Thu, 07 Apr 2011 09:53:20 -0700
7009266: G1: assert(obj->is_oop_or_null(true )) failed: Error
Summary: A referent object that is only weakly reachable at the start of concurrent marking but is re-attached to the strongly reachable object graph during marking may not be marked as live. This can cause the reference object to be processed prematurely and leave dangling pointers to the referent object. Implement a read barrier for the java.lang.ref.Reference::referent field by intrinsifying the Reference.get() method, and intercepting accesses though JNI, reflection, and Unsafe, so that when a non-null referent object is read it is also logged in an SATB buffer.
Reviewed-by: kvn, iveresov, never, tonyp, dholmes
1 /*
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25 #ifndef CPU_SPARC_VM_JNITYPES_SPARC_HPP
26 #define CPU_SPARC_VM_JNITYPES_SPARC_HPP
28 #include "memory/allocation.hpp"
29 #include "oops/oop.hpp"
30 #include "prims/jni.h"
32 // This file holds platform-dependent routines used to write primitive jni
33 // types to the array of arguments passed into JavaCalls::call
35 class JNITypes : AllStatic {
36 // These functions write a java primitive type (in native format)
37 // to a java stack slot array to be passed as an argument to JavaCalls:calls.
38 // I.e., they are functionally 'push' operations if they have a 'pos'
39 // formal parameter. Note that jlong's and jdouble's are written
40 // _in reverse_ of the order in which they appear in the interpreter
41 // stack. This is because call stubs (see stubGenerator_sparc.cpp)
42 // reverse the argument list constructed by JavaCallArguments (see
43 // javaCalls.hpp).
45 private:
46 // Helper routines.
47 static inline void put_int2 (jint *from, jint *to) { to[0] = from[0]; to[1] = from[1]; }
48 static inline void put_int2 (jint *from, jint *to, int& pos) { put_int2 (from, (jint *)((intptr_t *)to + pos)); pos += 2; }
49 static inline void put_int2r(jint *from, jint *to) { to[0] = from[1]; to[1] = from[0]; }
50 static inline void put_int2r(jint *from, jint *to, int& pos) { put_int2r(from, (jint *)((intptr_t *)to + pos)); pos += 2; }
52 public:
53 // Ints are stored in native format in one JavaCallArgument slot at *to.
54 static inline void put_int(jint from, intptr_t *to) { *(jint *)(to + 0 ) = from; }
55 static inline void put_int(jint from, intptr_t *to, int& pos) { *(jint *)(to + pos++) = from; }
56 static inline void put_int(jint *from, intptr_t *to, int& pos) { *(jint *)(to + pos++) = *from; }
58 #ifdef _LP64
59 // Longs are stored in native format in one JavaCallArgument slot at *(to+1).
60 static inline void put_long(jlong from, intptr_t *to) { *(jlong *)(to + 1 + 0) = from; }
61 static inline void put_long(jlong from, intptr_t *to, int& pos) { *(jlong *)(to + 1 + pos) = from; pos += 2; }
62 static inline void put_long(jlong *from, intptr_t *to, int& pos) { *(jlong *)(to + 1 + pos) = *from; pos += 2; }
63 #else
64 // Longs are stored in reversed native word format in two JavaCallArgument slots at *to.
65 // The high half is in *(to+1) and the low half in *to.
66 static inline void put_long(jlong from, intptr_t *to) { put_int2r((jint *)&from, (jint *)to); }
67 static inline void put_long(jlong from, intptr_t *to, int& pos) { put_int2r((jint *)&from, (jint *)to, pos); }
68 static inline void put_long(jlong *from, intptr_t *to, int& pos) { put_int2r((jint *) from, (jint *)to, pos); }
69 #endif
71 // Oops are stored in native format in one JavaCallArgument slot at *to.
72 static inline void put_obj(oop from, intptr_t *to) { *(oop *)(to + 0 ) = from; }
73 static inline void put_obj(oop from, intptr_t *to, int& pos) { *(oop *)(to + pos++) = from; }
74 static inline void put_obj(oop *from, intptr_t *to, int& pos) { *(oop *)(to + pos++) = *from; }
76 // Floats are stored in native format in one JavaCallArgument slot at *to.
77 static inline void put_float(jfloat from, intptr_t *to) { *(jfloat *)(to + 0 ) = from; }
78 static inline void put_float(jfloat from, intptr_t *to, int& pos) { *(jfloat *)(to + pos++) = from; }
79 static inline void put_float(jfloat *from, intptr_t *to, int& pos) { *(jfloat *)(to + pos++) = *from; }
81 #ifdef _LP64
82 // Doubles are stored in native word format in one JavaCallArgument slot at *(to+1).
83 static inline void put_double(jdouble from, intptr_t *to) { *(jdouble *)(to + 1 + 0) = from; }
84 static inline void put_double(jdouble from, intptr_t *to, int& pos) { *(jdouble *)(to + 1 + pos) = from; pos += 2; }
85 static inline void put_double(jdouble *from, intptr_t *to, int& pos) { *(jdouble *)(to + 1 + pos) = *from; pos += 2; }
86 #else
87 // Doubles are stored in reversed native word format in two JavaCallArgument slots at *to.
88 static inline void put_double(jdouble from, intptr_t *to) { put_int2r((jint *)&from, (jint *)to); }
89 static inline void put_double(jdouble from, intptr_t *to, int& pos) { put_int2r((jint *)&from, (jint *)to, pos); }
90 static inline void put_double(jdouble *from, intptr_t *to, int& pos) { put_int2r((jint *) from, (jint *)to, pos); }
91 #endif
93 // The get_xxx routines, on the other hand, actually _do_ fetch
94 // java primitive types from the interpreter stack.
95 static inline jint get_int(intptr_t *from) { return *(jint *)from; }
97 #ifdef _LP64
98 static inline jlong get_long(intptr_t *from) { return *(jlong *)from; }
99 #else
100 static inline jlong get_long(intptr_t *from) { return ((jlong)(*( signed int *)((jint *)from )) << 32) |
101 ((jlong)(*(unsigned int *)((jint *)from + 1)) << 0); }
102 #endif
104 static inline oop get_obj(intptr_t *from) { return *(oop *)from; }
105 static inline jfloat get_float(intptr_t *from) { return *(jfloat *)from; }
107 #ifdef _LP64
108 static inline jdouble get_double(intptr_t *from) { return *(jdouble *)from; }
109 #else
110 static inline jdouble get_double(intptr_t *from) { jlong jl = ((jlong)(*( signed int *)((jint *)from )) << 32) |
111 ((jlong)(*(unsigned int *)((jint *)from + 1)) << 0);
112 return *(jdouble *)&jl; }
113 #endif
115 };
117 #endif // CPU_SPARC_VM_JNITYPES_SPARC_HPP