ac49cedc7e
pthread's and semaphore's default behavior is to use CLOCK_REALTIME,
however this behavior is essentially never intended, as that clock is
prone to change discontinuously.
What users really intend is to use CLOCK_MONOTONIC, however only
pthread_cond_timedwait() provides this as an option and even there, a
large amount of existing code does not opt into CLOCK_MONOTONIC.
We have seen numerous bugs directly attributable to this difference.
Therefore, we provide this general workaround to always use
CLOCK_MONOTONIC for waiting, regardless of what the input timespec
is.
Specifically this impacts the below APIs:
pthread_mutex_timedlock()
pthread_cond_timedwait()
pthread_rwlock_timedrdlock()
pthread_rwlock_timedwrlock()
sem_timedwait()
Test: boot bullhead, boot sailfish
Test: bionic pthread/semaphore unit tests
Test: check that pthread_cond_timedwait() timeouts are uneffected by
CLOCK_REALTIME time changes
Bug: 64694413
Bug: 64623895
Bug: 35756266
Bug: 35678943
Change-Id: Ibba98f5d88be1c306d14e9b9366302ecbef6d534
74 lines
2.7 KiB
C++
74 lines
2.7 KiB
C++
/*
|
|
* Copyright (C) 2013 The Android Open Source Project
|
|
* 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.
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#include "private/bionic_time_conversions.h"
|
|
|
|
#include "private/bionic_constants.h"
|
|
|
|
bool timespec_from_timeval(timespec& ts, const timeval& tv) {
|
|
// Whole seconds can just be copied.
|
|
ts.tv_sec = tv.tv_sec;
|
|
|
|
// But we might overflow when converting microseconds to nanoseconds.
|
|
if (tv.tv_usec >= 1000000 || tv.tv_usec < 0) {
|
|
return false;
|
|
}
|
|
ts.tv_nsec = tv.tv_usec * 1000;
|
|
return true;
|
|
}
|
|
|
|
void timespec_from_ms(timespec& ts, const int ms) {
|
|
ts.tv_sec = ms / 1000;
|
|
ts.tv_nsec = (ms % 1000) * 1000000;
|
|
}
|
|
|
|
void timeval_from_timespec(timeval& tv, const timespec& ts) {
|
|
tv.tv_sec = ts.tv_sec;
|
|
tv.tv_usec = ts.tv_nsec / 1000;
|
|
}
|
|
|
|
void monotonic_time_from_realtime_time(timespec& monotonic_time, const timespec& realtime_time) {
|
|
monotonic_time = realtime_time;
|
|
|
|
timespec cur_monotonic_time;
|
|
clock_gettime(CLOCK_MONOTONIC, &cur_monotonic_time);
|
|
timespec cur_realtime_time;
|
|
clock_gettime(CLOCK_REALTIME, &cur_realtime_time);
|
|
|
|
monotonic_time.tv_nsec -= cur_realtime_time.tv_nsec;
|
|
monotonic_time.tv_nsec += cur_monotonic_time.tv_nsec;
|
|
if (monotonic_time.tv_nsec >= NS_PER_S) {
|
|
monotonic_time.tv_nsec -= NS_PER_S;
|
|
monotonic_time.tv_sec += 1;
|
|
} else if (monotonic_time.tv_nsec < 0) {
|
|
monotonic_time.tv_nsec += NS_PER_S;
|
|
monotonic_time.tv_sec -= 1;
|
|
}
|
|
monotonic_time.tv_sec -= cur_realtime_time.tv_sec;
|
|
monotonic_time.tv_sec += cur_monotonic_time.tv_sec;
|
|
}
|