Mercurial > hg > truffle
view src/share/vm/code/stubs.cpp @ 4877:c03e06373b47
Merge
author | stefank |
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date | Sat, 28 Jan 2012 01:15:34 -0800 |
parents | f95d63e2154a |
children | b31471cdc53e 8c5333c80cfd |
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/* * Copyright (c) 1997, 2010, 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/codeBlob.hpp" #include "code/stubs.hpp" #include "memory/allocation.inline.hpp" #include "oops/oop.inline.hpp" #include "runtime/mutexLocker.hpp" // Implementation of StubQueue // // Standard wrap-around queue implementation; the queue dimensions // are specified by the _queue_begin & _queue_end indices. The queue // can be in two states (transparent to the outside): // // a) contiguous state: all queue entries in one block (or empty) // // Queue: |...|XXXXXXX|...............| // ^0 ^begin ^end ^size = limit // |_______| // one block // // b) non-contiguous state: queue entries in two blocks // // Queue: |XXX|.......|XXXXXXX|.......| // ^0 ^end ^begin ^limit ^size // |___| |_______| // 1st block 2nd block // // In the non-contiguous state, the wrap-around point is // indicated via the _buffer_limit index since the last // queue entry may not fill up the queue completely in // which case we need to know where the 2nd block's end // is to do the proper wrap-around. When removing the // last entry of the 2nd block, _buffer_limit is reset // to _buffer_size. // // CAUTION: DO NOT MESS WITH THIS CODE IF YOU CANNOT PROVE // ITS CORRECTNESS! THIS CODE IS MORE SUBTLE THAN IT LOOKS! StubQueue::StubQueue(StubInterface* stub_interface, int buffer_size, Mutex* lock, const char* name) : _mutex(lock) { intptr_t size = round_to(buffer_size, 2*BytesPerWord); BufferBlob* blob = BufferBlob::create(name, size); if( blob == NULL) { vm_exit_out_of_memory(size, err_msg("CodeCache: no room for %s", name)); } _stub_interface = stub_interface; _buffer_size = blob->content_size(); _buffer_limit = blob->content_size(); _stub_buffer = blob->content_begin(); _queue_begin = 0; _queue_end = 0; _number_of_stubs = 0; register_queue(this); } StubQueue::~StubQueue() { // Note: Currently StubQueues are never destroyed so nothing needs to be done here. // If we want to implement the destructor, we need to release the BufferBlob // allocated in the constructor (i.e., we need to keep it around or look it // up via CodeCache::find_blob(...). Unimplemented(); } Stub* StubQueue::stub_containing(address pc) const { if (contains(pc)) { for (Stub* s = first(); s != NULL; s = next(s)) { if (stub_contains(s, pc)) return s; } } return NULL; } Stub* StubQueue::request_committed(int code_size) { Stub* s = request(code_size); if (s != NULL) commit(code_size); return s; } Stub* StubQueue::request(int requested_code_size) { assert(requested_code_size > 0, "requested_code_size must be > 0"); if (_mutex != NULL) _mutex->lock(); Stub* s = current_stub(); int requested_size = round_to(stub_code_size_to_size(requested_code_size), CodeEntryAlignment); if (requested_size <= available_space()) { if (is_contiguous()) { // Queue: |...|XXXXXXX|.............| // ^0 ^begin ^end ^size = limit assert(_buffer_limit == _buffer_size, "buffer must be fully usable"); if (_queue_end + requested_size <= _buffer_size) { // code fits in at the end => nothing to do stub_initialize(s, requested_size); return s; } else { // stub doesn't fit in at the queue end // => reduce buffer limit & wrap around assert(!is_empty(), "just checkin'"); _buffer_limit = _queue_end; _queue_end = 0; } } } if (requested_size <= available_space()) { assert(!is_contiguous(), "just checkin'"); assert(_buffer_limit <= _buffer_size, "queue invariant broken"); // Queue: |XXX|.......|XXXXXXX|.......| // ^0 ^end ^begin ^limit ^size s = current_stub(); stub_initialize(s, requested_size); return s; } // Not enough space left if (_mutex != NULL) _mutex->unlock(); return NULL; } void StubQueue::commit(int committed_code_size) { assert(committed_code_size > 0, "committed_code_size must be > 0"); int committed_size = round_to(stub_code_size_to_size(committed_code_size), CodeEntryAlignment); Stub* s = current_stub(); assert(committed_size <= stub_size(s), "committed size must not exceed requested size"); stub_initialize(s, committed_size); _queue_end += committed_size; _number_of_stubs++; if (_mutex != NULL) _mutex->unlock(); debug_only(stub_verify(s);) } void StubQueue::remove_first() { if (number_of_stubs() == 0) return; Stub* s = first(); debug_only(stub_verify(s);) stub_finalize(s); _queue_begin += stub_size(s); assert(_queue_begin <= _buffer_limit, "sanity check"); if (_queue_begin == _queue_end) { // buffer empty // => reset queue indices _queue_begin = 0; _queue_end = 0; _buffer_limit = _buffer_size; } else if (_queue_begin == _buffer_limit) { // buffer limit reached // => reset buffer limit & wrap around _buffer_limit = _buffer_size; _queue_begin = 0; } _number_of_stubs--; } void StubQueue::remove_first(int n) { int i = MIN2(n, number_of_stubs()); while (i-- > 0) remove_first(); } void StubQueue::remove_all(){ debug_only(verify();) remove_first(number_of_stubs()); assert(number_of_stubs() == 0, "sanity check"); } enum { StubQueueLimit = 10 }; // there are only a few in the world static StubQueue* registered_stub_queues[StubQueueLimit]; void StubQueue::register_queue(StubQueue* sq) { for (int i = 0; i < StubQueueLimit; i++) { if (registered_stub_queues[i] == NULL) { registered_stub_queues[i] = sq; return; } } ShouldNotReachHere(); } void StubQueue::queues_do(void f(StubQueue* sq)) { for (int i = 0; i < StubQueueLimit; i++) { if (registered_stub_queues[i] != NULL) { f(registered_stub_queues[i]); } } } void StubQueue::stubs_do(void f(Stub* s)) { debug_only(verify();) MutexLockerEx lock(_mutex); for (Stub* s = first(); s != NULL; s = next(s)) f(s); } void StubQueue::verify() { // verify only if initialized if (_stub_buffer == NULL) return; MutexLockerEx lock(_mutex); // verify index boundaries guarantee(0 <= _buffer_size, "buffer size must be positive"); guarantee(0 <= _buffer_limit && _buffer_limit <= _buffer_size , "_buffer_limit out of bounds"); guarantee(0 <= _queue_begin && _queue_begin < _buffer_limit, "_queue_begin out of bounds"); guarantee(0 <= _queue_end && _queue_end <= _buffer_limit, "_queue_end out of bounds"); // verify alignment guarantee(_buffer_size % CodeEntryAlignment == 0, "_buffer_size not aligned"); guarantee(_buffer_limit % CodeEntryAlignment == 0, "_buffer_limit not aligned"); guarantee(_queue_begin % CodeEntryAlignment == 0, "_queue_begin not aligned"); guarantee(_queue_end % CodeEntryAlignment == 0, "_queue_end not aligned"); // verify buffer limit/size relationship if (is_contiguous()) { guarantee(_buffer_limit == _buffer_size, "_buffer_limit must equal _buffer_size"); } // verify contents int n = 0; for (Stub* s = first(); s != NULL; s = next(s)) { stub_verify(s); n++; } guarantee(n == number_of_stubs(), "number of stubs inconsistent"); guarantee(_queue_begin != _queue_end || n == 0, "buffer indices must be the same"); } void StubQueue::print() { MutexLockerEx lock(_mutex); for (Stub* s = first(); s != NULL; s = next(s)) { stub_print(s); } }