src/share/vm/prims/unsafe.cpp

Thu, 24 Mar 2016 21:38:15 -0700

author
iklam
date
Thu, 24 Mar 2016 21:38:15 -0700
changeset 8497
50e62b688ddc
parent 8368
32b682649973
child 8415
d109bda16490
permissions
-rw-r--r--

8150752: Share Class Data
Reviewed-by: acorn, hseigel, mschoene

     1 /*
     2  * Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 #include "precompiled.hpp"
    26 #include "classfile/vmSymbols.hpp"
    27 #include "utilities/macros.hpp"
    28 #if INCLUDE_ALL_GCS
    29 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
    30 #endif // INCLUDE_ALL_GCS
    31 #include "memory/allocation.inline.hpp"
    32 #include "prims/jni.h"
    33 #include "prims/jvm.h"
    34 #include "runtime/globals.hpp"
    35 #include "runtime/interfaceSupport.hpp"
    36 #include "runtime/prefetch.inline.hpp"
    37 #include "runtime/orderAccess.inline.hpp"
    38 #include "runtime/reflection.hpp"
    39 #include "runtime/synchronizer.hpp"
    40 #include "services/threadService.hpp"
    41 #include "trace/tracing.hpp"
    42 #include "utilities/copy.hpp"
    43 #include "utilities/dtrace.hpp"
    45 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
    47 /*
    48  *      Implementation of class sun.misc.Unsafe
    49  */
    51 #ifndef USDT2
    52 HS_DTRACE_PROBE_DECL3(hotspot, thread__park__begin, uintptr_t, int, long long);
    53 HS_DTRACE_PROBE_DECL1(hotspot, thread__park__end, uintptr_t);
    54 HS_DTRACE_PROBE_DECL1(hotspot, thread__unpark, uintptr_t);
    55 #endif /* !USDT2 */
    57 #define MAX_OBJECT_SIZE \
    58   ( arrayOopDesc::header_size(T_DOUBLE) * HeapWordSize \
    59     + ((julong)max_jint * sizeof(double)) )
    62 #define UNSAFE_ENTRY(result_type, header) \
    63   JVM_ENTRY(result_type, header)
    65 // Can't use UNSAFE_LEAF because it has the signature of a straight
    66 // call into the runtime (just like JVM_LEAF, funny that) but it's
    67 // called like a Java Native and thus the wrapper built for it passes
    68 // arguments like a JNI call.  It expects those arguments to be popped
    69 // from the stack on Intel like all good JNI args are, and adjusts the
    70 // stack according.  Since the JVM_LEAF call expects no extra
    71 // arguments the stack isn't popped in the C code, is pushed by the
    72 // wrapper and we get sick.
    73 //#define UNSAFE_LEAF(result_type, header) \
    74 //  JVM_LEAF(result_type, header)
    76 #define UNSAFE_END JVM_END
    78 #define UnsafeWrapper(arg) /*nothing, for the present*/
    81 inline void* addr_from_java(jlong addr) {
    82   // This assert fails in a variety of ways on 32-bit systems.
    83   // It is impossible to predict whether native code that converts
    84   // pointers to longs will sign-extend or zero-extend the addresses.
    85   //assert(addr == (uintptr_t)addr, "must not be odd high bits");
    86   return (void*)(uintptr_t)addr;
    87 }
    89 inline jlong addr_to_java(void* p) {
    90   assert(p == (void*)(uintptr_t)p, "must not be odd high bits");
    91   return (uintptr_t)p;
    92 }
    95 // Note: The VM's obj_field and related accessors use byte-scaled
    96 // ("unscaled") offsets, just as the unsafe methods do.
    98 // However, the method Unsafe.fieldOffset explicitly declines to
    99 // guarantee this.  The field offset values manipulated by the Java user
   100 // through the Unsafe API are opaque cookies that just happen to be byte
   101 // offsets.  We represent this state of affairs by passing the cookies
   102 // through conversion functions when going between the VM and the Unsafe API.
   103 // The conversion functions just happen to be no-ops at present.
   105 inline jlong field_offset_to_byte_offset(jlong field_offset) {
   106   return field_offset;
   107 }
   109 inline jlong field_offset_from_byte_offset(jlong byte_offset) {
   110   return byte_offset;
   111 }
   113 inline jint invocation_key_from_method_slot(jint slot) {
   114   return slot;
   115 }
   117 inline jint invocation_key_to_method_slot(jint key) {
   118   return key;
   119 }
   121 inline void* index_oop_from_field_offset_long(oop p, jlong field_offset) {
   122   jlong byte_offset = field_offset_to_byte_offset(field_offset);
   123 #ifdef ASSERT
   124   if (p != NULL) {
   125     assert(byte_offset >= 0 && byte_offset <= (jlong)MAX_OBJECT_SIZE, "sane offset");
   126     if (byte_offset == (jint)byte_offset) {
   127       void* ptr_plus_disp = (address)p + byte_offset;
   128       assert((void*)p->obj_field_addr<oop>((jint)byte_offset) == ptr_plus_disp,
   129              "raw [ptr+disp] must be consistent with oop::field_base");
   130     }
   131     jlong p_size = HeapWordSize * (jlong)(p->size());
   132     assert(byte_offset < p_size, err_msg("Unsafe access: offset " INT64_FORMAT " > object's size " INT64_FORMAT, byte_offset, p_size));
   133   }
   134 #endif
   135   if (sizeof(char*) == sizeof(jint))    // (this constant folds!)
   136     return (address)p + (jint) byte_offset;
   137   else
   138     return (address)p +        byte_offset;
   139 }
   141 // Externally callable versions:
   142 // (Use these in compiler intrinsics which emulate unsafe primitives.)
   143 jlong Unsafe_field_offset_to_byte_offset(jlong field_offset) {
   144   return field_offset;
   145 }
   146 jlong Unsafe_field_offset_from_byte_offset(jlong byte_offset) {
   147   return byte_offset;
   148 }
   149 jint Unsafe_invocation_key_from_method_slot(jint slot) {
   150   return invocation_key_from_method_slot(slot);
   151 }
   152 jint Unsafe_invocation_key_to_method_slot(jint key) {
   153   return invocation_key_to_method_slot(key);
   154 }
   157 ///// Data in the Java heap.
   159 #define truncate_jboolean(x) ((x) & 1)
   160 #define truncate_jbyte(x) (x)
   161 #define truncate_jshort(x) (x)
   162 #define truncate_jchar(x) (x)
   163 #define truncate_jint(x) (x)
   164 #define truncate_jlong(x) (x)
   165 #define truncate_jfloat(x) (x)
   166 #define truncate_jdouble(x) (x)
   168 #define GET_FIELD(obj, offset, type_name, v) \
   169   oop p = JNIHandles::resolve(obj); \
   170   type_name v = *(type_name*)index_oop_from_field_offset_long(p, offset)
   172 #define SET_FIELD(obj, offset, type_name, x) \
   173   oop p = JNIHandles::resolve(obj); \
   174   *(type_name*)index_oop_from_field_offset_long(p, offset) = truncate_##type_name(x)
   176 #define GET_FIELD_VOLATILE(obj, offset, type_name, v) \
   177   oop p = JNIHandles::resolve(obj); \
   178   if (support_IRIW_for_not_multiple_copy_atomic_cpu) { \
   179     OrderAccess::fence(); \
   180   } \
   181   volatile type_name v = OrderAccess::load_acquire((volatile type_name*)index_oop_from_field_offset_long(p, offset));
   183 #define SET_FIELD_VOLATILE(obj, offset, type_name, x) \
   184   oop p = JNIHandles::resolve(obj); \
   185   OrderAccess::release_store_fence((volatile type_name*)index_oop_from_field_offset_long(p, offset), truncate_##type_name(x));
   187 // Macros for oops that check UseCompressedOops
   189 #define GET_OOP_FIELD(obj, offset, v) \
   190   oop p = JNIHandles::resolve(obj);   \
   191   oop v;                              \
   192   if (UseCompressedOops) {            \
   193     narrowOop n = *(narrowOop*)index_oop_from_field_offset_long(p, offset); \
   194     v = oopDesc::decode_heap_oop(n);                                \
   195   } else {                            \
   196     v = *(oop*)index_oop_from_field_offset_long(p, offset);                 \
   197   }
   200 // Get/SetObject must be special-cased, since it works with handles.
   202 // The xxx140 variants for backward compatibility do not allow a full-width offset.
   203 UNSAFE_ENTRY(jobject, Unsafe_GetObject140(JNIEnv *env, jobject unsafe, jobject obj, jint offset))
   204   UnsafeWrapper("Unsafe_GetObject");
   205   if (obj == NULL)  THROW_0(vmSymbols::java_lang_NullPointerException());
   206   GET_OOP_FIELD(obj, offset, v)
   207   jobject ret = JNIHandles::make_local(env, v);
   208 #if INCLUDE_ALL_GCS
   209   // We could be accessing the referent field in a reference
   210   // object. If G1 is enabled then we need to register a non-null
   211   // referent with the SATB barrier.
   212   if (UseG1GC) {
   213     bool needs_barrier = false;
   215     if (ret != NULL) {
   216       if (offset == java_lang_ref_Reference::referent_offset) {
   217         oop o = JNIHandles::resolve_non_null(obj);
   218         Klass* k = o->klass();
   219         if (InstanceKlass::cast(k)->reference_type() != REF_NONE) {
   220           assert(InstanceKlass::cast(k)->is_subclass_of(SystemDictionary::Reference_klass()), "sanity");
   221           needs_barrier = true;
   222         }
   223       }
   224     }
   226     if (needs_barrier) {
   227       oop referent = JNIHandles::resolve(ret);
   228       G1SATBCardTableModRefBS::enqueue(referent);
   229     }
   230   }
   231 #endif // INCLUDE_ALL_GCS
   232   return ret;
   233 UNSAFE_END
   235 UNSAFE_ENTRY(void, Unsafe_SetObject140(JNIEnv *env, jobject unsafe, jobject obj, jint offset, jobject x_h))
   236   UnsafeWrapper("Unsafe_SetObject");
   237   if (obj == NULL)  THROW(vmSymbols::java_lang_NullPointerException());
   238   oop x = JNIHandles::resolve(x_h);
   239   //SET_FIELD(obj, offset, oop, x);
   240   oop p = JNIHandles::resolve(obj);
   241   if (UseCompressedOops) {
   242     if (x != NULL) {
   243       // If there is a heap base pointer, we are obliged to emit a store barrier.
   244       oop_store((narrowOop*)index_oop_from_field_offset_long(p, offset), x);
   245     } else {
   246       narrowOop n = oopDesc::encode_heap_oop_not_null(x);
   247       *(narrowOop*)index_oop_from_field_offset_long(p, offset) = n;
   248     }
   249   } else {
   250     if (x != NULL) {
   251       // If there is a heap base pointer, we are obliged to emit a store barrier.
   252       oop_store((oop*)index_oop_from_field_offset_long(p, offset), x);
   253     } else {
   254       *(oop*)index_oop_from_field_offset_long(p, offset) = x;
   255     }
   256   }
   257 UNSAFE_END
   259 // The normal variants allow a null base pointer with an arbitrary address.
   260 // But if the base pointer is non-null, the offset should make some sense.
   261 // That is, it should be in the range [0, MAX_OBJECT_SIZE].
   262 UNSAFE_ENTRY(jobject, Unsafe_GetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset))
   263   UnsafeWrapper("Unsafe_GetObject");
   264   GET_OOP_FIELD(obj, offset, v)
   265   jobject ret = JNIHandles::make_local(env, v);
   266 #if INCLUDE_ALL_GCS
   267   // We could be accessing the referent field in a reference
   268   // object. If G1 is enabled then we need to register non-null
   269   // referent with the SATB barrier.
   270   if (UseG1GC) {
   271     bool needs_barrier = false;
   273     if (ret != NULL) {
   274       if (offset == java_lang_ref_Reference::referent_offset && obj != NULL) {
   275         oop o = JNIHandles::resolve(obj);
   276         Klass* k = o->klass();
   277         if (InstanceKlass::cast(k)->reference_type() != REF_NONE) {
   278           assert(InstanceKlass::cast(k)->is_subclass_of(SystemDictionary::Reference_klass()), "sanity");
   279           needs_barrier = true;
   280         }
   281       }
   282     }
   284     if (needs_barrier) {
   285       oop referent = JNIHandles::resolve(ret);
   286       G1SATBCardTableModRefBS::enqueue(referent);
   287     }
   288   }
   289 #endif // INCLUDE_ALL_GCS
   290   return ret;
   291 UNSAFE_END
   293 UNSAFE_ENTRY(void, Unsafe_SetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h))
   294   UnsafeWrapper("Unsafe_SetObject");
   295   oop x = JNIHandles::resolve(x_h);
   296   oop p = JNIHandles::resolve(obj);
   297   if (UseCompressedOops) {
   298     oop_store((narrowOop*)index_oop_from_field_offset_long(p, offset), x);
   299   } else {
   300     oop_store((oop*)index_oop_from_field_offset_long(p, offset), x);
   301   }
   302 UNSAFE_END
   304 UNSAFE_ENTRY(jobject, Unsafe_GetObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset))
   305   UnsafeWrapper("Unsafe_GetObjectVolatile");
   306   oop p = JNIHandles::resolve(obj);
   307   void* addr = index_oop_from_field_offset_long(p, offset);
   308   volatile oop v;
   309   if (UseCompressedOops) {
   310     volatile narrowOop n = *(volatile narrowOop*) addr;
   311     (void)const_cast<oop&>(v = oopDesc::decode_heap_oop(n));
   312   } else {
   313     (void)const_cast<oop&>(v = *(volatile oop*) addr);
   314   }
   315   OrderAccess::acquire();
   316   return JNIHandles::make_local(env, v);
   317 UNSAFE_END
   319 UNSAFE_ENTRY(void, Unsafe_SetObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h))
   320   UnsafeWrapper("Unsafe_SetObjectVolatile");
   321   oop x = JNIHandles::resolve(x_h);
   322   oop p = JNIHandles::resolve(obj);
   323   void* addr = index_oop_from_field_offset_long(p, offset);
   324   OrderAccess::release();
   325   if (UseCompressedOops) {
   326     oop_store((narrowOop*)addr, x);
   327   } else {
   328     oop_store((oop*)addr, x);
   329   }
   330   OrderAccess::fence();
   331 UNSAFE_END
   333 #ifndef SUPPORTS_NATIVE_CX8
   335 // VM_Version::supports_cx8() is a surrogate for 'supports atomic long memory ops'.
   336 //
   337 // On platforms which do not support atomic compare-and-swap of jlong (8 byte)
   338 // values we have to use a lock-based scheme to enforce atomicity. This has to be
   339 // applied to all Unsafe operations that set the value of a jlong field. Even so
   340 // the compareAndSwapLong operation will not be atomic with respect to direct stores
   341 // to the field from Java code. It is important therefore that any Java code that
   342 // utilizes these Unsafe jlong operations does not perform direct stores. To permit
   343 // direct loads of the field from Java code we must also use Atomic::store within the
   344 // locked regions. And for good measure, in case there are direct stores, we also
   345 // employ Atomic::load within those regions. Note that the field in question must be
   346 // volatile and so must have atomic load/store accesses applied at the Java level.
   347 //
   348 // The locking scheme could utilize a range of strategies for controlling the locking
   349 // granularity: from a lock per-field through to a single global lock. The latter is
   350 // the simplest and is used for the current implementation. Note that the Java object
   351 // that contains the field, can not, in general, be used for locking. To do so can lead
   352 // to deadlocks as we may introduce locking into what appears to the Java code to be a
   353 // lock-free path.
   354 //
   355 // As all the locked-regions are very short and themselves non-blocking we can treat
   356 // them as leaf routines and elide safepoint checks (ie we don't perform any thread
   357 // state transitions even when blocking for the lock). Note that if we do choose to
   358 // add safepoint checks and thread state transitions, we must ensure that we calculate
   359 // the address of the field _after_ we have acquired the lock, else the object may have
   360 // been moved by the GC
   362 UNSAFE_ENTRY(jlong, Unsafe_GetLongVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset))
   363   UnsafeWrapper("Unsafe_GetLongVolatile");
   364   {
   365     if (VM_Version::supports_cx8()) {
   366       GET_FIELD_VOLATILE(obj, offset, jlong, v);
   367       return v;
   368     }
   369     else {
   370       Handle p (THREAD, JNIHandles::resolve(obj));
   371       jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset));
   372       MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
   373       jlong value = Atomic::load(addr);
   374       return value;
   375     }
   376   }
   377 UNSAFE_END
   379 UNSAFE_ENTRY(void, Unsafe_SetLongVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong x))
   380   UnsafeWrapper("Unsafe_SetLongVolatile");
   381   {
   382     if (VM_Version::supports_cx8()) {
   383       SET_FIELD_VOLATILE(obj, offset, jlong, x);
   384     }
   385     else {
   386       Handle p (THREAD, JNIHandles::resolve(obj));
   387       jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset));
   388       MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
   389       Atomic::store(x, addr);
   390     }
   391   }
   392 UNSAFE_END
   394 #endif // not SUPPORTS_NATIVE_CX8
   396 #define DEFINE_GETSETOOP(jboolean, Boolean) \
   397  \
   398 UNSAFE_ENTRY(jboolean, Unsafe_Get##Boolean##140(JNIEnv *env, jobject unsafe, jobject obj, jint offset)) \
   399   UnsafeWrapper("Unsafe_Get"#Boolean); \
   400   if (obj == NULL)  THROW_0(vmSymbols::java_lang_NullPointerException()); \
   401   GET_FIELD(obj, offset, jboolean, v); \
   402   return v; \
   403 UNSAFE_END \
   404  \
   405 UNSAFE_ENTRY(void, Unsafe_Set##Boolean##140(JNIEnv *env, jobject unsafe, jobject obj, jint offset, jboolean x)) \
   406   UnsafeWrapper("Unsafe_Set"#Boolean); \
   407   if (obj == NULL)  THROW(vmSymbols::java_lang_NullPointerException()); \
   408   SET_FIELD(obj, offset, jboolean, x); \
   409 UNSAFE_END \
   410  \
   411 UNSAFE_ENTRY(jboolean, Unsafe_Get##Boolean(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) \
   412   UnsafeWrapper("Unsafe_Get"#Boolean); \
   413   GET_FIELD(obj, offset, jboolean, v); \
   414   return v; \
   415 UNSAFE_END \
   416  \
   417 UNSAFE_ENTRY(void, Unsafe_Set##Boolean(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jboolean x)) \
   418   UnsafeWrapper("Unsafe_Set"#Boolean); \
   419   SET_FIELD(obj, offset, jboolean, x); \
   420 UNSAFE_END \
   421  \
   422 // END DEFINE_GETSETOOP.
   424 DEFINE_GETSETOOP(jboolean, Boolean)
   425 DEFINE_GETSETOOP(jbyte, Byte)
   426 DEFINE_GETSETOOP(jshort, Short);
   427 DEFINE_GETSETOOP(jchar, Char);
   428 DEFINE_GETSETOOP(jint, Int);
   429 DEFINE_GETSETOOP(jlong, Long);
   430 DEFINE_GETSETOOP(jfloat, Float);
   431 DEFINE_GETSETOOP(jdouble, Double);
   433 #undef DEFINE_GETSETOOP
   435 #define DEFINE_GETSETOOP_VOLATILE(jboolean, Boolean) \
   436  \
   437 UNSAFE_ENTRY(jboolean, Unsafe_Get##Boolean##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) \
   438   UnsafeWrapper("Unsafe_Get"#Boolean); \
   439   GET_FIELD_VOLATILE(obj, offset, jboolean, v); \
   440   return v; \
   441 UNSAFE_END \
   442  \
   443 UNSAFE_ENTRY(void, Unsafe_Set##Boolean##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jboolean x)) \
   444   UnsafeWrapper("Unsafe_Set"#Boolean); \
   445   SET_FIELD_VOLATILE(obj, offset, jboolean, x); \
   446 UNSAFE_END \
   447  \
   448 // END DEFINE_GETSETOOP_VOLATILE.
   450 DEFINE_GETSETOOP_VOLATILE(jboolean, Boolean)
   451 DEFINE_GETSETOOP_VOLATILE(jbyte, Byte)
   452 DEFINE_GETSETOOP_VOLATILE(jshort, Short);
   453 DEFINE_GETSETOOP_VOLATILE(jchar, Char);
   454 DEFINE_GETSETOOP_VOLATILE(jint, Int);
   455 DEFINE_GETSETOOP_VOLATILE(jfloat, Float);
   456 DEFINE_GETSETOOP_VOLATILE(jdouble, Double);
   458 #ifdef SUPPORTS_NATIVE_CX8
   459 DEFINE_GETSETOOP_VOLATILE(jlong, Long);
   460 #endif
   462 #undef DEFINE_GETSETOOP_VOLATILE
   464 // The non-intrinsified versions of setOrdered just use setVolatile
   466 UNSAFE_ENTRY(void, Unsafe_SetOrderedInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint x))
   467   UnsafeWrapper("Unsafe_SetOrderedInt");
   468   SET_FIELD_VOLATILE(obj, offset, jint, x);
   469 UNSAFE_END
   471 UNSAFE_ENTRY(void, Unsafe_SetOrderedObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h))
   472   UnsafeWrapper("Unsafe_SetOrderedObject");
   473   oop x = JNIHandles::resolve(x_h);
   474   oop p = JNIHandles::resolve(obj);
   475   void* addr = index_oop_from_field_offset_long(p, offset);
   476   OrderAccess::release();
   477   if (UseCompressedOops) {
   478     oop_store((narrowOop*)addr, x);
   479   } else {
   480     oop_store((oop*)addr, x);
   481   }
   482   OrderAccess::fence();
   483 UNSAFE_END
   485 UNSAFE_ENTRY(void, Unsafe_SetOrderedLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong x))
   486   UnsafeWrapper("Unsafe_SetOrderedLong");
   487 #ifdef SUPPORTS_NATIVE_CX8
   488   SET_FIELD_VOLATILE(obj, offset, jlong, x);
   489 #else
   490   // Keep old code for platforms which may not have atomic long (8 bytes) instructions
   491   {
   492     if (VM_Version::supports_cx8()) {
   493       SET_FIELD_VOLATILE(obj, offset, jlong, x);
   494     }
   495     else {
   496       Handle p (THREAD, JNIHandles::resolve(obj));
   497       jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset));
   498       MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
   499       Atomic::store(x, addr);
   500     }
   501   }
   502 #endif
   503 UNSAFE_END
   505 UNSAFE_ENTRY(void, Unsafe_LoadFence(JNIEnv *env, jobject unsafe))
   506   UnsafeWrapper("Unsafe_LoadFence");
   507   OrderAccess::acquire();
   508 UNSAFE_END
   510 UNSAFE_ENTRY(void, Unsafe_StoreFence(JNIEnv *env, jobject unsafe))
   511   UnsafeWrapper("Unsafe_StoreFence");
   512   OrderAccess::release();
   513 UNSAFE_END
   515 UNSAFE_ENTRY(void, Unsafe_FullFence(JNIEnv *env, jobject unsafe))
   516   UnsafeWrapper("Unsafe_FullFence");
   517   OrderAccess::fence();
   518 UNSAFE_END
   520 ////// Data in the C heap.
   522 // Note:  These do not throw NullPointerException for bad pointers.
   523 // They just crash.  Only a oop base pointer can generate a NullPointerException.
   524 //
   525 #define DEFINE_GETSETNATIVE(java_type, Type, native_type) \
   526  \
   527 UNSAFE_ENTRY(java_type, Unsafe_GetNative##Type(JNIEnv *env, jobject unsafe, jlong addr)) \
   528   UnsafeWrapper("Unsafe_GetNative"#Type); \
   529   void* p = addr_from_java(addr); \
   530   JavaThread* t = JavaThread::current(); \
   531   t->set_doing_unsafe_access(true); \
   532   java_type x = *(volatile native_type*)p; \
   533   t->set_doing_unsafe_access(false); \
   534   return x; \
   535 UNSAFE_END \
   536  \
   537 UNSAFE_ENTRY(void, Unsafe_SetNative##Type(JNIEnv *env, jobject unsafe, jlong addr, java_type x)) \
   538   UnsafeWrapper("Unsafe_SetNative"#Type); \
   539   JavaThread* t = JavaThread::current(); \
   540   t->set_doing_unsafe_access(true); \
   541   void* p = addr_from_java(addr); \
   542   *(volatile native_type*)p = x; \
   543   t->set_doing_unsafe_access(false); \
   544 UNSAFE_END \
   545  \
   546 // END DEFINE_GETSETNATIVE.
   548 DEFINE_GETSETNATIVE(jbyte, Byte, signed char)
   549 DEFINE_GETSETNATIVE(jshort, Short, signed short);
   550 DEFINE_GETSETNATIVE(jchar, Char, unsigned short);
   551 DEFINE_GETSETNATIVE(jint, Int, jint);
   552 // no long -- handled specially
   553 DEFINE_GETSETNATIVE(jfloat, Float, float);
   554 DEFINE_GETSETNATIVE(jdouble, Double, double);
   556 #undef DEFINE_GETSETNATIVE
   558 UNSAFE_ENTRY(jlong, Unsafe_GetNativeLong(JNIEnv *env, jobject unsafe, jlong addr))
   559   UnsafeWrapper("Unsafe_GetNativeLong");
   560   JavaThread* t = JavaThread::current();
   561   // We do it this way to avoid problems with access to heap using 64
   562   // bit loads, as jlong in heap could be not 64-bit aligned, and on
   563   // some CPUs (SPARC) it leads to SIGBUS.
   564   t->set_doing_unsafe_access(true);
   565   void* p = addr_from_java(addr);
   566   jlong x;
   567   if (((intptr_t)p & 7) == 0) {
   568     // jlong is aligned, do a volatile access
   569     x = *(volatile jlong*)p;
   570   } else {
   571     jlong_accessor acc;
   572     acc.words[0] = ((volatile jint*)p)[0];
   573     acc.words[1] = ((volatile jint*)p)[1];
   574     x = acc.long_value;
   575   }
   576   t->set_doing_unsafe_access(false);
   577   return x;
   578 UNSAFE_END
   580 UNSAFE_ENTRY(void, Unsafe_SetNativeLong(JNIEnv *env, jobject unsafe, jlong addr, jlong x))
   581   UnsafeWrapper("Unsafe_SetNativeLong");
   582   JavaThread* t = JavaThread::current();
   583   // see comment for Unsafe_GetNativeLong
   584   t->set_doing_unsafe_access(true);
   585   void* p = addr_from_java(addr);
   586   if (((intptr_t)p & 7) == 0) {
   587     // jlong is aligned, do a volatile access
   588     *(volatile jlong*)p = x;
   589   } else {
   590     jlong_accessor acc;
   591     acc.long_value = x;
   592     ((volatile jint*)p)[0] = acc.words[0];
   593     ((volatile jint*)p)[1] = acc.words[1];
   594   }
   595   t->set_doing_unsafe_access(false);
   596 UNSAFE_END
   599 UNSAFE_ENTRY(jlong, Unsafe_GetNativeAddress(JNIEnv *env, jobject unsafe, jlong addr))
   600   UnsafeWrapper("Unsafe_GetNativeAddress");
   601   void* p = addr_from_java(addr);
   602   return addr_to_java(*(void**)p);
   603 UNSAFE_END
   605 UNSAFE_ENTRY(void, Unsafe_SetNativeAddress(JNIEnv *env, jobject unsafe, jlong addr, jlong x))
   606   UnsafeWrapper("Unsafe_SetNativeAddress");
   607   void* p = addr_from_java(addr);
   608   *(void**)p = addr_from_java(x);
   609 UNSAFE_END
   612 ////// Allocation requests
   614 UNSAFE_ENTRY(jobject, Unsafe_AllocateInstance(JNIEnv *env, jobject unsafe, jclass cls))
   615   UnsafeWrapper("Unsafe_AllocateInstance");
   616   {
   617     ThreadToNativeFromVM ttnfv(thread);
   618     return env->AllocObject(cls);
   619   }
   620 UNSAFE_END
   622 UNSAFE_ENTRY(jlong, Unsafe_AllocateMemory(JNIEnv *env, jobject unsafe, jlong size))
   623   UnsafeWrapper("Unsafe_AllocateMemory");
   624   size_t sz = (size_t)size;
   625   if (sz != (julong)size || size < 0) {
   626     THROW_0(vmSymbols::java_lang_IllegalArgumentException());
   627   }
   628   if (sz == 0) {
   629     return 0;
   630   }
   631   sz = round_to(sz, HeapWordSize);
   632   void* x = os::malloc(sz, mtInternal);
   633   if (x == NULL) {
   634     THROW_0(vmSymbols::java_lang_OutOfMemoryError());
   635   }
   636   //Copy::fill_to_words((HeapWord*)x, sz / HeapWordSize);
   637   return addr_to_java(x);
   638 UNSAFE_END
   640 UNSAFE_ENTRY(jlong, Unsafe_ReallocateMemory(JNIEnv *env, jobject unsafe, jlong addr, jlong size))
   641   UnsafeWrapper("Unsafe_ReallocateMemory");
   642   void* p = addr_from_java(addr);
   643   size_t sz = (size_t)size;
   644   if (sz != (julong)size || size < 0) {
   645     THROW_0(vmSymbols::java_lang_IllegalArgumentException());
   646   }
   647   if (sz == 0) {
   648     os::free(p);
   649     return 0;
   650   }
   651   sz = round_to(sz, HeapWordSize);
   652   void* x = (p == NULL) ? os::malloc(sz, mtInternal) : os::realloc(p, sz, mtInternal);
   653   if (x == NULL) {
   654     THROW_0(vmSymbols::java_lang_OutOfMemoryError());
   655   }
   656   return addr_to_java(x);
   657 UNSAFE_END
   659 UNSAFE_ENTRY(void, Unsafe_FreeMemory(JNIEnv *env, jobject unsafe, jlong addr))
   660   UnsafeWrapper("Unsafe_FreeMemory");
   661   void* p = addr_from_java(addr);
   662   if (p == NULL) {
   663     return;
   664   }
   665   os::free(p);
   666 UNSAFE_END
   668 UNSAFE_ENTRY(void, Unsafe_SetMemory(JNIEnv *env, jobject unsafe, jlong addr, jlong size, jbyte value))
   669   UnsafeWrapper("Unsafe_SetMemory");
   670   size_t sz = (size_t)size;
   671   if (sz != (julong)size || size < 0) {
   672     THROW(vmSymbols::java_lang_IllegalArgumentException());
   673   }
   674   char* p = (char*) addr_from_java(addr);
   675   Copy::fill_to_memory_atomic(p, sz, value);
   676 UNSAFE_END
   678 UNSAFE_ENTRY(void, Unsafe_SetMemory2(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong size, jbyte value))
   679   UnsafeWrapper("Unsafe_SetMemory");
   680   size_t sz = (size_t)size;
   681   if (sz != (julong)size || size < 0) {
   682     THROW(vmSymbols::java_lang_IllegalArgumentException());
   683   }
   684   oop base = JNIHandles::resolve(obj);
   685   void* p = index_oop_from_field_offset_long(base, offset);
   686   Copy::fill_to_memory_atomic(p, sz, value);
   687 UNSAFE_END
   689 UNSAFE_ENTRY(void, Unsafe_CopyMemory(JNIEnv *env, jobject unsafe, jlong srcAddr, jlong dstAddr, jlong size))
   690   UnsafeWrapper("Unsafe_CopyMemory");
   691   if (size == 0) {
   692     return;
   693   }
   694   size_t sz = (size_t)size;
   695   if (sz != (julong)size || size < 0) {
   696     THROW(vmSymbols::java_lang_IllegalArgumentException());
   697   }
   698   void* src = addr_from_java(srcAddr);
   699   void* dst = addr_from_java(dstAddr);
   700   Copy::conjoint_memory_atomic(src, dst, sz);
   701 UNSAFE_END
   703 UNSAFE_ENTRY(void, Unsafe_CopyMemory2(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size))
   704   UnsafeWrapper("Unsafe_CopyMemory");
   705   if (size == 0) {
   706     return;
   707   }
   708   size_t sz = (size_t)size;
   709   if (sz != (julong)size || size < 0) {
   710     THROW(vmSymbols::java_lang_IllegalArgumentException());
   711   }
   712   oop srcp = JNIHandles::resolve(srcObj);
   713   oop dstp = JNIHandles::resolve(dstObj);
   714   if (dstp != NULL && !dstp->is_typeArray()) {
   715     // NYI:  This works only for non-oop arrays at present.
   716     // Generalizing it would be reasonable, but requires card marking.
   717     // Also, autoboxing a Long from 0L in copyMemory(x,y, 0L,z, n) would be bad.
   718     THROW(vmSymbols::java_lang_IllegalArgumentException());
   719   }
   720   void* src = index_oop_from_field_offset_long(srcp, srcOffset);
   721   void* dst = index_oop_from_field_offset_long(dstp, dstOffset);
   722   Copy::conjoint_memory_atomic(src, dst, sz);
   723 UNSAFE_END
   726 ////// Random queries
   728 // See comment at file start about UNSAFE_LEAF
   729 //UNSAFE_LEAF(jint, Unsafe_AddressSize())
   730 UNSAFE_ENTRY(jint, Unsafe_AddressSize(JNIEnv *env, jobject unsafe))
   731   UnsafeWrapper("Unsafe_AddressSize");
   732   return sizeof(void*);
   733 UNSAFE_END
   735 // See comment at file start about UNSAFE_LEAF
   736 //UNSAFE_LEAF(jint, Unsafe_PageSize())
   737 UNSAFE_ENTRY(jint, Unsafe_PageSize(JNIEnv *env, jobject unsafe))
   738   UnsafeWrapper("Unsafe_PageSize");
   739   return os::vm_page_size();
   740 UNSAFE_END
   742 jint find_field_offset(jobject field, int must_be_static, TRAPS) {
   743   if (field == NULL) {
   744     THROW_0(vmSymbols::java_lang_NullPointerException());
   745   }
   747   oop reflected   = JNIHandles::resolve_non_null(field);
   748   oop mirror      = java_lang_reflect_Field::clazz(reflected);
   749   Klass* k      = java_lang_Class::as_Klass(mirror);
   750   int slot        = java_lang_reflect_Field::slot(reflected);
   751   int modifiers   = java_lang_reflect_Field::modifiers(reflected);
   753   if (must_be_static >= 0) {
   754     int really_is_static = ((modifiers & JVM_ACC_STATIC) != 0);
   755     if (must_be_static != really_is_static) {
   756       THROW_0(vmSymbols::java_lang_IllegalArgumentException());
   757     }
   758   }
   760   int offset = InstanceKlass::cast(k)->field_offset(slot);
   761   return field_offset_from_byte_offset(offset);
   762 }
   764 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset(JNIEnv *env, jobject unsafe, jobject field))
   765   UnsafeWrapper("Unsafe_ObjectFieldOffset");
   766   return find_field_offset(field, 0, THREAD);
   767 UNSAFE_END
   769 UNSAFE_ENTRY(jlong, Unsafe_StaticFieldOffset(JNIEnv *env, jobject unsafe, jobject field))
   770   UnsafeWrapper("Unsafe_StaticFieldOffset");
   771   return find_field_offset(field, 1, THREAD);
   772 UNSAFE_END
   774 UNSAFE_ENTRY(jobject, Unsafe_StaticFieldBaseFromField(JNIEnv *env, jobject unsafe, jobject field))
   775   UnsafeWrapper("Unsafe_StaticFieldBase");
   776   // Note:  In this VM implementation, a field address is always a short
   777   // offset from the base of a a klass metaobject.  Thus, the full dynamic
   778   // range of the return type is never used.  However, some implementations
   779   // might put the static field inside an array shared by many classes,
   780   // or even at a fixed address, in which case the address could be quite
   781   // large.  In that last case, this function would return NULL, since
   782   // the address would operate alone, without any base pointer.
   784   if (field == NULL)  THROW_0(vmSymbols::java_lang_NullPointerException());
   786   oop reflected   = JNIHandles::resolve_non_null(field);
   787   oop mirror      = java_lang_reflect_Field::clazz(reflected);
   788   int modifiers   = java_lang_reflect_Field::modifiers(reflected);
   790   if ((modifiers & JVM_ACC_STATIC) == 0) {
   791     THROW_0(vmSymbols::java_lang_IllegalArgumentException());
   792   }
   794   return JNIHandles::make_local(env, mirror);
   795 UNSAFE_END
   797 //@deprecated
   798 UNSAFE_ENTRY(jint, Unsafe_FieldOffset(JNIEnv *env, jobject unsafe, jobject field))
   799   UnsafeWrapper("Unsafe_FieldOffset");
   800   // tries (but fails) to be polymorphic between static and non-static:
   801   jlong offset = find_field_offset(field, -1, THREAD);
   802   guarantee(offset == (jint)offset, "offset fits in 32 bits");
   803   return (jint)offset;
   804 UNSAFE_END
   806 //@deprecated
   807 UNSAFE_ENTRY(jobject, Unsafe_StaticFieldBaseFromClass(JNIEnv *env, jobject unsafe, jobject clazz))
   808   UnsafeWrapper("Unsafe_StaticFieldBase");
   809   if (clazz == NULL) {
   810     THROW_0(vmSymbols::java_lang_NullPointerException());
   811   }
   812   return JNIHandles::make_local(env, JNIHandles::resolve_non_null(clazz));
   813 UNSAFE_END
   815 UNSAFE_ENTRY(void, Unsafe_EnsureClassInitialized(JNIEnv *env, jobject unsafe, jobject clazz)) {
   816   UnsafeWrapper("Unsafe_EnsureClassInitialized");
   817   if (clazz == NULL) {
   818     THROW(vmSymbols::java_lang_NullPointerException());
   819   }
   820   oop mirror = JNIHandles::resolve_non_null(clazz);
   822   Klass* klass = java_lang_Class::as_Klass(mirror);
   823   if (klass != NULL && klass->should_be_initialized()) {
   824     InstanceKlass* k = InstanceKlass::cast(klass);
   825     k->initialize(CHECK);
   826   }
   827 }
   828 UNSAFE_END
   830 UNSAFE_ENTRY(jboolean, Unsafe_ShouldBeInitialized(JNIEnv *env, jobject unsafe, jobject clazz)) {
   831   UnsafeWrapper("Unsafe_ShouldBeInitialized");
   832   if (clazz == NULL) {
   833     THROW_(vmSymbols::java_lang_NullPointerException(), false);
   834   }
   835   oop mirror = JNIHandles::resolve_non_null(clazz);
   836   Klass* klass = java_lang_Class::as_Klass(mirror);
   837   if (klass != NULL && klass->should_be_initialized()) {
   838     return true;
   839   }
   840   return false;
   841 }
   842 UNSAFE_END
   844 static void getBaseAndScale(int& base, int& scale, jclass acls, TRAPS) {
   845   if (acls == NULL) {
   846     THROW(vmSymbols::java_lang_NullPointerException());
   847   }
   848   oop      mirror = JNIHandles::resolve_non_null(acls);
   849   Klass* k      = java_lang_Class::as_Klass(mirror);
   850   if (k == NULL || !k->oop_is_array()) {
   851     THROW(vmSymbols::java_lang_InvalidClassException());
   852   } else if (k->oop_is_objArray()) {
   853     base  = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
   854     scale = heapOopSize;
   855   } else if (k->oop_is_typeArray()) {
   856     TypeArrayKlass* tak = TypeArrayKlass::cast(k);
   857     base  = tak->array_header_in_bytes();
   858     assert(base == arrayOopDesc::base_offset_in_bytes(tak->element_type()), "array_header_size semantics ok");
   859     scale = (1 << tak->log2_element_size());
   860   } else {
   861     ShouldNotReachHere();
   862   }
   863 }
   865 UNSAFE_ENTRY(jint, Unsafe_ArrayBaseOffset(JNIEnv *env, jobject unsafe, jclass acls))
   866   UnsafeWrapper("Unsafe_ArrayBaseOffset");
   867   int base, scale;
   868   getBaseAndScale(base, scale, acls, CHECK_0);
   869   return field_offset_from_byte_offset(base);
   870 UNSAFE_END
   873 UNSAFE_ENTRY(jint, Unsafe_ArrayIndexScale(JNIEnv *env, jobject unsafe, jclass acls))
   874   UnsafeWrapper("Unsafe_ArrayIndexScale");
   875   int base, scale;
   876   getBaseAndScale(base, scale, acls, CHECK_0);
   877   // This VM packs both fields and array elements down to the byte.
   878   // But watch out:  If this changes, so that array references for
   879   // a given primitive type (say, T_BOOLEAN) use different memory units
   880   // than fields, this method MUST return zero for such arrays.
   881   // For example, the VM used to store sub-word sized fields in full
   882   // words in the object layout, so that accessors like getByte(Object,int)
   883   // did not really do what one might expect for arrays.  Therefore,
   884   // this function used to report a zero scale factor, so that the user
   885   // would know not to attempt to access sub-word array elements.
   886   // // Code for unpacked fields:
   887   // if (scale < wordSize)  return 0;
   889   // The following allows for a pretty general fieldOffset cookie scheme,
   890   // but requires it to be linear in byte offset.
   891   return field_offset_from_byte_offset(scale) - field_offset_from_byte_offset(0);
   892 UNSAFE_END
   895 static inline void throw_new(JNIEnv *env, const char *ename) {
   896   char buf[100];
   897   strcpy(buf, "java/lang/");
   898   strcat(buf, ename);
   899   jclass cls = env->FindClass(buf);
   900   if (env->ExceptionCheck()) {
   901     env->ExceptionClear();
   902     tty->print_cr("Unsafe: cannot throw %s because FindClass has failed", buf);
   903     return;
   904   }
   905   char* msg = NULL;
   906   env->ThrowNew(cls, msg);
   907 }
   909 static jclass Unsafe_DefineClass_impl(JNIEnv *env, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd) {
   910   {
   911     // Code lifted from JDK 1.3 ClassLoader.c
   913     jbyte *body;
   914     char *utfName;
   915     jclass result = 0;
   916     char buf[128];
   918     if (UsePerfData) {
   919       ClassLoader::unsafe_defineClassCallCounter()->inc();
   920     }
   922     if (data == NULL) {
   923         throw_new(env, "NullPointerException");
   924         return 0;
   925     }
   927     /* Work around 4153825. malloc crashes on Solaris when passed a
   928      * negative size.
   929      */
   930     if (length < 0) {
   931         throw_new(env, "ArrayIndexOutOfBoundsException");
   932         return 0;
   933     }
   935     body = NEW_C_HEAP_ARRAY(jbyte, length, mtInternal);
   937     if (body == 0) {
   938         throw_new(env, "OutOfMemoryError");
   939         return 0;
   940     }
   942     env->GetByteArrayRegion(data, offset, length, body);
   944     if (env->ExceptionOccurred())
   945         goto free_body;
   947     if (name != NULL) {
   948         uint len = env->GetStringUTFLength(name);
   949         int unicode_len = env->GetStringLength(name);
   950         if (len >= sizeof(buf)) {
   951             utfName = NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
   952             if (utfName == NULL) {
   953                 throw_new(env, "OutOfMemoryError");
   954                 goto free_body;
   955             }
   956         } else {
   957             utfName = buf;
   958         }
   959         env->GetStringUTFRegion(name, 0, unicode_len, utfName);
   960         //VerifyFixClassname(utfName);
   961         for (uint i = 0; i < len; i++) {
   962           if (utfName[i] == '.')   utfName[i] = '/';
   963         }
   964     } else {
   965         utfName = NULL;
   966     }
   968     result = JVM_DefineClass(env, utfName, loader, body, length, pd);
   970     if (utfName && utfName != buf)
   971         FREE_C_HEAP_ARRAY(char, utfName, mtInternal);
   973  free_body:
   974     FREE_C_HEAP_ARRAY(jbyte, body, mtInternal);
   975     return result;
   976   }
   977 }
   980 UNSAFE_ENTRY(jclass, Unsafe_DefineClass(JNIEnv *env, jobject unsafe, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd))
   981   UnsafeWrapper("Unsafe_DefineClass");
   982   {
   983     ThreadToNativeFromVM ttnfv(thread);
   984     return Unsafe_DefineClass_impl(env, name, data, offset, length, loader, pd);
   985   }
   986 UNSAFE_END
   988 static jobject get_class_loader(JNIEnv* env, jclass cls) {
   989   if (java_lang_Class::is_primitive(JNIHandles::resolve_non_null(cls))) {
   990     return NULL;
   991   }
   992   Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(cls));
   993   oop loader = k->class_loader();
   994   return JNIHandles::make_local(env, loader);
   995 }
   997 UNSAFE_ENTRY(jclass, Unsafe_DefineClass0(JNIEnv *env, jobject unsafe, jstring name, jbyteArray data, int offset, int length))
   998   UnsafeWrapper("Unsafe_DefineClass");
   999   {
  1000     ThreadToNativeFromVM ttnfv(thread);
  1002     int depthFromDefineClass0 = 1;
  1003     jclass  caller = JVM_GetCallerClass(env, depthFromDefineClass0);
  1004     jobject loader = (caller == NULL) ? NULL : get_class_loader(env, caller);
  1005     jobject pd     = (caller == NULL) ? NULL : JVM_GetProtectionDomain(env, caller);
  1007     return Unsafe_DefineClass_impl(env, name, data, offset, length, loader, pd);
  1009 UNSAFE_END
  1012 #define DAC_Args CLS"[B["OBJ
  1013 // define a class but do not make it known to the class loader or system dictionary
  1014 // - host_class:  supplies context for linkage, access control, protection domain, and class loader
  1015 // - data:  bytes of a class file, a raw memory address (length gives the number of bytes)
  1016 // - cp_patches:  where non-null entries exist, they replace corresponding CP entries in data
  1018 // When you load an anonymous class U, it works as if you changed its name just before loading,
  1019 // to a name that you will never use again.  Since the name is lost, no other class can directly
  1020 // link to any member of U.  Just after U is loaded, the only way to use it is reflectively,
  1021 // through java.lang.Class methods like Class.newInstance.
  1023 // Access checks for linkage sites within U continue to follow the same rules as for named classes.
  1024 // The package of an anonymous class is given by the package qualifier on the name under which it was loaded.
  1025 // An anonymous class also has special privileges to access any member of its host class.
  1026 // This is the main reason why this loading operation is unsafe.  The purpose of this is to
  1027 // allow language implementations to simulate "open classes"; a host class in effect gets
  1028 // new code when an anonymous class is loaded alongside it.  A less convenient but more
  1029 // standard way to do this is with reflection, which can also be set to ignore access
  1030 // restrictions.
  1032 // Access into an anonymous class is possible only through reflection.  Therefore, there
  1033 // are no special access rules for calling into an anonymous class.  The relaxed access
  1034 // rule for the host class is applied in the opposite direction:  A host class reflectively
  1035 // access one of its anonymous classes.
  1037 // If you load the same bytecodes twice, you get two different classes.  You can reload
  1038 // the same bytecodes with or without varying CP patches.
  1040 // By using the CP patching array, you can have a new anonymous class U2 refer to an older one U1.
  1041 // The bytecodes for U2 should refer to U1 by a symbolic name (doesn't matter what the name is).
  1042 // The CONSTANT_Class entry for that name can be patched to refer directly to U1.
  1044 // This allows, for example, U2 to use U1 as a superclass or super-interface, or as
  1045 // an outer class (so that U2 is an anonymous inner class of anonymous U1).
  1046 // It is not possible for a named class, or an older anonymous class, to refer by
  1047 // name (via its CP) to a newer anonymous class.
  1049 // CP patching may also be used to modify (i.e., hack) the names of methods, classes,
  1050 // or type descriptors used in the loaded anonymous class.
  1052 // Finally, CP patching may be used to introduce "live" objects into the constant pool,
  1053 // instead of "dead" strings.  A compiled statement like println((Object)"hello") can
  1054 // be changed to println(greeting), where greeting is an arbitrary object created before
  1055 // the anonymous class is loaded.  This is useful in dynamic languages, in which
  1056 // various kinds of metaobjects must be introduced as constants into bytecode.
  1057 // Note the cast (Object), which tells the verifier to expect an arbitrary object,
  1058 // not just a literal string.  For such ldc instructions, the verifier uses the
  1059 // type Object instead of String, if the loaded constant is not in fact a String.
  1061 static instanceKlassHandle
  1062 Unsafe_DefineAnonymousClass_impl(JNIEnv *env,
  1063                                  jclass host_class, jbyteArray data, jobjectArray cp_patches_jh,
  1064                                  HeapWord* *temp_alloc,
  1065                                  TRAPS) {
  1067   if (UsePerfData) {
  1068     ClassLoader::unsafe_defineClassCallCounter()->inc();
  1071   if (data == NULL) {
  1072     THROW_0(vmSymbols::java_lang_NullPointerException());
  1075   jint length = typeArrayOop(JNIHandles::resolve_non_null(data))->length();
  1076   jint word_length = (length + sizeof(HeapWord)-1) / sizeof(HeapWord);
  1077   HeapWord* body = NEW_C_HEAP_ARRAY(HeapWord, word_length, mtInternal);
  1078   if (body == NULL) {
  1079     THROW_0(vmSymbols::java_lang_OutOfMemoryError());
  1082   // caller responsible to free it:
  1083   (*temp_alloc) = body;
  1086     jbyte* array_base = typeArrayOop(JNIHandles::resolve_non_null(data))->byte_at_addr(0);
  1087     Copy::conjoint_words((HeapWord*) array_base, body, word_length);
  1090   u1* class_bytes = (u1*) body;
  1091   int class_bytes_length = (int) length;
  1092   if (class_bytes_length < 0)  class_bytes_length = 0;
  1093   if (class_bytes == NULL
  1094       || host_class == NULL
  1095       || length != class_bytes_length)
  1096     THROW_0(vmSymbols::java_lang_IllegalArgumentException());
  1098   objArrayHandle cp_patches_h;
  1099   if (cp_patches_jh != NULL) {
  1100     oop p = JNIHandles::resolve_non_null(cp_patches_jh);
  1101     if (!p->is_objArray())
  1102       THROW_0(vmSymbols::java_lang_IllegalArgumentException());
  1103     cp_patches_h = objArrayHandle(THREAD, (objArrayOop)p);
  1106   KlassHandle host_klass(THREAD, java_lang_Class::as_Klass(JNIHandles::resolve_non_null(host_class)));
  1107   const char* host_source = host_klass->external_name();
  1108   Handle      host_loader(THREAD, host_klass->class_loader());
  1109   Handle      host_domain(THREAD, host_klass->protection_domain());
  1111   GrowableArray<Handle>* cp_patches = NULL;
  1112   if (cp_patches_h.not_null()) {
  1113     int alen = cp_patches_h->length();
  1114     for (int i = alen-1; i >= 0; i--) {
  1115       oop p = cp_patches_h->obj_at(i);
  1116       if (p != NULL) {
  1117         Handle patch(THREAD, p);
  1118         if (cp_patches == NULL)
  1119           cp_patches = new GrowableArray<Handle>(i+1, i+1, Handle());
  1120         cp_patches->at_put(i, patch);
  1125   ClassFileStream st(class_bytes, class_bytes_length, (char*) host_source);
  1127   instanceKlassHandle anon_klass;
  1129     Symbol* no_class_name = NULL;
  1130     Klass* anonk = SystemDictionary::parse_stream(no_class_name,
  1131                                                     host_loader, host_domain,
  1132                                                     &st, host_klass, cp_patches,
  1133                                                     CHECK_NULL);
  1134     if (anonk == NULL)  return NULL;
  1135     anon_klass = instanceKlassHandle(THREAD, anonk);
  1138   return anon_klass;
  1141 UNSAFE_ENTRY(jclass, Unsafe_DefineAnonymousClass(JNIEnv *env, jobject unsafe, jclass host_class, jbyteArray data, jobjectArray cp_patches_jh))
  1143   instanceKlassHandle anon_klass;
  1144   jobject res_jh = NULL;
  1146   UnsafeWrapper("Unsafe_DefineAnonymousClass");
  1147   ResourceMark rm(THREAD);
  1149   HeapWord* temp_alloc = NULL;
  1151   anon_klass = Unsafe_DefineAnonymousClass_impl(env, host_class, data,
  1152                                                 cp_patches_jh,
  1153                                                    &temp_alloc, THREAD);
  1154   if (anon_klass() != NULL)
  1155     res_jh = JNIHandles::make_local(env, anon_klass->java_mirror());
  1157   // try/finally clause:
  1158   if (temp_alloc != NULL) {
  1159     FREE_C_HEAP_ARRAY(HeapWord, temp_alloc, mtInternal);
  1162   // The anonymous class loader data has been artificially been kept alive to
  1163   // this point.   The mirror and any instances of this class have to keep
  1164   // it alive afterwards.
  1165   if (anon_klass() != NULL) {
  1166     anon_klass->class_loader_data()->set_keep_alive(false);
  1169   // let caller initialize it as needed...
  1171   return (jclass) res_jh;
  1173 UNSAFE_END
  1177 UNSAFE_ENTRY(void, Unsafe_MonitorEnter(JNIEnv *env, jobject unsafe, jobject jobj))
  1178   UnsafeWrapper("Unsafe_MonitorEnter");
  1180     if (jobj == NULL) {
  1181       THROW(vmSymbols::java_lang_NullPointerException());
  1183     Handle obj(thread, JNIHandles::resolve_non_null(jobj));
  1184     ObjectSynchronizer::jni_enter(obj, CHECK);
  1186 UNSAFE_END
  1189 UNSAFE_ENTRY(jboolean, Unsafe_TryMonitorEnter(JNIEnv *env, jobject unsafe, jobject jobj))
  1190   UnsafeWrapper("Unsafe_TryMonitorEnter");
  1192     if (jobj == NULL) {
  1193       THROW_(vmSymbols::java_lang_NullPointerException(), JNI_FALSE);
  1195     Handle obj(thread, JNIHandles::resolve_non_null(jobj));
  1196     bool res = ObjectSynchronizer::jni_try_enter(obj, CHECK_0);
  1197     return (res ? JNI_TRUE : JNI_FALSE);
  1199 UNSAFE_END
  1202 UNSAFE_ENTRY(void, Unsafe_MonitorExit(JNIEnv *env, jobject unsafe, jobject jobj))
  1203   UnsafeWrapper("Unsafe_MonitorExit");
  1205     if (jobj == NULL) {
  1206       THROW(vmSymbols::java_lang_NullPointerException());
  1208     Handle obj(THREAD, JNIHandles::resolve_non_null(jobj));
  1209     ObjectSynchronizer::jni_exit(obj(), CHECK);
  1211 UNSAFE_END
  1214 UNSAFE_ENTRY(void, Unsafe_ThrowException(JNIEnv *env, jobject unsafe, jthrowable thr))
  1215   UnsafeWrapper("Unsafe_ThrowException");
  1217     ThreadToNativeFromVM ttnfv(thread);
  1218     env->Throw(thr);
  1220 UNSAFE_END
  1222 // JSR166 ------------------------------------------------------------------
  1224 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h))
  1225   UnsafeWrapper("Unsafe_CompareAndSwapObject");
  1226   oop x = JNIHandles::resolve(x_h);
  1227   oop e = JNIHandles::resolve(e_h);
  1228   oop p = JNIHandles::resolve(obj);
  1229   HeapWord* addr = (HeapWord *)index_oop_from_field_offset_long(p, offset);
  1230   oop res = oopDesc::atomic_compare_exchange_oop(x, addr, e, true);
  1231   jboolean success  = (res == e);
  1232   if (success)
  1233     update_barrier_set((void*)addr, x);
  1234   return success;
  1235 UNSAFE_END
  1237 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x))
  1238   UnsafeWrapper("Unsafe_CompareAndSwapInt");
  1239   oop p = JNIHandles::resolve(obj);
  1240   jint* addr = (jint *) index_oop_from_field_offset_long(p, offset);
  1241   return (jint)(Atomic::cmpxchg(x, addr, e)) == e;
  1242 UNSAFE_END
  1244 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x))
  1245   UnsafeWrapper("Unsafe_CompareAndSwapLong");
  1246   Handle p (THREAD, JNIHandles::resolve(obj));
  1247   jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset));
  1248 #ifdef SUPPORTS_NATIVE_CX8
  1249   return (jlong)(Atomic::cmpxchg(x, addr, e)) == e;
  1250 #else
  1251   if (VM_Version::supports_cx8())
  1252     return (jlong)(Atomic::cmpxchg(x, addr, e)) == e;
  1253   else {
  1254     jboolean success = false;
  1255     MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
  1256     jlong val = Atomic::load(addr);
  1257     if (val == e) { Atomic::store(x, addr); success = true; }
  1258     return success;
  1260 #endif
  1261 UNSAFE_END
  1263 UNSAFE_ENTRY(void, Unsafe_Park(JNIEnv *env, jobject unsafe, jboolean isAbsolute, jlong time))
  1264   UnsafeWrapper("Unsafe_Park");
  1265   EventThreadPark event;
  1266 #ifndef USDT2
  1267   HS_DTRACE_PROBE3(hotspot, thread__park__begin, thread->parker(), (int) isAbsolute, time);
  1268 #else /* USDT2 */
  1269    HOTSPOT_THREAD_PARK_BEGIN(
  1270                              (uintptr_t) thread->parker(), (int) isAbsolute, time);
  1271 #endif /* USDT2 */
  1272   JavaThreadParkedState jtps(thread, time != 0);
  1273   thread->parker()->park(isAbsolute != 0, time);
  1274 #ifndef USDT2
  1275   HS_DTRACE_PROBE1(hotspot, thread__park__end, thread->parker());
  1276 #else /* USDT2 */
  1277   HOTSPOT_THREAD_PARK_END(
  1278                           (uintptr_t) thread->parker());
  1279 #endif /* USDT2 */
  1280   if (event.should_commit()) {
  1281     oop obj = thread->current_park_blocker();
  1282     event.set_klass((obj != NULL) ? obj->klass() : NULL);
  1283     event.set_timeout(time);
  1284     event.set_address((obj != NULL) ? (TYPE_ADDRESS) cast_from_oop<uintptr_t>(obj) : 0);
  1285     event.commit();
  1287 UNSAFE_END
  1289 UNSAFE_ENTRY(void, Unsafe_Unpark(JNIEnv *env, jobject unsafe, jobject jthread))
  1290   UnsafeWrapper("Unsafe_Unpark");
  1291   Parker* p = NULL;
  1292   if (jthread != NULL) {
  1293     oop java_thread = JNIHandles::resolve_non_null(jthread);
  1294     if (java_thread != NULL) {
  1295       jlong lp = java_lang_Thread::park_event(java_thread);
  1296       if (lp != 0) {
  1297         // This cast is OK even though the jlong might have been read
  1298         // non-atomically on 32bit systems, since there, one word will
  1299         // always be zero anyway and the value set is always the same
  1300         p = (Parker*)addr_from_java(lp);
  1301       } else {
  1302         // Grab lock if apparently null or using older version of library
  1303         MutexLocker mu(Threads_lock);
  1304         java_thread = JNIHandles::resolve_non_null(jthread);
  1305         if (java_thread != NULL) {
  1306           JavaThread* thr = java_lang_Thread::thread(java_thread);
  1307           if (thr != NULL) {
  1308             p = thr->parker();
  1309             if (p != NULL) { // Bind to Java thread for next time.
  1310               java_lang_Thread::set_park_event(java_thread, addr_to_java(p));
  1317   if (p != NULL) {
  1318 #ifndef USDT2
  1319     HS_DTRACE_PROBE1(hotspot, thread__unpark, p);
  1320 #else /* USDT2 */
  1321     HOTSPOT_THREAD_UNPARK(
  1322                           (uintptr_t) p);
  1323 #endif /* USDT2 */
  1324     p->unpark();
  1326 UNSAFE_END
  1328 UNSAFE_ENTRY(jint, Unsafe_Loadavg(JNIEnv *env, jobject unsafe, jdoubleArray loadavg, jint nelem))
  1329   UnsafeWrapper("Unsafe_Loadavg");
  1330   const int max_nelem = 3;
  1331   double la[max_nelem];
  1332   jint ret;
  1334   typeArrayOop a = typeArrayOop(JNIHandles::resolve_non_null(loadavg));
  1335   assert(a->is_typeArray(), "must be type array");
  1337   if (nelem < 0 || nelem > max_nelem || a->length() < nelem) {
  1338     ThreadToNativeFromVM ttnfv(thread);
  1339     throw_new(env, "ArrayIndexOutOfBoundsException");
  1340     return -1;
  1343   ret = os::loadavg(la, nelem);
  1344   if (ret == -1) return -1;
  1346   // if successful, ret is the number of samples actually retrieved.
  1347   assert(ret >= 0 && ret <= max_nelem, "Unexpected loadavg return value");
  1348   switch(ret) {
  1349     case 3: a->double_at_put(2, (jdouble)la[2]); // fall through
  1350     case 2: a->double_at_put(1, (jdouble)la[1]); // fall through
  1351     case 1: a->double_at_put(0, (jdouble)la[0]); break;
  1353   return ret;
  1354 UNSAFE_END
  1356 UNSAFE_ENTRY(void, Unsafe_PrefetchRead(JNIEnv* env, jclass ignored, jobject obj, jlong offset))
  1357   UnsafeWrapper("Unsafe_PrefetchRead");
  1358   oop p = JNIHandles::resolve(obj);
  1359   void* addr = index_oop_from_field_offset_long(p, 0);
  1360   Prefetch::read(addr, (intx)offset);
  1361 UNSAFE_END
  1363 UNSAFE_ENTRY(void, Unsafe_PrefetchWrite(JNIEnv* env, jclass ignored, jobject obj, jlong offset))
  1364   UnsafeWrapper("Unsafe_PrefetchWrite");
  1365   oop p = JNIHandles::resolve(obj);
  1366   void* addr = index_oop_from_field_offset_long(p, 0);
  1367   Prefetch::write(addr, (intx)offset);
  1368 UNSAFE_END
  1371 /// JVM_RegisterUnsafeMethods
  1373 #define ADR "J"
  1375 #define LANG "Ljava/lang/"
  1377 #define OBJ LANG"Object;"
  1378 #define CLS LANG"Class;"
  1379 #define CTR LANG"reflect/Constructor;"
  1380 #define FLD LANG"reflect/Field;"
  1381 #define MTH LANG"reflect/Method;"
  1382 #define THR LANG"Throwable;"
  1384 #define DC0_Args LANG"String;[BII"
  1385 #define DC_Args  DC0_Args LANG"ClassLoader;" "Ljava/security/ProtectionDomain;"
  1387 #define CC (char*)  /*cast a literal from (const char*)*/
  1388 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
  1390 // define deprecated accessors for compabitility with 1.4.0
  1391 #define DECLARE_GETSETOOP_140(Boolean, Z) \
  1392     {CC"get"#Boolean,      CC"("OBJ"I)"#Z,      FN_PTR(Unsafe_Get##Boolean##140)}, \
  1393     {CC"put"#Boolean,      CC"("OBJ"I"#Z")V",   FN_PTR(Unsafe_Set##Boolean##140)}
  1395 // Note:  In 1.4.1, getObject and kin take both int and long offsets.
  1396 #define DECLARE_GETSETOOP_141(Boolean, Z) \
  1397     {CC"get"#Boolean,      CC"("OBJ"J)"#Z,      FN_PTR(Unsafe_Get##Boolean)}, \
  1398     {CC"put"#Boolean,      CC"("OBJ"J"#Z")V",   FN_PTR(Unsafe_Set##Boolean)}
  1400 // Note:  In 1.5.0, there are volatile versions too
  1401 #define DECLARE_GETSETOOP(Boolean, Z) \
  1402     {CC"get"#Boolean,      CC"("OBJ"J)"#Z,      FN_PTR(Unsafe_Get##Boolean)}, \
  1403     {CC"put"#Boolean,      CC"("OBJ"J"#Z")V",   FN_PTR(Unsafe_Set##Boolean)}, \
  1404     {CC"get"#Boolean"Volatile",      CC"("OBJ"J)"#Z,      FN_PTR(Unsafe_Get##Boolean##Volatile)}, \
  1405     {CC"put"#Boolean"Volatile",      CC"("OBJ"J"#Z")V",   FN_PTR(Unsafe_Set##Boolean##Volatile)}
  1408 #define DECLARE_GETSETNATIVE(Byte, B) \
  1409     {CC"get"#Byte,         CC"("ADR")"#B,       FN_PTR(Unsafe_GetNative##Byte)}, \
  1410     {CC"put"#Byte,         CC"("ADR#B")V",      FN_PTR(Unsafe_SetNative##Byte)}
  1414 // These are the methods for 1.4.0
  1415 static JNINativeMethod methods_140[] = {
  1416     {CC"getObject",        CC"("OBJ"I)"OBJ"",   FN_PTR(Unsafe_GetObject140)},
  1417     {CC"putObject",        CC"("OBJ"I"OBJ")V",  FN_PTR(Unsafe_SetObject140)},
  1419     DECLARE_GETSETOOP_140(Boolean, Z),
  1420     DECLARE_GETSETOOP_140(Byte, B),
  1421     DECLARE_GETSETOOP_140(Short, S),
  1422     DECLARE_GETSETOOP_140(Char, C),
  1423     DECLARE_GETSETOOP_140(Int, I),
  1424     DECLARE_GETSETOOP_140(Long, J),
  1425     DECLARE_GETSETOOP_140(Float, F),
  1426     DECLARE_GETSETOOP_140(Double, D),
  1428     DECLARE_GETSETNATIVE(Byte, B),
  1429     DECLARE_GETSETNATIVE(Short, S),
  1430     DECLARE_GETSETNATIVE(Char, C),
  1431     DECLARE_GETSETNATIVE(Int, I),
  1432     DECLARE_GETSETNATIVE(Long, J),
  1433     DECLARE_GETSETNATIVE(Float, F),
  1434     DECLARE_GETSETNATIVE(Double, D),
  1436     {CC"getAddress",         CC"("ADR")"ADR,             FN_PTR(Unsafe_GetNativeAddress)},
  1437     {CC"putAddress",         CC"("ADR""ADR")V",          FN_PTR(Unsafe_SetNativeAddress)},
  1439     {CC"allocateMemory",     CC"(J)"ADR,                 FN_PTR(Unsafe_AllocateMemory)},
  1440     {CC"reallocateMemory",   CC"("ADR"J)"ADR,            FN_PTR(Unsafe_ReallocateMemory)},
  1441     {CC"freeMemory",         CC"("ADR")V",               FN_PTR(Unsafe_FreeMemory)},
  1443     {CC"fieldOffset",        CC"("FLD")I",               FN_PTR(Unsafe_FieldOffset)},
  1444     {CC"staticFieldBase",    CC"("CLS")"OBJ,             FN_PTR(Unsafe_StaticFieldBaseFromClass)},
  1445     {CC"ensureClassInitialized",CC"("CLS")V",            FN_PTR(Unsafe_EnsureClassInitialized)},
  1446     {CC"arrayBaseOffset",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayBaseOffset)},
  1447     {CC"arrayIndexScale",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayIndexScale)},
  1448     {CC"addressSize",        CC"()I",                    FN_PTR(Unsafe_AddressSize)},
  1449     {CC"pageSize",           CC"()I",                    FN_PTR(Unsafe_PageSize)},
  1451     {CC"defineClass",        CC"("DC0_Args")"CLS,        FN_PTR(Unsafe_DefineClass0)},
  1452     {CC"defineClass",        CC"("DC_Args")"CLS,         FN_PTR(Unsafe_DefineClass)},
  1453     {CC"allocateInstance",   CC"("CLS")"OBJ,             FN_PTR(Unsafe_AllocateInstance)},
  1454     {CC"monitorEnter",       CC"("OBJ")V",               FN_PTR(Unsafe_MonitorEnter)},
  1455     {CC"monitorExit",        CC"("OBJ")V",               FN_PTR(Unsafe_MonitorExit)},
  1456     {CC"throwException",     CC"("THR")V",               FN_PTR(Unsafe_ThrowException)}
  1457 };
  1459 // These are the methods prior to the JSR 166 changes in 1.5.0
  1460 static JNINativeMethod methods_141[] = {
  1461     {CC"getObject",        CC"("OBJ"J)"OBJ"",   FN_PTR(Unsafe_GetObject)},
  1462     {CC"putObject",        CC"("OBJ"J"OBJ")V",  FN_PTR(Unsafe_SetObject)},
  1464     DECLARE_GETSETOOP_141(Boolean, Z),
  1465     DECLARE_GETSETOOP_141(Byte, B),
  1466     DECLARE_GETSETOOP_141(Short, S),
  1467     DECLARE_GETSETOOP_141(Char, C),
  1468     DECLARE_GETSETOOP_141(Int, I),
  1469     DECLARE_GETSETOOP_141(Long, J),
  1470     DECLARE_GETSETOOP_141(Float, F),
  1471     DECLARE_GETSETOOP_141(Double, D),
  1473     DECLARE_GETSETNATIVE(Byte, B),
  1474     DECLARE_GETSETNATIVE(Short, S),
  1475     DECLARE_GETSETNATIVE(Char, C),
  1476     DECLARE_GETSETNATIVE(Int, I),
  1477     DECLARE_GETSETNATIVE(Long, J),
  1478     DECLARE_GETSETNATIVE(Float, F),
  1479     DECLARE_GETSETNATIVE(Double, D),
  1481     {CC"getAddress",         CC"("ADR")"ADR,             FN_PTR(Unsafe_GetNativeAddress)},
  1482     {CC"putAddress",         CC"("ADR""ADR")V",          FN_PTR(Unsafe_SetNativeAddress)},
  1484     {CC"allocateMemory",     CC"(J)"ADR,                 FN_PTR(Unsafe_AllocateMemory)},
  1485     {CC"reallocateMemory",   CC"("ADR"J)"ADR,            FN_PTR(Unsafe_ReallocateMemory)},
  1486     {CC"freeMemory",         CC"("ADR")V",               FN_PTR(Unsafe_FreeMemory)},
  1488     {CC"objectFieldOffset",  CC"("FLD")J",               FN_PTR(Unsafe_ObjectFieldOffset)},
  1489     {CC"staticFieldOffset",  CC"("FLD")J",               FN_PTR(Unsafe_StaticFieldOffset)},
  1490     {CC"staticFieldBase",    CC"("FLD")"OBJ,             FN_PTR(Unsafe_StaticFieldBaseFromField)},
  1491     {CC"ensureClassInitialized",CC"("CLS")V",            FN_PTR(Unsafe_EnsureClassInitialized)},
  1492     {CC"arrayBaseOffset",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayBaseOffset)},
  1493     {CC"arrayIndexScale",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayIndexScale)},
  1494     {CC"addressSize",        CC"()I",                    FN_PTR(Unsafe_AddressSize)},
  1495     {CC"pageSize",           CC"()I",                    FN_PTR(Unsafe_PageSize)},
  1497     {CC"defineClass",        CC"("DC0_Args")"CLS,        FN_PTR(Unsafe_DefineClass0)},
  1498     {CC"defineClass",        CC"("DC_Args")"CLS,         FN_PTR(Unsafe_DefineClass)},
  1499     {CC"allocateInstance",   CC"("CLS")"OBJ,             FN_PTR(Unsafe_AllocateInstance)},
  1500     {CC"monitorEnter",       CC"("OBJ")V",               FN_PTR(Unsafe_MonitorEnter)},
  1501     {CC"monitorExit",        CC"("OBJ")V",               FN_PTR(Unsafe_MonitorExit)},
  1502     {CC"throwException",     CC"("THR")V",               FN_PTR(Unsafe_ThrowException)}
  1504 };
  1506 // These are the methods prior to the JSR 166 changes in 1.6.0
  1507 static JNINativeMethod methods_15[] = {
  1508     {CC"getObject",        CC"("OBJ"J)"OBJ"",   FN_PTR(Unsafe_GetObject)},
  1509     {CC"putObject",        CC"("OBJ"J"OBJ")V",  FN_PTR(Unsafe_SetObject)},
  1510     {CC"getObjectVolatile",CC"("OBJ"J)"OBJ"",   FN_PTR(Unsafe_GetObjectVolatile)},
  1511     {CC"putObjectVolatile",CC"("OBJ"J"OBJ")V",  FN_PTR(Unsafe_SetObjectVolatile)},
  1514     DECLARE_GETSETOOP(Boolean, Z),
  1515     DECLARE_GETSETOOP(Byte, B),
  1516     DECLARE_GETSETOOP(Short, S),
  1517     DECLARE_GETSETOOP(Char, C),
  1518     DECLARE_GETSETOOP(Int, I),
  1519     DECLARE_GETSETOOP(Long, J),
  1520     DECLARE_GETSETOOP(Float, F),
  1521     DECLARE_GETSETOOP(Double, D),
  1523     DECLARE_GETSETNATIVE(Byte, B),
  1524     DECLARE_GETSETNATIVE(Short, S),
  1525     DECLARE_GETSETNATIVE(Char, C),
  1526     DECLARE_GETSETNATIVE(Int, I),
  1527     DECLARE_GETSETNATIVE(Long, J),
  1528     DECLARE_GETSETNATIVE(Float, F),
  1529     DECLARE_GETSETNATIVE(Double, D),
  1531     {CC"getAddress",         CC"("ADR")"ADR,             FN_PTR(Unsafe_GetNativeAddress)},
  1532     {CC"putAddress",         CC"("ADR""ADR")V",          FN_PTR(Unsafe_SetNativeAddress)},
  1534     {CC"allocateMemory",     CC"(J)"ADR,                 FN_PTR(Unsafe_AllocateMemory)},
  1535     {CC"reallocateMemory",   CC"("ADR"J)"ADR,            FN_PTR(Unsafe_ReallocateMemory)},
  1536     {CC"freeMemory",         CC"("ADR")V",               FN_PTR(Unsafe_FreeMemory)},
  1538     {CC"objectFieldOffset",  CC"("FLD")J",               FN_PTR(Unsafe_ObjectFieldOffset)},
  1539     {CC"staticFieldOffset",  CC"("FLD")J",               FN_PTR(Unsafe_StaticFieldOffset)},
  1540     {CC"staticFieldBase",    CC"("FLD")"OBJ,             FN_PTR(Unsafe_StaticFieldBaseFromField)},
  1541     {CC"ensureClassInitialized",CC"("CLS")V",            FN_PTR(Unsafe_EnsureClassInitialized)},
  1542     {CC"arrayBaseOffset",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayBaseOffset)},
  1543     {CC"arrayIndexScale",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayIndexScale)},
  1544     {CC"addressSize",        CC"()I",                    FN_PTR(Unsafe_AddressSize)},
  1545     {CC"pageSize",           CC"()I",                    FN_PTR(Unsafe_PageSize)},
  1547     {CC"defineClass",        CC"("DC0_Args")"CLS,        FN_PTR(Unsafe_DefineClass0)},
  1548     {CC"defineClass",        CC"("DC_Args")"CLS,         FN_PTR(Unsafe_DefineClass)},
  1549     {CC"allocateInstance",   CC"("CLS")"OBJ,             FN_PTR(Unsafe_AllocateInstance)},
  1550     {CC"monitorEnter",       CC"("OBJ")V",               FN_PTR(Unsafe_MonitorEnter)},
  1551     {CC"monitorExit",        CC"("OBJ")V",               FN_PTR(Unsafe_MonitorExit)},
  1552     {CC"throwException",     CC"("THR")V",               FN_PTR(Unsafe_ThrowException)},
  1553     {CC"compareAndSwapObject", CC"("OBJ"J"OBJ""OBJ")Z",  FN_PTR(Unsafe_CompareAndSwapObject)},
  1554     {CC"compareAndSwapInt",  CC"("OBJ"J""I""I"")Z",      FN_PTR(Unsafe_CompareAndSwapInt)},
  1555     {CC"compareAndSwapLong", CC"("OBJ"J""J""J"")Z",      FN_PTR(Unsafe_CompareAndSwapLong)},
  1556     {CC"park",               CC"(ZJ)V",                  FN_PTR(Unsafe_Park)},
  1557     {CC"unpark",             CC"("OBJ")V",               FN_PTR(Unsafe_Unpark)}
  1559 };
  1561 // These are the methods for 1.6.0 and 1.7.0
  1562 static JNINativeMethod methods_16[] = {
  1563     {CC"getObject",        CC"("OBJ"J)"OBJ"",   FN_PTR(Unsafe_GetObject)},
  1564     {CC"putObject",        CC"("OBJ"J"OBJ")V",  FN_PTR(Unsafe_SetObject)},
  1565     {CC"getObjectVolatile",CC"("OBJ"J)"OBJ"",   FN_PTR(Unsafe_GetObjectVolatile)},
  1566     {CC"putObjectVolatile",CC"("OBJ"J"OBJ")V",  FN_PTR(Unsafe_SetObjectVolatile)},
  1568     DECLARE_GETSETOOP(Boolean, Z),
  1569     DECLARE_GETSETOOP(Byte, B),
  1570     DECLARE_GETSETOOP(Short, S),
  1571     DECLARE_GETSETOOP(Char, C),
  1572     DECLARE_GETSETOOP(Int, I),
  1573     DECLARE_GETSETOOP(Long, J),
  1574     DECLARE_GETSETOOP(Float, F),
  1575     DECLARE_GETSETOOP(Double, D),
  1577     DECLARE_GETSETNATIVE(Byte, B),
  1578     DECLARE_GETSETNATIVE(Short, S),
  1579     DECLARE_GETSETNATIVE(Char, C),
  1580     DECLARE_GETSETNATIVE(Int, I),
  1581     DECLARE_GETSETNATIVE(Long, J),
  1582     DECLARE_GETSETNATIVE(Float, F),
  1583     DECLARE_GETSETNATIVE(Double, D),
  1585     {CC"getAddress",         CC"("ADR")"ADR,             FN_PTR(Unsafe_GetNativeAddress)},
  1586     {CC"putAddress",         CC"("ADR""ADR")V",          FN_PTR(Unsafe_SetNativeAddress)},
  1588     {CC"allocateMemory",     CC"(J)"ADR,                 FN_PTR(Unsafe_AllocateMemory)},
  1589     {CC"reallocateMemory",   CC"("ADR"J)"ADR,            FN_PTR(Unsafe_ReallocateMemory)},
  1590     {CC"freeMemory",         CC"("ADR")V",               FN_PTR(Unsafe_FreeMemory)},
  1592     {CC"objectFieldOffset",  CC"("FLD")J",               FN_PTR(Unsafe_ObjectFieldOffset)},
  1593     {CC"staticFieldOffset",  CC"("FLD")J",               FN_PTR(Unsafe_StaticFieldOffset)},
  1594     {CC"staticFieldBase",    CC"("FLD")"OBJ,             FN_PTR(Unsafe_StaticFieldBaseFromField)},
  1595     {CC"ensureClassInitialized",CC"("CLS")V",            FN_PTR(Unsafe_EnsureClassInitialized)},
  1596     {CC"arrayBaseOffset",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayBaseOffset)},
  1597     {CC"arrayIndexScale",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayIndexScale)},
  1598     {CC"addressSize",        CC"()I",                    FN_PTR(Unsafe_AddressSize)},
  1599     {CC"pageSize",           CC"()I",                    FN_PTR(Unsafe_PageSize)},
  1601     {CC"defineClass",        CC"("DC0_Args")"CLS,        FN_PTR(Unsafe_DefineClass0)},
  1602     {CC"defineClass",        CC"("DC_Args")"CLS,         FN_PTR(Unsafe_DefineClass)},
  1603     {CC"allocateInstance",   CC"("CLS")"OBJ,             FN_PTR(Unsafe_AllocateInstance)},
  1604     {CC"monitorEnter",       CC"("OBJ")V",               FN_PTR(Unsafe_MonitorEnter)},
  1605     {CC"monitorExit",        CC"("OBJ")V",               FN_PTR(Unsafe_MonitorExit)},
  1606     {CC"tryMonitorEnter",    CC"("OBJ")Z",               FN_PTR(Unsafe_TryMonitorEnter)},
  1607     {CC"throwException",     CC"("THR")V",               FN_PTR(Unsafe_ThrowException)},
  1608     {CC"compareAndSwapObject", CC"("OBJ"J"OBJ""OBJ")Z",  FN_PTR(Unsafe_CompareAndSwapObject)},
  1609     {CC"compareAndSwapInt",  CC"("OBJ"J""I""I"")Z",      FN_PTR(Unsafe_CompareAndSwapInt)},
  1610     {CC"compareAndSwapLong", CC"("OBJ"J""J""J"")Z",      FN_PTR(Unsafe_CompareAndSwapLong)},
  1611     {CC"putOrderedObject",   CC"("OBJ"J"OBJ")V",         FN_PTR(Unsafe_SetOrderedObject)},
  1612     {CC"putOrderedInt",      CC"("OBJ"JI)V",             FN_PTR(Unsafe_SetOrderedInt)},
  1613     {CC"putOrderedLong",     CC"("OBJ"JJ)V",             FN_PTR(Unsafe_SetOrderedLong)},
  1614     {CC"park",               CC"(ZJ)V",                  FN_PTR(Unsafe_Park)},
  1615     {CC"unpark",             CC"("OBJ")V",               FN_PTR(Unsafe_Unpark)}
  1616 };
  1618 // These are the methods for 1.8.0
  1619 static JNINativeMethod methods_18[] = {
  1620     {CC"getObject",        CC"("OBJ"J)"OBJ"",   FN_PTR(Unsafe_GetObject)},
  1621     {CC"putObject",        CC"("OBJ"J"OBJ")V",  FN_PTR(Unsafe_SetObject)},
  1622     {CC"getObjectVolatile",CC"("OBJ"J)"OBJ"",   FN_PTR(Unsafe_GetObjectVolatile)},
  1623     {CC"putObjectVolatile",CC"("OBJ"J"OBJ")V",  FN_PTR(Unsafe_SetObjectVolatile)},
  1625     DECLARE_GETSETOOP(Boolean, Z),
  1626     DECLARE_GETSETOOP(Byte, B),
  1627     DECLARE_GETSETOOP(Short, S),
  1628     DECLARE_GETSETOOP(Char, C),
  1629     DECLARE_GETSETOOP(Int, I),
  1630     DECLARE_GETSETOOP(Long, J),
  1631     DECLARE_GETSETOOP(Float, F),
  1632     DECLARE_GETSETOOP(Double, D),
  1634     DECLARE_GETSETNATIVE(Byte, B),
  1635     DECLARE_GETSETNATIVE(Short, S),
  1636     DECLARE_GETSETNATIVE(Char, C),
  1637     DECLARE_GETSETNATIVE(Int, I),
  1638     DECLARE_GETSETNATIVE(Long, J),
  1639     DECLARE_GETSETNATIVE(Float, F),
  1640     DECLARE_GETSETNATIVE(Double, D),
  1642     {CC"getAddress",         CC"("ADR")"ADR,             FN_PTR(Unsafe_GetNativeAddress)},
  1643     {CC"putAddress",         CC"("ADR""ADR")V",          FN_PTR(Unsafe_SetNativeAddress)},
  1645     {CC"allocateMemory",     CC"(J)"ADR,                 FN_PTR(Unsafe_AllocateMemory)},
  1646     {CC"reallocateMemory",   CC"("ADR"J)"ADR,            FN_PTR(Unsafe_ReallocateMemory)},
  1647     {CC"freeMemory",         CC"("ADR")V",               FN_PTR(Unsafe_FreeMemory)},
  1649     {CC"objectFieldOffset",  CC"("FLD")J",               FN_PTR(Unsafe_ObjectFieldOffset)},
  1650     {CC"staticFieldOffset",  CC"("FLD")J",               FN_PTR(Unsafe_StaticFieldOffset)},
  1651     {CC"staticFieldBase",    CC"("FLD")"OBJ,             FN_PTR(Unsafe_StaticFieldBaseFromField)},
  1652     {CC"ensureClassInitialized",CC"("CLS")V",            FN_PTR(Unsafe_EnsureClassInitialized)},
  1653     {CC"arrayBaseOffset",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayBaseOffset)},
  1654     {CC"arrayIndexScale",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayIndexScale)},
  1655     {CC"addressSize",        CC"()I",                    FN_PTR(Unsafe_AddressSize)},
  1656     {CC"pageSize",           CC"()I",                    FN_PTR(Unsafe_PageSize)},
  1658     {CC"defineClass",        CC"("DC_Args")"CLS,         FN_PTR(Unsafe_DefineClass)},
  1659     {CC"allocateInstance",   CC"("CLS")"OBJ,             FN_PTR(Unsafe_AllocateInstance)},
  1660     {CC"monitorEnter",       CC"("OBJ")V",               FN_PTR(Unsafe_MonitorEnter)},
  1661     {CC"monitorExit",        CC"("OBJ")V",               FN_PTR(Unsafe_MonitorExit)},
  1662     {CC"tryMonitorEnter",    CC"("OBJ")Z",               FN_PTR(Unsafe_TryMonitorEnter)},
  1663     {CC"throwException",     CC"("THR")V",               FN_PTR(Unsafe_ThrowException)},
  1664     {CC"compareAndSwapObject", CC"("OBJ"J"OBJ""OBJ")Z",  FN_PTR(Unsafe_CompareAndSwapObject)},
  1665     {CC"compareAndSwapInt",  CC"("OBJ"J""I""I"")Z",      FN_PTR(Unsafe_CompareAndSwapInt)},
  1666     {CC"compareAndSwapLong", CC"("OBJ"J""J""J"")Z",      FN_PTR(Unsafe_CompareAndSwapLong)},
  1667     {CC"putOrderedObject",   CC"("OBJ"J"OBJ")V",         FN_PTR(Unsafe_SetOrderedObject)},
  1668     {CC"putOrderedInt",      CC"("OBJ"JI)V",             FN_PTR(Unsafe_SetOrderedInt)},
  1669     {CC"putOrderedLong",     CC"("OBJ"JJ)V",             FN_PTR(Unsafe_SetOrderedLong)},
  1670     {CC"park",               CC"(ZJ)V",                  FN_PTR(Unsafe_Park)},
  1671     {CC"unpark",             CC"("OBJ")V",               FN_PTR(Unsafe_Unpark)}
  1672 };
  1674 JNINativeMethod loadavg_method[] = {
  1675     {CC"getLoadAverage",     CC"([DI)I",                 FN_PTR(Unsafe_Loadavg)}
  1676 };
  1678 JNINativeMethod prefetch_methods[] = {
  1679     {CC"prefetchRead",       CC"("OBJ"J)V",              FN_PTR(Unsafe_PrefetchRead)},
  1680     {CC"prefetchWrite",      CC"("OBJ"J)V",              FN_PTR(Unsafe_PrefetchWrite)},
  1681     {CC"prefetchReadStatic", CC"("OBJ"J)V",              FN_PTR(Unsafe_PrefetchRead)},
  1682     {CC"prefetchWriteStatic",CC"("OBJ"J)V",              FN_PTR(Unsafe_PrefetchWrite)}
  1683 };
  1685 JNINativeMethod memcopy_methods_17[] = {
  1686     {CC"copyMemory",         CC"("OBJ"J"OBJ"JJ)V",       FN_PTR(Unsafe_CopyMemory2)},
  1687     {CC"setMemory",          CC"("OBJ"JJB)V",            FN_PTR(Unsafe_SetMemory2)}
  1688 };
  1690 JNINativeMethod memcopy_methods_15[] = {
  1691     {CC"setMemory",          CC"("ADR"JB)V",             FN_PTR(Unsafe_SetMemory)},
  1692     {CC"copyMemory",         CC"("ADR ADR"J)V",          FN_PTR(Unsafe_CopyMemory)}
  1693 };
  1695 JNINativeMethod anonk_methods[] = {
  1696     {CC"defineAnonymousClass", CC"("DAC_Args")"CLS,      FN_PTR(Unsafe_DefineAnonymousClass)},
  1697 };
  1699 JNINativeMethod lform_methods[] = {
  1700     {CC"shouldBeInitialized",CC"("CLS")Z",               FN_PTR(Unsafe_ShouldBeInitialized)},
  1701 };
  1703 JNINativeMethod fence_methods[] = {
  1704     {CC"loadFence",          CC"()V",                    FN_PTR(Unsafe_LoadFence)},
  1705     {CC"storeFence",         CC"()V",                    FN_PTR(Unsafe_StoreFence)},
  1706     {CC"fullFence",          CC"()V",                    FN_PTR(Unsafe_FullFence)},
  1707 };
  1709 #undef CC
  1710 #undef FN_PTR
  1712 #undef ADR
  1713 #undef LANG
  1714 #undef OBJ
  1715 #undef CLS
  1716 #undef CTR
  1717 #undef FLD
  1718 #undef MTH
  1719 #undef THR
  1720 #undef DC0_Args
  1721 #undef DC_Args
  1723 #undef DECLARE_GETSETOOP
  1724 #undef DECLARE_GETSETNATIVE
  1727 /**
  1728  * Helper method to register native methods.
  1729  */
  1730 static bool register_natives(const char* message, JNIEnv* env, jclass clazz, const JNINativeMethod* methods, jint nMethods) {
  1731   int status = env->RegisterNatives(clazz, methods, nMethods);
  1732   if (status < 0 || env->ExceptionOccurred()) {
  1733     if (PrintMiscellaneous && (Verbose || WizardMode)) {
  1734       tty->print_cr("Unsafe:  failed registering %s", message);
  1736     env->ExceptionClear();
  1737     return false;
  1738   } else {
  1739     if (PrintMiscellaneous && (Verbose || WizardMode)) {
  1740       tty->print_cr("Unsafe:  successfully registered %s", message);
  1742     return true;
  1747 // This one function is exported, used by NativeLookup.
  1748 // The Unsafe_xxx functions above are called only from the interpreter.
  1749 // The optimizer looks at names and signatures to recognize
  1750 // individual functions.
  1752 JVM_ENTRY(void, JVM_RegisterUnsafeMethods(JNIEnv *env, jclass unsafecls))
  1753   UnsafeWrapper("JVM_RegisterUnsafeMethods");
  1755     ThreadToNativeFromVM ttnfv(thread);
  1757     // Unsafe methods
  1759       bool success = false;
  1760       // We need to register the 1.6 methods first because the 1.8 methods would register fine on 1.7 and 1.6
  1761       if (!success) {
  1762         success = register_natives("1.6 methods",   env, unsafecls, methods_16,  sizeof(methods_16)/sizeof(JNINativeMethod));
  1764       if (!success) {
  1765         success = register_natives("1.8 methods",   env, unsafecls, methods_18,  sizeof(methods_18)/sizeof(JNINativeMethod));
  1767       if (!success) {
  1768         success = register_natives("1.5 methods",   env, unsafecls, methods_15,  sizeof(methods_15)/sizeof(JNINativeMethod));
  1770       if (!success) {
  1771         success = register_natives("1.4.1 methods", env, unsafecls, methods_141, sizeof(methods_141)/sizeof(JNINativeMethod));
  1773       if (!success) {
  1774         success = register_natives("1.4.0 methods", env, unsafecls, methods_140, sizeof(methods_140)/sizeof(JNINativeMethod));
  1776       guarantee(success, "register unsafe natives");
  1779     // Unsafe.getLoadAverage
  1780     register_natives("1.6 loadavg method", env, unsafecls, loadavg_method, sizeof(loadavg_method)/sizeof(JNINativeMethod));
  1782     // Prefetch methods
  1783     register_natives("1.6 prefetch methods", env, unsafecls, prefetch_methods, sizeof(prefetch_methods)/sizeof(JNINativeMethod));
  1785     // Memory copy methods
  1787       bool success = false;
  1788       if (!success) {
  1789         success = register_natives("1.7 memory copy methods", env, unsafecls, memcopy_methods_17, sizeof(memcopy_methods_17)/sizeof(JNINativeMethod));
  1791       if (!success) {
  1792         success = register_natives("1.5 memory copy methods", env, unsafecls, memcopy_methods_15, sizeof(memcopy_methods_15)/sizeof(JNINativeMethod));
  1796     // Unsafe.defineAnonymousClass
  1797     if (EnableInvokeDynamic) {
  1798       register_natives("1.7 define anonymous class method", env, unsafecls, anonk_methods, sizeof(anonk_methods)/sizeof(JNINativeMethod));
  1801     // Unsafe.shouldBeInitialized
  1802     if (EnableInvokeDynamic) {
  1803       register_natives("1.7 LambdaForm support", env, unsafecls, lform_methods, sizeof(lform_methods)/sizeof(JNINativeMethod));
  1806     // Fence methods
  1807     register_natives("1.8 fence methods", env, unsafecls, fence_methods, sizeof(fence_methods)/sizeof(JNINativeMethod));
  1809 JVM_END

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