QSemaphore: add <chrono> overload of tryAcquire()

... and C++20 std::counting_semaphore API compatibility.

[ChangeLog][QtCore][QSemaphore] tryAcquire() now optionally takes a
<chrono> duration as timeout, not just int milliseconds.

[ChangeLog][QtCore][QSemaphore] Added try_acquire{,_for,_until}() for
C++20 std::counting_semaphore compatibility.

Change-Id: I34b6b4bf57a54745d4b97349903d090c4995338a
Reviewed-by: David Faure <david.faure@kdab.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

1 files changed, 40 insertions, 0 deletions

diff --git a/src/corelib/thread/qsemaphore.cpp b/src/corelib/thread/qsemaphore.cpp
index dfc179486c..23fded1cc0 100644
--- a/src/corelib/thread/qsemaphore.cpp
+++ b/src/corelib/thread/qsemaphore.cpp
@@ -486,6 +486,46 @@ bool QSemaphore::tryAcquire(int n, int timeout)
 }
 
 /*!
+    \fn template <typename Rep, typename Period> QSemaphore::tryAcquire(int n, std::chrono::duration<Rep, Period> timeout)
+    \overload
+    \since 6.3
+*/
+
+/*!
+    \fn QSemaphore::try_acquire()
+    \since 6.3
+
+    This function is provided for \c{std::counting_semaphore} compatibility.
+
+    It is equivalent to calling \c{tryAcquire(1)}.
+
+    \sa tryAcquire(), try_acquire_for(), try_acquire_until()
+*/
+
+/*!
+    \fn template <typename Rep, typename Period> QSemaphore::try_acquire_for(std::chrono::duration<Rep, Period> timeout)
+    \since 6.3
+
+    This function is provided for \c{std::counting_semaphore} compatibility.
+
+    It is equivalent to calling \c{tryAcquire(1, timeout)}.
+
+    \sa tryAcquire(), try_acquire(), try_acquire_until()
+*/
+
+/*!
+    \fn template <typename Clock, typename Duration> QSemaphore::try_acquire_until(std::chrono::time_point<Clock, Duration> timeout)
+    \since 6.3
+
+    This function is provided for \c{std::counting_semaphore} compatibility.
+
+    It is equivalent to calling \c{tryAcquire(1, timeout - Clock::now())},
+    which means that adjustments to \c{Clock} are ignored while waiting.
+
+    \sa tryAcquire(), try_acquire(), try_acquire_for()
+*/
+
+/*!
     \class QSemaphoreReleaser
     \brief The QSemaphoreReleaser class provides exception-safe deferral of a QSemaphore::release() call.
     \since 5.10