# HG changeset patch # User kvn # Date 1355881064 28800 # Node ID 61b025224ac93f15cb51fc951a2f68d455ef3d52 # Parent 84828ee2a91cd3b8832eef877a830daa424eee3d 8004318: JEP-171: Support Unsafe fences intrinsics Summary: Add three memory-ordering intrinsics to the sun.misc.Unsafe class. Reviewed-by: twisti, kvn Contributed-by: Aleksey Shipilev diff -r 84828ee2a91c -r 61b025224ac9 hotspot/src/share/vm/c1/c1_GraphBuilder.cpp --- a/hotspot/src/share/vm/c1/c1_GraphBuilder.cpp Tue Dec 18 10:47:23 2012 -0800 +++ b/hotspot/src/share/vm/c1/c1_GraphBuilder.cpp Tue Dec 18 17:37:44 2012 -0800 @@ -3442,6 +3442,11 @@ preserves_state = true; break; + case vmIntrinsics::_loadFence : + case vmIntrinsics::_storeFence: + case vmIntrinsics::_fullFence : + break; + default : return false; // do not inline } // create intrinsic node diff -r 84828ee2a91c -r 61b025224ac9 hotspot/src/share/vm/c1/c1_LIRGenerator.cpp --- a/hotspot/src/share/vm/c1/c1_LIRGenerator.cpp Tue Dec 18 10:47:23 2012 -0800 +++ b/hotspot/src/share/vm/c1/c1_LIRGenerator.cpp Tue Dec 18 17:37:44 2012 -0800 @@ -2977,6 +2977,16 @@ do_CompareAndSwap(x, longType); break; + case vmIntrinsics::_loadFence : + if (os::is_MP()) __ membar_acquire(); + break; + case vmIntrinsics::_storeFence: + if (os::is_MP()) __ membar_release(); + break; + case vmIntrinsics::_fullFence : + if (os::is_MP()) __ membar(); + break; + case vmIntrinsics::_Reference_get: do_Reference_get(x); break; diff -r 84828ee2a91c -r 61b025224ac9 hotspot/src/share/vm/classfile/vmSymbols.hpp --- a/hotspot/src/share/vm/classfile/vmSymbols.hpp Tue Dec 18 10:47:23 2012 -0800 +++ b/hotspot/src/share/vm/classfile/vmSymbols.hpp Tue Dec 18 17:37:44 2012 -0800 @@ -756,6 +756,15 @@ do_intrinsic(_unpark, sun_misc_Unsafe, unpark_name, unpark_signature, F_RN) \ do_name( unpark_name, "unpark") \ do_alias( unpark_signature, /*(LObject;)V*/ object_void_signature) \ + do_intrinsic(_loadFence, sun_misc_Unsafe, loadFence_name, loadFence_signature, F_RN) \ + do_name( loadFence_name, "loadFence") \ + do_alias( loadFence_signature, void_method_signature) \ + do_intrinsic(_storeFence, sun_misc_Unsafe, storeFence_name, storeFence_signature, F_RN) \ + do_name( storeFence_name, "storeFence") \ + do_alias( storeFence_signature, void_method_signature) \ + do_intrinsic(_fullFence, sun_misc_Unsafe, fullFence_name, fullFence_signature, F_RN) \ + do_name( fullFence_name, "fullFence") \ + do_alias( fullFence_signature, void_method_signature) \ \ /* unsafe memory references (there are a lot of them...) */ \ do_signature(getObject_signature, "(Ljava/lang/Object;J)Ljava/lang/Object;") \ diff -r 84828ee2a91c -r 61b025224ac9 hotspot/src/share/vm/opto/library_call.cpp --- a/hotspot/src/share/vm/opto/library_call.cpp Tue Dec 18 10:47:23 2012 -0800 +++ b/hotspot/src/share/vm/opto/library_call.cpp Tue Dec 18 17:37:44 2012 -0800 @@ -282,6 +282,7 @@ typedef enum { LS_xadd, LS_xchg, LS_cmpxchg } LoadStoreKind; bool inline_unsafe_load_store(BasicType type, LoadStoreKind kind); bool inline_unsafe_ordered_store(BasicType type); + bool inline_unsafe_fence(vmIntrinsics::ID id); bool inline_fp_conversions(vmIntrinsics::ID id); bool inline_number_methods(vmIntrinsics::ID id); bool inline_reference_get(); @@ -334,6 +335,9 @@ case vmIntrinsics::_getAndSetInt: case vmIntrinsics::_getAndSetLong: case vmIntrinsics::_getAndSetObject: + case vmIntrinsics::_loadFence: + case vmIntrinsics::_storeFence: + case vmIntrinsics::_fullFence: break; // InlineNatives does not control String.compareTo case vmIntrinsics::_Reference_get: break; // InlineNatives does not control Reference.get @@ -732,6 +736,10 @@ case vmIntrinsics::_getAndSetLong: return inline_unsafe_load_store(T_LONG, LS_xchg); case vmIntrinsics::_getAndSetObject: return inline_unsafe_load_store(T_OBJECT, LS_xchg); + case vmIntrinsics::_loadFence: + case vmIntrinsics::_storeFence: + case vmIntrinsics::_fullFence: return inline_unsafe_fence(intrinsic_id()); + case vmIntrinsics::_currentThread: return inline_native_currentThread(); case vmIntrinsics::_isInterrupted: return inline_native_isInterrupted(); @@ -2840,6 +2848,26 @@ return true; } +bool LibraryCallKit::inline_unsafe_fence(vmIntrinsics::ID id) { + // Regardless of form, don't allow previous ld/st to move down, + // then issue acquire, release, or volatile mem_bar. + insert_mem_bar(Op_MemBarCPUOrder); + switch(id) { + case vmIntrinsics::_loadFence: + insert_mem_bar(Op_MemBarAcquire); + return true; + case vmIntrinsics::_storeFence: + insert_mem_bar(Op_MemBarRelease); + return true; + case vmIntrinsics::_fullFence: + insert_mem_bar(Op_MemBarVolatile); + return true; + default: + fatal_unexpected_iid(id); + return false; + } +} + //----------------------------inline_unsafe_allocate--------------------------- // public native Object sun.mics.Unsafe.allocateInstance(Class cls); bool LibraryCallKit::inline_unsafe_allocate() { diff -r 84828ee2a91c -r 61b025224ac9 hotspot/src/share/vm/prims/unsafe.cpp --- a/hotspot/src/share/vm/prims/unsafe.cpp Tue Dec 18 10:47:23 2012 -0800 +++ b/hotspot/src/share/vm/prims/unsafe.cpp Tue Dec 18 17:37:44 2012 -0800 @@ -468,6 +468,21 @@ #endif UNSAFE_END +UNSAFE_ENTRY(void, Unsafe_LoadFence(JNIEnv *env, jobject unsafe)) + UnsafeWrapper("Unsafe_LoadFence"); + OrderAccess::acquire(); +UNSAFE_END + +UNSAFE_ENTRY(void, Unsafe_StoreFence(JNIEnv *env, jobject unsafe)) + UnsafeWrapper("Unsafe_StoreFence"); + OrderAccess::release(); +UNSAFE_END + +UNSAFE_ENTRY(void, Unsafe_FullFence(JNIEnv *env, jobject unsafe)) + UnsafeWrapper("Unsafe_FullFence"); + OrderAccess::fence(); +UNSAFE_END + ////// Data in the C heap. // Note: These do not throw NullPointerException for bad pointers. @@ -1550,6 +1565,9 @@ {CC"putOrderedObject", CC"("OBJ"J"OBJ")V", FN_PTR(Unsafe_SetOrderedObject)}, {CC"putOrderedInt", CC"("OBJ"JI)V", FN_PTR(Unsafe_SetOrderedInt)}, {CC"putOrderedLong", CC"("OBJ"JJ)V", FN_PTR(Unsafe_SetOrderedLong)}, + {CC"loadFence", CC"()V", FN_PTR(Unsafe_LoadFence)}, + {CC"storeFence", CC"()V", FN_PTR(Unsafe_StoreFence)}, + {CC"fullFence", CC"()V", FN_PTR(Unsafe_FullFence)}, {CC"park", CC"(ZJ)V", FN_PTR(Unsafe_Park)}, {CC"unpark", CC"("OBJ")V", FN_PTR(Unsafe_Unpark)}