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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /docs/nspr/reference/pr_intervalnow.rst | |
parent | Initial commit. (diff) | |
download | firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'docs/nspr/reference/pr_intervalnow.rst')
-rw-r--r-- | docs/nspr/reference/pr_intervalnow.rst | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/docs/nspr/reference/pr_intervalnow.rst b/docs/nspr/reference/pr_intervalnow.rst new file mode 100644 index 0000000000..360dd6455a --- /dev/null +++ b/docs/nspr/reference/pr_intervalnow.rst @@ -0,0 +1,50 @@ +PR_IntervalNow +============== + +Returns the value of NSPR's free-running interval timer. + + +Syntax +------ + +.. code:: + + #include <prinrval.h> + + PRIntervalTime PR_IntervalNow(void); + + +Returns +~~~~~~~ + +A :ref:`PRIntervalTime` object. + + +Description +----------- + +You can use the value returned by ``PR_IntervalNow()`` to establish +epochs and to determine intervals (that is, compute the difference +between two times). ``PR_IntervalNow()`` is both very efficient and +nonblocking, so it is appropriate to use (for example) while holding a +mutex. + +The most common use for ``PR_IntervalNow()`` is to establish an epoch +and test for the expiration of intervals. In this case, you typically +call ``PR_IntervalNow()`` in a sequence that looks like this: + +.. code:: + + PRUint32 interval = ... ; // milliseconds + // ... + PRStatus rv; + PRIntervalTime epoch = PR_IntervalNow(); + PR_Lock(data->mutex); + while (!EvaluateData(data)) /* wait until condition is met */ + { + PRUint32 delta = PR_IntervalToMilliseconds(PR_IntervalNow() - epoch); + if (delta > interval) break; /* timeout */ + rv = PR_Wait(data->condition, PR_MillisecondsToInterval(interval - delta)); + if (PR_FAILURE == rv) break; /* likely an interrupt */ + } + PR_Unlock(data->mutex); |