src/share/vm/prims/unsafe.cpp
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*** old/src/share/vm/prims/unsafe.cpp Tue May 3 11:37:49 2016
--- new/src/share/vm/prims/unsafe.cpp Tue May 3 11:37:49 2016
*** 129,170 ****
--- 129,272 ----
jlong Unsafe_field_offset_from_byte_offset(jlong byte_offset) {
return byte_offset;
}
! ///// Data in the Java heap.
! ///// Data read/writes on the Java heap and in native (off-heap) memory
#define truncate_jboolean(x) ((x) & 1)
#define truncate_jbyte(x) (x)
#define truncate_jshort(x) (x)
#define truncate_jchar(x) (x)
#define truncate_jint(x) (x)
#define truncate_jlong(x) (x)
#define truncate_jfloat(x) (x)
#define truncate_jdouble(x) (x)
#define GET_FIELD(obj, offset, type_name, v) \
oop p = JNIHandles::resolve(obj); \
type_name v = *(type_name*)index_oop_from_field_offset_long(p, offset)
#define SET_FIELD(obj, offset, type_name, x) \
oop p = JNIHandles::resolve(obj); \
*(type_name*)index_oop_from_field_offset_long(p, offset) = truncate_##type_name(x)
#define GET_FIELD_VOLATILE(obj, offset, type_name, v) \
oop p = JNIHandles::resolve(obj); \
if (support_IRIW_for_not_multiple_copy_atomic_cpu) { \
OrderAccess::fence(); \
} \
! volatile type_name v = OrderAccess::load_acquire((volatile type_name*)index_oop_from_field_offset_long(p, offset));
#define SET_FIELD_VOLATILE(obj, offset, type_name, x) \
oop p = JNIHandles::resolve(obj); \
OrderAccess::release_store_fence((volatile type_name*)index_oop_from_field_offset_long(p, offset), truncate_##type_name(x));
+ /**
+ * Helper class for accessing memory.
+ *
+ * Normalizes values and wraps accesses in
+ * JavaThread::doing_unsafe_access() if needed.
+ */
+ class MemoryAccess : StackObj {
+ JavaThread* _thread;
+ jobject _obj;
+ jlong _offset;
+
+ // Resolves and returns the address of the memory access
+ void* addr() {
+ return index_oop_from_field_offset_long(JNIHandles::resolve(_obj), _offset);
+ }
+
+ template <typename T>
+ T normalize(T x) {
+ return x;
+ }
+
+ jboolean normalize(jboolean x) {
! return x & 1;
+ }
+
+ /**
+ * Helper class to wrap memory accesses in JavaThread::doing_unsafe_access()
+ */
+ class GuardUnsafeAccess {
+ JavaThread* _thread;
+ bool _active;
+
+ public:
+ GuardUnsafeAccess(JavaThread* thread, jobject _obj) : _thread(thread) {
+ if (JNIHandles::resolve(_obj) == NULL) {
+ // native/off-heap access which may raise SIGBUS if accessing
+ // memory mapped file data in a region of the file which has
+ // been truncated and is now invalid
+ _thread->set_doing_unsafe_access(true);
+ _active = true;
+ } else {
+ _active = false;
+ }
+ }
+
+ ~GuardUnsafeAccess() {
+ if (_active) {
+ _thread->set_doing_unsafe_access(false);
+ }
+ }
+ };
+
+ public:
+ MemoryAccess(JavaThread* thread, jobject obj, jlong offset)
+ : _thread(thread), _obj(obj), _offset(offset) {
+ }
+
+ template <typename T>
+ T get() {
+ GuardUnsafeAccess guard(_thread, _obj);
+
+ T* p = (T*)addr();
+
+ T x = *p;
+
+ return x;
+ }
+
+ template <typename T>
+ void put(T x) {
+ GuardUnsafeAccess guard(_thread, _obj);
+
+ T* p = (T*)addr();
+
+ *p = normalize(x);
+ }
+
+
+ template <typename T>
+ T get_volatile() {
+ GuardUnsafeAccess guard(_thread, _obj);
+
+ T* p = (T*)addr();
+
+ if (support_IRIW_for_not_multiple_copy_atomic_cpu) {
+ OrderAccess::fence();
+ }
+
+ T x = OrderAccess::load_acquire((volatile T*)p);
+
+ return x;
+ }
+
+ template <typename T>
+ void put_volatile(T x) {
+ GuardUnsafeAccess guard(_thread, _obj);
+
+ T* p = (T*)addr();
+
+ OrderAccess::release_store_fence((volatile T*)p, normalize(x));
+ }
+
+
+ #ifndef SUPPORTS_NATIVE_CX8
+ //
+ template <typename T>
+ T get_mutex() {
+ GuardUnsafeAccess guard(_thread, _obj);
+
+ MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
+
+ T* p = (T*)addr();
+
+ T x = Atomic::load(p);
+
+ return x;
+ }
+ template <typename T>
+ void put_mutex(T x) {
+ GuardUnsafeAccess guard(_thread, _obj);
// Get/SetObject must be special-cased, since it works with handles.
+ MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
+
+ T* p = (T*)addr();
+
+ Atomic::store(normalize(x), p);
+ }
+ #endif
+ };
+
+ // Get/PutObject must be special-cased, since it works with handles.
// These functions allow a null base pointer with an arbitrary address.
// But if the base pointer is non-null, the offset should make some sense.
// That is, it should be in the range [0, MAX_OBJECT_SIZE].
UNSAFE_ENTRY(jobject, Unsafe_GetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
*** 206,216 ****
--- 308,318 ----
#endif // INCLUDE_ALL_GCS
return ret;
} UNSAFE_END
! UNSAFE_ENTRY(void, Unsafe_SetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
! UNSAFE_ENTRY(void, Unsafe_PutObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
oop x = JNIHandles::resolve(x_h);
oop p = JNIHandles::resolve(obj);
if (UseCompressedOops) {
oop_store((narrowOop*)index_oop_from_field_offset_long(p, offset), x);
*** 234,244 ****
--- 336,346 ----
OrderAccess::acquire();
return JNIHandles::make_local(env, v);
} UNSAFE_END
! UNSAFE_ENTRY(void, Unsafe_SetObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
! UNSAFE_ENTRY(void, Unsafe_PutObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
oop x = JNIHandles::resolve(x_h);
oop p = JNIHandles::resolve(obj);
void* addr = index_oop_from_field_offset_long(p, offset);
OrderAccess::release();
*** 299,327 ****
--- 401,421 ----
// the address of the field _after_ we have acquired the lock, else the object may have
// been moved by the GC
UNSAFE_ENTRY(jlong, Unsafe_GetLongVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
if (VM_Version::supports_cx8()) {
! GET_FIELD_VOLATILE(obj, offset, jlong, v);
return v;
! return MemoryAccess(thread, obj, offset).get_volatile<jlong>();
} else {
! Handle p (THREAD, JNIHandles::resolve(obj));
jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset));
MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
jlong value = Atomic::load(addr);
return value;
! return MemoryAccess(thread, obj, offset).get_mutex<jlong>();
}
} UNSAFE_END
! UNSAFE_ENTRY(void, Unsafe_SetLongVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong x)) {
! UNSAFE_ENTRY(void, Unsafe_PutLongVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong x)) {
if (VM_Version::supports_cx8()) {
! SET_FIELD_VOLATILE(obj, offset, jlong, x);
! MemoryAccess(thread, obj, offset).put_volatile<jlong>(x);
} else {
! Handle p (THREAD, JNIHandles::resolve(obj));
jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset));
MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
Atomic::store(x, addr);
! MemoryAccess(thread, obj, offset).put_mutex<jlong>(x);
}
} UNSAFE_END
#endif // not SUPPORTS_NATIVE_CX8
*** 338,353 ****
--- 432,446 ----
} UNSAFE_END
#define DEFINE_GETSETOOP(java_type, Type) \
\
UNSAFE_ENTRY(java_type, Unsafe_Get##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \
! GET_FIELD(obj, offset, java_type, v); \
return v; \
! return MemoryAccess(thread, obj, offset).get<java_type>(); \
} UNSAFE_END \
\
! UNSAFE_ENTRY(void, Unsafe_Set##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
! SET_FIELD(obj, offset, java_type, x); \
! UNSAFE_ENTRY(void, Unsafe_Put##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
! MemoryAccess(thread, obj, offset).put<java_type>(x); \
} UNSAFE_END \
\
// END DEFINE_GETSETOOP.
DEFINE_GETSETOOP(jboolean, Boolean)
*** 362,377 ****
--- 455,469 ----
#undef DEFINE_GETSETOOP
#define DEFINE_GETSETOOP_VOLATILE(java_type, Type) \
\
UNSAFE_ENTRY(java_type, Unsafe_Get##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \
! GET_FIELD_VOLATILE(obj, offset, java_type, v); \
return v; \
! return MemoryAccess(thread, obj, offset).get_volatile<java_type>(); \
} UNSAFE_END \
\
! UNSAFE_ENTRY(void, Unsafe_Set##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
! SET_FIELD_VOLATILE(obj, offset, java_type, x); \
! UNSAFE_ENTRY(void, Unsafe_Put##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
! MemoryAccess(thread, obj, offset).put_volatile<java_type>(x); \
} UNSAFE_END \
\
// END DEFINE_GETSETOOP_VOLATILE.
DEFINE_GETSETOOP_VOLATILE(jboolean, Boolean)
*** 398,499 ****
--- 490,499 ----
UNSAFE_LEAF(void, Unsafe_FullFence(JNIEnv *env, jobject unsafe)) {
OrderAccess::fence();
} UNSAFE_END
////// Data in the C heap.
// Note: These do not throw NullPointerException for bad pointers.
// They just crash. Only a oop base pointer can generate a NullPointerException.
//
#define DEFINE_GETSETNATIVE(java_type, Type, native_type) \
\
UNSAFE_ENTRY(java_type, Unsafe_GetNative##Type(JNIEnv *env, jobject unsafe, jlong addr)) { \
void* p = addr_from_java(addr); \
JavaThread* t = JavaThread::current(); \
t->set_doing_unsafe_access(true); \
java_type x = *(volatile native_type*)p; \
t->set_doing_unsafe_access(false); \
return x; \
} UNSAFE_END \
\
UNSAFE_ENTRY(void, Unsafe_SetNative##Type(JNIEnv *env, jobject unsafe, jlong addr, java_type x)) { \
JavaThread* t = JavaThread::current(); \
t->set_doing_unsafe_access(true); \
void* p = addr_from_java(addr); \
*(volatile native_type*)p = x; \
t->set_doing_unsafe_access(false); \
} UNSAFE_END \
\
// END DEFINE_GETSETNATIVE.
DEFINE_GETSETNATIVE(jbyte, Byte, signed char)
DEFINE_GETSETNATIVE(jshort, Short, signed short);
DEFINE_GETSETNATIVE(jchar, Char, unsigned short);
DEFINE_GETSETNATIVE(jint, Int, jint);
// no long -- handled specially
DEFINE_GETSETNATIVE(jfloat, Float, float);
DEFINE_GETSETNATIVE(jdouble, Double, double);
#undef DEFINE_GETSETNATIVE
UNSAFE_ENTRY(jlong, Unsafe_GetNativeLong(JNIEnv *env, jobject unsafe, jlong addr)) {
JavaThread* t = JavaThread::current();
// We do it this way to avoid problems with access to heap using 64
// bit loads, as jlong in heap could be not 64-bit aligned, and on
// some CPUs (SPARC) it leads to SIGBUS.
t->set_doing_unsafe_access(true);
void* p = addr_from_java(addr);
jlong x;
if (is_ptr_aligned(p, sizeof(jlong)) == 0) {
// jlong is aligned, do a volatile access
x = *(volatile jlong*)p;
} else {
jlong_accessor acc;
acc.words[0] = ((volatile jint*)p)[0];
acc.words[1] = ((volatile jint*)p)[1];
x = acc.long_value;
}
t->set_doing_unsafe_access(false);
return x;
} UNSAFE_END
UNSAFE_ENTRY(void, Unsafe_SetNativeLong(JNIEnv *env, jobject unsafe, jlong addr, jlong x)) {
JavaThread* t = JavaThread::current();
// see comment for Unsafe_GetNativeLong
t->set_doing_unsafe_access(true);
void* p = addr_from_java(addr);
if (is_ptr_aligned(p, sizeof(jlong))) {
// jlong is aligned, do a volatile access
*(volatile jlong*)p = x;
} else {
jlong_accessor acc;
acc.long_value = x;
((volatile jint*)p)[0] = acc.words[0];
((volatile jint*)p)[1] = acc.words[1];
}
t->set_doing_unsafe_access(false);
} UNSAFE_END
UNSAFE_LEAF(jlong, Unsafe_GetNativeAddress(JNIEnv *env, jobject unsafe, jlong addr)) {
void* p = addr_from_java(addr);
return addr_to_java(*(void**)p);
} UNSAFE_END
UNSAFE_LEAF(void, Unsafe_SetNativeAddress(JNIEnv *env, jobject unsafe, jlong addr, jlong x)) {
void* p = addr_from_java(addr);
*(void**)p = addr_from_java(x);
} UNSAFE_END
////// Allocation requests
UNSAFE_ENTRY(jobject, Unsafe_AllocateInstance(JNIEnv *env, jobject unsafe, jclass cls)) {
ThreadToNativeFromVM ttnfv(thread);
return env->AllocObject(cls);
*** 978,989 ****
--- 978,989 ----
return (jint)(Atomic::cmpxchg(x, addr, e));
} UNSAFE_END
UNSAFE_ENTRY(jlong, Unsafe_CompareAndExchangeLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
- Handle p (THREAD, JNIHandles::resolve(obj));
! jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset));
#ifdef SUPPORTS_NATIVE_CX8
return (jlong)(Atomic::cmpxchg(x, addr, e));
#else
if (VM_Version::supports_cx8()) {
*** 1015,1025 ****
--- 1015,1025 ----
return true;
} UNSAFE_END
UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
oop p = JNIHandles::resolve(obj);
- jint* addr = (jint *) index_oop_from_field_offset_long(p, offset);
return (jint)(Atomic::cmpxchg(x, addr, e)) == e;
} UNSAFE_END
UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
*** 1141,1164 ****
--- 1141,1160 ----
#define CC (char*) /*cast a literal from (const char*)*/
#define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
#define DECLARE_GETPUTOOP(Type, Desc) \
{CC "get" #Type, CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type)}, \
! {CC "put" #Type, CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Set##Type)}, \
! {CC "put" #Type, CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type)}, \
{CC "get" #Type "Volatile", CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type##Volatile)}, \
! {CC "put" #Type "Volatile", CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Set##Type##Volatile)}
! {CC "put" #Type "Volatile", CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type##Volatile)}
#define DECLARE_GETPUTNATIVE(Byte, B) \
{CC "get" #Byte, CC "(" ADR ")" #B, FN_PTR(Unsafe_GetNative##Byte)}, \
{CC "put" #Byte, CC "(" ADR#B ")V", FN_PTR(Unsafe_SetNative##Byte)}
static JNINativeMethod jdk_internal_misc_Unsafe_methods[] = {
{CC "getObject", CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetObject)},
! {CC "putObject", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_SetObject)},
! {CC "putObject", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutObject)},
{CC "getObjectVolatile",CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetObjectVolatile)},
! {CC "putObjectVolatile",CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_SetObjectVolatile)},
! {CC "putObjectVolatile",CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutObjectVolatile)},
{CC "getUncompressedObject", CC "(" ADR ")" OBJ, FN_PTR(Unsafe_GetUncompressedObject)},
{CC "getJavaMirror", CC "(" ADR ")" CLS, FN_PTR(Unsafe_GetJavaMirror)},
{CC "getKlassPointer", CC "(" OBJ ")" ADR, FN_PTR(Unsafe_GetKlassPointer)},
*** 1169,1189 ****
--- 1165,1174 ----
DECLARE_GETPUTOOP(Int, I),
DECLARE_GETPUTOOP(Long, J),
DECLARE_GETPUTOOP(Float, F),
DECLARE_GETPUTOOP(Double, D),
DECLARE_GETPUTNATIVE(Byte, B),
DECLARE_GETPUTNATIVE(Short, S),
DECLARE_GETPUTNATIVE(Char, C),
DECLARE_GETPUTNATIVE(Int, I),
DECLARE_GETPUTNATIVE(Long, J),
DECLARE_GETPUTNATIVE(Float, F),
DECLARE_GETPUTNATIVE(Double, D),
{CC "getAddress", CC "(" ADR ")" ADR, FN_PTR(Unsafe_GetNativeAddress)},
{CC "putAddress", CC "(" ADR "" ADR ")V", FN_PTR(Unsafe_SetNativeAddress)},
{CC "allocateMemory0", CC "(J)" ADR, FN_PTR(Unsafe_AllocateMemory0)},
{CC "reallocateMemory0", CC "(" ADR "J)" ADR, FN_PTR(Unsafe_ReallocateMemory0)},
{CC "freeMemory0", CC "(" ADR ")V", FN_PTR(Unsafe_FreeMemory0)},
{CC "objectFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_ObjectFieldOffset0)},
*** 1237,1247 ****
--- 1222,1231 ----
#undef THR
#undef DC_Args
#undef DAC_Args
#undef DECLARE_GETPUTOOP
#undef DECLARE_GETPUTNATIVE
// This function is exported, used by NativeLookup.
// The Unsafe_xxx functions above are called only from the interpreter.
// The optimizer looks at names and signatures to recognize
src/share/vm/prims/unsafe.cpp
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