29 #include "runtime/thread.hpp"
30 #if INCLUDE_ALL_GCS
31 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
32 #endif
33
34
35 // The closure for GetLoadedClasses
36 class LoadedClassesClosure : public KlassClosure {
37 private:
38 Stack<jclass, mtInternal> _classStack;
39 JvmtiEnv* _env;
40
41 // Tell the GC to keep this klass alive
42 static void ensure_klass_alive(oop o) {
43 // A klass that was previously considered dead can be looked up in the
44 // CLD/SD, and its _java_mirror or _class_loader can be stored in a root
45 // or a reachable object making it alive again. The SATB part of G1 needs
46 // to get notified about this potential resurrection, otherwise the marking
47 // might not find the object.
48 #if INCLUDE_ALL_GCS
49 if (UseG1GC && o != NULL) {
50 G1SATBCardTableModRefBS::enqueue(o);
51 }
52 #endif
53 }
54
55 public:
56 LoadedClassesClosure(JvmtiEnv* env) {
57 _env = env;
58 }
59
60 void do_klass(Klass* k) {
61 // Collect all jclasses
62 _classStack.push((jclass) _env->jni_reference(k->java_mirror()));
63 ensure_klass_alive(k->java_mirror());
64 }
65
66 int extract(jclass* result_list) {
67 // The size of the Stack will be 0 after extract, so get it here
68 int count = (int)_classStack.size();
69 int i = count;
70
71 // Pop all jclasses, fill backwards
72 while (!_classStack.is_empty()) {
73 result_list[--i] = _classStack.pop();
74 }
75
76 // Return the number of elements written
77 return count;
78 }
79
80 // Return current size of the Stack
81 int get_count() {
82 return (int)_classStack.size();
83 }
84 };
85
86 // The closure for GetClassLoaderClasses
87 class JvmtiGetLoadedClassesClosure : public StackObj {
88 // Since the SystemDictionary::classes_do callback
89 // doesn't pass a closureData pointer,
90 // we use a thread-local slot to hold a pointer to
91 // a stack allocated instance of this structure.
92 private:
93 jobject _initiatingLoader;
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29 #include "runtime/thread.hpp"
30 #if INCLUDE_ALL_GCS
31 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
32 #endif
33
34
35 // The closure for GetLoadedClasses
36 class LoadedClassesClosure : public KlassClosure {
37 private:
38 Stack<jclass, mtInternal> _classStack;
39 JvmtiEnv* _env;
40
41 // Tell the GC to keep this klass alive
42 static void ensure_klass_alive(oop o) {
43 // A klass that was previously considered dead can be looked up in the
44 // CLD/SD, and its _java_mirror or _class_loader can be stored in a root
45 // or a reachable object making it alive again. The SATB part of G1 needs
46 // to get notified about this potential resurrection, otherwise the marking
47 // might not find the object.
48 #if INCLUDE_ALL_GCS
49 if ((o != NULL) && (UseG1GC || (UseShenandoahGC && ShenandoahSATBBarrier))) {
50 G1SATBCardTableModRefBS::enqueue(o);
51 }
52 #endif
53 }
54
55 public:
56 LoadedClassesClosure(JvmtiEnv* env) {
57 _env = env;
58 }
59
60 void do_klass(Klass* k) {
61 // Collect all jclasses
62 _classStack.push((jclass) _env->jni_reference(k->java_mirror()));
63 }
64
65 int extract(jclass* result_list) {
66 // The size of the Stack will be 0 after extract, so get it here
67 int count = (int)_classStack.size();
68 int i = count;
69
70 // Pop all jclasses, fill backwards
71 while (!_classStack.is_empty()) {
72 jclass klass_handle = _classStack.pop();
73 oop klass_mirror = JNIHandles::resolve(klass_handle);
74 ensure_klass_alive(klass_mirror);
75 result_list[--i] = klass_handle;
76 }
77
78 // Return the number of elements written
79 return count;
80 }
81
82 // Return current size of the Stack
83 int get_count() {
84 return (int)_classStack.size();
85 }
86 };
87
88 // The closure for GetClassLoaderClasses
89 class JvmtiGetLoadedClassesClosure : public StackObj {
90 // Since the SystemDictionary::classes_do callback
91 // doesn't pass a closureData pointer,
92 // we use a thread-local slot to hold a pointer to
93 // a stack allocated instance of this structure.
94 private:
95 jobject _initiatingLoader;
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