Mercurial > hg > truffle
view src/cpu/sparc/vm/runtime_sparc.cpp @ 453:c96030fff130
6684579: SoftReference processing can be made more efficient
Summary: For current soft-ref clearing policies, we can decide at marking time if a soft-reference will definitely not be cleared, postponing the decision of whether it will definitely be cleared to the final reference processing phase. This can be especially beneficial in the case of concurrent collectors where the marking is usually concurrent but reference processing is usually not.
Reviewed-by: jmasa
author | ysr |
---|---|
date | Thu, 20 Nov 2008 16:56:09 -0800 |
parents | a61af66fc99e |
children | 6b2273dd6fa9 |
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/* * Copyright 1998-2006 Sun Microsystems, Inc. All Rights Reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * CA 95054 USA or visit www.sun.com if you need additional information or * have any questions. * */ #include "incls/_precompiled.incl" #include "incls/_runtime_sparc.cpp.incl" #define __ masm-> ExceptionBlob *OptoRuntime::_exception_blob; //------------------------------ generate_exception_blob --------------------------- // creates exception blob at the end // Using exception blob, this code is jumped from a compiled method. // (see emit_exception_handler in sparc.ad file) // // Given an exception pc at a call we call into the runtime for the // handler in this method. This handler might merely restore state // (i.e. callee save registers) unwind the frame and jump to the // exception handler for the nmethod if there is no Java level handler // for the nmethod. // // This code is entered with a jmp. // // Arguments: // O0: exception oop // O1: exception pc // // Results: // O0: exception oop // O1: exception pc in caller or ??? // destination: exception handler of caller // // Note: the exception pc MUST be at a call (precise debug information) // void OptoRuntime::generate_exception_blob() { // allocate space for code ResourceMark rm; int pad = VerifyThread ? 256 : 0;// Extra slop space for more verify code // setup code generation tools // Measured 8/7/03 at 256 in 32bit debug build (no VerifyThread) // Measured 8/7/03 at 528 in 32bit debug build (VerifyThread) CodeBuffer buffer("exception_blob", 600+pad, 512); MacroAssembler* masm = new MacroAssembler(&buffer); int framesize_in_bytes = __ total_frame_size_in_bytes(0); int framesize_in_words = framesize_in_bytes / wordSize; int framesize_in_slots = framesize_in_bytes / sizeof(jint); Label L; int start = __ offset(); __ verify_thread(); __ st_ptr(Oexception, Address(G2_thread, 0, in_bytes(JavaThread::exception_oop_offset()))); __ st_ptr(Oissuing_pc, Address(G2_thread, 0, in_bytes(JavaThread::exception_pc_offset()))); // This call does all the hard work. It checks if an exception catch // exists in the method. // If so, it returns the handler address. // If the nmethod has been deoptimized and it had a handler the handler // address is the deopt blob unpack_with_exception entry. // // If no handler exists it prepares for stack-unwinding, restoring the callee-save // registers of the frame being removed. // __ save_frame(0); __ mov(G2_thread, O0); __ set_last_Java_frame(SP, noreg); __ save_thread(L7_thread_cache); // This call can block at exit and nmethod can be deoptimized at that // point. If the nmethod had a catch point we would jump to the // now deoptimized catch point and fall thru the vanilla deopt // path and lose the exception // Sure would be simpler if this call didn't block! __ call(CAST_FROM_FN_PTR(address, OptoRuntime::handle_exception_C), relocInfo::runtime_call_type); __ delayed()->mov(L7_thread_cache, O0); // Set an oopmap for the call site. This oopmap will only be used if we // are unwinding the stack. Hence, all locations will be dead. // Callee-saved registers will be the same as the frame above (i.e., // handle_exception_stub), since they were restored when we got the // exception. OopMapSet *oop_maps = new OopMapSet(); oop_maps->add_gc_map( __ offset()-start, new OopMap(framesize_in_slots, 0)); __ bind(L); __ restore_thread(L7_thread_cache); __ reset_last_Java_frame(); __ mov(O0, G3_scratch); // Move handler address to temp __ restore(); // G3_scratch contains handler address // Since this may be the deopt blob we must set O7 to look like we returned // from the original pc that threw the exception __ ld_ptr(Address(G2_thread, 0, in_bytes(JavaThread::exception_pc_offset())), O7); __ sub(O7, frame::pc_return_offset, O7); assert(Assembler::is_simm13(in_bytes(JavaThread::exception_oop_offset())), "exception offset overflows simm13, following ld instruction cannot be in delay slot"); __ ld_ptr(Address(G2_thread, 0, in_bytes(JavaThread::exception_oop_offset())), Oexception); // O0 #ifdef ASSERT __ st_ptr(G0, Address(G2_thread, 0, in_bytes(JavaThread::exception_handler_pc_offset()))); __ st_ptr(G0, Address(G2_thread, 0, in_bytes(JavaThread::exception_pc_offset()))); #endif __ JMP(G3_scratch, 0); // Clear the exception oop so GC no longer processes it as a root. __ delayed()->st_ptr(G0, Address(G2_thread, 0, in_bytes(JavaThread::exception_oop_offset()))); // ------------- // make sure all code is generated masm->flush(); _exception_blob = ExceptionBlob::create(&buffer, oop_maps, framesize_in_words); }