graal-jvmci-8: src/cpu/x86/vm/assembler

comparison src/cpu/x86/vm/assembler_x86.cpp @ 3249:e1162778c1c8

7009266: G1: assert(obj->is_oop_or_null(true )) failed: Error Summary: A referent object that is only weakly reachable at the start of concurrent marking but is re-attached to the strongly reachable object graph during marking may not be marked as live. This can cause the reference object to be processed prematurely and leave dangling pointers to the referent object. Implement a read barrier for the java.lang.ref.Reference::referent field by intrinsifying the Reference.get() method, and intercepting accesses though JNI, reflection, and Unsafe, so that when a non-null referent object is read it is also logged in an SATB buffer. Reviewed-by: kvn, iveresov, never, tonyp, dholmes

author	johnc
date	Thu, 07 Apr 2011 09:53:20 -0700
parents	8033953d67ff
children	92add02409c9

comparison

equal deleted inserted replaced

-:e6beb62de02d
+:e1162778c1c8
 //////////////////////////////////////////////////////////////////////////////////
 #ifndef SERIALGC
 void MacroAssembler::g1_write_barrier_pre(Register obj,
-#ifndef _LP64
+Register pre_val,
 Register thread,
-#endif
 Register tmp,
-Register tmp2,
+bool tosca_live,
-bool tosca_live) {
+bool expand_call) {
-LP64_ONLY(Register thread = r15_thread;)
+// If expand_call is true then we expand the call_VM_leaf macro
+// directly to skip generating the check by
+// InterpreterMacroAssembler::call_VM_leaf_base that checks _last_sp.
+#ifdef _LP64
+assert(thread == r15_thread, "must be");
+#endif // _LP64
+Label done;
+Label runtime;
+assert(pre_val != noreg, "check this code");
+if (obj != noreg) {
+assert_different_registers(obj, pre_val, tmp);
+assert(pre_val != rax, "check this code");
+}
 Address in_progress(thread, in_bytes(JavaThread::satb_mark_queue_offset() +
 PtrQueue::byte_offset_of_active()));
 Address index(thread, in_bytes(JavaThread::satb_mark_queue_offset() +
 PtrQueue::byte_offset_of_index()));
 Address buffer(thread, in_bytes(JavaThread::satb_mark_queue_offset() +
 PtrQueue::byte_offset_of_buf()));
-Label done;
+// Is marking active?
-Label runtime;
-// if (!marking_in_progress) goto done;
 if (in_bytes(PtrQueue::byte_width_of_active()) == 4) {
 cmpl(in_progress, 0);
 } else {
 assert(in_bytes(PtrQueue::byte_width_of_active()) == 1, "Assumption");
 cmpb(in_progress, 0);
 }
 jcc(Assembler::equal, done);
-// if (x.f == NULL) goto done;
+// Do we need to load the previous value?
-#ifdef _LP64
+if (obj != noreg) {
-load_heap_oop(tmp2, Address(obj, 0));
+load_heap_oop(pre_val, Address(obj, 0));
-#else
+}
-movptr(tmp2, Address(obj, 0));
-#endif
+// Is the previous value null?
-cmpptr(tmp2, (int32_t) NULL_WORD);
+cmpptr(pre_val, (int32_t) NULL_WORD);
 jcc(Assembler::equal, done);
 // Can we store original value in the thread's buffer?
+// Is index == 0?
-#ifdef _LP64
+// (The index field is typed as size_t.)
-movslq(tmp, index);
-cmpq(tmp, 0);
+movptr(tmp, index);                   // tmp := *index_adr
-#else
+cmpptr(tmp, 0);                       // tmp == 0?
-cmpl(index, 0);
+jcc(Assembler::equal, runtime);       // If yes, goto runtime
-#endif
-jcc(Assembler::equal, runtime);
+subptr(tmp, wordSize);                // tmp := tmp - wordSize
-#ifdef _LP64
+movptr(index, tmp);                   // *index_adr := tmp
-subq(tmp, wordSize);
+addptr(tmp, buffer);                  // tmp := tmp + *buffer_adr
-movl(index, tmp);
-addq(tmp, buffer);
+// Record the previous value
-#else
+movptr(Address(tmp, 0), pre_val);
-subl(index, wordSize);
-movl(tmp, buffer);
-addl(tmp, index);
-#endif
-movptr(Address(tmp, 0), tmp2);
 jmp(done);
 bind(runtime);
 // save the live input values
 if(tosca_live) push(rax);
-push(obj);
-#ifdef _LP64
+if (obj != noreg && obj != rax)
-call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), tmp2, r15_thread);
+push(obj);
-#else
-push(thread);
+if (pre_val != rax)
-call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), tmp2, thread);
+push(pre_val);
-pop(thread);
-#endif
+// Calling the runtime using the regular call_VM_leaf mechanism generates
-pop(obj);
+// code (generated by InterpreterMacroAssember::call_VM_leaf_base)
+// that checks that the *(ebp+frame::interpreter_frame_last_sp) == NULL.
+//
+// If we care generating the pre-barrier without a frame (e.g. in the
+// intrinsified Reference.get() routine) then ebp might be pointing to
+// the caller frame and so this check will most likely fail at runtime.
+//
+// Expanding the call directly bypasses the generation of the check.
+// So when we do not have have a full interpreter frame on the stack
+// expand_call should be passed true.
+NOT_LP64( push(thread); )
+if (expand_call) {
+LP64_ONLY( assert(pre_val != c_rarg1, "smashed arg"); )
+pass_arg1(this, thread);
+pass_arg0(this, pre_val);
+MacroAssembler::call_VM_leaf_base(CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), 2);
+} else {
+call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), pre_val, thread);
+}
+NOT_LP64( pop(thread); )
+// save the live input values
+if (pre_val != rax)
+pop(pre_val);
+if (obj != noreg && obj != rax)
+pop(obj);
 if(tosca_live) pop(rax);
 bind(done);
 }
 void MacroAssembler::g1_write_barrier_post(Register store_addr,
 Register new_val,
-#ifndef _LP64
 Register thread,
-#endif
 Register tmp,
 Register tmp2) {
+#ifdef _LP64
-LP64_ONLY(Register thread = r15_thread;)
+assert(thread == r15_thread, "must be");
+#endif // _LP64
 Address queue_index(thread, in_bytes(JavaThread::dirty_card_queue_offset() +
 PtrQueue::byte_offset_of_index()));
 Address buffer(thread, in_bytes(JavaThread::dirty_card_queue_offset() +
 PtrQueue::byte_offset_of_buf()));
 BarrierSet* bs = Universe::heap()->barrier_set();
 CardTableModRefBS* ct = (CardTableModRefBS*)bs;
 Label done;
 Label runtime;
 #endif
 pop(new_val);
 pop(store_addr);
 bind(done);
 }
 #endif // SERIALGC
 //////////////////////////////////////////////////////////////////////////////////

Mercurial > hg > graal-jvmci-8

comparison src/cpu/x86/vm/assembler_x86.cpp @ 3249:e1162778c1c8