// Copyright 2012 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * 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.
// * Neither the name of Google Inc. 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 THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT
// OWNER OR 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.
// Platform specific code for Cygwin goes here. For the POSIX comaptible parts
// the implementation is in platform-posix.cc.
#include <errno.h>
#include <pthread.h>
#include <semaphore.h>
#include <stdarg.h>
#include <strings.h> // index
#include <sys/time.h>
#include <sys/mman.h> // mmap & munmap
#include <unistd.h> // sysconf
#undef MAP_TYPE
#include "v8.h"
#include "platform-posix.h"
#include "platform.h"
#include "v8threads.h"
#include "vm-state-inl.h"
#include "win32-headers.h"
namespace v8 {
namespace internal {
// 0 is never a valid thread id
static const pthread_t kNoThread = (pthread_t) 0;
double ceiling(double x) {
return ceil(x);
}
static Mutex* limit_mutex = NULL;
void OS::SetUp() {
// Seed the random number generator.
// Convert the current time to a 64-bit integer first, before converting it
// to an unsigned. Going directly can cause an overflow and the seed to be
// set to all ones. The seed will be identical for different instances that
// call this setup code within the same millisecond.
uint64_t seed = static_cast<uint64_t>(TimeCurrentMillis());
srandom(static_cast<unsigned int>(seed));
limit_mutex = CreateMutex();
}
void OS::PostSetUp() {
// Math functions depend on CPU features therefore they are initialized after
// CPU.
MathSetup();
}
uint64_t OS::CpuFeaturesImpliedByPlatform() {
return 0; // Nothing special about Cygwin.
}
int OS::ActivationFrameAlignment() {
// With gcc 4.4 the tree vectorization optimizer can generate code
// that requires 16 byte alignment such as movdqa on x86.
return 16;
}
void OS::ReleaseStore(volatile AtomicWord* ptr, AtomicWord value) {
__asm__ __volatile__("" : : : "memory");
// An x86 store acts as a release barrier.
*ptr = value;
}
const char* OS::LocalTimezone(double time) {
if (isnan(time)) return "";
time_t tv = static_cast<time_t>(floor(time/msPerSecond));
struct tm* t = localtime(&tv);
if (NULL == t) return "";
return tzname[0]; // The location of the timezone string on Cygwin.
}
double OS::LocalTimeOffset() {
// On Cygwin, struct tm does not contain a tm_gmtoff field.
time_t utc = time(NULL);
ASSERT(utc != -1);
struct tm* loc = localtime(&utc);
ASSERT(loc != NULL);
// time - localtime includes any daylight savings offset, so subtract it.
return static_cast<double>((mktime(loc) - utc) * msPerSecond -
(loc->tm_isdst > 0 ? 3600 * msPerSecond : 0));
}
// We keep the lowest and highest addresses mapped as a quick way of
// determining that pointers are outside the heap (used mostly in assertions
// and verification). The estimate is conservative, i.e., not all addresses in
// 'allocated' space are actually allocated to our heap. The range is
// [lowest, highest), inclusive on the low and and exclusive on the high end.
static void* lowest_ever_allocated = reinterpret_cast<void*>(-1);
static void* highest_ever_allocated = reinterpret_cast<void*>(0);
static void UpdateAllocatedSpaceLimits(void* address, int size) {
ASSERT(limit_mutex != NULL);
ScopedLock lock(limit_mutex);
lowest_ever_allocated = Min(lowest_ever_allocated, address);
highest_ever_allocated =
Max(highest_ever_allocated,
reinterpret_cast<void*>(reinterpret_cast<char*>(address) + size));
}
bool OS::IsOutsideAllocatedSpace(void* address) {
return address < lowest_ever_allocated || address >= highest_ever_allocated;
}
size_t OS::AllocateAlignment() {
return sysconf(_SC_PAGESIZE);
}
void* OS::Allocate(const size_t requested,
size_t* allocated,
bool is_executable) {
const size_t msize = RoundUp(requested, sysconf(_SC_PAGESIZE));
int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0);
void* mbase = mmap(NULL, msize, prot, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (mbase == MAP_FAILED) {
LOG(ISOLATE, StringEvent("OS::Allocate", "mmap failed"));
return NULL;
}
*allocated = msize;
UpdateAllocatedSpaceLimits(mbase, msize);
return mbase;
}
void OS::Free(void* address, const size_t size) {
// TODO(1240712): munmap has a return value which is ignored here.
int result = munmap(address, size);
USE(result);
ASSERT(result == 0);
}
void OS::ProtectCode(void* address, const size_t size) {
DWORD old_protect;
VirtualProtect(address, size, PAGE_EXECUTE_READ, &old_protect);
}
void OS::Guard(void* address, const size_t size) {
DWORD oldprotect;
VirtualProtect(address, size, PAGE_READONLY | PAGE_GUARD, &oldprotect);
}
void OS::Sleep(int milliseconds) {
unsigned int ms = static_cast<unsigned int>(milliseconds);
usleep(1000 * ms);
}
void OS::Abort() {
// Redirect to std abort to signal abnormal program termination.
abort();
}
void OS::DebugBreak() {
asm("int $3");
}
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(0, 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(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fileno(file), 0);
return new PosixMemoryMappedFile(file, memory, size);
}
PosixMemoryMappedFile::~PosixMemoryMappedFile() {
if (memory_) munmap(memory_, size_);
fclose(file_);
}
void OS::LogSharedLibraryAddresses() {
// This function assumes that the layout of the file is as follows:
// hex_start_addr-hex_end_addr rwxp <unused data> [binary_file_name]
// If we encounter an unexpected situation we abort scanning further entries.
FILE* fp = fopen("/proc/self/maps", "r");
if (fp == NULL) return;
// Allocate enough room to be able to store a full file name.
const int kLibNameLen = FILENAME_MAX + 1;
char* lib_name = reinterpret_cast<char*>(malloc(kLibNameLen));
i::Isolate* isolate = ISOLATE;
// This loop will terminate once the scanning hits an EOF.
while (true) {
uintptr_t start, end;
char attr_r, attr_w, attr_x, attr_p;
// Parse the addresses and permission bits at the beginning of the line.
if (fscanf(fp, "%" V8PRIxPTR "-%" V8PRIxPTR, &start, &end) != 2) break;
if (fscanf(fp, " %c%c%c%c", &attr_r, &attr_w, &attr_x, &attr_p) != 4) break;
int c;
if (attr_r == 'r' && attr_w != 'w' && attr_x == 'x') {
// Found a read-only executable entry. Skip characters until we reach
// the beginning of the filename or the end of the line.
do {
c = getc(fp);
} while ((c != EOF) && (c != '\n') && (c != '/'));
if (c == EOF) break; // EOF: Was unexpected, just exit.
// Process the filename if found.
if (c == '/') {
ungetc(c, fp); // Push the '/' back into the stream to be read below.
// Read to the end of the line. Exit if the read fails.
if (fgets(lib_name, kLibNameLen, fp) == NULL) break;
// Drop the newline character read by fgets. We do not need to check
// for a zero-length string because we know that we at least read the
// '/' character.
lib_name[strlen(lib_name) - 1] = '\0';
} else {
// No library name found, just record the raw address range.
snprintf(lib_name, kLibNameLen,
"%08" V8PRIxPTR "-%08" V8PRIxPTR, start, end);
}
LOG(isolate, SharedLibraryEvent(lib_name, start, end));
} else {
// Entry not describing executable data. Skip to end of line to set up
// reading the next entry.
do {
c = getc(fp);
} while ((c != EOF) && (c != '\n'));
if (c == EOF) break;
}
}
free(lib_name);
fclose(fp);
}
void OS::SignalCodeMovingGC() {
// Nothing to do on Cygwin.
}
int OS::StackWalk(Vector<OS::StackFrame> frames) {
// Not supported on Cygwin.
return 0;
}
// The VirtualMemory implementation is taken from platform-win32.cc.
// The mmap-based virtual memory implementation as it is used on most posix
// platforms does not work well because Cygwin does not support MAP_FIXED.
// This causes VirtualMemory::Commit to not always commit the memory region
// specified.
bool VirtualMemory::IsReserved() {
return address_ != NULL;
}
VirtualMemory::VirtualMemory(size_t size) {
address_ = VirtualAlloc(NULL, size, MEM_RESERVE, PAGE_NOACCESS);
size_ = size;
}
VirtualMemory::~VirtualMemory() {
if (IsReserved()) {
if (0 == VirtualFree(address(), 0, MEM_RELEASE)) address_ = NULL;
}
}
bool VirtualMemory::Commit(void* address, size_t size, bool is_executable) {
int prot = is_executable ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE;
if (NULL == VirtualAlloc(address, size, MEM_COMMIT, prot)) {
return false;
}
UpdateAllocatedSpaceLimits(address, static_cast<int>(size));
return true;
}
bool VirtualMemory::Uncommit(void* address, size_t size) {
ASSERT(IsReserved());
return VirtualFree(address, size, MEM_DECOMMIT) != false;
}
bool VirtualMemory::Guard(void* address) {
if (NULL == VirtualAlloc(address,
OS::CommitPageSize(),
MEM_COMMIT,
PAGE_READONLY | PAGE_GUARD)) {
return false;
}
return true;
}
class Thread::PlatformData : public Malloced {
public:
PlatformData() : thread_(kNoThread) {}
pthread_t thread_; // Thread handle for pthread.
};
Thread::Thread(const Options& options)
: data_(new PlatformData()),
stack_size_(options.stack_size()) {
set_name(options.name());
}
Thread::~Thread() {
delete data_;
}
static void* ThreadEntry(void* arg) {
Thread* thread = reinterpret_cast<Thread*>(arg);
// This is also initialized by the first argument to pthread_create() but we
// don't know which thread will run first (the original thread or the new
// one) so we initialize it here too.
thread->data()->thread_ = pthread_self();
ASSERT(thread->data()->thread_ != kNoThread);
thread->Run();
return NULL;
}
void Thread::set_name(const char* name) {
strncpy(name_, name, sizeof(name_));
name_[sizeof(name_) - 1] = '\0';
}
void Thread::Start() {
pthread_attr_t* attr_ptr = NULL;
pthread_attr_t attr;
if (stack_size_ > 0) {
pthread_attr_init(&attr);
pthread_attr_setstacksize(&attr, static_cast<size_t>(stack_size_));
attr_ptr = &attr;
}
pthread_create(&data_->thread_, attr_ptr, ThreadEntry, this);
ASSERT(data_->thread_ != kNoThread);
}
void Thread::Join() {
pthread_join(data_->thread_, NULL);
}
static inline Thread::LocalStorageKey PthreadKeyToLocalKey(
pthread_key_t pthread_key) {
// We need to cast pthread_key_t to Thread::LocalStorageKey in two steps
// because pthread_key_t is a pointer type on Cygwin. This will probably not
// work on 64-bit platforms, but Cygwin doesn't support 64-bit anyway.
STATIC_ASSERT(sizeof(Thread::LocalStorageKey) == sizeof(pthread_key_t));
intptr_t ptr_key = reinterpret_cast<intptr_t>(pthread_key);
return static_cast<Thread::LocalStorageKey>(ptr_key);
}
static inline pthread_key_t LocalKeyToPthreadKey(
Thread::LocalStorageKey local_key) {
STATIC_ASSERT(sizeof(Thread::LocalStorageKey) == sizeof(pthread_key_t));
intptr_t ptr_key = static_cast<intptr_t>(local_key);
return reinterpret_cast<pthread_key_t>(ptr_key);
}
Thread::LocalStorageKey Thread::CreateThreadLocalKey() {
pthread_key_t key;
int result = pthread_key_create(&key, NULL);
USE(result);
ASSERT(result == 0);
return PthreadKeyToLocalKey(key);
}
void Thread::DeleteThreadLocalKey(LocalStorageKey key) {
pthread_key_t pthread_key = LocalKeyToPthreadKey(key);
int result = pthread_key_delete(pthread_key);
USE(result);
ASSERT(result == 0);
}
void* Thread::GetThreadLocal(LocalStorageKey key) {
pthread_key_t pthread_key = LocalKeyToPthreadKey(key);
return pthread_getspecific(pthread_key);
}
void Thread::SetThreadLocal(LocalStorageKey key, void* value) {
pthread_key_t pthread_key = LocalKeyToPthreadKey(key);
pthread_setspecific(pthread_key, value);
}
void Thread::YieldCPU() {
sched_yield();
}
class CygwinMutex : public Mutex {
public:
CygwinMutex() {
pthread_mutexattr_t attrs;
memset(&attrs, 0, sizeof(attrs));
int result = pthread_mutexattr_init(&attrs);
ASSERT(result == 0);
result = pthread_mutexattr_settype(&attrs, PTHREAD_MUTEX_RECURSIVE);
ASSERT(result == 0);
result = pthread_mutex_init(&mutex_, &attrs);
ASSERT(result == 0);
}
virtual ~CygwinMutex() { pthread_mutex_destroy(&mutex_); }
virtual int Lock() {
int result = pthread_mutex_lock(&mutex_);
return result;
}
virtual int Unlock() {
int result = pthread_mutex_unlock(&mutex_);
return result;
}
virtual bool TryLock() {
int result = pthread_mutex_trylock(&mutex_);
// Return false if the lock is busy and locking failed.
if (result == EBUSY) {
return false;
}
ASSERT(result == 0); // Verify no other errors.
return true;
}
private:
pthread_mutex_t mutex_; // Pthread mutex for POSIX platforms.
};
Mutex* OS::CreateMutex() {
return new CygwinMutex();
}
class CygwinSemaphore : public Semaphore {
public:
explicit CygwinSemaphore(int count) { sem_init(&sem_, 0, count); }
virtual ~CygwinSemaphore() { sem_destroy(&sem_); }
virtual void Wait();
virtual bool Wait(int timeout);
virtual void Signal() { sem_post(&sem_); }
private:
sem_t sem_;
};
void CygwinSemaphore::Wait() {
while (true) {
int result = sem_wait(&sem_);
if (result == 0) return; // Successfully got semaphore.
CHECK(result == -1 && errno == EINTR); // Signal caused spurious wakeup.
}
}
#ifndef TIMEVAL_TO_TIMESPEC
#define TIMEVAL_TO_TIMESPEC(tv, ts) do { \
(ts)->tv_sec = (tv)->tv_sec; \
(ts)->tv_nsec = (tv)->tv_usec * 1000; \
} while (false)
#endif
bool CygwinSemaphore::Wait(int timeout) {
const long kOneSecondMicros = 1000000; // NOLINT
// Split timeout into second and nanosecond parts.
struct timeval delta;
delta.tv_usec = timeout % kOneSecondMicros;
delta.tv_sec = timeout / kOneSecondMicros;
struct timeval current_time;
// Get the current time.
if (gettimeofday(¤t_time, NULL) == -1) {
return false;
}
// Calculate time for end of timeout.
struct timeval end_time;
timeradd(¤t_time, &delta, &end_time);
struct timespec ts;
TIMEVAL_TO_TIMESPEC(&end_time, &ts);
// Wait for semaphore signalled or timeout.
while (true) {
int result = sem_timedwait(&sem_, &ts);
if (result == 0) return true; // Successfully got semaphore.
if (result == -1 && errno == ETIMEDOUT) return false; // Timeout.
CHECK(result == -1 && errno == EINTR); // Signal caused spurious wakeup.
}
}
Semaphore* OS::CreateSemaphore(int count) {
return new CygwinSemaphore(count);
}
// ----------------------------------------------------------------------------
// Cygwin profiler support.
//
// On Cygwin we use the same sampler implementation as on win32.
class Sampler::PlatformData : public Malloced {
public:
// Get a handle to the calling thread. This is the thread that we are
// going to profile. We need to make a copy of the handle because we are
// going to use it in the sampler thread. Using GetThreadHandle() will
// not work in this case. We're using OpenThread because DuplicateHandle
// for some reason doesn't work in Chrome's sandbox.
PlatformData() : profiled_thread_(OpenThread(THREAD_GET_CONTEXT |
THREAD_SUSPEND_RESUME |
THREAD_QUERY_INFORMATION,
false,
GetCurrentThreadId())) {}
~PlatformData() {
if (profiled_thread_ != NULL) {
CloseHandle(profiled_thread_);
profiled_thread_ = NULL;
}
}
HANDLE profiled_thread() { return profiled_thread_; }
private:
HANDLE profiled_thread_;
};
class SamplerThread : public Thread {
public:
static const int kSamplerThreadStackSize = 64 * KB;
explicit SamplerThread(int interval)
: Thread(Thread::Options("SamplerThread", kSamplerThreadStackSize)),
interval_(interval) {}
static void AddActiveSampler(Sampler* sampler) {
ScopedLock lock(mutex_.Pointer());
SamplerRegistry::AddActiveSampler(sampler);
if (instance_ == NULL) {
instance_ = new SamplerThread(sampler->interval());
instance_->Start();
} else {
ASSERT(instance_->interval_ == sampler->interval());
}
}
static void RemoveActiveSampler(Sampler* sampler) {
ScopedLock lock(mutex_.Pointer());
SamplerRegistry::RemoveActiveSampler(sampler);
if (SamplerRegistry::GetState() == SamplerRegistry::HAS_NO_SAMPLERS) {
RuntimeProfiler::StopRuntimeProfilerThreadBeforeShutdown(instance_);
delete instance_;
instance_ = NULL;
}
}
// Implement Thread::Run().
virtual void Run() {
SamplerRegistry::State state;
while ((state = SamplerRegistry::GetState()) !=
SamplerRegistry::HAS_NO_SAMPLERS) {
bool cpu_profiling_enabled =
(state == SamplerRegistry::HAS_CPU_PROFILING_SAMPLERS);
bool runtime_profiler_enabled = RuntimeProfiler::IsEnabled();
// When CPU profiling is enabled both JavaScript and C++ code is
// profiled. We must not suspend.
if (!cpu_profiling_enabled) {
if (rate_limiter_.SuspendIfNecessary()) continue;
}
if (cpu_profiling_enabled) {
if (!SamplerRegistry::IterateActiveSamplers(&DoCpuProfile, this)) {
return;
}
}
if (runtime_profiler_enabled) {
if (!SamplerRegistry::IterateActiveSamplers(&DoRuntimeProfile, NULL)) {
return;
}
}
OS::Sleep(interval_);
}
}
static void DoCpuProfile(Sampler* sampler, void* raw_sampler_thread) {
if (!sampler->isolate()->IsInitialized()) return;
if (!sampler->IsProfiling()) return;
SamplerThread* sampler_thread =
reinterpret_cast<SamplerThread*>(raw_sampler_thread);
sampler_thread->SampleContext(sampler);
}
static void DoRuntimeProfile(Sampler* sampler, void* ignored) {
if (!sampler->isolate()->IsInitialized()) return;
sampler->isolate()->runtime_profiler()->NotifyTick();
}
void SampleContext(Sampler* sampler) {
HANDLE profiled_thread = sampler->platform_data()->profiled_thread();
if (profiled_thread == NULL) return;
// Context used for sampling the register state of the profiled thread.
CONTEXT context;
memset(&context, 0, sizeof(context));
TickSample sample_obj;
TickSample* sample = CpuProfiler::TickSampleEvent(sampler->isolate());
if (sample == NULL) sample = &sample_obj;
static const DWORD kSuspendFailed = static_cast<DWORD>(-1);
if (SuspendThread(profiled_thread) == kSuspendFailed) return;
sample->state = sampler->isolate()->current_vm_state();
context.ContextFlags = CONTEXT_FULL;
if (GetThreadContext(profiled_thread, &context) != 0) {
#if V8_HOST_ARCH_X64
sample->pc = reinterpret_cast<Address>(context.Rip);
sample->sp = reinterpret_cast<Address>(context.Rsp);
sample->fp = reinterpret_cast<Address>(context.Rbp);
#else
sample->pc = reinterpret_cast<Address>(context.Eip);
sample->sp = reinterpret_cast<Address>(context.Esp);
sample->fp = reinterpret_cast<Address>(context.Ebp);
#endif
sampler->SampleStack(sample);
sampler->Tick(sample);
}
ResumeThread(profiled_thread);
}
const int interval_;
RuntimeProfilerRateLimiter rate_limiter_;
// Protects the process wide state below.
static LazyMutex mutex_;
static SamplerThread* instance_;
private:
DISALLOW_COPY_AND_ASSIGN(SamplerThread);
};
LazyMutex SamplerThread::mutex_ = LAZY_MUTEX_INITIALIZER;
SamplerThread* SamplerThread::instance_ = NULL;
Sampler::Sampler(Isolate* isolate, int interval)
: isolate_(isolate),
interval_(interval),
profiling_(false),
active_(false),
samples_taken_(0) {
data_ = new PlatformData;
}
Sampler::~Sampler() {
ASSERT(!IsActive());
delete data_;
}
void Sampler::Start() {
ASSERT(!IsActive());
SetActive(true);
SamplerThread::AddActiveSampler(this);
}
void Sampler::Stop() {
ASSERT(IsActive());
SamplerThread::RemoveActiveSampler(this);
SetActive(false);
}
} } // namespace v8::internal