Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 1 | // Copyright 2013 the V8 project authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | #include "src/base/platform/time.h" |
| 6 | |
| 7 | #if V8_OS_POSIX |
| 8 | #include <fcntl.h> // for O_RDONLY |
| 9 | #include <sys/time.h> |
| 10 | #include <unistd.h> |
| 11 | #endif |
| 12 | #if V8_OS_MACOSX |
| 13 | #include <mach/mach_time.h> |
| 14 | #endif |
| 15 | |
| 16 | #include <string.h> |
| 17 | |
| 18 | #if V8_OS_WIN |
| 19 | #include "src/base/lazy-instance.h" |
| 20 | #include "src/base/win32-headers.h" |
| 21 | #endif |
| 22 | #include "src/base/cpu.h" |
| 23 | #include "src/base/logging.h" |
| 24 | #include "src/base/platform/platform.h" |
| 25 | |
| 26 | namespace v8 { |
| 27 | namespace base { |
| 28 | |
| 29 | TimeDelta TimeDelta::FromDays(int days) { |
| 30 | return TimeDelta(days * Time::kMicrosecondsPerDay); |
| 31 | } |
| 32 | |
| 33 | |
| 34 | TimeDelta TimeDelta::FromHours(int hours) { |
| 35 | return TimeDelta(hours * Time::kMicrosecondsPerHour); |
| 36 | } |
| 37 | |
| 38 | |
| 39 | TimeDelta TimeDelta::FromMinutes(int minutes) { |
| 40 | return TimeDelta(minutes * Time::kMicrosecondsPerMinute); |
| 41 | } |
| 42 | |
| 43 | |
| 44 | TimeDelta TimeDelta::FromSeconds(int64_t seconds) { |
| 45 | return TimeDelta(seconds * Time::kMicrosecondsPerSecond); |
| 46 | } |
| 47 | |
| 48 | |
| 49 | TimeDelta TimeDelta::FromMilliseconds(int64_t milliseconds) { |
| 50 | return TimeDelta(milliseconds * Time::kMicrosecondsPerMillisecond); |
| 51 | } |
| 52 | |
| 53 | |
| 54 | TimeDelta TimeDelta::FromNanoseconds(int64_t nanoseconds) { |
| 55 | return TimeDelta(nanoseconds / Time::kNanosecondsPerMicrosecond); |
| 56 | } |
| 57 | |
| 58 | |
| 59 | int TimeDelta::InDays() const { |
| 60 | return static_cast<int>(delta_ / Time::kMicrosecondsPerDay); |
| 61 | } |
| 62 | |
| 63 | |
| 64 | int TimeDelta::InHours() const { |
| 65 | return static_cast<int>(delta_ / Time::kMicrosecondsPerHour); |
| 66 | } |
| 67 | |
| 68 | |
| 69 | int TimeDelta::InMinutes() const { |
| 70 | return static_cast<int>(delta_ / Time::kMicrosecondsPerMinute); |
| 71 | } |
| 72 | |
| 73 | |
| 74 | double TimeDelta::InSecondsF() const { |
| 75 | return static_cast<double>(delta_) / Time::kMicrosecondsPerSecond; |
| 76 | } |
| 77 | |
| 78 | |
| 79 | int64_t TimeDelta::InSeconds() const { |
| 80 | return delta_ / Time::kMicrosecondsPerSecond; |
| 81 | } |
| 82 | |
| 83 | |
| 84 | double TimeDelta::InMillisecondsF() const { |
| 85 | return static_cast<double>(delta_) / Time::kMicrosecondsPerMillisecond; |
| 86 | } |
| 87 | |
| 88 | |
| 89 | int64_t TimeDelta::InMilliseconds() const { |
| 90 | return delta_ / Time::kMicrosecondsPerMillisecond; |
| 91 | } |
| 92 | |
| 93 | |
| 94 | int64_t TimeDelta::InNanoseconds() const { |
| 95 | return delta_ * Time::kNanosecondsPerMicrosecond; |
| 96 | } |
| 97 | |
| 98 | |
| 99 | #if V8_OS_MACOSX |
| 100 | |
| 101 | TimeDelta TimeDelta::FromMachTimespec(struct mach_timespec ts) { |
| 102 | DCHECK_GE(ts.tv_nsec, 0); |
| 103 | DCHECK_LT(ts.tv_nsec, |
| 104 | static_cast<long>(Time::kNanosecondsPerSecond)); // NOLINT |
| 105 | return TimeDelta(ts.tv_sec * Time::kMicrosecondsPerSecond + |
| 106 | ts.tv_nsec / Time::kNanosecondsPerMicrosecond); |
| 107 | } |
| 108 | |
| 109 | |
| 110 | struct mach_timespec TimeDelta::ToMachTimespec() const { |
| 111 | struct mach_timespec ts; |
| 112 | DCHECK(delta_ >= 0); |
| 113 | ts.tv_sec = delta_ / Time::kMicrosecondsPerSecond; |
| 114 | ts.tv_nsec = (delta_ % Time::kMicrosecondsPerSecond) * |
| 115 | Time::kNanosecondsPerMicrosecond; |
| 116 | return ts; |
| 117 | } |
| 118 | |
| 119 | #endif // V8_OS_MACOSX |
| 120 | |
| 121 | |
| 122 | #if V8_OS_POSIX |
| 123 | |
| 124 | TimeDelta TimeDelta::FromTimespec(struct timespec ts) { |
| 125 | DCHECK_GE(ts.tv_nsec, 0); |
| 126 | DCHECK_LT(ts.tv_nsec, |
| 127 | static_cast<long>(Time::kNanosecondsPerSecond)); // NOLINT |
| 128 | return TimeDelta(ts.tv_sec * Time::kMicrosecondsPerSecond + |
| 129 | ts.tv_nsec / Time::kNanosecondsPerMicrosecond); |
| 130 | } |
| 131 | |
| 132 | |
| 133 | struct timespec TimeDelta::ToTimespec() const { |
| 134 | struct timespec ts; |
| 135 | ts.tv_sec = delta_ / Time::kMicrosecondsPerSecond; |
| 136 | ts.tv_nsec = (delta_ % Time::kMicrosecondsPerSecond) * |
| 137 | Time::kNanosecondsPerMicrosecond; |
| 138 | return ts; |
| 139 | } |
| 140 | |
| 141 | #endif // V8_OS_POSIX |
| 142 | |
| 143 | |
| 144 | #if V8_OS_WIN |
| 145 | |
| 146 | // We implement time using the high-resolution timers so that we can get |
| 147 | // timeouts which are smaller than 10-15ms. To avoid any drift, we |
| 148 | // periodically resync the internal clock to the system clock. |
| 149 | class Clock FINAL { |
| 150 | public: |
| 151 | Clock() : initial_ticks_(GetSystemTicks()), initial_time_(GetSystemTime()) {} |
| 152 | |
| 153 | Time Now() { |
| 154 | // Time between resampling the un-granular clock for this API (1 minute). |
| 155 | const TimeDelta kMaxElapsedTime = TimeDelta::FromMinutes(1); |
| 156 | |
| 157 | LockGuard<Mutex> lock_guard(&mutex_); |
| 158 | |
| 159 | // Determine current time and ticks. |
| 160 | TimeTicks ticks = GetSystemTicks(); |
| 161 | Time time = GetSystemTime(); |
| 162 | |
| 163 | // Check if we need to synchronize with the system clock due to a backwards |
| 164 | // time change or the amount of time elapsed. |
| 165 | TimeDelta elapsed = ticks - initial_ticks_; |
| 166 | if (time < initial_time_ || elapsed > kMaxElapsedTime) { |
| 167 | initial_ticks_ = ticks; |
| 168 | initial_time_ = time; |
| 169 | return time; |
| 170 | } |
| 171 | |
| 172 | return initial_time_ + elapsed; |
| 173 | } |
| 174 | |
| 175 | Time NowFromSystemTime() { |
| 176 | LockGuard<Mutex> lock_guard(&mutex_); |
| 177 | initial_ticks_ = GetSystemTicks(); |
| 178 | initial_time_ = GetSystemTime(); |
| 179 | return initial_time_; |
| 180 | } |
| 181 | |
| 182 | private: |
| 183 | static TimeTicks GetSystemTicks() { |
| 184 | return TimeTicks::Now(); |
| 185 | } |
| 186 | |
| 187 | static Time GetSystemTime() { |
| 188 | FILETIME ft; |
| 189 | ::GetSystemTimeAsFileTime(&ft); |
| 190 | return Time::FromFiletime(ft); |
| 191 | } |
| 192 | |
| 193 | TimeTicks initial_ticks_; |
| 194 | Time initial_time_; |
| 195 | Mutex mutex_; |
| 196 | }; |
| 197 | |
| 198 | |
| 199 | static LazyStaticInstance<Clock, DefaultConstructTrait<Clock>, |
| 200 | ThreadSafeInitOnceTrait>::type clock = |
| 201 | LAZY_STATIC_INSTANCE_INITIALIZER; |
| 202 | |
| 203 | |
| 204 | Time Time::Now() { |
| 205 | return clock.Pointer()->Now(); |
| 206 | } |
| 207 | |
| 208 | |
| 209 | Time Time::NowFromSystemTime() { |
| 210 | return clock.Pointer()->NowFromSystemTime(); |
| 211 | } |
| 212 | |
| 213 | |
| 214 | // Time between windows epoch and standard epoch. |
| 215 | static const int64_t kTimeToEpochInMicroseconds = V8_INT64_C(11644473600000000); |
| 216 | |
| 217 | |
| 218 | Time Time::FromFiletime(FILETIME ft) { |
| 219 | if (ft.dwLowDateTime == 0 && ft.dwHighDateTime == 0) { |
| 220 | return Time(); |
| 221 | } |
| 222 | if (ft.dwLowDateTime == std::numeric_limits<DWORD>::max() && |
| 223 | ft.dwHighDateTime == std::numeric_limits<DWORD>::max()) { |
| 224 | return Max(); |
| 225 | } |
| 226 | int64_t us = (static_cast<uint64_t>(ft.dwLowDateTime) + |
| 227 | (static_cast<uint64_t>(ft.dwHighDateTime) << 32)) / 10; |
| 228 | return Time(us - kTimeToEpochInMicroseconds); |
| 229 | } |
| 230 | |
| 231 | |
| 232 | FILETIME Time::ToFiletime() const { |
| 233 | DCHECK(us_ >= 0); |
| 234 | FILETIME ft; |
| 235 | if (IsNull()) { |
| 236 | ft.dwLowDateTime = 0; |
| 237 | ft.dwHighDateTime = 0; |
| 238 | return ft; |
| 239 | } |
| 240 | if (IsMax()) { |
| 241 | ft.dwLowDateTime = std::numeric_limits<DWORD>::max(); |
| 242 | ft.dwHighDateTime = std::numeric_limits<DWORD>::max(); |
| 243 | return ft; |
| 244 | } |
| 245 | uint64_t us = static_cast<uint64_t>(us_ + kTimeToEpochInMicroseconds) * 10; |
| 246 | ft.dwLowDateTime = static_cast<DWORD>(us); |
| 247 | ft.dwHighDateTime = static_cast<DWORD>(us >> 32); |
| 248 | return ft; |
| 249 | } |
| 250 | |
| 251 | #elif V8_OS_POSIX |
| 252 | |
| 253 | Time Time::Now() { |
| 254 | struct timeval tv; |
| 255 | int result = gettimeofday(&tv, NULL); |
| 256 | DCHECK_EQ(0, result); |
| 257 | USE(result); |
| 258 | return FromTimeval(tv); |
| 259 | } |
| 260 | |
| 261 | |
| 262 | Time Time::NowFromSystemTime() { |
| 263 | return Now(); |
| 264 | } |
| 265 | |
| 266 | |
| 267 | Time Time::FromTimespec(struct timespec ts) { |
| 268 | DCHECK(ts.tv_nsec >= 0); |
| 269 | DCHECK(ts.tv_nsec < static_cast<long>(kNanosecondsPerSecond)); // NOLINT |
| 270 | if (ts.tv_nsec == 0 && ts.tv_sec == 0) { |
| 271 | return Time(); |
| 272 | } |
| 273 | if (ts.tv_nsec == static_cast<long>(kNanosecondsPerSecond - 1) && // NOLINT |
| 274 | ts.tv_sec == std::numeric_limits<time_t>::max()) { |
| 275 | return Max(); |
| 276 | } |
| 277 | return Time(ts.tv_sec * kMicrosecondsPerSecond + |
| 278 | ts.tv_nsec / kNanosecondsPerMicrosecond); |
| 279 | } |
| 280 | |
| 281 | |
| 282 | struct timespec Time::ToTimespec() const { |
| 283 | struct timespec ts; |
| 284 | if (IsNull()) { |
| 285 | ts.tv_sec = 0; |
| 286 | ts.tv_nsec = 0; |
| 287 | return ts; |
| 288 | } |
| 289 | if (IsMax()) { |
| 290 | ts.tv_sec = std::numeric_limits<time_t>::max(); |
| 291 | ts.tv_nsec = static_cast<long>(kNanosecondsPerSecond - 1); // NOLINT |
| 292 | return ts; |
| 293 | } |
| 294 | ts.tv_sec = us_ / kMicrosecondsPerSecond; |
| 295 | ts.tv_nsec = (us_ % kMicrosecondsPerSecond) * kNanosecondsPerMicrosecond; |
| 296 | return ts; |
| 297 | } |
| 298 | |
| 299 | |
| 300 | Time Time::FromTimeval(struct timeval tv) { |
| 301 | DCHECK(tv.tv_usec >= 0); |
| 302 | DCHECK(tv.tv_usec < static_cast<suseconds_t>(kMicrosecondsPerSecond)); |
| 303 | if (tv.tv_usec == 0 && tv.tv_sec == 0) { |
| 304 | return Time(); |
| 305 | } |
| 306 | if (tv.tv_usec == static_cast<suseconds_t>(kMicrosecondsPerSecond - 1) && |
| 307 | tv.tv_sec == std::numeric_limits<time_t>::max()) { |
| 308 | return Max(); |
| 309 | } |
| 310 | return Time(tv.tv_sec * kMicrosecondsPerSecond + tv.tv_usec); |
| 311 | } |
| 312 | |
| 313 | |
| 314 | struct timeval Time::ToTimeval() const { |
| 315 | struct timeval tv; |
| 316 | if (IsNull()) { |
| 317 | tv.tv_sec = 0; |
| 318 | tv.tv_usec = 0; |
| 319 | return tv; |
| 320 | } |
| 321 | if (IsMax()) { |
| 322 | tv.tv_sec = std::numeric_limits<time_t>::max(); |
| 323 | tv.tv_usec = static_cast<suseconds_t>(kMicrosecondsPerSecond - 1); |
| 324 | return tv; |
| 325 | } |
| 326 | tv.tv_sec = us_ / kMicrosecondsPerSecond; |
| 327 | tv.tv_usec = us_ % kMicrosecondsPerSecond; |
| 328 | return tv; |
| 329 | } |
| 330 | |
| 331 | #endif // V8_OS_WIN |
| 332 | |
| 333 | |
| 334 | Time Time::FromJsTime(double ms_since_epoch) { |
| 335 | // The epoch is a valid time, so this constructor doesn't interpret |
| 336 | // 0 as the null time. |
| 337 | if (ms_since_epoch == std::numeric_limits<double>::max()) { |
| 338 | return Max(); |
| 339 | } |
| 340 | return Time( |
| 341 | static_cast<int64_t>(ms_since_epoch * kMicrosecondsPerMillisecond)); |
| 342 | } |
| 343 | |
| 344 | |
| 345 | double Time::ToJsTime() const { |
| 346 | if (IsNull()) { |
| 347 | // Preserve 0 so the invalid result doesn't depend on the platform. |
| 348 | return 0; |
| 349 | } |
| 350 | if (IsMax()) { |
| 351 | // Preserve max without offset to prevent overflow. |
| 352 | return std::numeric_limits<double>::max(); |
| 353 | } |
| 354 | return static_cast<double>(us_) / kMicrosecondsPerMillisecond; |
| 355 | } |
| 356 | |
| 357 | |
| 358 | #if V8_OS_WIN |
| 359 | |
| 360 | class TickClock { |
| 361 | public: |
| 362 | virtual ~TickClock() {} |
| 363 | virtual int64_t Now() = 0; |
| 364 | virtual bool IsHighResolution() = 0; |
| 365 | }; |
| 366 | |
| 367 | |
| 368 | // Overview of time counters: |
| 369 | // (1) CPU cycle counter. (Retrieved via RDTSC) |
| 370 | // The CPU counter provides the highest resolution time stamp and is the least |
| 371 | // expensive to retrieve. However, the CPU counter is unreliable and should not |
| 372 | // be used in production. Its biggest issue is that it is per processor and it |
| 373 | // is not synchronized between processors. Also, on some computers, the counters |
| 374 | // will change frequency due to thermal and power changes, and stop in some |
| 375 | // states. |
| 376 | // |
| 377 | // (2) QueryPerformanceCounter (QPC). The QPC counter provides a high- |
| 378 | // resolution (100 nanoseconds) time stamp but is comparatively more expensive |
| 379 | // to retrieve. What QueryPerformanceCounter actually does is up to the HAL. |
| 380 | // (with some help from ACPI). |
| 381 | // According to http://blogs.msdn.com/oldnewthing/archive/2005/09/02/459952.aspx |
| 382 | // in the worst case, it gets the counter from the rollover interrupt on the |
| 383 | // programmable interrupt timer. In best cases, the HAL may conclude that the |
| 384 | // RDTSC counter runs at a constant frequency, then it uses that instead. On |
| 385 | // multiprocessor machines, it will try to verify the values returned from |
| 386 | // RDTSC on each processor are consistent with each other, and apply a handful |
| 387 | // of workarounds for known buggy hardware. In other words, QPC is supposed to |
| 388 | // give consistent result on a multiprocessor computer, but it is unreliable in |
| 389 | // reality due to bugs in BIOS or HAL on some, especially old computers. |
| 390 | // With recent updates on HAL and newer BIOS, QPC is getting more reliable but |
| 391 | // it should be used with caution. |
| 392 | // |
| 393 | // (3) System time. The system time provides a low-resolution (typically 10ms |
| 394 | // to 55 milliseconds) time stamp but is comparatively less expensive to |
| 395 | // retrieve and more reliable. |
| 396 | class HighResolutionTickClock FINAL : public TickClock { |
| 397 | public: |
| 398 | explicit HighResolutionTickClock(int64_t ticks_per_second) |
| 399 | : ticks_per_second_(ticks_per_second) { |
| 400 | DCHECK_LT(0, ticks_per_second); |
| 401 | } |
| 402 | virtual ~HighResolutionTickClock() {} |
| 403 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame^] | 404 | int64_t Now() OVERRIDE { |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 405 | LARGE_INTEGER now; |
| 406 | BOOL result = QueryPerformanceCounter(&now); |
| 407 | DCHECK(result); |
| 408 | USE(result); |
| 409 | |
| 410 | // Intentionally calculate microseconds in a round about manner to avoid |
| 411 | // overflow and precision issues. Think twice before simplifying! |
| 412 | int64_t whole_seconds = now.QuadPart / ticks_per_second_; |
| 413 | int64_t leftover_ticks = now.QuadPart % ticks_per_second_; |
| 414 | int64_t ticks = (whole_seconds * Time::kMicrosecondsPerSecond) + |
| 415 | ((leftover_ticks * Time::kMicrosecondsPerSecond) / ticks_per_second_); |
| 416 | |
| 417 | // Make sure we never return 0 here, so that TimeTicks::HighResolutionNow() |
| 418 | // will never return 0. |
| 419 | return ticks + 1; |
| 420 | } |
| 421 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame^] | 422 | bool IsHighResolution() OVERRIDE { return true; } |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 423 | |
| 424 | private: |
| 425 | int64_t ticks_per_second_; |
| 426 | }; |
| 427 | |
| 428 | |
| 429 | class RolloverProtectedTickClock FINAL : public TickClock { |
| 430 | public: |
| 431 | // We initialize rollover_ms_ to 1 to ensure that we will never |
| 432 | // return 0 from TimeTicks::HighResolutionNow() and TimeTicks::Now() below. |
| 433 | RolloverProtectedTickClock() : last_seen_now_(0), rollover_ms_(1) {} |
| 434 | virtual ~RolloverProtectedTickClock() {} |
| 435 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame^] | 436 | int64_t Now() OVERRIDE { |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 437 | LockGuard<Mutex> lock_guard(&mutex_); |
| 438 | // We use timeGetTime() to implement TimeTicks::Now(), which rolls over |
| 439 | // every ~49.7 days. We try to track rollover ourselves, which works if |
| 440 | // TimeTicks::Now() is called at least every 49 days. |
| 441 | // Note that we do not use GetTickCount() here, since timeGetTime() gives |
| 442 | // more predictable delta values, as described here: |
| 443 | // http://blogs.msdn.com/b/larryosterman/archive/2009/09/02/what-s-the-difference-between-gettickcount-and-timegettime.aspx |
| 444 | // timeGetTime() provides 1ms granularity when combined with |
| 445 | // timeBeginPeriod(). If the host application for V8 wants fast timers, it |
| 446 | // can use timeBeginPeriod() to increase the resolution. |
| 447 | DWORD now = timeGetTime(); |
| 448 | if (now < last_seen_now_) { |
| 449 | rollover_ms_ += V8_INT64_C(0x100000000); // ~49.7 days. |
| 450 | } |
| 451 | last_seen_now_ = now; |
| 452 | return (now + rollover_ms_) * Time::kMicrosecondsPerMillisecond; |
| 453 | } |
| 454 | |
Emily Bernier | d0a1eb7 | 2015-03-24 16:35:39 -0400 | [diff] [blame^] | 455 | bool IsHighResolution() OVERRIDE { return false; } |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 456 | |
| 457 | private: |
| 458 | Mutex mutex_; |
| 459 | DWORD last_seen_now_; |
| 460 | int64_t rollover_ms_; |
| 461 | }; |
| 462 | |
| 463 | |
| 464 | static LazyStaticInstance<RolloverProtectedTickClock, |
| 465 | DefaultConstructTrait<RolloverProtectedTickClock>, |
| 466 | ThreadSafeInitOnceTrait>::type tick_clock = |
| 467 | LAZY_STATIC_INSTANCE_INITIALIZER; |
| 468 | |
| 469 | |
| 470 | struct CreateHighResTickClockTrait { |
| 471 | static TickClock* Create() { |
| 472 | // Check if the installed hardware supports a high-resolution performance |
| 473 | // counter, and if not fallback to the low-resolution tick clock. |
| 474 | LARGE_INTEGER ticks_per_second; |
| 475 | if (!QueryPerformanceFrequency(&ticks_per_second)) { |
| 476 | return tick_clock.Pointer(); |
| 477 | } |
| 478 | |
| 479 | // On Athlon X2 CPUs (e.g. model 15) the QueryPerformanceCounter |
| 480 | // is unreliable, fallback to the low-resolution tick clock. |
| 481 | CPU cpu; |
| 482 | if (strcmp(cpu.vendor(), "AuthenticAMD") == 0 && cpu.family() == 15) { |
| 483 | return tick_clock.Pointer(); |
| 484 | } |
| 485 | |
| 486 | return new HighResolutionTickClock(ticks_per_second.QuadPart); |
| 487 | } |
| 488 | }; |
| 489 | |
| 490 | |
| 491 | static LazyDynamicInstance<TickClock, CreateHighResTickClockTrait, |
| 492 | ThreadSafeInitOnceTrait>::type high_res_tick_clock = |
| 493 | LAZY_DYNAMIC_INSTANCE_INITIALIZER; |
| 494 | |
| 495 | |
| 496 | TimeTicks TimeTicks::Now() { |
| 497 | // Make sure we never return 0 here. |
| 498 | TimeTicks ticks(tick_clock.Pointer()->Now()); |
| 499 | DCHECK(!ticks.IsNull()); |
| 500 | return ticks; |
| 501 | } |
| 502 | |
| 503 | |
| 504 | TimeTicks TimeTicks::HighResolutionNow() { |
| 505 | // Make sure we never return 0 here. |
| 506 | TimeTicks ticks(high_res_tick_clock.Pointer()->Now()); |
| 507 | DCHECK(!ticks.IsNull()); |
| 508 | return ticks; |
| 509 | } |
| 510 | |
| 511 | |
| 512 | // static |
| 513 | bool TimeTicks::IsHighResolutionClockWorking() { |
| 514 | return high_res_tick_clock.Pointer()->IsHighResolution(); |
| 515 | } |
| 516 | |
| 517 | |
| 518 | // static |
| 519 | TimeTicks TimeTicks::KernelTimestampNow() { return TimeTicks(0); } |
| 520 | |
| 521 | |
| 522 | // static |
| 523 | bool TimeTicks::KernelTimestampAvailable() { return false; } |
| 524 | |
| 525 | #else // V8_OS_WIN |
| 526 | |
| 527 | TimeTicks TimeTicks::Now() { |
| 528 | return HighResolutionNow(); |
| 529 | } |
| 530 | |
| 531 | |
| 532 | TimeTicks TimeTicks::HighResolutionNow() { |
| 533 | int64_t ticks; |
| 534 | #if V8_OS_MACOSX |
| 535 | static struct mach_timebase_info info; |
| 536 | if (info.denom == 0) { |
| 537 | kern_return_t result = mach_timebase_info(&info); |
| 538 | DCHECK_EQ(KERN_SUCCESS, result); |
| 539 | USE(result); |
| 540 | } |
| 541 | ticks = (mach_absolute_time() / Time::kNanosecondsPerMicrosecond * |
| 542 | info.numer / info.denom); |
| 543 | #elif V8_OS_SOLARIS |
| 544 | ticks = (gethrtime() / Time::kNanosecondsPerMicrosecond); |
| 545 | #elif V8_LIBRT_NOT_AVAILABLE |
| 546 | // TODO(bmeurer): This is a temporary hack to support cross-compiling |
| 547 | // Chrome for Android in AOSP. Remove this once AOSP is fixed, also |
| 548 | // cleanup the tools/gyp/v8.gyp file. |
| 549 | struct timeval tv; |
| 550 | int result = gettimeofday(&tv, NULL); |
| 551 | DCHECK_EQ(0, result); |
| 552 | USE(result); |
| 553 | ticks = (tv.tv_sec * Time::kMicrosecondsPerSecond + tv.tv_usec); |
| 554 | #elif V8_OS_POSIX |
| 555 | struct timespec ts; |
| 556 | int result = clock_gettime(CLOCK_MONOTONIC, &ts); |
| 557 | DCHECK_EQ(0, result); |
| 558 | USE(result); |
| 559 | ticks = (ts.tv_sec * Time::kMicrosecondsPerSecond + |
| 560 | ts.tv_nsec / Time::kNanosecondsPerMicrosecond); |
| 561 | #endif // V8_OS_MACOSX |
| 562 | // Make sure we never return 0 here. |
| 563 | return TimeTicks(ticks + 1); |
| 564 | } |
| 565 | |
| 566 | |
| 567 | // static |
| 568 | bool TimeTicks::IsHighResolutionClockWorking() { |
| 569 | return true; |
| 570 | } |
| 571 | |
| 572 | |
| 573 | #if V8_OS_LINUX && !V8_LIBRT_NOT_AVAILABLE |
| 574 | |
| 575 | class KernelTimestampClock { |
| 576 | public: |
| 577 | KernelTimestampClock() : clock_fd_(-1), clock_id_(kClockInvalid) { |
| 578 | clock_fd_ = open(kTraceClockDevice, O_RDONLY); |
| 579 | if (clock_fd_ == -1) { |
| 580 | return; |
| 581 | } |
| 582 | clock_id_ = get_clockid(clock_fd_); |
| 583 | } |
| 584 | |
| 585 | virtual ~KernelTimestampClock() { |
| 586 | if (clock_fd_ != -1) { |
| 587 | close(clock_fd_); |
| 588 | } |
| 589 | } |
| 590 | |
| 591 | int64_t Now() { |
| 592 | if (clock_id_ == kClockInvalid) { |
| 593 | return 0; |
| 594 | } |
| 595 | |
| 596 | struct timespec ts; |
| 597 | |
| 598 | clock_gettime(clock_id_, &ts); |
| 599 | return ((int64_t)ts.tv_sec * kNsecPerSec) + ts.tv_nsec; |
| 600 | } |
| 601 | |
| 602 | bool Available() { return clock_id_ != kClockInvalid; } |
| 603 | |
| 604 | private: |
| 605 | static const clockid_t kClockInvalid = -1; |
| 606 | static const char kTraceClockDevice[]; |
| 607 | static const uint64_t kNsecPerSec = 1000000000; |
| 608 | |
| 609 | int clock_fd_; |
| 610 | clockid_t clock_id_; |
| 611 | |
| 612 | static int get_clockid(int fd) { return ((~(clockid_t)(fd) << 3) | 3); } |
| 613 | }; |
| 614 | |
| 615 | |
| 616 | // Timestamp module name |
| 617 | const char KernelTimestampClock::kTraceClockDevice[] = "/dev/trace_clock"; |
| 618 | |
| 619 | #else |
| 620 | |
| 621 | class KernelTimestampClock { |
| 622 | public: |
| 623 | KernelTimestampClock() {} |
| 624 | |
| 625 | int64_t Now() { return 0; } |
| 626 | bool Available() { return false; } |
| 627 | }; |
| 628 | |
| 629 | #endif // V8_OS_LINUX && !V8_LIBRT_NOT_AVAILABLE |
| 630 | |
| 631 | static LazyStaticInstance<KernelTimestampClock, |
| 632 | DefaultConstructTrait<KernelTimestampClock>, |
| 633 | ThreadSafeInitOnceTrait>::type kernel_tick_clock = |
| 634 | LAZY_STATIC_INSTANCE_INITIALIZER; |
| 635 | |
| 636 | |
| 637 | // static |
| 638 | TimeTicks TimeTicks::KernelTimestampNow() { |
| 639 | return TimeTicks(kernel_tick_clock.Pointer()->Now()); |
| 640 | } |
| 641 | |
| 642 | |
| 643 | // static |
| 644 | bool TimeTicks::KernelTimestampAvailable() { |
| 645 | return kernel_tick_clock.Pointer()->Available(); |
| 646 | } |
| 647 | |
| 648 | #endif // V8_OS_WIN |
| 649 | |
| 650 | } } // namespace v8::base |