Leon Clarke | d91b9f7 | 2010-01-27 17:25:45 +0000 | [diff] [blame] | 1 | // Copyright 2006-2009 the V8 project authors. All rights reserved. |
| 2 | // Redistribution and use in source and binary forms, with or without |
| 3 | // modification, are permitted provided that the following conditions are |
| 4 | // met: |
| 5 | // |
| 6 | // * Redistributions of source code must retain the above copyright |
| 7 | // notice, this list of conditions and the following disclaimer. |
| 8 | // * Redistributions in binary form must reproduce the above |
| 9 | // copyright notice, this list of conditions and the following |
| 10 | // disclaimer in the documentation and/or other materials provided |
| 11 | // with the distribution. |
| 12 | // * Neither the name of Google Inc. nor the names of its |
| 13 | // contributors may be used to endorse or promote products derived |
| 14 | // from this software without specific prior written permission. |
| 15 | // |
| 16 | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 17 | // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 18 | // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 19 | // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 20 | // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 21 | // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 22 | // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 23 | // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 24 | // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 25 | // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 26 | // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 27 | |
| 28 | // Platform specific code for Solaris 10 goes here. For the POSIX comaptible |
| 29 | // parts the implementation is in platform-posix.cc. |
| 30 | |
| 31 | #ifdef __sparc |
| 32 | # error "V8 does not support the SPARC CPU architecture." |
| 33 | #endif |
| 34 | |
| 35 | #include <sys/stack.h> // for stack alignment |
| 36 | #include <unistd.h> // getpagesize(), usleep() |
| 37 | #include <sys/mman.h> // mmap() |
| 38 | #include <execinfo.h> // backtrace(), backtrace_symbols() |
| 39 | #include <pthread.h> |
| 40 | #include <sched.h> // for sched_yield |
| 41 | #include <semaphore.h> |
| 42 | #include <time.h> |
| 43 | #include <sys/time.h> // gettimeofday(), timeradd() |
| 44 | #include <errno.h> |
| 45 | #include <ieeefp.h> // finite() |
| 46 | #include <signal.h> // sigemptyset(), etc |
| 47 | |
| 48 | |
| 49 | #undef MAP_TYPE |
| 50 | |
| 51 | #include "v8.h" |
| 52 | |
| 53 | #include "platform.h" |
| 54 | |
| 55 | |
| 56 | namespace v8 { |
| 57 | namespace internal { |
| 58 | |
| 59 | |
| 60 | // 0 is never a valid thread id on Solaris since the main thread is 1 and |
| 61 | // subsequent have their ids incremented from there |
| 62 | static const pthread_t kNoThread = (pthread_t) 0; |
| 63 | |
| 64 | |
| 65 | double ceiling(double x) { |
| 66 | return ceil(x); |
| 67 | } |
| 68 | |
| 69 | |
| 70 | void OS::Setup() { |
| 71 | // Seed the random number generator. |
| 72 | // Convert the current time to a 64-bit integer first, before converting it |
| 73 | // to an unsigned. Going directly will cause an overflow and the seed to be |
| 74 | // set to all ones. The seed will be identical for different instances that |
| 75 | // call this setup code within the same millisecond. |
| 76 | uint64_t seed = static_cast<uint64_t>(TimeCurrentMillis()); |
| 77 | srandom(static_cast<unsigned int>(seed)); |
| 78 | } |
| 79 | |
| 80 | |
| 81 | uint64_t OS::CpuFeaturesImpliedByPlatform() { |
| 82 | return 0; // Solaris runs on a lot of things. |
| 83 | } |
| 84 | |
| 85 | |
| 86 | int OS::ActivationFrameAlignment() { |
| 87 | return STACK_ALIGN; |
| 88 | } |
| 89 | |
| 90 | |
| 91 | const char* OS::LocalTimezone(double time) { |
| 92 | if (isnan(time)) return ""; |
| 93 | time_t tv = static_cast<time_t>(floor(time/msPerSecond)); |
| 94 | struct tm* t = localtime(&tv); |
| 95 | if (NULL == t) return ""; |
| 96 | return tzname[0]; // The location of the timezone string on Solaris. |
| 97 | } |
| 98 | |
| 99 | |
| 100 | double OS::LocalTimeOffset() { |
| 101 | // On Solaris, struct tm does not contain a tm_gmtoff field. |
| 102 | time_t utc = time(NULL); |
| 103 | ASSERT(utc != -1); |
| 104 | struct tm* loc = localtime(&utc); |
| 105 | ASSERT(loc != NULL); |
| 106 | return static_cast<double>((mktime(loc) - utc) * msPerSecond); |
| 107 | } |
| 108 | |
| 109 | |
| 110 | // We keep the lowest and highest addresses mapped as a quick way of |
| 111 | // determining that pointers are outside the heap (used mostly in assertions |
| 112 | // and verification). The estimate is conservative, ie, not all addresses in |
| 113 | // 'allocated' space are actually allocated to our heap. The range is |
| 114 | // [lowest, highest), inclusive on the low and and exclusive on the high end. |
| 115 | static void* lowest_ever_allocated = reinterpret_cast<void*>(-1); |
| 116 | static void* highest_ever_allocated = reinterpret_cast<void*>(0); |
| 117 | |
| 118 | |
| 119 | static void UpdateAllocatedSpaceLimits(void* address, int size) { |
| 120 | lowest_ever_allocated = Min(lowest_ever_allocated, address); |
| 121 | highest_ever_allocated = |
| 122 | Max(highest_ever_allocated, |
| 123 | reinterpret_cast<void*>(reinterpret_cast<char*>(address) + size)); |
| 124 | } |
| 125 | |
| 126 | |
| 127 | bool OS::IsOutsideAllocatedSpace(void* address) { |
| 128 | return address < lowest_ever_allocated || address >= highest_ever_allocated; |
| 129 | } |
| 130 | |
| 131 | |
| 132 | size_t OS::AllocateAlignment() { |
| 133 | return static_cast<size_t>(getpagesize()); |
| 134 | } |
| 135 | |
| 136 | |
| 137 | void* OS::Allocate(const size_t requested, |
| 138 | size_t* allocated, |
| 139 | bool is_executable) { |
| 140 | const size_t msize = RoundUp(requested, getpagesize()); |
| 141 | int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0); |
| 142 | void* mbase = mmap(NULL, msize, prot, MAP_PRIVATE | MAP_ANON, -1, 0); |
| 143 | |
| 144 | if (mbase == MAP_FAILED) { |
| 145 | LOG(StringEvent("OS::Allocate", "mmap failed")); |
| 146 | return NULL; |
| 147 | } |
| 148 | *allocated = msize; |
| 149 | UpdateAllocatedSpaceLimits(mbase, msize); |
| 150 | return mbase; |
| 151 | } |
| 152 | |
| 153 | |
| 154 | void OS::Free(void* address, const size_t size) { |
| 155 | // TODO(1240712): munmap has a return value which is ignored here. |
| 156 | int result = munmap(address, size); |
| 157 | USE(result); |
| 158 | ASSERT(result == 0); |
| 159 | } |
| 160 | |
| 161 | |
| 162 | #ifdef ENABLE_HEAP_PROTECTION |
| 163 | |
| 164 | void OS::Protect(void* address, size_t size) { |
| 165 | // TODO(1240712): mprotect has a return value which is ignored here. |
| 166 | mprotect(address, size, PROT_READ); |
| 167 | } |
| 168 | |
| 169 | |
| 170 | void OS::Unprotect(void* address, size_t size, bool is_executable) { |
| 171 | // TODO(1240712): mprotect has a return value which is ignored here. |
| 172 | int prot = PROT_READ | PROT_WRITE | (is_executable ? PROT_EXEC : 0); |
| 173 | mprotect(address, size, prot); |
| 174 | } |
| 175 | |
| 176 | #endif |
| 177 | |
| 178 | |
| 179 | void OS::Sleep(int milliseconds) { |
| 180 | useconds_t ms = static_cast<useconds_t>(milliseconds); |
| 181 | usleep(1000 * ms); |
| 182 | } |
| 183 | |
| 184 | |
| 185 | void OS::Abort() { |
| 186 | // Redirect to std abort to signal abnormal program termination. |
| 187 | abort(); |
| 188 | } |
| 189 | |
| 190 | |
| 191 | void OS::DebugBreak() { |
| 192 | asm("int $3"); |
| 193 | } |
| 194 | |
| 195 | |
| 196 | class PosixMemoryMappedFile : public OS::MemoryMappedFile { |
| 197 | public: |
| 198 | PosixMemoryMappedFile(FILE* file, void* memory, int size) |
| 199 | : file_(file), memory_(memory), size_(size) { } |
| 200 | virtual ~PosixMemoryMappedFile(); |
| 201 | virtual void* memory() { return memory_; } |
| 202 | private: |
| 203 | FILE* file_; |
| 204 | void* memory_; |
| 205 | int size_; |
| 206 | }; |
| 207 | |
| 208 | |
| 209 | OS::MemoryMappedFile* OS::MemoryMappedFile::create(const char* name, int size, |
| 210 | void* initial) { |
| 211 | FILE* file = fopen(name, "w+"); |
| 212 | if (file == NULL) return NULL; |
| 213 | int result = fwrite(initial, size, 1, file); |
| 214 | if (result < 1) { |
| 215 | fclose(file); |
| 216 | return NULL; |
| 217 | } |
| 218 | void* memory = |
| 219 | mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fileno(file), 0); |
| 220 | return new PosixMemoryMappedFile(file, memory, size); |
| 221 | } |
| 222 | |
| 223 | |
| 224 | PosixMemoryMappedFile::~PosixMemoryMappedFile() { |
| 225 | if (memory_) munmap(memory_, size_); |
| 226 | fclose(file_); |
| 227 | } |
| 228 | |
| 229 | |
| 230 | void OS::LogSharedLibraryAddresses() { |
| 231 | } |
| 232 | |
| 233 | |
| 234 | int OS::StackWalk(Vector<OS::StackFrame> frames) { |
| 235 | int frames_size = frames.length(); |
| 236 | void** addresses = NewArray<void*>(frames_size); |
| 237 | |
| 238 | int frames_count = backtrace(addresses, frames_size); |
| 239 | |
| 240 | char** symbols; |
| 241 | symbols = backtrace_symbols(addresses, frames_count); |
| 242 | if (symbols == NULL) { |
| 243 | DeleteArray(addresses); |
| 244 | return kStackWalkError; |
| 245 | } |
| 246 | |
| 247 | for (int i = 0; i < frames_count; i++) { |
| 248 | frames[i].address = addresses[i]; |
| 249 | // Format a text representation of the frame based on the information |
| 250 | // available. |
| 251 | SNPrintF(MutableCStrVector(frames[i].text, kStackWalkMaxTextLen), |
| 252 | "%s", |
| 253 | symbols[i]); |
| 254 | // Make sure line termination is in place. |
| 255 | frames[i].text[kStackWalkMaxTextLen - 1] = '\0'; |
| 256 | } |
| 257 | |
| 258 | DeleteArray(addresses); |
| 259 | free(symbols); |
| 260 | |
| 261 | return frames_count; |
| 262 | } |
| 263 | |
| 264 | |
| 265 | // Constants used for mmap. |
| 266 | static const int kMmapFd = -1; |
| 267 | static const int kMmapFdOffset = 0; |
| 268 | |
| 269 | |
| 270 | VirtualMemory::VirtualMemory(size_t size) { |
| 271 | address_ = mmap(NULL, size, PROT_NONE, |
| 272 | MAP_PRIVATE | MAP_ANON | MAP_NORESERVE, |
| 273 | kMmapFd, kMmapFdOffset); |
| 274 | size_ = size; |
| 275 | } |
| 276 | |
| 277 | |
| 278 | VirtualMemory::~VirtualMemory() { |
| 279 | if (IsReserved()) { |
| 280 | if (0 == munmap(address(), size())) address_ = MAP_FAILED; |
| 281 | } |
| 282 | } |
| 283 | |
| 284 | |
| 285 | bool VirtualMemory::IsReserved() { |
| 286 | return address_ != MAP_FAILED; |
| 287 | } |
| 288 | |
| 289 | |
| 290 | bool VirtualMemory::Commit(void* address, size_t size, bool executable) { |
| 291 | int prot = PROT_READ | PROT_WRITE | (executable ? PROT_EXEC : 0); |
| 292 | if (MAP_FAILED == mmap(address, size, prot, |
| 293 | MAP_PRIVATE | MAP_ANON | MAP_FIXED, |
| 294 | kMmapFd, kMmapFdOffset)) { |
| 295 | return false; |
| 296 | } |
| 297 | |
| 298 | UpdateAllocatedSpaceLimits(address, size); |
| 299 | return true; |
| 300 | } |
| 301 | |
| 302 | |
| 303 | bool VirtualMemory::Uncommit(void* address, size_t size) { |
| 304 | return mmap(address, size, PROT_NONE, |
| 305 | MAP_PRIVATE | MAP_ANON | MAP_NORESERVE | MAP_FIXED, |
| 306 | kMmapFd, kMmapFdOffset) != MAP_FAILED; |
| 307 | } |
| 308 | |
| 309 | |
| 310 | class ThreadHandle::PlatformData : public Malloced { |
| 311 | public: |
| 312 | explicit PlatformData(ThreadHandle::Kind kind) { |
| 313 | Initialize(kind); |
| 314 | } |
| 315 | |
| 316 | void Initialize(ThreadHandle::Kind kind) { |
| 317 | switch (kind) { |
| 318 | case ThreadHandle::SELF: thread_ = pthread_self(); break; |
| 319 | case ThreadHandle::INVALID: thread_ = kNoThread; break; |
| 320 | } |
| 321 | } |
| 322 | |
| 323 | pthread_t thread_; // Thread handle for pthread. |
| 324 | }; |
| 325 | |
| 326 | |
| 327 | ThreadHandle::ThreadHandle(Kind kind) { |
| 328 | data_ = new PlatformData(kind); |
| 329 | } |
| 330 | |
| 331 | |
| 332 | void ThreadHandle::Initialize(ThreadHandle::Kind kind) { |
| 333 | data_->Initialize(kind); |
| 334 | } |
| 335 | |
| 336 | |
| 337 | ThreadHandle::~ThreadHandle() { |
| 338 | delete data_; |
| 339 | } |
| 340 | |
| 341 | |
| 342 | bool ThreadHandle::IsSelf() const { |
| 343 | return pthread_equal(data_->thread_, pthread_self()); |
| 344 | } |
| 345 | |
| 346 | |
| 347 | bool ThreadHandle::IsValid() const { |
| 348 | return data_->thread_ != kNoThread; |
| 349 | } |
| 350 | |
| 351 | |
| 352 | Thread::Thread() : ThreadHandle(ThreadHandle::INVALID) { |
| 353 | } |
| 354 | |
| 355 | |
| 356 | Thread::~Thread() { |
| 357 | } |
| 358 | |
| 359 | |
| 360 | static void* ThreadEntry(void* arg) { |
| 361 | Thread* thread = reinterpret_cast<Thread*>(arg); |
| 362 | // This is also initialized by the first argument to pthread_create() but we |
| 363 | // don't know which thread will run first (the original thread or the new |
| 364 | // one) so we initialize it here too. |
| 365 | thread->thread_handle_data()->thread_ = pthread_self(); |
| 366 | ASSERT(thread->IsValid()); |
| 367 | thread->Run(); |
| 368 | return NULL; |
| 369 | } |
| 370 | |
| 371 | |
| 372 | void Thread::Start() { |
| 373 | pthread_create(&thread_handle_data()->thread_, NULL, ThreadEntry, this); |
| 374 | ASSERT(IsValid()); |
| 375 | } |
| 376 | |
| 377 | |
| 378 | void Thread::Join() { |
| 379 | pthread_join(thread_handle_data()->thread_, NULL); |
| 380 | } |
| 381 | |
| 382 | |
| 383 | Thread::LocalStorageKey Thread::CreateThreadLocalKey() { |
| 384 | pthread_key_t key; |
| 385 | int result = pthread_key_create(&key, NULL); |
| 386 | USE(result); |
| 387 | ASSERT(result == 0); |
| 388 | return static_cast<LocalStorageKey>(key); |
| 389 | } |
| 390 | |
| 391 | |
| 392 | void Thread::DeleteThreadLocalKey(LocalStorageKey key) { |
| 393 | pthread_key_t pthread_key = static_cast<pthread_key_t>(key); |
| 394 | int result = pthread_key_delete(pthread_key); |
| 395 | USE(result); |
| 396 | ASSERT(result == 0); |
| 397 | } |
| 398 | |
| 399 | |
| 400 | void* Thread::GetThreadLocal(LocalStorageKey key) { |
| 401 | pthread_key_t pthread_key = static_cast<pthread_key_t>(key); |
| 402 | return pthread_getspecific(pthread_key); |
| 403 | } |
| 404 | |
| 405 | |
| 406 | void Thread::SetThreadLocal(LocalStorageKey key, void* value) { |
| 407 | pthread_key_t pthread_key = static_cast<pthread_key_t>(key); |
| 408 | pthread_setspecific(pthread_key, value); |
| 409 | } |
| 410 | |
| 411 | |
| 412 | void Thread::YieldCPU() { |
| 413 | sched_yield(); |
| 414 | } |
| 415 | |
| 416 | |
| 417 | class SolarisMutex : public Mutex { |
| 418 | public: |
| 419 | |
| 420 | SolarisMutex() { |
| 421 | pthread_mutexattr_t attr; |
| 422 | pthread_mutexattr_init(&attr); |
| 423 | pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE); |
| 424 | pthread_mutex_init(&mutex_, &attr); |
| 425 | } |
| 426 | |
| 427 | ~SolarisMutex() { pthread_mutex_destroy(&mutex_); } |
| 428 | |
| 429 | int Lock() { return pthread_mutex_lock(&mutex_); } |
| 430 | |
| 431 | int Unlock() { return pthread_mutex_unlock(&mutex_); } |
| 432 | |
| 433 | private: |
| 434 | pthread_mutex_t mutex_; |
| 435 | }; |
| 436 | |
| 437 | |
| 438 | Mutex* OS::CreateMutex() { |
| 439 | return new SolarisMutex(); |
| 440 | } |
| 441 | |
| 442 | |
| 443 | class SolarisSemaphore : public Semaphore { |
| 444 | public: |
| 445 | explicit SolarisSemaphore(int count) { sem_init(&sem_, 0, count); } |
| 446 | virtual ~SolarisSemaphore() { sem_destroy(&sem_); } |
| 447 | |
| 448 | virtual void Wait(); |
| 449 | virtual bool Wait(int timeout); |
| 450 | virtual void Signal() { sem_post(&sem_); } |
| 451 | private: |
| 452 | sem_t sem_; |
| 453 | }; |
| 454 | |
| 455 | |
| 456 | void SolarisSemaphore::Wait() { |
| 457 | while (true) { |
| 458 | int result = sem_wait(&sem_); |
| 459 | if (result == 0) return; // Successfully got semaphore. |
| 460 | CHECK(result == -1 && errno == EINTR); // Signal caused spurious wakeup. |
| 461 | } |
| 462 | } |
| 463 | |
| 464 | |
| 465 | #ifndef TIMEVAL_TO_TIMESPEC |
| 466 | #define TIMEVAL_TO_TIMESPEC(tv, ts) do { \ |
| 467 | (ts)->tv_sec = (tv)->tv_sec; \ |
| 468 | (ts)->tv_nsec = (tv)->tv_usec * 1000; \ |
| 469 | } while (false) |
| 470 | #endif |
| 471 | |
| 472 | |
| 473 | #ifndef timeradd |
| 474 | #define timeradd(a, b, result) \ |
| 475 | do { \ |
| 476 | (result)->tv_sec = (a)->tv_sec + (b)->tv_sec; \ |
| 477 | (result)->tv_usec = (a)->tv_usec + (b)->tv_usec; \ |
| 478 | if ((result)->tv_usec >= 1000000) { \ |
| 479 | ++(result)->tv_sec; \ |
| 480 | (result)->tv_usec -= 1000000; \ |
| 481 | } \ |
| 482 | } while (0) |
| 483 | #endif |
| 484 | |
| 485 | |
| 486 | bool SolarisSemaphore::Wait(int timeout) { |
| 487 | const long kOneSecondMicros = 1000000; // NOLINT |
| 488 | |
| 489 | // Split timeout into second and nanosecond parts. |
| 490 | struct timeval delta; |
| 491 | delta.tv_usec = timeout % kOneSecondMicros; |
| 492 | delta.tv_sec = timeout / kOneSecondMicros; |
| 493 | |
| 494 | struct timeval current_time; |
| 495 | // Get the current time. |
| 496 | if (gettimeofday(¤t_time, NULL) == -1) { |
| 497 | return false; |
| 498 | } |
| 499 | |
| 500 | // Calculate time for end of timeout. |
| 501 | struct timeval end_time; |
| 502 | timeradd(¤t_time, &delta, &end_time); |
| 503 | |
| 504 | struct timespec ts; |
| 505 | TIMEVAL_TO_TIMESPEC(&end_time, &ts); |
| 506 | // Wait for semaphore signalled or timeout. |
| 507 | while (true) { |
| 508 | int result = sem_timedwait(&sem_, &ts); |
| 509 | if (result == 0) return true; // Successfully got semaphore. |
| 510 | if (result == -1 && errno == ETIMEDOUT) return false; // Timeout. |
| 511 | CHECK(result == -1 && errno == EINTR); // Signal caused spurious wakeup. |
| 512 | } |
| 513 | } |
| 514 | |
| 515 | |
| 516 | Semaphore* OS::CreateSemaphore(int count) { |
| 517 | return new SolarisSemaphore(count); |
| 518 | } |
| 519 | |
| 520 | |
| 521 | #ifdef ENABLE_LOGGING_AND_PROFILING |
| 522 | |
| 523 | static Sampler* active_sampler_ = NULL; |
| 524 | |
| 525 | static void ProfilerSignalHandler(int signal, siginfo_t* info, void* context) { |
| 526 | USE(info); |
| 527 | if (signal != SIGPROF) return; |
| 528 | if (active_sampler_ == NULL) return; |
| 529 | |
| 530 | TickSample sample; |
| 531 | sample.pc = 0; |
| 532 | sample.sp = 0; |
| 533 | sample.fp = 0; |
| 534 | |
| 535 | // We always sample the VM state. |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame^] | 536 | sample.state = VMState::current_state(); |
Leon Clarke | d91b9f7 | 2010-01-27 17:25:45 +0000 | [diff] [blame] | 537 | |
| 538 | active_sampler_->Tick(&sample); |
| 539 | } |
| 540 | |
| 541 | |
| 542 | class Sampler::PlatformData : public Malloced { |
| 543 | public: |
| 544 | PlatformData() { |
| 545 | signal_handler_installed_ = false; |
| 546 | } |
| 547 | |
| 548 | bool signal_handler_installed_; |
| 549 | struct sigaction old_signal_handler_; |
| 550 | struct itimerval old_timer_value_; |
| 551 | }; |
| 552 | |
| 553 | |
| 554 | Sampler::Sampler(int interval, bool profiling) |
| 555 | : interval_(interval), profiling_(profiling), active_(false) { |
| 556 | data_ = new PlatformData(); |
| 557 | } |
| 558 | |
| 559 | |
| 560 | Sampler::~Sampler() { |
| 561 | delete data_; |
| 562 | } |
| 563 | |
| 564 | |
| 565 | void Sampler::Start() { |
| 566 | // There can only be one active sampler at the time on POSIX |
| 567 | // platforms. |
| 568 | if (active_sampler_ != NULL) return; |
| 569 | |
| 570 | // Request profiling signals. |
| 571 | struct sigaction sa; |
| 572 | sa.sa_sigaction = ProfilerSignalHandler; |
| 573 | sigemptyset(&sa.sa_mask); |
| 574 | sa.sa_flags = SA_SIGINFO; |
| 575 | if (sigaction(SIGPROF, &sa, &data_->old_signal_handler_) != 0) return; |
| 576 | data_->signal_handler_installed_ = true; |
| 577 | |
| 578 | // Set the itimer to generate a tick for each interval. |
| 579 | itimerval itimer; |
| 580 | itimer.it_interval.tv_sec = interval_ / 1000; |
| 581 | itimer.it_interval.tv_usec = (interval_ % 1000) * 1000; |
| 582 | itimer.it_value.tv_sec = itimer.it_interval.tv_sec; |
| 583 | itimer.it_value.tv_usec = itimer.it_interval.tv_usec; |
| 584 | setitimer(ITIMER_PROF, &itimer, &data_->old_timer_value_); |
| 585 | |
| 586 | // Set this sampler as the active sampler. |
| 587 | active_sampler_ = this; |
| 588 | active_ = true; |
| 589 | } |
| 590 | |
| 591 | |
| 592 | void Sampler::Stop() { |
| 593 | // Restore old signal handler |
| 594 | if (data_->signal_handler_installed_) { |
| 595 | setitimer(ITIMER_PROF, &data_->old_timer_value_, NULL); |
| 596 | sigaction(SIGPROF, &data_->old_signal_handler_, 0); |
| 597 | data_->signal_handler_installed_ = false; |
| 598 | } |
| 599 | |
| 600 | // This sampler is no longer the active sampler. |
| 601 | active_sampler_ = NULL; |
| 602 | active_ = false; |
| 603 | } |
| 604 | |
| 605 | #endif // ENABLE_LOGGING_AND_PROFILING |
| 606 | |
| 607 | } } // namespace v8::internal |