type_size = sizeof(address);
1483 } else if (type == T_PRIMITIVE_OBJECT) {
1484 // TODO: FIXME
1485 fatal("Not supported yet"); // FIXME: JDK-8325678
1486 } else {
1487 type_size = type2aelembytes(type);
1488 }
1489
1490 return calculate_array_max_length(writer, array, type_size, header_size);
1491 }
1492
1493 // creates HPROF_GC_OBJ_ARRAY_DUMP record for the given object array
1494 void DumperSupport::dump_object_array(AbstractDumpWriter* writer, objArrayOop array) {
1495 // sizeof(u1) + 2 * sizeof(u4) + sizeof(objectID) + sizeof(classID)
1496 short header_size = 1 + 2 * 4 + 2 * sizeof(address);
1497 int length = calculate_array_max_length(writer, array, header_size);
1498 u4 size = checked_cast<u4>(header_size + length * sizeof(address));
1499
1500 writer->start_sub_record(HPROF_GC_OBJ_ARRAY_DUMP, size);
1501 writer->write_objectID(array);
1502 writer->write_u4(STACK_TRACE_ID);
1503 writer->write_u4(length);
1504
1505 // array class ID
1506 writer->write_classID(array->klass());
1507
1508 // [id]* elements
1509 for (int index = 0; index < length; index++) {
1510 oop o = array->obj_at(index);
1511 if (o != nullptr && log_is_enabled(Debug, cds, heap) && mask_dormant_archived_object(o) == nullptr) {
1512 ResourceMark rm;
1513 log_debug(cds, heap)("skipped dormant archived object " INTPTR_FORMAT " (%s) referenced by " INTPTR_FORMAT " (%s)",
1514 p2i(o), o->klass()->external_name(),
1515 p2i(array), array->klass()->external_name());
1516 }
1517 o = mask_dormant_archived_object(o);
1518 writer->write_objectID(o);
1519 }
1520
1521 writer->end_sub_record();
1522 }
1523
1524 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given flat array
1525 void DumperSupport::dump_flat_array(AbstractDumpWriter* writer, flatArrayOop array, DumperClassCacheTable* class_cache) {
1526 FlatArrayKlass* array_klass = FlatArrayKlass::cast(array->klass());
1527 InlineKlass* element_klass = array_klass->element_klass();
1528 int element_size = instance_size(element_klass);
1529 /* id array object ID
1530 * u4 stack trace serial number
1531 * u4 number of elements
1532 * u1 element type
1533 */
1534 short header_size = 1 + sizeof(address) + 2 * 4 + 1;
1535
1536 // TODO: use T_SHORT/T_INT/T_LONG if needed to avoid truncation
1537 BasicType type = T_BYTE;
1538 int type_size = type2aelembytes(type);
1539 int length = calculate_array_max_length(writer, array, element_size, header_size);
1540 u4 length_in_bytes = (u4)(length * element_size);
1541 u4 size = header_size + length_in_bytes;
1542
1543 writer->start_sub_record(HPROF_GC_PRIM_ARRAY_DUMP, size);
1544 writer->write_objectID(array);
1545 writer->write_u4(STACK_TRACE_ID);
1546 // TODO: round up array length for T_SHORT/T_INT/T_LONG
1547 writer->write_u4(length * element_size);
1548 writer->write_u1(type2tag(type));
1549
1550 for (int index = 0; index < length; index++) {
1551 // need offset in the holder to read inlined object. calculate it from flatArrayOop::value_at_addr()
1552 int offset = (int)((address)array->value_at_addr(index, array_klass->layout_helper())
1553 - cast_from_oop<address>(array));
1554 DumperClassCacheTableEntry* class_cache_entry = class_cache->lookup_or_create(element_klass);
1555 dump_inlined_object_fields(writer, array, offset, class_cache, class_cache_entry);
1556 }
1557
1558 // TODO: write padding bytes for T_SHORT/T_INT/T_LONG
1559
1560 InlinedObjects::get_instance()->add_flat_array(array);
1561
1562 writer->end_sub_record();
1563 }
1564
1565 #define WRITE_ARRAY(Array, Type, Size, Length) \
1566 for (int i = 0; i < Length; i++) { writer->write_##Size((Size)Array->Type##_at(i)); }
1567
1568 // creates HPROF_GC_PRIM_ARRAY_DUMP record for the given type array
1569 void DumperSupport::dump_prim_array(AbstractDumpWriter* writer, typeArrayOop array) {
1570 BasicType type = TypeArrayKlass::cast(array->klass())->element_type();
1571 // 2 * sizeof(u1) + 2 * sizeof(u4) + sizeof(objectID)
1572 short header_size = 2 * 1 + 2 * 4 + sizeof(address);
1573
1574 int length = calculate_array_max_length(writer, array, header_size);
1575 int type_size = type2aelembytes(type);
1576 u4 length_in_bytes = (u4)length * type_size;
1577 u4 size = header_size + length_in_bytes;
1578
1579 writer->start_sub_record(HPROF_GC_PRIM_ARRAY_DUMP, size);
1580 writer->write_objectID(array);
1581 writer->write_u4(STACK_TRACE_ID);
1582 writer->write_u4(length);
1583 writer->write_u1(type2tag(type));
1584
1666 int bci) {
1667 int line_number;
1668 if (m->is_native()) {
1669 line_number = -3; // native frame
1670 } else {
1671 line_number = m->line_number_from_bci(bci);
1672 }
1673
1674 write_header(writer, HPROF_FRAME, 4*oopSize + 2*sizeof(u4));
1675 writer->write_id(frame_serial_num); // frame serial number
1676 writer->write_symbolID(m->name()); // method's name
1677 writer->write_symbolID(m->signature()); // method's signature
1678
1679 assert(m->method_holder()->is_instance_klass(), "not InstanceKlass");
1680 writer->write_symbolID(m->method_holder()->source_file_name()); // source file name
1681 writer->write_u4(class_serial_num); // class serial number
1682 writer->write_u4((u4) line_number); // line number
1683 }
1684
1685
1686 class InlinedFieldNameDumper : public LockedClassesDo {
1687 public:
1688 typedef void (*Callback)(InlinedObjects *owner, const Klass *klass, uintx base_index, int count);
1689
1690 private:
1691 AbstractDumpWriter* _writer;
1692 InlinedObjects *_owner;
1693 Callback _callback;
1694 uintx _index;
1695
1696 void dump_inlined_field_names(GrowableArray<Symbol*>* super_names, Symbol* field_name, InlineKlass* klass) {
1697 super_names->push(field_name);
1698 for (HierarchicalFieldStream<JavaFieldStream> fld(klass); !fld.done(); fld.next()) {
1699 if (!fld.access_flags().is_static()) {
1700 if (DumperSupport::is_inlined_field(fld.field_descriptor())) {
1701 dump_inlined_field_names(super_names, fld.name(), DumperSupport::get_inlined_field_klass(fld.field_descriptor()));
1702 } else {
1703 // get next string ID.
1704 uintx next_index = _owner->get_next_string_id(_index);
1705 if (next_index == 0) {
1706 // something went wrong (overflow?)
1707 // stop generation; the rest of inlined objects will have original field names.
1708 return;
1709 }
1710 _index = next_index;
1711
1712 // Calculate length.
1713 int len = fld.name()->utf8_length();
1714 for (GrowableArrayIterator<Symbol*> it = super_names->begin(); it != super_names->end(); ++it) {
1715 len += (*it)->utf8_length() + 1; // +1 for ".".
1716 }
1717
1718 DumperSupport::write_header(_writer, HPROF_UTF8, oopSize + len);
1719 _writer->write_symbolID(reinterpret_cast<Symbol*>(_index));
1720 // Write the string value.
1721 // 1) super_names.
1722 for (GrowableArrayIterator<Symbol*> it = super_names->begin(); it != super_names->end(); ++it) {
1723 _writer->write_raw((*it)->bytes(), (*it)->utf8_length());
1724 _writer->write_u1('.');
1725 }
1726 // 2) field name.
1727 _writer->write_raw(fld.name()->bytes(), fld.name()->utf8_length());
1728 }
1729 }
1730 }
1731 super_names->pop();
1732 }
1733
1734 void dump_inlined_field_names(Symbol* field_name, InlineKlass* field_klass) {
1735 GrowableArray<Symbol*> super_names(4, mtServiceability);
1736 dump_inlined_field_names(&super_names, field_name, field_klass);
1737 }
1738
1739 public:
1740 InlinedFieldNameDumper(AbstractDumpWriter* writer, InlinedObjects* owner, Callback callback)
1741 : _writer(writer), _owner(owner), _callback(callback), _index(0) {
1742 }
1743
1744 void do_klass(Klass* k) {
1745 if (!k->is_instance_klass()) {
1746 return;
1747 }
1748 InstanceKlass* ik = InstanceKlass::cast(k);
1749 // if (ik->has_inline_type_fields()) {
1750 // return;
1751 // }
1752
1753 uintx base_index = _index;
1754 int count = 0;
1755
1756 for (HierarchicalFieldStream<JavaFieldStream> fld(ik); !fld.done(); fld.next()) {
1757 if (!fld.access_flags().is_static()) {
1758 if (DumperSupport::is_inlined_field(fld.field_descriptor())) {
1759 dump_inlined_field_names(fld.name(), DumperSupport::get_inlined_field_klass(fld.field_descriptor()));
1760 count++;
1761 }
1762 }
1763 }
1764
1765 if (count != 0) {
1766 _callback(_owner, k, base_index, count);
1767 }
1768 }
1769 };
1770
1771 class InlinedFieldsDumper : public LockedClassesDo {
1772 private:
1773 AbstractDumpWriter* _writer;
1774
1775 public:
1776 InlinedFieldsDumper(AbstractDumpWriter* writer) : _writer(writer) {}
1777
1778 void do_klass(Klass* k) {
1779 if (!k->is_instance_klass()) {
1780 return;
1781 }
1782 InstanceKlass* ik = InstanceKlass::cast(k);
1783 // if (ik->has_inline_type_fields()) {
1784 // return;
1785 // }
1786
1787 // We can be at a point where java mirror does not exist yet.
1788 // So we need to check that the class is at least loaded, to avoid crash from a null mirror.
1789 if (!ik->is_loaded()) {
1790 return;
1791 }
1792
1793 u2 inlined_count = 0;
1794 for (HierarchicalFieldStream<JavaFieldStream> fld(ik); !fld.done(); fld.next()) {
1795 if (!fld.access_flags().is_static()) {
1796 if (DumperSupport::is_inlined_field(fld.field_descriptor())) {
1797 inlined_count++;
1798 }
1799 }
1800 }
1801 if (inlined_count != 0) {
1802 _writer->write_u1(HPROF_CLASS_WITH_INLINED_FIELDS);
1803
1804 // class ID
1805 _writer->write_classID(ik);
1806 // number of inlined fields
1807 _writer->write_u2(inlined_count);
1808 u2 index = 0;
1809 for (HierarchicalFieldStream<JavaFieldStream> fld(ik); !fld.done(); fld.next()) {
1810 if (!fld.access_flags().is_static()) {
1811 if (DumperSupport::is_inlined_field(fld.field_descriptor())) {
1812 // inlined field index
1813 _writer->write_u2(index);
1814 // synthetic field count
1815 u2 field_count = DumperSupport::get_instance_fields_count(DumperSupport::get_inlined_field_klass(fld.field_descriptor()));
1816 _writer->write_u2(field_count);
1817 // original field name
1818 _writer->write_symbolID(fld.name());
1819 // inlined field class ID
1820 _writer->write_classID(DumperSupport::get_inlined_field_klass(fld.field_descriptor()));
1821
1822 index += field_count;
1823 } else {
1824 index++;
1825 }
1826 }
1827 }
1828 }
1829 }
1830 };
1831
1832
1833 void InlinedObjects::init() {
1834 _instance = this;
1835
1836 struct Closure : public SymbolClosure {
1837 uintx _min_id = max_uintx;
1838 uintx _max_id = 0;
1839 Closure() : _min_id(max_uintx), _max_id(0) {}
1840
1841 void do_symbol(Symbol** p) {
1842 uintx val = reinterpret_cast<uintx>(*p);
1843 if (val < _min_id) {
1844 _min_id = val;
1845 }
1846 if (val > _max_id) {
1847 _max_id = val;
1848 }
1849 }
1850 } closure;
1851
1852 SymbolTable::symbols_do(&closure);
1853
1854 _min_string_id = closure._min_id;
1855 _max_string_id = closure._max_id;
1856 }
1857
1858 void InlinedObjects::release() {
1859 _instance = nullptr;
1860
1861 if (_inlined_field_map != nullptr) {
1862 delete _inlined_field_map;
1863 _inlined_field_map = nullptr;
1864 }
1865 if (_flat_arrays != nullptr) {
1866 delete _flat_arrays;
1867 _flat_arrays = nullptr;
1868 }
1869 }
1870
1871 void InlinedObjects::inlined_field_names_callback(InlinedObjects* _this, const Klass* klass, uintx base_index, int count) {
1872 if (_this->_inlined_field_map == nullptr) {
1873 _this->_inlined_field_map = new (mtServiceability) GrowableArray<ClassInlinedFields>(100, mtServiceability);
1874 }
1875 _this->_inlined_field_map->append(ClassInlinedFields(klass, base_index));
1876
1877 // counters for dumping classes with inlined fields
1878 _this->_classes_count++;
1879 _this->_inlined_fields_count += count;
1880 }
1881
1882 void InlinedObjects::dump_inlined_field_names(AbstractDumpWriter* writer) {
1883 InlinedFieldNameDumper nameDumper(writer, this, inlined_field_names_callback);
1884 ClassLoaderDataGraph::classes_do(&nameDumper);
1885
1886 if (_inlined_field_map != nullptr) {
1887 // prepare the map for get_base_index_for().
1888 _inlined_field_map->sort(ClassInlinedFields::compare);
1889 }
1890 }
1891
1892 uintx InlinedObjects::get_base_index_for(Klass* k) {
1893 if (_inlined_field_map != nullptr) {
1894 bool found = false;
1895 int idx = _inlined_field_map->find_sorted<ClassInlinedFields, ClassInlinedFields::compare>(ClassInlinedFields(k, 0), found);
1896 if (found) {
1897 return _inlined_field_map->at(idx).base_index;
1898 }
1899 }
1900
1901 // return max_uintx, so get_next_string_id returns 0.
1902 return max_uintx;
1903 }
1904
1905 uintx InlinedObjects::get_next_string_id(uintx id) {
1906 if (++id == _min_string_id) {
1907 return _max_string_id + 1;
1908 }
1909 return id;
1910 }
1911
1912 void InlinedObjects::dump_classed_with_inlined_fields(AbstractDumpWriter* writer) {
1913 if (_classes_count != 0) {
1914 // Record for each class contains tag(u1), class ID and count(u2)
1915 // for each inlined field index(u2), synthetic fields count(u2), original field name and class ID
1916 int size = _classes_count * (1 + sizeof(address) + 2)
1917 + _inlined_fields_count * (2 + 2 + sizeof(address) + sizeof(address));
1918 DumperSupport::write_header(writer, HPROF_INLINED_FIELDS, (u4)size);
1919
1920 InlinedFieldsDumper dumper(writer);
1921 ClassLoaderDataGraph::classes_do(&dumper);
1922 }
1923 }
1924
1925 void InlinedObjects::add_flat_array(oop array) {
1926 if (_flat_arrays == nullptr) {
1927 _flat_arrays = new (mtServiceability) GrowableArray<oop>(100, mtServiceability);
1928 }
1929 _flat_arrays->append(array);
1930 }
1931
1932 void InlinedObjects::dump_flat_arrays(AbstractDumpWriter* writer) {
1933 if (_flat_arrays != nullptr) {
1934 // For each flat array the record contains tag (u1), object ID and class ID.
1935 int size = _flat_arrays->length() * (1 + sizeof(address) + sizeof(address));
1936
1937 DumperSupport::write_header(writer, HPROF_FLAT_ARRAYS, (u4)size);
1938 for (GrowableArrayIterator<oop> it = _flat_arrays->begin(); it != _flat_arrays->end(); ++it) {
1939 flatArrayOop array = flatArrayOop(*it);
1940 FlatArrayKlass* array_klass = FlatArrayKlass::cast(array->klass());
1941 InlineKlass* element_klass = array_klass->element_klass();
1942 writer->write_u1(HPROF_FLAT_ARRAY);
1943 writer->write_objectID(array);
1944 writer->write_classID(element_klass);
1945 }
1946 }
1947 }
1948
1949
1950 // Support class used to generate HPROF_UTF8 records from the entries in the
1951 // SymbolTable.
1952
1953 class SymbolTableDumper : public SymbolClosure {
1954 private:
1955 AbstractDumpWriter* _writer;
1956 AbstractDumpWriter* writer() const { return _writer; }
1957 public:
1958 SymbolTableDumper(AbstractDumpWriter* writer) { _writer = writer; }
1959 void do_symbol(Symbol** p);
1960 };
1961
1962 void SymbolTableDumper::do_symbol(Symbol** p) {
1963 ResourceMark rm;
1964 Symbol* sym = *p;
1965 int len = sym->utf8_length();
1966 if (len > 0) {
1967 char* s = sym->as_utf8();
1968 DumperSupport::write_header(writer(), HPROF_UTF8, oopSize + len);
1969 writer()->write_symbolID(sym);
2380
2381 void HeapObjectDumper::do_object(oop o) {
2382 // skip classes as these emitted as HPROF_GC_CLASS_DUMP records
2383 if (o->klass() == vmClasses::Class_klass()) {
2384 if (!java_lang_Class::is_primitive(o)) {
2385 return;
2386 }
2387 }
2388
2389 if (DumperSupport::mask_dormant_archived_object(o) == nullptr) {
2390 log_debug(cds, heap)("skipped dormant archived object " INTPTR_FORMAT " (%s)", p2i(o), o->klass()->external_name());
2391 return;
2392 }
2393
2394 if (o->is_instance()) {
2395 // create a HPROF_GC_INSTANCE record for each object
2396 DumperSupport::dump_instance(writer(), o, &_class_cache);
2397 } else if (o->is_objArray()) {
2398 // create a HPROF_GC_OBJ_ARRAY_DUMP record for each object array
2399 DumperSupport::dump_object_array(writer(), objArrayOop(o));
2400 } else if (o->is_flatArray()) {
2401 DumperSupport::dump_flat_array(writer(), flatArrayOop(o), &_class_cache);
2402 } else if (o->is_typeArray()) {
2403 // create a HPROF_GC_PRIM_ARRAY_DUMP record for each type array
2404 DumperSupport::dump_prim_array(writer(), typeArrayOop(o));
2405 }
2406 }
2407
2408 // The dumper controller for parallel heap dump
2409 class DumperController : public CHeapObj<mtInternal> {
2410 private:
2411 Monitor* _lock;
2412 const uint _dumper_number;
2413 uint _complete_number;
2414
2415 public:
2416 DumperController(uint number) :
2417 _lock(new (std::nothrow) PaddedMonitor(Mutex::safepoint, "DumperController_lock")),
2418 _dumper_number(number),
2419 _complete_number(0) { }
2420
2421 ~DumperController() { delete _lock; }
2425 _complete_number++;
2426 // propagate local error to global if any
2427 if (local_writer->has_error()) {
2428 global_writer->set_error(local_writer->error());
2429 }
2430 ml.notify();
2431 }
2432
2433 void wait_all_dumpers_complete() {
2434 MonitorLocker ml(_lock, Mutex::_no_safepoint_check_flag);
2435 while (_complete_number != _dumper_number) {
2436 ml.wait();
2437 }
2438 }
2439 };
2440
2441 // DumpMerger merges separate dump files into a complete one
2442 class DumpMerger : public StackObj {
2443 private:
2444 DumpWriter* _writer;
2445 InlinedObjects* _inlined_objects;
2446 const char* _path;
2447 bool _has_error;
2448 int _dump_seq;
2449
2450 private:
2451 void merge_file(char* path);
2452 void merge_done();
2453 void set_error(const char* msg);
2454
2455 public:
2456 DumpMerger(const char* path, DumpWriter* writer, InlinedObjects* inlined_objects, int dump_seq) :
2457 _writer(writer),
2458 _inlined_objects(inlined_objects),
2459 _path(path),
2460 _has_error(_writer->has_error()),
2461 _dump_seq(dump_seq) {}
2462
2463 void do_merge();
2464 };
2465
2466 void DumpMerger::merge_done() {
2467 // Writes the HPROF_HEAP_DUMP_END record.
2468 if (!_has_error) {
2469 DumperSupport::end_of_dump(_writer);
2470 _inlined_objects->dump_flat_arrays(_writer);
2471 _writer->flush();
2472 _inlined_objects->release();
2473 }
2474 _dump_seq = 0; //reset
2475 }
2476
2477 void DumpMerger::set_error(const char* msg) {
2478 assert(msg != nullptr, "sanity check");
2479 log_error(heapdump)("%s (file: %s)", msg, _path);
2480 _writer->set_error(msg);
2481 _has_error = true;
2482 }
2483
2484 #ifdef LINUX
2485 // Merge segmented heap files via sendfile, it's more efficient than the
2486 // read+write combination, which would require transferring data to and from
2487 // user space.
2488 void DumpMerger::merge_file(char* path) {
2489 assert(!SafepointSynchronize::is_at_safepoint(), "merging happens outside safepoint");
2490 TraceTime timer("Merge segmented heap file directly", TRACETIME_LOG(Info, heapdump));
2491
2492 int segment_fd = os::open(path, O_RDONLY, 0);
2591 }
2592 };
2593
2594 // The VM operation that performs the heap dump
2595 class VM_HeapDumper : public VM_GC_Operation, public WorkerTask {
2596 private:
2597 static VM_HeapDumper* _global_dumper;
2598 static DumpWriter* _global_writer;
2599 DumpWriter* _local_writer;
2600 JavaThread* _oome_thread;
2601 Method* _oome_constructor;
2602 bool _gc_before_heap_dump;
2603 GrowableArray<Klass*>* _klass_map;
2604
2605 ThreadDumper** _thread_dumpers; // platform, carrier and mounted virtual threads
2606 int _thread_dumpers_count;
2607 volatile int _thread_serial_num;
2608 volatile int _frame_serial_num;
2609
2610 volatile int _dump_seq;
2611
2612 // Inlined object support.
2613 InlinedObjects _inlined_objects;
2614
2615 // parallel heap dump support
2616 uint _num_dumper_threads;
2617 DumperController* _dumper_controller;
2618 ParallelObjectIterator* _poi;
2619 // worker id of VMDumper thread.
2620 static const size_t VMDumperWorkerId = 0;
2621 // VM dumper dumps both heap and non-heap data, other dumpers dump heap-only data.
2622 static bool is_vm_dumper(uint worker_id) { return worker_id == VMDumperWorkerId; }
2623
2624 // accessors and setters
2625 static VM_HeapDumper* dumper() { assert(_global_dumper != nullptr, "Error"); return _global_dumper; }
2626 static DumpWriter* writer() { assert(_global_writer != nullptr, "Error"); return _global_writer; }
2627
2628 void set_global_dumper() {
2629 assert(_global_dumper == nullptr, "Error");
2630 _global_dumper = this;
2631 }
2632 void set_global_writer() {
2633 assert(_global_writer == nullptr, "Error");
2634 _global_writer = _local_writer;
2696 }
2697
2698 ~VM_HeapDumper() {
2699 if (_thread_dumpers != nullptr) {
2700 for (int i = 0; i < _thread_dumpers_count; i++) {
2701 delete _thread_dumpers[i];
2702 }
2703 FREE_C_HEAP_ARRAY(ThreadDumper*, _thread_dumpers);
2704 }
2705
2706 if (_dumper_controller != nullptr) {
2707 delete _dumper_controller;
2708 _dumper_controller = nullptr;
2709 }
2710 delete _klass_map;
2711 }
2712 int dump_seq() { return _dump_seq; }
2713 bool is_parallel_dump() { return _num_dumper_threads > 1; }
2714 bool can_parallel_dump(WorkerThreads* workers);
2715
2716 InlinedObjects* inlined_objects() { return &_inlined_objects; }
2717
2718 VMOp_Type type() const { return VMOp_HeapDumper; }
2719 virtual bool doit_prologue();
2720 void doit();
2721 void work(uint worker_id);
2722 };
2723
2724 VM_HeapDumper* VM_HeapDumper::_global_dumper = nullptr;
2725 DumpWriter* VM_HeapDumper::_global_writer = nullptr;
2726
2727 bool VM_HeapDumper::skip_operation() const {
2728 return false;
2729 }
2730
2731 // fixes up the current dump record and writes HPROF_HEAP_DUMP_END record
2732 void DumperSupport::end_of_dump(AbstractDumpWriter* writer) {
2733 writer->finish_dump_segment();
2734
2735 writer->write_u1(HPROF_HEAP_DUMP_END);
2736 writer->write_u4(0);
2737 writer->write_u4(0);
2895 DumpWriter* local_writer = new DumpWriter(path, writer()->is_overwrite(), compressor);
2896 return local_writer;
2897 }
2898
2899 void VM_HeapDumper::work(uint worker_id) {
2900 // VM Dumper works on all non-heap data dumping and part of heap iteration.
2901 if (is_vm_dumper(worker_id)) {
2902 TraceTime timer("Dump non-objects", TRACETIME_LOG(Info, heapdump));
2903 // Write the file header - we always use 1.0.2
2904 const char* header = "JAVA PROFILE 1.0.2";
2905
2906 // header is few bytes long - no chance to overflow int
2907 writer()->write_raw(header, strlen(header) + 1); // NUL terminated
2908 writer()->write_u4(oopSize);
2909 // timestamp is current time in ms
2910 writer()->write_u8(os::javaTimeMillis());
2911 // HPROF_UTF8 records
2912 SymbolTableDumper sym_dumper(writer());
2913 SymbolTable::symbols_do(&sym_dumper);
2914
2915 // HPROF_UTF8 records for inlined field names.
2916 inlined_objects()->init();
2917 inlined_objects()->dump_inlined_field_names(writer());
2918
2919 // HPROF_INLINED_FIELDS
2920 inlined_objects()->dump_classed_with_inlined_fields(writer());
2921
2922 // write HPROF_LOAD_CLASS records
2923 {
2924 LockedClassesDo locked_load_classes(&do_load_class);
2925 ClassLoaderDataGraph::classes_do(&locked_load_classes);
2926 }
2927
2928 // write HPROF_FRAME and HPROF_TRACE records
2929 // this must be called after _klass_map is built when iterating the classes above.
2930 dump_stack_traces();
2931
2932 // HPROF_HEAP_DUMP/HPROF_HEAP_DUMP_SEGMENT starts here
2933
2934 // Writes HPROF_GC_CLASS_DUMP records
2935 {
2936 LockedClassesDo locked_dump_class(&do_class_dump);
2937 ClassLoaderDataGraph::classes_do(&locked_dump_class);
2938 }
2939
2940 // HPROF_GC_ROOT_THREAD_OBJ + frames + jni locals
2941 dump_threads();
2953 ClassLoaderData::the_null_class_loader_data()->classes_do(&class_dumper);
2954 }
2955
2956 // Heap iteration.
2957 // writes HPROF_GC_INSTANCE_DUMP records.
2958 // After each sub-record is written check_segment_length will be invoked
2959 // to check if the current segment exceeds a threshold. If so, a new
2960 // segment is started.
2961 // The HPROF_GC_CLASS_DUMP and HPROF_GC_INSTANCE_DUMP are the vast bulk
2962 // of the heap dump.
2963 if (!is_parallel_dump()) {
2964 assert(is_vm_dumper(worker_id), "must be");
2965 // == Serial dump
2966 ResourceMark rm;
2967 TraceTime timer("Dump heap objects", TRACETIME_LOG(Info, heapdump));
2968 HeapObjectDumper obj_dumper(writer());
2969 Universe::heap()->object_iterate(&obj_dumper);
2970 writer()->finish_dump_segment();
2971 // Writes the HPROF_HEAP_DUMP_END record because merge does not happen in serial dump
2972 DumperSupport::end_of_dump(writer());
2973 inlined_objects()->dump_flat_arrays(writer());
2974 writer()->flush();
2975 inlined_objects()->release();
2976 } else {
2977 // == Parallel dump
2978 ResourceMark rm;
2979 TraceTime timer("Dump heap objects in parallel", TRACETIME_LOG(Info, heapdump));
2980 DumpWriter* local_writer = is_vm_dumper(worker_id) ? writer() : create_local_writer();
2981 if (!local_writer->has_error()) {
2982 HeapObjectDumper obj_dumper(local_writer);
2983 _poi->object_iterate(&obj_dumper, worker_id);
2984 local_writer->finish_dump_segment();
2985 local_writer->flush();
2986 }
2987 if (is_vm_dumper(worker_id)) {
2988 _dumper_controller->wait_all_dumpers_complete();
2989 } else {
2990 _dumper_controller->dumper_complete(local_writer, writer());
2991 delete local_writer;
2992 return;
2993 }
2994 }
2995 // At this point, all fragments of the heapdump have been written to separate files.
3074 return -1;
3075 }
3076
3077 // generate the segmented heap dump into separate files
3078 VM_HeapDumper dumper(&writer, _gc_before_heap_dump, _oome, num_dump_threads);
3079 VMThread::execute(&dumper);
3080
3081 // record any error that the writer may have encountered
3082 set_error(writer.error());
3083
3084 // For serial dump, once VM_HeapDumper completes, the whole heap dump process
3085 // is done, no further phases needed. For parallel dump, the whole heap dump
3086 // process is done in two phases
3087 //
3088 // Phase 1: Concurrent threads directly write heap data to multiple heap files.
3089 // This is done by VM_HeapDumper, which is performed within safepoint.
3090 //
3091 // Phase 2: Merge multiple heap files into one complete heap dump file.
3092 // This is done by DumpMerger, which is performed outside safepoint
3093 if (dumper.is_parallel_dump()) {
3094 DumpMerger merger(path, &writer, dumper.inlined_objects(), dumper.dump_seq());
3095 Thread* current_thread = Thread::current();
3096 if (current_thread->is_AttachListener_thread()) {
3097 // perform heapdump file merge operation in the current thread prevents us
3098 // from occupying the VM Thread, which in turn affects the occurrence of
3099 // GC and other VM operations.
3100 merger.do_merge();
3101 } else {
3102 // otherwise, performs it by VM thread
3103 VM_HeapDumpMerge op(&merger);
3104 VMThread::execute(&op);
3105 }
3106 set_error(writer.error());
3107 }
3108
3109 // emit JFR event
3110 if (error() == nullptr) {
3111 event.set_destination(path);
3112 event.set_gcBeforeDump(_gc_before_heap_dump);
3113 event.set_size(writer.bytes_written());
3114 event.set_onOutOfMemoryError(_oome);
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