1 files changed, 105 insertions, 0 deletions
diff --git a/src/libcamera/timer.cpp b/src/libcamera/timer.cpp
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--- /dev/null
+++ b/src/libcamera/timer.cpp
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+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2019, Google Inc.
+ *
+ * timer.cpp - Generic timer
+ */
+
+#include <time.h>
+
+#include <libcamera/camera_manager.h>
+#include <libcamera/event_dispatcher.h>
+#include <libcamera/timer.h>
+
+#include "log.h"
+
+/**
+ * \file timer.h
+ * \brief Generic timer
+ */
+
+namespace libcamera {
+
+/**
+ * \class Timer
+ * \brief Single-shot timer interface
+ *
+ * The Timer class models a single-shot timer that is started with start() and
+ * emits the \ref timeout signal when it times out.
+ *
+ * Once started the timer will run until it times out. It can be stopped with
+ * stop(), and once it times out or is stopped, can be started again with
+ * start().
+ */
+
+/**
+ * \brief Construct a timer
+ */
+Timer::Timer()
+{
+}
+
+/**
+ * \brief Start or restart the timer with a timeout of \a msec
+ * \param msec The timer duration in milliseconds
+ *
+ * If the timer is already running it will be stopped and restarted.
+ */
+void Timer::start(unsigned int msec)
+{
+	struct timespec tp;
+	clock_gettime(CLOCK_MONOTONIC, &tp);
+
+	interval_ = msec;
+	deadline_ = tp.tv_sec * 1000000000ULL + tp.tv_nsec + msec * 1000000;
+
+	LOG(Debug) << "Starting timer " << this << " with interval " << msec
+		   << ": deadline " << deadline_;
+
+	CameraManager::instance()->eventDispatcher()->registerTimer(this);
+}
+
+/**
+ * \brief Stop the timer
+ *
+ * After this function returns the timer is guaranteed not to emit the
+ * \ref timeout signal.
+ *
+ * If the timer is not running this function performs no operation.
+ */
+void Timer::stop()
+{
+	CameraManager::instance()->eventDispatcher()->unregisterTimer(this);
+
+	deadline_ = 0;
+}
+
+/**
+ * \brief Check if the timer is running
+ * \return True if the timer is running, false otherwise
+ */
+bool Timer::isRunning() const
+{
+	return deadline_ != 0;
+}
+
+/**
+ * \fn Timer::interval()
+ * \brief Retrieve the timer interval
+ * \return The timer interval in milliseconds
+ */
+
+/**
+ * \fn Timer::deadline()
+ * \brief Retrieve the timer deadline
+ * \return The timer deadline in nanoseconds
+ */
+
+/**
+ * \var Timer::timeout
+ * \brief Signal emitted when the timer times out
+ *
+ * The timer pointer is passed as a parameter.
+ */
+
+} /* namespace libcamera */