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Issue 1153543004: Version 4.5.18.1 (cherry-pick) (Closed) Base URL: https://chromium.googlesource.com/v8/v8.git@4.5.18
Patch Set: Created 5 years, 7 months ago
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1 // Copyright 2013 the V8 project authors. All rights reserved. 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 2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file. 3 // found in the LICENSE file.
4 4
5 #include "src/base/platform/time.h" 5 #include "src/base/platform/time.h"
6 6
7 #if V8_OS_POSIX 7 #if V8_OS_POSIX
8 #include <fcntl.h> // for O_RDONLY 8 #include <fcntl.h> // for O_RDONLY
9 #include <sys/time.h> 9 #include <sys/time.h>
10 #include <unistd.h> 10 #include <unistd.h>
11 #endif 11 #endif
12 #if V8_OS_MACOSX 12 #if V8_OS_MACOSX
13 #include <mach/mach_time.h> 13 #include <mach/mach_time.h>
14 #endif 14 #endif
15 15
16 #include <cstring> 16 #include <cstring>
17 #include <ostream> 17 #include <ostream>
18 18
19 #if V8_OS_WIN 19 #if V8_OS_WIN
20 #include "src/base/lazy-instance.h" 20 #include "src/base/lazy-instance.h"
21 #include "src/base/win32-headers.h" 21 #include "src/base/win32-headers.h"
22 #endif 22 #endif
23 #include "src/base/atomicops.h"
24 #include "src/base/cpu.h" 23 #include "src/base/cpu.h"
25 #include "src/base/logging.h" 24 #include "src/base/logging.h"
26 #include "src/base/platform/platform.h" 25 #include "src/base/platform/platform.h"
27 26
28 // CLOCK_REALTIME_COARSE was added in Linux 2.6.32.
29 #if V8_OS_LINUX && !defined(CLOCK_REALTIME_COARSE)
30 #define CLOCK_REALTIME_COARSE 5
31 #endif
32
33 namespace v8 { 27 namespace v8 {
34 namespace base { 28 namespace base {
35 29
36 TimeDelta TimeDelta::FromDays(int days) { 30 TimeDelta TimeDelta::FromDays(int days) {
37 return TimeDelta(days * Time::kMicrosecondsPerDay); 31 return TimeDelta(days * Time::kMicrosecondsPerDay);
38 } 32 }
39 33
40 34
41 TimeDelta TimeDelta::FromHours(int hours) { 35 TimeDelta TimeDelta::FromHours(int hours) {
42 return TimeDelta(hours * Time::kMicrosecondsPerHour); 36 return TimeDelta(hours * Time::kMicrosecondsPerHour);
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251 } 245 }
252 uint64_t us = static_cast<uint64_t>(us_ + kTimeToEpochInMicroseconds) * 10; 246 uint64_t us = static_cast<uint64_t>(us_ + kTimeToEpochInMicroseconds) * 10;
253 ft.dwLowDateTime = static_cast<DWORD>(us); 247 ft.dwLowDateTime = static_cast<DWORD>(us);
254 ft.dwHighDateTime = static_cast<DWORD>(us >> 32); 248 ft.dwHighDateTime = static_cast<DWORD>(us >> 32);
255 return ft; 249 return ft;
256 } 250 }
257 251
258 #elif V8_OS_POSIX 252 #elif V8_OS_POSIX
259 253
260 Time Time::Now() { 254 Time Time::Now() {
261 #ifdef CLOCK_REALTIME_COARSE
262 struct timespec ts;
263 static const clockid_t kInvalidClockId = static_cast<clockid_t>(-1);
264 static clockid_t cached_clock_id = kInvalidClockId;
265 clockid_t clock_id = NoBarrier_Load(&cached_clock_id);
266 if (V8_UNLIKELY(clock_id == kInvalidClockId)) {
267 // Use CLOCK_REALTIME_COARSE when available (linux >= 2.6.32) and precise
268 // enough. Unlike CLOCK_REALTIME, its coarse cousin is normally serviced
269 // from the vDSO, without making an actual system call.
270 //
271 // CLOCK_REALTIME_COARSE precision is determined by CONFIG_HZ, the number
272 // of ticks per second that the kernel runs at. Granularity can be as low
273 // as one update every few hundred milliseconds so we need to ensure it is
274 // not _too_ coarse. Most kernels are built with CONFIG_HZ=1000, providing
275 // a one millisecond precision that is good enough for our purposes.
276 if (clock_getres(CLOCK_REALTIME_COARSE, &ts) < 0 || ts.tv_sec > 0 ||
277 ts.tv_nsec > 1000 * 1000) {
278 clock_id = CLOCK_REALTIME; // Not available or not suitable.
279 } else {
280 clock_id = CLOCK_REALTIME_COARSE;
281 }
282 NoBarrier_Store(&cached_clock_id, clock_id);
283 }
284 int result = clock_gettime(clock_id, &ts);
285 DCHECK_EQ(0, result);
286 USE(result);
287 return FromTimespec(ts);
288 #else
289 struct timeval tv; 255 struct timeval tv;
290 int result = gettimeofday(&tv, NULL); 256 int result = gettimeofday(&tv, NULL);
291 DCHECK_EQ(0, result); 257 DCHECK_EQ(0, result);
292 USE(result); 258 USE(result);
293 return FromTimeval(tv); 259 return FromTimeval(tv);
294 #endif
295 } 260 }
296 261
297 262
298 Time Time::NowFromSystemTime() { 263 Time Time::NowFromSystemTime() {
299 return Now(); 264 return Now();
300 } 265 }
301 266
302 267
303 Time Time::FromTimespec(struct timespec ts) { 268 Time Time::FromTimespec(struct timespec ts) {
304 DCHECK(ts.tv_nsec >= 0); 269 DCHECK(ts.tv_nsec >= 0);
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673 638
674 639
675 // static 640 // static
676 bool TimeTicks::KernelTimestampAvailable() { 641 bool TimeTicks::KernelTimestampAvailable() {
677 return kernel_tick_clock.Pointer()->Available(); 642 return kernel_tick_clock.Pointer()->Available();
678 } 643 }
679 644
680 #endif // V8_OS_WIN 645 #endif // V8_OS_WIN
681 646
682 } } // namespace v8::base 647 } } // namespace v8::base
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