https://github.com/mozilla/gecko-dev
Tip revision: f121ca1ea1bc090de53d5b39fcfe0afb02c360e6 authored by Aki Sasaki on 28 April 2014, 19:28:13 UTC
tagging B2G_1_1_0_hd for mergeday. r=a=mergeday DONTBUILD
tagging B2G_1_1_0_hd for mergeday. r=a=mergeday DONTBUILD
Tip revision: f121ca1
Memory.cpp
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=8 sw=4 et tw=78:
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "mozilla/Assertions.h"
#include "jstypes.h"
#include "js/Utility.h"
#include "gc/Memory.h"
namespace js {
namespace gc {
/* Unused memory decommiting requires the arena size match the page size. */
extern const size_t PageSize;
extern const size_t ArenaSize;
static bool
DecommitEnabled()
{
return PageSize == ArenaSize;
}
#if defined(XP_WIN)
#include "jswin.h"
#include <psapi.h>
static size_t AllocationGranularity = 0;
void
InitMemorySubsystem()
{
SYSTEM_INFO sysinfo;
GetSystemInfo(&sysinfo);
if (sysinfo.dwPageSize != PageSize) {
fprintf(stderr,"SpiderMonkey compiled with incorrect page size; please update js/src/gc/Heap.h.\n");
MOZ_CRASH();
}
AllocationGranularity = sysinfo.dwAllocationGranularity;
}
void *
MapAlignedPages(size_t size, size_t alignment)
{
JS_ASSERT(size >= alignment);
JS_ASSERT(size % alignment == 0);
JS_ASSERT(size % PageSize == 0);
JS_ASSERT(alignment % AllocationGranularity == 0);
/* Special case: If we want allocation alignment, no further work is needed. */
if (alignment == AllocationGranularity) {
return VirtualAlloc(NULL, size, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
}
/*
* Windows requires that there be a 1:1 mapping between VM allocation
* and deallocation operations. Therefore, take care here to acquire the
* final result via one mapping operation. This means unmapping any
* preliminary result that is not correctly aligned.
*/
void *p = NULL;
while (!p) {
/*
* Over-allocate in order to map a memory region that is
* definitely large enough then deallocate and allocate again the
* correct sizee, within the over-sized mapping.
*
* Since we're going to unmap the whole thing anyway, the first
* mapping doesn't have to commit pages.
*/
p = VirtualAlloc(NULL, size * 2, MEM_RESERVE, PAGE_READWRITE);
if (!p)
return NULL;
void *chunkStart = (void *)(uintptr_t(p) + (alignment - (uintptr_t(p) % alignment)));
UnmapPages(p, size * 2);
p = VirtualAlloc(chunkStart, size, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
/* Failure here indicates a race with another thread, so try again. */
}
JS_ASSERT(uintptr_t(p) % alignment == 0);
return p;
}
void
UnmapPages(void *p, size_t size)
{
JS_ALWAYS_TRUE(VirtualFree(p, 0, MEM_RELEASE));
}
bool
MarkPagesUnused(void *p, size_t size)
{
if (!DecommitEnabled())
return false;
JS_ASSERT(uintptr_t(p) % PageSize == 0);
LPVOID p2 = VirtualAlloc(p, size, MEM_RESET, PAGE_READWRITE);
return p2 == p;
}
bool
MarkPagesInUse(void *p, size_t size)
{
JS_ASSERT(uintptr_t(p) % PageSize == 0);
return true;
}
size_t
GetPageFaultCount()
{
PROCESS_MEMORY_COUNTERS pmc;
if (!GetProcessMemoryInfo(GetCurrentProcess(), &pmc, sizeof(pmc)))
return 0;
return pmc.PageFaultCount;
}
#elif defined(XP_OS2)
#define INCL_DOSMEMMGR
#include <os2.h>
#define JS_GC_HAS_MAP_ALIGN 1
#define OS2_MAX_RECURSIONS 16
void
InitMemorySubsystem()
{
}
void
UnmapPages(void *addr, size_t size)
{
if (!DosFreeMem(addr))
return;
/*
* If DosFreeMem() failed, 'addr' is probably part of an "expensive"
* allocation, so calculate the base address and try again.
*/
unsigned long cb = 2 * size;
unsigned long flags;
if (DosQueryMem(addr, &cb, &flags) || cb < size)
return;
uintptr_t base = reinterpret_cast<uintptr_t>(addr) - ((2 * size) - cb);
DosFreeMem(reinterpret_cast<void*>(base));
return;
}
static void *
MapAlignedPagesRecursively(size_t size, size_t alignment, int& recursions)
{
if (++recursions >= OS2_MAX_RECURSIONS)
return NULL;
void *tmp;
if (DosAllocMem(&tmp, size,
OBJ_ANY | PAG_COMMIT | PAG_READ | PAG_WRITE)) {
JS_ALWAYS_TRUE(DosAllocMem(&tmp, size,
PAG_COMMIT | PAG_READ | PAG_WRITE) == 0);
}
size_t offset = reinterpret_cast<uintptr_t>(tmp) & (alignment - 1);
if (!offset)
return tmp;
/*
* If there are 'filler' bytes of free space above 'tmp', free 'tmp',
* then reallocate it as a 'filler'-sized block; assuming we're not
* in a race with another thread, the next recursion should succeed.
*/
size_t filler = size + alignment - offset;
unsigned long cb = filler;
unsigned long flags = 0;
unsigned long rc = DosQueryMem(&(static_cast<char*>(tmp))[size],
&cb, &flags);
if (!rc && (flags & PAG_FREE) && cb >= filler) {
UnmapPages(tmp, 0);
if (DosAllocMem(&tmp, filler,
OBJ_ANY | PAG_COMMIT | PAG_READ | PAG_WRITE)) {
JS_ALWAYS_TRUE(DosAllocMem(&tmp, filler,
PAG_COMMIT | PAG_READ | PAG_WRITE) == 0);
}
}
void *p = MapAlignedPagesRecursively(size, alignment, recursions);
UnmapPages(tmp, 0);
return p;
}
void *
MapAlignedPages(size_t size, size_t alignment)
{
JS_ASSERT(size >= alignment);
JS_ASSERT(size % alignment == 0);
JS_ASSERT(size % PageSize == 0);
JS_ASSERT(alignment % PageSize == 0);
int recursions = -1;
/*
* Make up to OS2_MAX_RECURSIONS attempts to get an aligned block
* of the right size by recursively allocating blocks of unaligned
* free memory until only an aligned allocation is possible.
*/
void *p = MapAlignedPagesRecursively(size, alignment, recursions);
if (p)
return p;
/*
* If memory is heavily fragmented, the recursive strategy may fail;
* instead, use the "expensive" strategy: allocate twice as much
* as requested and return an aligned address within this block.
*/
if (DosAllocMem(&p, 2 * size,
OBJ_ANY | PAG_COMMIT | PAG_READ | PAG_WRITE)) {
JS_ALWAYS_TRUE(DosAllocMem(&p, 2 * size,
PAG_COMMIT | PAG_READ | PAG_WRITE) == 0);
}
uintptr_t addr = reinterpret_cast<uintptr_t>(p);
addr = (addr + (alignment - 1)) & ~(alignment - 1);
return reinterpret_cast<void *>(addr);
}
bool
MarkPagesUnused(void *p, size_t size)
{
JS_ASSERT(uintptr_t(p) % PageSize == 0);
return true;
}
bool
MarkPagesInUse(void *p, size_t size)
{
JS_ASSERT(uintptr_t(p) % PageSize == 0);
return true;
}
size_t
GetPageFaultCount()
{
return 0;
}
#elif defined(SOLARIS)
#include <sys/mman.h>
#include <unistd.h>
#ifndef MAP_NOSYNC
# define MAP_NOSYNC 0
#endif
void
InitMemorySubsystem()
{
}
void *
MapAlignedPages(size_t size, size_t alignment)
{
JS_ASSERT(size >= alignment);
JS_ASSERT(size % alignment == 0);
JS_ASSERT(size % PageSize == 0);
JS_ASSERT(alignment % PageSize == 0);
int prot = PROT_READ | PROT_WRITE;
int flags = MAP_PRIVATE | MAP_ANON | MAP_ALIGN | MAP_NOSYNC;
void *p = mmap((caddr_t)alignment, size, prot, flags, -1, 0);
if (p == MAP_FAILED)
return NULL;
return p;
}
void
UnmapPages(void *p, size_t size)
{
JS_ALWAYS_TRUE(0 == munmap((caddr_t)p, size));
}
bool
MarkPagesUnused(void *p, size_t size)
{
JS_ASSERT(uintptr_t(p) % PageSize == 0);
return true;
}
bool
MarkPagesInUse(void *p, size_t size)
{
JS_ASSERT(uintptr_t(p) % PageSize == 0);
return true;
}
size_t
GetPageFaultCount()
{
return 0;
}
#elif defined(XP_UNIX) || defined(XP_MACOSX) || defined(DARWIN)
#include <sys/mman.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <unistd.h>
void
InitMemorySubsystem()
{
if (size_t(sysconf(_SC_PAGESIZE)) != PageSize) {
fprintf(stderr,"SpiderMonkey compiled with incorrect page size; please update js/src/gc/Heap.h.\n");
MOZ_CRASH();
}
}
void *
MapAlignedPages(size_t size, size_t alignment)
{
JS_ASSERT(size >= alignment);
JS_ASSERT(size % alignment == 0);
JS_ASSERT(size % PageSize == 0);
JS_ASSERT(alignment % PageSize == 0);
int prot = PROT_READ | PROT_WRITE;
int flags = MAP_PRIVATE | MAP_ANON;
/* Special case: If we want page alignment, no further work is needed. */
if (alignment == PageSize) {
return mmap(NULL, size, prot, flags, -1, 0);
}
/* Overallocate and unmap the region's edges. */
size_t reqSize = Min(size + 2 * alignment, 2 * size);
void *region = mmap(NULL, reqSize, prot, flags, -1, 0);
if (region == MAP_FAILED)
return NULL;
uintptr_t regionEnd = uintptr_t(region) + reqSize;
uintptr_t offset = uintptr_t(region) % alignment;
JS_ASSERT(offset < reqSize - size);
void *front = (void *)(uintptr_t(region) + (alignment - offset));
void *end = (void *)(uintptr_t(front) + size);
if (front != region)
JS_ALWAYS_TRUE(0 == munmap(region, alignment - offset));
if (uintptr_t(end) != regionEnd)
JS_ALWAYS_TRUE(0 == munmap(end, regionEnd - uintptr_t(end)));
JS_ASSERT(uintptr_t(front) % alignment == 0);
return front;
}
void
UnmapPages(void *p, size_t size)
{
JS_ALWAYS_TRUE(0 == munmap(p, size));
}
bool
MarkPagesUnused(void *p, size_t size)
{
if (!DecommitEnabled())
return false;
JS_ASSERT(uintptr_t(p) % PageSize == 0);
int result = madvise(p, size, MADV_DONTNEED);
return result != -1;
}
bool
MarkPagesInUse(void *p, size_t size)
{
JS_ASSERT(uintptr_t(p) % PageSize == 0);
return true;
}
size_t
GetPageFaultCount()
{
struct rusage usage;
int err = getrusage(RUSAGE_SELF, &usage);
if (err)
return 0;
return usage.ru_minflt + usage.ru_majflt;
}
#else
#error "Memory mapping functions are not defined for your OS."
#endif
} /* namespace gc */
} /* namespace js */