src/third_party/mozjs-45/js/src/jit/ExecutableAllocator.cpp

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
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 * Copyright (C) 2008 Apple Inc. All rights reserved.
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#include "jit/ExecutableAllocator.h"

#include "js/MemoryMetrics.h"

#ifdef __APPLE__
#include <TargetConditionals.h>
#endif

using namespace js::jit;

size_t ExecutableAllocator::pageSize = 0;
size_t ExecutableAllocator::largeAllocSize = 0;

ExecutablePool::~ExecutablePool()
{
    MOZ_ASSERT(m_ionCodeBytes == 0);
    MOZ_ASSERT(m_baselineCodeBytes == 0);
    MOZ_ASSERT(m_regexpCodeBytes == 0);
    MOZ_ASSERT(m_otherCodeBytes == 0);

    m_allocator->releasePoolPages(this);
}

/* static */ void
ExecutableAllocator::initStatic()
{
    if (!pageSize) {
        pageSize = determinePageSize();
        // On Windows, VirtualAlloc effectively allocates in 64K chunks.
        // (Technically, it allocates in page chunks, but the starting
        // address is always a multiple of 64K, so each allocation uses up
        // 64K of address space.)  So a size less than that would be
        // pointless.  But it turns out that 64KB is a reasonable size for
        // all platforms.  (This assumes 4KB pages.) On 64-bit windows,
        // AllocateExecutableMemory prepends an extra page for structured
        // exception handling data (see comments in function) onto whatever
        // is passed in, so subtract one page here.
#if defined(JS_CPU_X64) && defined(XP_WIN)
        largeAllocSize = pageSize * 15;
#else
        largeAllocSize = pageSize * 16;
#endif
    }
}

void
ExecutableAllocator::addSizeOfCode(JS::CodeSizes* sizes) const
{
    if (m_pools.initialized()) {
        for (ExecPoolHashSet::Range r = m_pools.all(); !r.empty(); r.popFront()) {
            ExecutablePool* pool = r.front();
            sizes->ion      += pool->m_ionCodeBytes;
            sizes->baseline += pool->m_baselineCodeBytes;
            sizes->regexp   += pool->m_regexpCodeBytes;
            sizes->other    += pool->m_otherCodeBytes;
            sizes->unused   += pool->m_allocation.size - pool->m_ionCodeBytes
                                                       - pool->m_baselineCodeBytes
                                                       - pool->m_regexpCodeBytes
                                                       - pool->m_otherCodeBytes;
        }
    }
}

#if defined(STARBOARD)

bool ExecutableAllocator::nonWritableJitCode = false;

#else

#if TARGET_OS_IPHONE
bool ExecutableAllocator::nonWritableJitCode = true;
#else
bool ExecutableAllocator::nonWritableJitCode = false;
#endif

#endif