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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
commit36d22d82aa202bb199967e9512281e9a53db42c9 (patch)
tree105e8c98ddea1c1e4784a60a5a6410fa416be2de /netwerk/base/PollableEvent.h
parentInitial commit. (diff)
downloadfirefox-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 'netwerk/base/PollableEvent.h')
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1 files changed, 67 insertions, 0 deletions
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+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef PollableEvent_h__
+#define PollableEvent_h__
+
+#include "mozilla/Mutex.h"
+#include "mozilla/TimeStamp.h"
+
+struct PRFileDesc;
+
+namespace mozilla {
+namespace net {
+
+// class must be called locked
+class PollableEvent {
+ public:
+ PollableEvent();
+ ~PollableEvent();
+
+ // Signal/Clear return false only if they fail
+ bool Signal();
+ // This is called only when we get non-null out_flags for the socket pair
+ bool Clear();
+ bool Valid() { return mWriteFD && mReadFD; }
+
+ // We want to detect if writing to one of the socket pair sockets takes
+ // too long to be received by the other socket from the pair.
+ // Hence, we remember the timestamp of the earliest write by a call to
+ // MarkFirstSignalTimestamp() from Signal(). After waking up from poll()
+ // we check how long it took get the 'readable' signal on the socket pair.
+ void MarkFirstSignalTimestamp();
+ // Called right before we enter poll() to exclude any possible delay between
+ // the earlist call to Signal() and entering poll() caused by processing
+ // of events dispatched to the socket transport thread.
+ void AdjustFirstSignalTimestamp();
+ // This returns false on following conditions:
+ // - PR_Write has failed
+ // - no out_flags were signalled on the socket pair for too long after
+ // the earliest Signal()
+ bool IsSignallingAlive(TimeDuration const& timeout);
+
+ PRFileDesc* PollableFD() { return mReadFD; }
+
+ private:
+ PRFileDesc* mWriteFD{nullptr};
+ PRFileDesc* mReadFD{nullptr};
+ bool mSignaled{false};
+ // true when PR_Write to the socket pair has failed (status < 1)
+ bool mWriteFailed{false};
+ // Set true after AdjustFirstSignalTimestamp() was called
+ // Set false after Clear() was called
+ // Ensures shifting the timestamp before entering poll() only once
+ // between Clear()'ings.
+ bool mSignalTimestampAdjusted{false};
+ // Timestamp of the first call to Signal() (or time we enter poll())
+ // that happened after the last Clear() call
+ TimeStamp mFirstSignalAfterClear;
+};
+
+} // namespace net
+} // namespace mozilla
+
+#endif