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QtLinuxFutex, QBasicMutex, QSemaphore: use chrono for time arithmetic

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Done-With: Thiago Macieira <thiago.macieira@intel.com>
Change-Id: I7c696d58ee596254f91bcd131fe884b6e6ef0852
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
This commit is contained in:
Ahmad Samir 2022-10-31 12:50:39 +02:00
parent 71c9b9f05b
commit 3e7d68a6f4
3 changed files with 26 additions and 20 deletions
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18
src/corelib/thread/qfutex_p.h
View File

@ -18,12 +18,14 @@
#include <private/qglobal_p.h>
#include <QtCore/qtsan_impl.h>
#include <chrono>
QT_BEGIN_NAMESPACE
namespace QtDummyFutex {
constexpr inline bool futexAvailable() { return false; }
template <typename Atomic>
inline bool futexWait(Atomic &, typename Atomic::Type, int = 0)
inline bool futexWait(Atomic &, typename Atomic::Type, std::chrono::nanoseconds = {})
{ Q_UNREACHABLE_RETURN(false); }
template <typename Atomic> inline void futexWakeOne(Atomic &)
{ Q_UNREACHABLE(); }
@ -34,6 +36,7 @@ namespace QtDummyFutex {
QT_END_NAMESPACE
#if defined(Q_OS_LINUX) && !defined(QT_LINUXBASE)
# include <private/qcore_unix_p.h>
// use Linux mutexes everywhere except for LSB builds
# include <sys/syscall.h>
# include <errno.h>
@ -83,11 +86,9 @@ namespace QtLinuxFutex {
_q_futex(addr(&futex), FUTEX_WAIT, qintptr(expectedValue));
}
template <typename Atomic>
inline bool futexWait(Atomic &futex, typename Atomic::Type expectedValue, qint64 nstimeout)
inline bool futexWait(Atomic &futex, typename Atomic::Type expectedValue, std::chrono::nanoseconds timeout)
{
struct timespec ts;
ts.tv_sec = nstimeout / 1000 / 1000 / 1000;
ts.tv_nsec = nstimeout % (1000 * 1000 * 1000);
struct timespec ts= durationToTimespec(timeout);
int r = _q_futex(addr(&futex), FUTEX_WAIT, qintptr(expectedValue), quintptr(&ts));
return r == 0 || errno != ETIMEDOUT;
}
@ -124,9 +125,12 @@ inline void futexWait(Atomic &futex, typename Atomic::Type expectedValue)
QtTsan::futexAcquire(&futex);
}
template <typename Atomic>
inline bool futexWait(Atomic &futex, typename Atomic::Type expectedValue, qint64 nstimeout)
inline bool futexWait(Atomic &futex, typename Atomic::Type expectedValue, std::chrono::nanoseconds timeout)
{
BOOL r = WaitOnAddress(&futex, &expectedValue, sizeof(expectedValue), DWORD(nstimeout / 1000 / 1000));
using namespace std::chrono;
// Using ceil so that any non-zero timeout doesn't get trunated to 0ms
auto msecs = ceil<milliseconds>(timeout);
BOOL r = WaitOnAddress(&futex, &expectedValue, sizeof(expectedValue), DWORD(msecs.count()));
return r || GetLastError() != ERROR_TIMEOUT;
}
template <typename Atomic> inline void futexWakeAll(Atomic &futex)

19
src/corelib/thread/qmutex.cpp
View File

@ -673,12 +673,13 @@ bool QBasicMutex::lockInternal(int timeout) QT_MUTEX_LOCK_NOEXCEPT
*/
bool QBasicMutex::lockInternal(QDeadlineTimer deadlineTimer) QT_MUTEX_LOCK_NOEXCEPT
{
qint64 remainingTime = deadlineTimer.remainingTimeNSecs();
if (remainingTime == 0)
using namespace std::chrono;
nanoseconds remainingTime = deadlineTimer.remainingTimeAsDuration();
if (remainingTime == 0ns)
return false;
if (futexAvailable()) {
if (Q_UNLIKELY(remainingTime < 0)) { // deadlineTimer.isForever()
if (Q_UNLIKELY(deadlineTimer.isForever())) {
lockInternal();
return true;
}
@ -689,7 +690,7 @@ bool QBasicMutex::lockInternal(QDeadlineTimer deadlineTimer) QT_MUTEX_LOCK_NOEXC
if (d_ptr.fetchAndStoreAcquire(dummyFutexValue()) == nullptr)
return true;
Q_FOREVER {
for (;;) {
if (!futexWait(d_ptr, dummyFutexValue(), remainingTime))
return false;
@ -700,8 +701,8 @@ bool QBasicMutex::lockInternal(QDeadlineTimer deadlineTimer) QT_MUTEX_LOCK_NOEXC
return true;
// calculate the remaining time
remainingTime = deadlineTimer.remainingTimeNSecs();
if (remainingTime <= 0)
remainingTime = deadlineTimer.remainingTimeAsDuration();
if (remainingTime == 0ns)
return false;
}
}
@ -713,7 +714,7 @@ bool QBasicMutex::lockInternal(QDeadlineTimer deadlineTimer) QT_MUTEX_LOCK_NOEXC
continue;
if (copy == dummyLocked()) {
if (remainingTime == 0)
if (remainingTime == 0ns)
return false;
// The mutex is locked but does not have a QMutexPrivate yet.
// we need to allocate a QMutexPrivate
@ -728,7 +729,7 @@ bool QBasicMutex::lockInternal(QDeadlineTimer deadlineTimer) QT_MUTEX_LOCK_NOEXC
}
QMutexPrivate *d = static_cast<QMutexPrivate *>(copy);
if (remainingTime == 0 && !d->possiblyUnlocked.loadRelaxed())
if (remainingTime == 0ns && !d->possiblyUnlocked.loadRelaxed())
return false;
// At this point we have a pointer to a QMutexPrivate. But the other thread
@ -790,7 +791,7 @@ bool QBasicMutex::lockInternal(QDeadlineTimer deadlineTimer) QT_MUTEX_LOCK_NOEXC
Q_ASSERT(d == d_ptr.loadRelaxed());
return true;
} else {
Q_ASSERT(remainingTime >= 0);
Q_ASSERT(remainingTime >= 0ns);
// timed out
d->derefWaiters(1);
//There may be a race in which the mutex is unlocked right after we timed out,

9
src/corelib/thread/qsemaphore.cpp
View File

@ -148,7 +148,8 @@ template <bool IsTimed> bool
futexSemaphoreTryAcquire_loop(QBasicAtomicInteger<quintptr> &u, quintptr curValue, quintptr nn,
QDeadlineTimer timer)
{
qint64 remainingTime = IsTimed ? timer.remainingTimeNSecs() : -1;
using namespace std::chrono;
nanoseconds remainingTime = IsTimed ? timer.remainingTimeAsDuration() : -1ns;
int n = int(unsigned(nn));
// we're called after one testAndSet, so start by waiting first
@ -165,7 +166,7 @@ futexSemaphoreTryAcquire_loop(QBasicAtomicInteger<quintptr> &u, quintptr curValu
}
}
if (IsTimed && remainingTime > 0) {
if (IsTimed && remainingTime > 0ns) {
bool timedout = !futexWait(*ptr, curValue, remainingTime);
if (timedout)
return false;
@ -175,7 +176,7 @@ futexSemaphoreTryAcquire_loop(QBasicAtomicInteger<quintptr> &u, quintptr curValu
curValue = u.loadAcquire();
if (IsTimed)
remainingTime = timer.remainingTimeNSecs();
remainingTime = timer.remainingTimeAsDuration();
// try to acquire
while (futexAvailCounter(curValue) >= n) {
@ -185,7 +186,7 @@ futexSemaphoreTryAcquire_loop(QBasicAtomicInteger<quintptr> &u, quintptr curValu
}
// not enough tokens available, put us to wait
if (remainingTime == 0)
if (IsTimed && remainingTime == 0ns)
return false;
}
}