deps/v8/src/base/platform/platform-macos.cc
// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Platform-specific code for MacOS goes here. For the POSIX-compatible
// parts, the implementation is in platform-posix.cc.
#include <dlfcn.h>
#include <mach/mach_init.h>
#include <mach-o/dyld.h>
#include <mach-o/getsect.h>
#include <sys/mman.h>
#include <unistd.h>
#include <AvailabilityMacros.h>
#include <errno.h>
#include <libkern/OSAtomic.h>
#include <mach/mach.h>
#include <mach/semaphore.h>
#include <mach/task.h>
#include <mach/vm_statistics.h>
#include <pthread.h>
#include <semaphore.h>
#include <signal.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <sys/resource.h>
#include <sys/sysctl.h>
#include <sys/time.h>
#include <sys/types.h>
#include <cmath>
#undef MAP_TYPE
#include "src/base/macros.h"
#include "src/base/platform/platform.h"
namespace v8 {
namespace base {
// Constants used for mmap.
// kMmapFd is used to pass vm_alloc flags to tag the region with the user
// defined tag 255 This helps identify V8-allocated regions in memory analysis
// tools like vmmap(1).
static const int kMmapFd = VM_MAKE_TAG(255);
static const off_t kMmapFdOffset = 0;
void* OS::Allocate(const size_t requested,
size_t* allocated,
bool is_executable) {
const size_t msize = RoundUp(requested, getpagesize());
int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0);
void* mbase = mmap(OS::GetRandomMmapAddr(),
msize,
prot,
MAP_PRIVATE | MAP_ANON,
kMmapFd,
kMmapFdOffset);
if (mbase == MAP_FAILED) return NULL;
*allocated = msize;
return mbase;
}
class PosixMemoryMappedFile : public OS::MemoryMappedFile {
public:
PosixMemoryMappedFile(FILE* file, void* memory, int size)
: file_(file), memory_(memory), size_(size) { }
virtual ~PosixMemoryMappedFile();
virtual void* memory() { return memory_; }
virtual int size() { return size_; }
private:
FILE* file_;
void* memory_;
int size_;
};
OS::MemoryMappedFile* OS::MemoryMappedFile::open(const char* name) {
FILE* file = fopen(name, "r+");
if (file == NULL) return NULL;
fseek(file, 0, SEEK_END);
int size = ftell(file);
void* memory =
mmap(OS::GetRandomMmapAddr(),
size,
PROT_READ | PROT_WRITE,
MAP_SHARED,
fileno(file),
0);
return new PosixMemoryMappedFile(file, memory, size);
}
OS::MemoryMappedFile* OS::MemoryMappedFile::create(const char* name, int size,
void* initial) {
FILE* file = fopen(name, "w+");
if (file == NULL) return NULL;
int result = fwrite(initial, size, 1, file);
if (result < 1) {
fclose(file);
return NULL;
}
void* memory =
mmap(OS::GetRandomMmapAddr(),
size,
PROT_READ | PROT_WRITE,
MAP_SHARED,
fileno(file),
0);
return new PosixMemoryMappedFile(file, memory, size);
}
PosixMemoryMappedFile::~PosixMemoryMappedFile() {
if (memory_) OS::Free(memory_, size_);
fclose(file_);
}
std::vector<OS::SharedLibraryAddress> OS::GetSharedLibraryAddresses() {
std::vector<SharedLibraryAddress> result;
unsigned int images_count = _dyld_image_count();
for (unsigned int i = 0; i < images_count; ++i) {
const mach_header* header = _dyld_get_image_header(i);
if (header == NULL) continue;
#if V8_HOST_ARCH_X64
uint64_t size;
char* code_ptr = getsectdatafromheader_64(
reinterpret_cast<const mach_header_64*>(header),
SEG_TEXT,
SECT_TEXT,
&size);
#else
unsigned int size;
char* code_ptr = getsectdatafromheader(header, SEG_TEXT, SECT_TEXT, &size);
#endif
if (code_ptr == NULL) continue;
const uintptr_t slide = _dyld_get_image_vmaddr_slide(i);
const uintptr_t start = reinterpret_cast<uintptr_t>(code_ptr) + slide;
result.push_back(
SharedLibraryAddress(_dyld_get_image_name(i), start, start + size));
}
return result;
}
void OS::SignalCodeMovingGC() {
}
const char* OS::LocalTimezone(double time, TimezoneCache* cache) {
if (std::isnan(time)) return "";
time_t tv = static_cast<time_t>(std::floor(time/msPerSecond));
struct tm* t = localtime(&tv);
if (NULL == t) return "";
return t->tm_zone;
}
double OS::LocalTimeOffset(TimezoneCache* cache) {
time_t tv = time(NULL);
struct tm* t = localtime(&tv);
// tm_gmtoff includes any daylight savings offset, so subtract it.
return static_cast<double>(t->tm_gmtoff * msPerSecond -
(t->tm_isdst > 0 ? 3600 * msPerSecond : 0));
}
VirtualMemory::VirtualMemory() : address_(NULL), size_(0) { }
VirtualMemory::VirtualMemory(size_t size)
: address_(ReserveRegion(size)), size_(size) { }
VirtualMemory::VirtualMemory(size_t size, size_t alignment)
: address_(NULL), size_(0) {
DCHECK(IsAligned(alignment, static_cast<intptr_t>(OS::AllocateAlignment())));
size_t request_size = RoundUp(size + alignment,
static_cast<intptr_t>(OS::AllocateAlignment()));
void* reservation = mmap(OS::GetRandomMmapAddr(),
request_size,
PROT_NONE,
MAP_PRIVATE | MAP_ANON | MAP_NORESERVE,
kMmapFd,
kMmapFdOffset);
if (reservation == MAP_FAILED) return;
uint8_t* base = static_cast<uint8_t*>(reservation);
uint8_t* aligned_base = RoundUp(base, alignment);
DCHECK_LE(base, aligned_base);
// Unmap extra memory reserved before and after the desired block.
if (aligned_base != base) {
size_t prefix_size = static_cast<size_t>(aligned_base - base);
OS::Free(base, prefix_size);
request_size -= prefix_size;
}
size_t aligned_size = RoundUp(size, OS::AllocateAlignment());
DCHECK_LE(aligned_size, request_size);
if (aligned_size != request_size) {
size_t suffix_size = request_size - aligned_size;
OS::Free(aligned_base + aligned_size, suffix_size);
request_size -= suffix_size;
}
DCHECK(aligned_size == request_size);
address_ = static_cast<void*>(aligned_base);
size_ = aligned_size;
}
VirtualMemory::~VirtualMemory() {
if (IsReserved()) {
bool result = ReleaseRegion(address(), size());
DCHECK(result);
USE(result);
}
}
bool VirtualMemory::IsReserved() {
return address_ != NULL;
}
void VirtualMemory::Reset() {
address_ = NULL;
size_ = 0;
}
bool VirtualMemory::Commit(void* address, size_t size, bool is_executable) {
return CommitRegion(address, size, is_executable);
}
bool VirtualMemory::Uncommit(void* address, size_t size) {
return UncommitRegion(address, size);
}
bool VirtualMemory::Guard(void* address) {
OS::Guard(address, OS::CommitPageSize());
return true;
}
void* VirtualMemory::ReserveRegion(size_t size) {
void* result = mmap(OS::GetRandomMmapAddr(),
size,
PROT_NONE,
MAP_PRIVATE | MAP_ANON | MAP_NORESERVE,
kMmapFd,
kMmapFdOffset);
if (result == MAP_FAILED) return NULL;
return result;
}
bool VirtualMemory::CommitRegion(void* address,
size_t size,
bool is_executable) {
int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0);
if (MAP_FAILED == mmap(address,
size,
prot,
MAP_PRIVATE | MAP_ANON | MAP_FIXED,
kMmapFd,
kMmapFdOffset)) {
return false;
}
return true;
}
bool VirtualMemory::UncommitRegion(void* address, size_t size) {
return mmap(address,
size,
PROT_NONE,
MAP_PRIVATE | MAP_ANON | MAP_NORESERVE | MAP_FIXED,
kMmapFd,
kMmapFdOffset) != MAP_FAILED;
}
bool VirtualMemory::ReleaseRegion(void* address, size_t size) {
return munmap(address, size) == 0;
}
bool VirtualMemory::HasLazyCommits() {
return false;
}
} } // namespace v8::base