Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright (c) 1997, 2012, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  *

  */

 #include "precompiled.hpp"

 #include "code/codeCache.hpp"

 #include "code/compiledIC.hpp"

 #include "code/icBuffer.hpp"

 #include "code/nmethod.hpp"

 #include "code/scopeDesc.hpp"

 #include "gc_interface/collectedHeap.inline.hpp"

 #include "interpreter/interpreter.hpp"

 #include "interpreter/linkResolver.hpp"

 #include "memory/resourceArea.hpp"

 #include "memory/universe.inline.hpp"

 #include "oops/method.hpp"

 #include "oops/oop.inline.hpp"

 #include "oops/oop.inline2.hpp"

 #include "runtime/mutexLocker.hpp"

 #include "runtime/stubRoutines.hpp"

 DEF_STUB_INTERFACE(ICStub);

 StubQueue* InlineCacheBuffer::_buffer    = NULL;

 ICStub*    InlineCacheBuffer::_next_stub = NULL;

 CompiledICHolder* InlineCacheBuffer::_pending_released = NULL;

 int InlineCacheBuffer::_pending_count = 0;

 void ICStub::finalize() {

   if (!is_empty()) {

     ResourceMark rm;

     CompiledIC *ic = CompiledIC_at(CodeCache::find_nmethod(ic_site()), ic_site());

     assert(CodeCache::find_nmethod(ic->instruction_address()) != NULL, "inline cache in non-nmethod?");

     assert(this == ICStub_from_destination_address(ic->stub_address()), "wrong owner of ic buffer");

     ic->set_ic_destination_and_value(destination(), cached_value());

   }

 }

 address ICStub::destination() const {

   return InlineCacheBuffer::ic_buffer_entry_point(code_begin());

 }

 void* ICStub::cached_value() const {

   return InlineCacheBuffer::ic_buffer_cached_value(code_begin());

 }

 void ICStub::set_stub(CompiledIC *ic, void* cached_val, address dest_addr) {

   // We cannot store a pointer to the 'ic' object, since it is resource allocated. Instead we

   // store the location of the inline cache. Then we have enough information recreate the CompiledIC

   // object when we need to remove the stub.

   _ic_site = ic->instruction_address();

   // Assemble new stub

   InlineCacheBuffer::assemble_ic_buffer_code(code_begin(), cached_val, dest_addr);

   assert(destination() == dest_addr,   "can recover destination");

   assert(cached_value() == cached_val, "can recover destination");

 }

 void ICStub::clear() {

   if (CompiledIC::is_icholder_entry(destination())) {

     InlineCacheBuffer::queue_for_release((CompiledICHolder*)cached_value());

   }

   _ic_site = NULL;

 }

 #ifndef PRODUCT

 // anybody calling to this stub will trap

 void ICStub::verify() {

 }

 void ICStub::print() {

   tty->print_cr("ICStub: site: " INTPTR_FORMAT, _ic_site);

 }

 #endif

 //-----------------------------------------------------------------------------------------------

 // Implementation of InlineCacheBuffer

 void InlineCacheBuffer::init_next_stub() {

   ICStub* ic_stub = (ICStub*)buffer()->request_committed (ic_stub_code_size());

   assert (ic_stub != NULL, "no room for a single stub");

   set_next_stub(ic_stub);

 }

 void InlineCacheBuffer::initialize() {

   if (_buffer != NULL) return; // already initialized

   _buffer = new StubQueue(new ICStubInterface, 10*K, InlineCacheBuffer_lock, "InlineCacheBuffer");

   assert (_buffer != NULL, "cannot allocate InlineCacheBuffer");

   init_next_stub();

 }

 ICStub* InlineCacheBuffer::new_ic_stub() {

   while (true) {

     ICStub* ic_stub = (ICStub*)buffer()->request_committed(ic_stub_code_size());

     if (ic_stub != NULL) {

       return ic_stub;

     }

     // we ran out of inline cache buffer space; must enter safepoint.

     // We do this by forcing a safepoint

     EXCEPTION_MARK;

     VM_ForceSafepoint vfs;

     VMThread::execute(&vfs);

     // We could potential get an async. exception at this point.

     // In that case we will rethrow it to ourselvs.

     if (HAS_PENDING_EXCEPTION) {

       oop exception = PENDING_EXCEPTION;

       CLEAR_PENDING_EXCEPTION;

       Thread::send_async_exception(JavaThread::current()->threadObj(), exception);

     }

   }

   ShouldNotReachHere();

   return NULL;

 }

 void InlineCacheBuffer::update_inline_caches() {

   if (buffer()->number_of_stubs() > 1) {

     if (TraceICBuffer) {

       tty->print_cr("[updating inline caches with %d stubs]", buffer()->number_of_stubs());

     }

     buffer()->remove_all();

     init_next_stub();

   }

   release_pending_icholders();

 }

 bool InlineCacheBuffer::contains(address instruction_address) {

   return buffer()->contains(instruction_address);

 }

 bool InlineCacheBuffer::is_empty() {

   return buffer()->number_of_stubs() == 1;    // always has sentinel

 }

 void InlineCacheBuffer_init() {

   InlineCacheBuffer::initialize();

 }

 void InlineCacheBuffer::create_transition_stub(CompiledIC *ic, void* cached_value, address entry) {

   assert(!SafepointSynchronize::is_at_safepoint(), "should not be called during a safepoint");

   assert (CompiledIC_lock->is_locked(), "");

   if (TraceICBuffer) {

     tty->print_cr("  create transition stub for " INTPTR_FORMAT " destination " INTPTR_FORMAT " cached value " INTPTR_FORMAT,

                   ic->instruction_address(), entry, cached_value);

   }

   // If an transition stub is already associate with the inline cache, then we remove the association.

   if (ic->is_in_transition_state()) {

     ICStub* old_stub = ICStub_from_destination_address(ic->stub_address());

     old_stub->clear();

   }

   // allocate and initialize new "out-of-line" inline-cache

   ICStub* ic_stub = get_next_stub();

   ic_stub->set_stub(ic, cached_value, entry);

   // Update inline cache in nmethod to point to new "out-of-line" allocated inline cache

   ic->set_ic_destination(ic_stub);

   set_next_stub(new_ic_stub()); // can cause safepoint synchronization

 }

 address InlineCacheBuffer::ic_destination_for(CompiledIC *ic) {

   ICStub* stub = ICStub_from_destination_address(ic->stub_address());

   return stub->destination();

 }

 void* InlineCacheBuffer::cached_value_for(CompiledIC *ic) {

   ICStub* stub = ICStub_from_destination_address(ic->stub_address());

   return stub->cached_value();

 }

 // Free CompiledICHolder*s that are no longer in use

 void InlineCacheBuffer::release_pending_icholders() {

   assert(SafepointSynchronize::is_at_safepoint(), "should only be called during a safepoint");

   CompiledICHolder* holder = _pending_released;

   _pending_released = NULL;

   while (holder != NULL) {

     CompiledICHolder* next = holder->next();

     delete holder;

     holder = next;

     _pending_count--;

   }

   assert(_pending_count == 0, "wrong count");

 }

 // Enqueue this icholder for release during the next safepoint.  It's

 // not safe to free them until them since they might be visible to

 // another thread.

 void InlineCacheBuffer::queue_for_release(CompiledICHolder* icholder) {

   MutexLockerEx mex(InlineCacheBuffer_lock);

   icholder->set_next(_pending_released);

   _pending_released = icholder;

   _pending_count++;

   if (TraceICBuffer) {

     tty->print_cr("enqueueing icholder " INTPTR_FORMAT " to be freed", icholder);

   }

 }