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/*
* Copyright (C) 2008 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "JSStack.h"
#include "JSStackInlines.h"
#include "ConservativeRoots.h"
#include "Interpreter.h"
namespace JSC {
static size_t committedBytesCount = 0;
static Mutex& stackStatisticsMutex()
{
DEFINE_STATIC_LOCAL(Mutex, staticMutex, ());
return staticMutex;
}
JSStack::JSStack(VM& vm, size_t capacity)
: m_end(0)
, m_topCallFrame(vm.topCallFrame)
{
ASSERT(capacity && isPageAligned(capacity));
m_reservation = PageReservation::reserve(roundUpAllocationSize(capacity * sizeof(Register), commitSize), OSAllocator::JSVMStackPages);
m_end = static_cast<Register*>(m_reservation.base());
m_commitEnd = static_cast<Register*>(m_reservation.base());
disableErrorStackReserve();
m_topCallFrame = 0;
}
JSStack::~JSStack()
{
void* base = m_reservation.base();
m_reservation.decommit(base, reinterpret_cast<intptr_t>(m_commitEnd) - reinterpret_cast<intptr_t>(base));
addToCommittedByteCount(-(reinterpret_cast<intptr_t>(m_commitEnd) - reinterpret_cast<intptr_t>(base)));
m_reservation.deallocate();
}
bool JSStack::growSlowCase(Register* newEnd)
{
// If we have already committed enough memory to satisfy this request,
// just update the end pointer and return.
if (newEnd <= m_commitEnd) {
m_end = newEnd;
return true;
}
// Compute the chunk size of additional memory to commit, and see if we
// have it is still within our budget. If not, we'll fail to grow and
// return false.
long delta = roundUpAllocationSize(reinterpret_cast<char*>(newEnd) - reinterpret_cast<char*>(m_commitEnd), commitSize);
if (reinterpret_cast<char*>(m_commitEnd) + delta > reinterpret_cast<char*>(m_useableEnd))
return false;
// Otherwise, the growth is still within our budget. Go ahead and commit
// it and return true.
m_reservation.commit(m_commitEnd, delta);
addToCommittedByteCount(delta);
m_commitEnd = reinterpret_cast_ptr<Register*>(reinterpret_cast<char*>(m_commitEnd) + delta);
m_end = newEnd;
return true;
}
void JSStack::gatherConservativeRoots(ConservativeRoots& conservativeRoots)
{
conservativeRoots.add(begin(), getTopOfStack());
}
void JSStack::gatherConservativeRoots(ConservativeRoots& conservativeRoots, JITStubRoutineSet& jitStubRoutines, DFGCodeBlocks& dfgCodeBlocks)
{
conservativeRoots.add(begin(), getTopOfStack(), jitStubRoutines, dfgCodeBlocks);
}
void JSStack::releaseExcessCapacity()
{
ptrdiff_t delta = reinterpret_cast<uintptr_t>(m_commitEnd) - reinterpret_cast<uintptr_t>(m_reservation.base());
m_reservation.decommit(m_reservation.base(), delta);
addToCommittedByteCount(-delta);
m_commitEnd = static_cast<Register*>(m_reservation.base());
}
void JSStack::initializeThreading()
{
stackStatisticsMutex();
}
size_t JSStack::committedByteCount()
{
MutexLocker locker(stackStatisticsMutex());
return committedBytesCount;
}
void JSStack::addToCommittedByteCount(long byteCount)
{
MutexLocker locker(stackStatisticsMutex());
ASSERT(static_cast<long>(committedBytesCount) + byteCount > -1);
committedBytesCount += byteCount;
}
void JSStack::enableErrorStackReserve()
{
m_useableEnd = reservationEnd();
}
void JSStack::disableErrorStackReserve()
{
char* useableEnd = reinterpret_cast<char*>(reservationEnd()) - commitSize;
m_useableEnd = reinterpret_cast_ptr<Register*>(useableEnd);
// By the time we get here, we are guaranteed to be destructing the last
// Interpreter::ErrorHandlingMode that enabled this reserve in the first
// place. That means the stack space beyond m_useableEnd before we
// enabled the reserve was not previously in use. Hence, it is safe to
// shrink back to that m_useableEnd.
if (m_end > m_useableEnd) {
ASSERT(m_topCallFrame->frameExtent() <= m_useableEnd);
shrink(m_useableEnd);
}
}
} // namespace JSC
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