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Diffstat (limited to 'src/3rdparty/v8/src/platform-linux.cc')
-rw-r--r-- | src/3rdparty/v8/src/platform-linux.cc | 1120 |
1 files changed, 1120 insertions, 0 deletions
diff --git a/src/3rdparty/v8/src/platform-linux.cc b/src/3rdparty/v8/src/platform-linux.cc new file mode 100644 index 0000000..73a6ccb --- /dev/null +++ b/src/3rdparty/v8/src/platform-linux.cc @@ -0,0 +1,1120 @@ +// 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 Linux 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/prctl.h> +#include <sys/time.h> +#include <sys/resource.h> +#include <sys/syscall.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 "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); +} + + +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(); +} + + +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; +#elif(defined(__mips_hard_float) && __mips_hard_float != 0) + // Here gcc is telling us that we are on an MIPS and gcc is assuming that we + // have FPU instructions. If gcc can assume it then so can we. + return 1u << FPU; +#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__ + + +#ifdef __mips__ +bool OS::MipsCpuHasFeature(CpuFeature feature) { + const char* search_string = NULL; + const char* file_name = "/proc/cpuinfo"; + // Simple detection of FPU at runtime for Linux. + // It is based on /proc/cpuinfo, which reveals hardware configuration + // to user-space applications. According to MIPS (early 2010), no similar + // facility is universally available on the MIPS architectures, + // so it's up to individual OSes to provide such. + // + // 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. + + switch (feature) { + case FPU: + search_string = "FPU"; + break; + default: + UNREACHABLE(); + } + + 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; +} +#endif // def __mips__ + + +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) { +#if (defined(V8_TARGET_ARCH_ARM) && defined(__arm__)) || \ + (defined(V8_TARGET_ARCH_MIPS) && defined(__mips__)) + // Only use on ARM or MIPS hardware. + MemoryBarrier(); +#else + __asm__ __volatile__("" : : : "memory"); + // An x86 store acts as a release barrier. +#endif + *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 t->tm_zone; +} + + +double OS::LocalTimeOffset() { + 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)); +} + + +// 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) { + 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) { + // TODO(805): Port randomization of allocated executable memory to Linux. + 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(i::Isolate::Current(), + 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__)) +# if defined(CAN_USE_ARMV5_INSTRUCTIONS) + asm("bkpt 0"); +# endif +#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, "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() { +#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)); + + 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 setup + // reading the next entry. + do { + c = getc(fp); + } while ((c != EOF) && (c != '\n')); + if (c == EOF) break; + } + } + free(lib_name); + fclose(fp); +#endif +} + + +static const char kGCFakeMmap[] = "/tmp/__v8_gc__"; + + +void OS::SignalCodeMovingGC() { +#ifdef ENABLE_LOGGING_AND_PROFILING + // Support for ll_prof.py. + // + // The Linux profiler built into the kernel logs all mmap's with + // PROT_EXEC so that analysis tools can properly attribute ticks. We + // do a mmap with a name known by ll_prof.py and immediately munmap + // it. This injects a GC marker into the stream of events generated + // by the kernel and allows us to synchronize V8 code log and the + // kernel log. + int size = sysconf(_SC_PAGESIZE); + FILE* f = fopen(kGCFakeMmap, "w+"); + void* addr = mmap(NULL, size, PROT_READ | PROT_EXEC, MAP_PRIVATE, + fileno(f), 0); + ASSERT(addr != MAP_FAILED); + munmap(addr, size); + fclose(f); +#endif +} + + +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 (MAP_FAILED == mmap(address, size, prot, + MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, + kMmapFd, kMmapFdOffset)) { + 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, + 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(Isolate* isolate, const Options& options) + : ThreadHandle(ThreadHandle::INVALID), + isolate_(isolate), + stack_size_(options.stack_size) { + set_name(options.name); +} + + +Thread::Thread(Isolate* isolate, const char* name) + : ThreadHandle(ThreadHandle::INVALID), + isolate_(isolate), + stack_size_(0) { + 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. + prctl(PR_SET_NAME, + reinterpret_cast<unsigned long>(thread->name()), // NOLINT + 0, 0, 0); + thread->thread_handle_data()->thread_ = pthread_self(); + ASSERT(thread->IsValid()); + Thread::SetThreadLocal(Isolate::isolate_key(), thread->isolate()); + 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(&thread_handle_data()->thread_, attr_ptr, 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 LinuxMutex : public Mutex { + public: + + LinuxMutex() { + pthread_mutexattr_t 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 ~LinuxMutex() { 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 LinuxMutex(); +} + + +class LinuxSemaphore : public Semaphore { + public: + explicit LinuxSemaphore(int count) { sem_init(&sem_, 0, count); } + virtual ~LinuxSemaphore() { sem_destroy(&sem_); } + + virtual void Wait(); + virtual bool Wait(int timeout); + virtual void Signal() { sem_post(&sem_); } + private: + sem_t sem_; +}; + + +void LinuxSemaphore::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 LinuxSemaphore::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 > 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 LinuxSemaphore(count); +} + + +#ifdef ENABLE_LOGGING_AND_PROFILING + +#if !defined(__GLIBC__) && (defined(__arm__) || defined(__thumb__)) +// Android runs a fairly new Linux kernel, so signal info is there, +// but the C library doesn't have the structs defined. + +struct sigcontext { + uint32_t trap_no; + uint32_t error_code; + uint32_t oldmask; + uint32_t gregs[16]; + uint32_t arm_cpsr; + uint32_t fault_address; +}; +typedef uint32_t __sigset_t; +typedef struct sigcontext mcontext_t; +typedef struct ucontext { + uint32_t uc_flags; + struct ucontext* uc_link; + stack_t uc_stack; + mcontext_t uc_mcontext; + __sigset_t uc_sigmask; +} ucontext_t; +enum ArmRegisters {R15 = 15, R13 = 13, R11 = 11}; + +#endif + + +static int GetThreadID() { + // Glibc doesn't provide a wrapper for gettid(2). +#if defined(ANDROID) + return syscall(__NR_gettid); +#else + return syscall(SYS_gettid); +#endif +} + + +static void ProfilerSignalHandler(int signal, siginfo_t* info, void* context) { +#ifndef V8_HOST_ARCH_MIPS + USE(info); + if (signal != SIGPROF) return; + Isolate* isolate = Isolate::UncheckedCurrent(); + if (isolate == NULL || !isolate->IsInitialized() || !isolate->IsInUse()) { + // We require a fully initialized and entered isolate. + return; + } + Sampler* sampler = isolate->logger()->sampler(); + if (sampler == NULL || !sampler->IsActive()) return; + + TickSample sample_obj; + TickSample* sample = CpuProfiler::TickSampleEvent(isolate); + if (sample == NULL) sample = &sample_obj; + + // Extracting the sample from the context is extremely machine dependent. + ucontext_t* ucontext = reinterpret_cast<ucontext_t*>(context); + mcontext_t& mcontext = ucontext->uc_mcontext; + sample->state = isolate->current_vm_state(); +#if V8_HOST_ARCH_IA32 + sample->pc = reinterpret_cast<Address>(mcontext.gregs[REG_EIP]); + sample->sp = reinterpret_cast<Address>(mcontext.gregs[REG_ESP]); + sample->fp = reinterpret_cast<Address>(mcontext.gregs[REG_EBP]); +#elif V8_HOST_ARCH_X64 + sample->pc = reinterpret_cast<Address>(mcontext.gregs[REG_RIP]); + sample->sp = reinterpret_cast<Address>(mcontext.gregs[REG_RSP]); + sample->fp = reinterpret_cast<Address>(mcontext.gregs[REG_RBP]); +#elif V8_HOST_ARCH_ARM +// An undefined macro evaluates to 0, so this applies to Android's Bionic also. +#if (__GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ <= 3)) + sample->pc = reinterpret_cast<Address>(mcontext.gregs[R15]); + sample->sp = reinterpret_cast<Address>(mcontext.gregs[R13]); + sample->fp = reinterpret_cast<Address>(mcontext.gregs[R11]); +#else + sample->pc = reinterpret_cast<Address>(mcontext.arm_pc); + sample->sp = reinterpret_cast<Address>(mcontext.arm_sp); + sample->fp = reinterpret_cast<Address>(mcontext.arm_fp); +#endif +#elif V8_HOST_ARCH_MIPS + sample.pc = reinterpret_cast<Address>(mcontext.pc); + sample.sp = reinterpret_cast<Address>(mcontext.gregs[29]); + sample.fp = reinterpret_cast<Address>(mcontext.gregs[30]); +#endif + sampler->SampleStack(sample); + sampler->Tick(sample); +#endif +} + + +class Sampler::PlatformData : public Malloced { + public: + PlatformData() : vm_tid_(GetThreadID()) {} + + int vm_tid() const { return vm_tid_; } + + private: + const int vm_tid_; +}; + + +class SignalSender : public Thread { + public: + enum SleepInterval { + HALF_INTERVAL, + FULL_INTERVAL + }; + + explicit SignalSender(int interval) + : Thread(NULL, "SignalSender"), + vm_tgid_(getpid()), + interval_(interval) {} + + static void AddActiveSampler(Sampler* sampler) { + ScopedLock lock(mutex_); + SamplerRegistry::AddActiveSampler(sampler); + if (instance_ == NULL) { + // Install a signal handler. + struct sigaction sa; + sa.sa_sigaction = ProfilerSignalHandler; + sigemptyset(&sa.sa_mask); + sa.sa_flags = SA_RESTART | SA_SIGINFO; + signal_handler_installed_ = + (sigaction(SIGPROF, &sa, &old_signal_handler_) == 0); + + // Start a thread that sends SIGPROF signal to VM threads. + instance_ = new SignalSender(sampler->interval()); + instance_->Start(); + } else { + ASSERT(instance_->interval_ == sampler->interval()); + } + } + + static void RemoveActiveSampler(Sampler* sampler) { + ScopedLock lock(mutex_); + SamplerRegistry::RemoveActiveSampler(sampler); + if (SamplerRegistry::GetState() == SamplerRegistry::HAS_NO_SAMPLERS) { + RuntimeProfiler::WakeUpRuntimeProfilerThreadBeforeShutdown(); + instance_->Join(); + delete instance_; + instance_ = NULL; + + // Restore the old signal handler. + if (signal_handler_installed_) { + sigaction(SIGPROF, &old_signal_handler_, 0); + signal_handler_installed_ = false; + } + } + } + + // 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 && runtime_profiler_enabled) { + if (!SamplerRegistry::IterateActiveSamplers(&DoCpuProfile, this)) { + return; + } + Sleep(HALF_INTERVAL); + if (!SamplerRegistry::IterateActiveSamplers(&DoRuntimeProfile, NULL)) { + return; + } + Sleep(HALF_INTERVAL); + } else { + if (cpu_profiling_enabled) { + if (!SamplerRegistry::IterateActiveSamplers(&DoCpuProfile, + this)) { + return; + } + } + if (runtime_profiler_enabled) { + if (!SamplerRegistry::IterateActiveSamplers(&DoRuntimeProfile, + NULL)) { + return; + } + } + Sleep(FULL_INTERVAL); + } + } + } + + static void DoCpuProfile(Sampler* sampler, void* raw_sender) { + if (!sampler->IsProfiling()) return; + SignalSender* sender = reinterpret_cast<SignalSender*>(raw_sender); + sender->SendProfilingSignal(sampler->platform_data()->vm_tid()); + } + + static void DoRuntimeProfile(Sampler* sampler, void* ignored) { + if (!sampler->isolate()->IsInitialized()) return; + sampler->isolate()->runtime_profiler()->NotifyTick(); + } + + void SendProfilingSignal(int tid) { + if (!signal_handler_installed_) return; + // Glibc doesn't provide a wrapper for tgkill(2). +#if defined(ANDROID) + syscall(__NR_tgkill, vm_tgid_, tid, SIGPROF); +#else + syscall(SYS_tgkill, vm_tgid_, tid, SIGPROF); +#endif + } + + void Sleep(SleepInterval full_or_half) { + // Convert ms to us and subtract 100 us to compensate delays + // occuring during signal delivery. + useconds_t interval = interval_ * 1000 - 100; + if (full_or_half == HALF_INTERVAL) interval /= 2; + int result = usleep(interval); +#ifdef DEBUG + if (result != 0 && errno != EINTR) { + fprintf(stderr, + "SignalSender usleep error; interval = %u, errno = %d\n", + interval, + errno); + ASSERT(result == 0 || errno == EINTR); + } +#endif + USE(result); + } + + const int vm_tgid_; + const int interval_; + RuntimeProfilerRateLimiter rate_limiter_; + + // Protects the process wide state below. + static Mutex* mutex_; + static SignalSender* instance_; + static bool signal_handler_installed_; + static struct sigaction old_signal_handler_; + + DISALLOW_COPY_AND_ASSIGN(SignalSender); +}; + + +Mutex* SignalSender::mutex_ = OS::CreateMutex(); +SignalSender* SignalSender::instance_ = NULL; +struct sigaction SignalSender::old_signal_handler_; +bool SignalSender::signal_handler_installed_ = false; + + +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); + SignalSender::AddActiveSampler(this); +} + + +void Sampler::Stop() { + ASSERT(IsActive()); + SignalSender::RemoveActiveSampler(this); + SetActive(false); +} + +#endif // ENABLE_LOGGING_AND_PROFILING + +} } // namespace v8::internal |