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cd5127b11e
This reverts commit dfe19719e5.
Reason for revert: Breaks fuzzers in Chromium builds. See https://ci.chromium.org/ui/p/chromium/builders/try/linux-libfuzzer-asan-rel/685438/overview. I am reverting since this blocks the roll but I will be in touch for a fix.
Original change's description:
> Enable use of rtc::SystemTimeNanos() provided by Chromium
>
> This is the third CL out of three to enable overriding
> of the function SystemTimeNanos() in rtc_base/system_time.cc
>
> When WebRTC is built as part of Chromium the rtc::SystemTimeNanos()
> function provided by Chromium will be used. This is controlled
> by the build argument rtc_exclude_system_time which directly
> maps to the macro WEBRTC_EXCLUDE_SYSTEM_TIME.
>
> By doing this we are making sure that the WebRTC and Chromium
> clocks are the same.
>
> Bug: chromium:516700
> Change-Id: If7f749c4aadefb1cfc07ba4c7e3f45dc6c31118b
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/208223
> Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
> Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#33337}
TBR=kron@webrtc.org
Bug: chromium:516700
Change-Id: I9ecd1784a6c1cdac8bae07d34f7df20c62a21a95
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/208740
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33340}
92 lines
2.9 KiB
C++
92 lines
2.9 KiB
C++
/*
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* Copyright 2021 The WebRTC Project Authors. All rights reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include <stdint.h>
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#include <limits>
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#if defined(WEBRTC_POSIX)
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#include <sys/time.h>
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#if defined(WEBRTC_MAC)
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#include <mach/mach_time.h>
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#endif
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#endif
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#if defined(WEBRTC_WIN)
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// clang-format off
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// clang formatting would put <windows.h> last,
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// which leads to compilation failure.
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#include <windows.h>
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#include <mmsystem.h>
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#include <sys/timeb.h>
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// clang-format on
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#endif
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#include "rtc_base/checks.h"
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#include "rtc_base/numerics/safe_conversions.h"
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#include "rtc_base/system_time.h"
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#include "rtc_base/time_utils.h"
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namespace rtc {
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int64_t SystemTimeNanos() {
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int64_t ticks;
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#if defined(WEBRTC_MAC)
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static mach_timebase_info_data_t timebase;
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if (timebase.denom == 0) {
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// Get the timebase if this is the first time we run.
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// Recommended by Apple's QA1398.
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if (mach_timebase_info(&timebase) != KERN_SUCCESS) {
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RTC_NOTREACHED();
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}
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}
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// Use timebase to convert absolute time tick units into nanoseconds.
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const auto mul = [](uint64_t a, uint32_t b) -> int64_t {
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RTC_DCHECK_NE(b, 0);
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RTC_DCHECK_LE(a, std::numeric_limits<int64_t>::max() / b)
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<< "The multiplication " << a << " * " << b << " overflows";
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return rtc::dchecked_cast<int64_t>(a * b);
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};
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ticks = mul(mach_absolute_time(), timebase.numer) / timebase.denom;
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#elif defined(WEBRTC_POSIX)
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struct timespec ts;
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// TODO(deadbeef): Do we need to handle the case when CLOCK_MONOTONIC is not
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// supported?
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clock_gettime(CLOCK_MONOTONIC, &ts);
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ticks = kNumNanosecsPerSec * static_cast<int64_t>(ts.tv_sec) +
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static_cast<int64_t>(ts.tv_nsec);
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#elif defined(WINUWP)
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ticks = WinUwpSystemTimeNanos();
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#elif defined(WEBRTC_WIN)
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static volatile LONG last_timegettime = 0;
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static volatile int64_t num_wrap_timegettime = 0;
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volatile LONG* last_timegettime_ptr = &last_timegettime;
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DWORD now = timeGetTime();
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// Atomically update the last gotten time
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DWORD old = InterlockedExchange(last_timegettime_ptr, now);
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if (now < old) {
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// If now is earlier than old, there may have been a race between threads.
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// 0x0fffffff ~3.1 days, the code will not take that long to execute
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// so it must have been a wrap around.
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if (old > 0xf0000000 && now < 0x0fffffff) {
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num_wrap_timegettime++;
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}
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}
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ticks = now + (num_wrap_timegettime << 32);
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// TODO(deadbeef): Calculate with nanosecond precision. Otherwise, we're
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// just wasting a multiply and divide when doing Time() on Windows.
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ticks = ticks * kNumNanosecsPerMillisec;
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#else
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#error Unsupported platform.
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#endif
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return ticks;
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}
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} // namespace rtc
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