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// Copyright 2006-2008 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 <pthread.h>
#include <semaphore.h>
#include <signal.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/types.h>
#include <stdlib.h>
// Ubuntu Dapper requires memory pages to be marked as
// executable. Otherwise, OS raises an exception when executing code
// in that page.
#include <sys/types.h> // mmap & munmap
#include <sys/mman.h> // mmap & munmap
#include <sys/stat.h> // open
#include <fcntl.h> // open
#include <unistd.h> // sysconf
#ifdef __GLIBC__
#include <execinfo.h> // backtrace, backtrace_symbols
#endif // def __GLIBC__
#include <strings.h> // index
#include <errno.h>
#include <stdarg.h>
#undef MAP_TYPE
#include "v8.h"
#include "platform.h"
#include "top.h"
#include "v8threads.h"
#include "vm-state-inl.h"
namespace v8 {
namespace internal {
// 0 is never a valid thread id on Linux since tids and pids share a
// name space and pid 0 is reserved (see man 2 kill).
static const pthread_t kNoThread = (pthread_t) 0;
double ceiling(double x) {
return ceil(x);
}
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));
}
uint64_t OS::CpuFeaturesImpliedByPlatform() {
#if (defined(__VFP_FP__) && !defined(__SOFTFP__))
// Here gcc is telling us that we are on an ARM and gcc is assuming that we
// have VFP3 instructions. If gcc can assume it then so can we.
return 1u << VFP3;
#elif CAN_USE_ARMV7_INSTRUCTIONS
return 1u << ARMv7;
#else
return 0; // Linux runs on anything.
#endif
}
#ifdef __arm__
static bool CPUInfoContainsString(const char * search_string) {
const char* file_name = "/proc/cpuinfo";
// This is written as a straight shot one pass parser
// and not using STL string and ifstream because,
// on Linux, it's reading from a (non-mmap-able)
// character special device.
FILE* f = NULL;
const char* what = search_string;
if (NULL == (f = fopen(file_name, "r")))
return false;
int k;
while (EOF != (k = fgetc(f))) {
if (k == *what) {
++what;
while ((*what != '\0') && (*what == fgetc(f))) {
++what;
}
if (*what == '\0') {
fclose(f);
return true;
} else {
what = search_string;
}
}
}
fclose(f);
// Did not find string in the proc file.
return false;
}
bool OS::ArmCpuHasFeature(CpuFeature feature) {
const char* search_string = NULL;
// Simple detection of VFP at runtime for Linux.
// It is based on /proc/cpuinfo, which reveals hardware configuration
// to user-space applications. According to ARM (mid 2009), no similar
// facility is universally available on the ARM architectures,
// so it's up to individual OSes to provide such.
switch (feature) {
case VFP3:
search_string = "vfpv3";
break;
case ARMv7:
search_string = "ARMv7";
break;
default:
UNREACHABLE();
}
if (CPUInfoContainsString(search_string)) {
return true;
}
if (feature == VFP3) {
// Some old kernels will report vfp not vfpv3. Here we make a last attempt
// to detect vfpv3 by checking for vfp *and* neon, since neon is only
// available on architectures with vfpv3.
// Checking neon on its own is not enough as it is possible to have neon
// without vfp.
if (CPUInfoContainsString("vfp") && CPUInfoContainsString("neon")) {
return true;
}
}
return false;
}
#endif // def __arm__
int OS::ActivationFrameAlignment() {
#ifdef V8_TARGET_ARCH_ARM
// On EABI ARM targets this is required for fp correctness in the
// runtime system.
return 8;
#elif V8_TARGET_ARCH_MIPS
return 8;
#endif
// 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 Cywin.
}
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);
return static_cast<double>((mktime(loc) - utc) * msPerSecond);
}
// 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, ie, 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) {
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(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);
}
#ifdef ENABLE_HEAP_PROTECTION
void OS::Protect(void* address, size_t size) {
// TODO(1240712): mprotect has a return value which is ignored here.
mprotect(address, size, PROT_READ);
}
void OS::Unprotect(void* address, size_t size, bool is_executable) {
// TODO(1240712): mprotect has a return value which is ignored here.
int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0);
mprotect(address, size, prot);
}
#endif
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() {
// TODO(lrn): Introduce processor define for runtime system (!= V8_ARCH_x,
// which is the architecture of generated code).
#if (defined(__arm__) || defined(__thumb__)) && \
defined(CAN_USE_ARMV5_INSTRUCTIONS)
asm("bkpt 0");
#elif defined(__mips__)
asm("break");
#else
asm("int $3");
#endif
}
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, "w+");
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() {
#ifdef ENABLE_LOGGING_AND_PROFILING
// 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));
// 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(SharedLibraryEvent(lib_name, start, end));
} else {
// Entry not describing executable data. Skip to end of line to setup
// reading the next entry.
do {
c = getc(fp);
} while ((c != EOF) && (c != '\n'));
if (c == EOF) break;
}
}
free(lib_name);
fclose(fp);
#endif
}
void OS::SignalCodeMovingGC() {
}
int OS::StackWalk(Vector<OS::StackFrame> frames) {
// backtrace is a glibc extension.
#ifdef __GLIBC__
int frames_size = frames.length();
ScopedVector<void*> addresses(frames_size);
int frames_count = backtrace(addresses.start(), frames_size);
char** symbols = backtrace_symbols(addresses.start(), frames_count);
if (symbols == NULL) {
return kStackWalkError;
}
for (int i = 0; i < frames_count; i++) {
frames[i].address = addresses[i];
// Format a text representation of the frame based on the information
// available.
SNPrintF(MutableCStrVector(frames[i].text, kStackWalkMaxTextLen),
"%s",
symbols[i]);
// Make sure line termination is in place.
frames[i].text[kStackWalkMaxTextLen - 1] = '\0';
}
free(symbols);
return frames_count;
#else // ndef __GLIBC__
return 0;
#endif // ndef __GLIBC__
}
// Constants used for mmap.
static const int kMmapFd = -1;
static const int kMmapFdOffset = 0;
VirtualMemory::VirtualMemory(size_t size) {
address_ = mmap(NULL, size, PROT_NONE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE,
kMmapFd, kMmapFdOffset);
size_ = size;
}
VirtualMemory::~VirtualMemory() {
if (IsReserved()) {
if (0 == munmap(address(), size())) address_ = MAP_FAILED;
}
}
bool VirtualMemory::IsReserved() {
return address_ != MAP_FAILED;
}
bool VirtualMemory::Commit(void* address, size_t size, bool is_executable) {
int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0);
if (mprotect(address, size, prot) != 0) {
return false;
}
UpdateAllocatedSpaceLimits(address, size);
return true;
}
bool VirtualMemory::Uncommit(void* address, size_t size) {
return mmap(address, size, PROT_NONE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE, // | MAP_FIXED, - Cygwin doesn't have MAP_FIXED
kMmapFd, kMmapFdOffset) != MAP_FAILED;
}
class ThreadHandle::PlatformData : public Malloced {
public:
explicit PlatformData(ThreadHandle::Kind kind) {
Initialize(kind);
}
void Initialize(ThreadHandle::Kind kind) {
switch (kind) {
case ThreadHandle::SELF: thread_ = pthread_self(); break;
case ThreadHandle::INVALID: thread_ = kNoThread; break;
}
}
pthread_t thread_; // Thread handle for pthread.
};
ThreadHandle::ThreadHandle(Kind kind) {
data_ = new PlatformData(kind);
}
void ThreadHandle::Initialize(ThreadHandle::Kind kind) {
data_->Initialize(kind);
}
ThreadHandle::~ThreadHandle() {
delete data_;
}
bool ThreadHandle::IsSelf() const {
return pthread_equal(data_->thread_, pthread_self());
}
bool ThreadHandle::IsValid() const {
return data_->thread_ != kNoThread;
}
Thread::Thread() : ThreadHandle(ThreadHandle::INVALID) {
set_name("v8:<unknown>");
}
Thread::Thread(const char* name) : ThreadHandle(ThreadHandle::INVALID) {
set_name(name);
}
Thread::~Thread() {
}
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->thread_handle_data()->thread_ = pthread_self();
ASSERT(thread->IsValid());
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_create(&thread_handle_data()->thread_, NULL, ThreadEntry, this);
ASSERT(IsValid());
}
void Thread::Join() {
pthread_join(thread_handle_data()->thread_, NULL);
}
Thread::LocalStorageKey Thread::CreateThreadLocalKey() {
pthread_key_t key;
int result = pthread_key_create(&key, NULL);
USE(result);
ASSERT(result == 0);
return static_cast<LocalStorageKey>(key);
}
void Thread::DeleteThreadLocalKey(LocalStorageKey key) {
pthread_key_t pthread_key = static_cast<pthread_key_t>(key);
int result = pthread_key_delete(pthread_key);
USE(result);
ASSERT(result == 0);
}
void* Thread::GetThreadLocal(LocalStorageKey key) {
pthread_key_t pthread_key = static_cast<pthread_key_t>(key);
return pthread_getspecific(pthread_key);
}
void Thread::SetThreadLocal(LocalStorageKey key, void* value) {
pthread_key_t pthread_key = static_cast<pthread_key_t>(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(&current_time, NULL) == -1) {
return false;
}
// Calculate time for end of timeout.
struct timeval end_time;
timeradd(&current_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 > 0) {
// For glibc prior to 2.3.4 sem_timedwait returns the error instead of -1.
errno = result;
result = -1;
}
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);
}
#ifdef ENABLE_LOGGING_AND_PROFILING
class Sampler::PlatformData : public Malloced {
public:
explicit PlatformData(Sampler* sampler)
: sampler_(sampler),
signal_handler_installed_(false) {
}
void SignalSender() {
}
void SendProfilingSignal() {
}
Sampler* sampler_;
bool signal_handler_installed_;
struct sigaction old_signal_handler_;
};
Sampler::Sampler(int interval)
: interval_(interval),
profiling_(false),
active_(false),
samples_taken_(0) {
data_ = new PlatformData(this);
}
Sampler::~Sampler() {
ASSERT(!data_->signal_sender_launched_);
delete data_;
}
void Sampler::Start() {
active_ = true;
}
void Sampler::Stop() {
active_ = false;
}
#endif // ENABLE_LOGGING_AND_PROFILING
} } // namespace v8::internal
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