29 #include "runtime/atomic.hpp"
30 #include "runtime/handles.hpp"
31 #include "utilities/sizes.hpp"
32
33 class BasicLock {
34 friend class VMStructs;
35 friend class JVMCIVMStructs;
36 private:
37 // This is either the actual displaced header from a locked object, or
38 // a sentinel zero value indicating a recursive stack-lock.
39 volatile markWord _displaced_header;
40 public:
41 markWord displaced_header() const {
42 return Atomic::load(&_displaced_header);
43 }
44
45 void set_displaced_header(markWord header) {
46 Atomic::store(&_displaced_header, header);
47 }
48
49 void print_on(outputStream* st, oop owner) const;
50
51 // move a basic lock (used during deoptimization)
52 void move_to(oop obj, BasicLock* dest);
53
54 static int displaced_header_offset_in_bytes() { return (int)offset_of(BasicLock, _displaced_header); }
55 };
56
57 // A BasicObjectLock associates a specific Java object with a BasicLock.
58 // It is currently embedded in an interpreter frame.
59
60 // Because some machines have alignment restrictions on the control stack,
61 // the actual space allocated by the interpreter may include padding words
62 // after the end of the BasicObjectLock. Also, in order to guarantee
63 // alignment of the embedded BasicLock objects on such machines, we
64 // put the embedded BasicLock at the beginning of the struct.
65
66 class BasicObjectLock {
67 friend class VMStructs;
68 private:
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29 #include "runtime/atomic.hpp"
30 #include "runtime/handles.hpp"
31 #include "utilities/sizes.hpp"
32
33 class BasicLock {
34 friend class VMStructs;
35 friend class JVMCIVMStructs;
36 private:
37 // This is either the actual displaced header from a locked object, or
38 // a sentinel zero value indicating a recursive stack-lock.
39 volatile markWord _displaced_header;
40 public:
41 markWord displaced_header() const {
42 return Atomic::load(&_displaced_header);
43 }
44
45 void set_displaced_header(markWord header) {
46 Atomic::store(&_displaced_header, header);
47 }
48
49 // TODO[OMWorld]: Cleanup these names, the storage `_displaced_header` usage depends on the locking mode.
50 void clear_displaced_header() {
51 Atomic::store(&_displaced_header, markWord(0));
52 }
53
54 void set_displaced_header(ObjectMonitor* mon) {
55 Atomic::store(&_displaced_header, markWord::from_pointer(mon));
56 }
57
58 void print_on(outputStream* st, oop owner) const;
59
60 // move a basic lock (used during deoptimization)
61 void move_to(oop obj, BasicLock* dest);
62
63 static int displaced_header_offset_in_bytes() { return (int)offset_of(BasicLock, _displaced_header); }
64 };
65
66 // A BasicObjectLock associates a specific Java object with a BasicLock.
67 // It is currently embedded in an interpreter frame.
68
69 // Because some machines have alignment restrictions on the control stack,
70 // the actual space allocated by the interpreter may include padding words
71 // after the end of the BasicObjectLock. Also, in order to guarantee
72 // alignment of the embedded BasicLock objects on such machines, we
73 // put the embedded BasicLock at the beginning of the struct.
74
75 class BasicObjectLock {
76 friend class VMStructs;
77 private:
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