From d370c1b46e1733905fd76eec004be26475afae9d Mon Sep 17 00:00:00 2001
From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date: Wed, 23 Jan 2019 10:00:35 +0200
Subject: [PATCH] libcamera: event_dispatcher_poll: Handle interrupted ppoll()
 calls
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The ppoll() call can be interrupted if a signal is delivered. Handle the
EINTR error code gracefully by restarting the call. This fixes the
event-dispatcher test failure.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
---
 src/libcamera/event_dispatcher_poll.cpp       | 58 +++++++++++--------
 src/libcamera/include/event_dispatcher_poll.h |  1 +
 2 files changed, 34 insertions(+), 25 deletions(-)

diff --git a/src/libcamera/event_dispatcher_poll.cpp b/src/libcamera/event_dispatcher_poll.cpp
index eefac54ca..6e0609c34 100644
--- a/src/libcamera/event_dispatcher_poll.cpp
+++ b/src/libcamera/event_dispatcher_poll.cpp
@@ -128,6 +128,37 @@ void EventDispatcherPoll::processEvents()
 	for (auto notifier : notifiers_)
 		pollfds.push_back({ notifier.first, notifier.second.events(), 0 });
 
+	/* Wait for events and process notifiers and timers. */
+	do {
+		ret = poll(&pollfds);
+	} while (ret == -1 && errno == EINTR);
+
+	if (ret < 0) {
+		ret = -errno;
+		LOG(Event, Warning) << "poll() failed with " << strerror(-ret);
+	} else if (ret > 0) {
+		processNotifiers(pollfds);
+	}
+
+	processTimers();
+}
+
+short EventDispatcherPoll::EventNotifierSetPoll::events() const
+{
+	short events = 0;
+
+	if (notifiers[EventNotifier::Read])
+		events |= POLLIN;
+	if (notifiers[EventNotifier::Write])
+		events |= POLLOUT;
+	if (notifiers[EventNotifier::Exception])
+		events |= POLLPRI;
+
+	return events;
+}
+
+int EventDispatcherPoll::poll(std::vector<struct pollfd> *pollfds)
+{
 	/* Compute the timeout. */
 	Timer *nextTimer = !timers_.empty() ? timers_.front() : nullptr;
 	struct timespec timeout;
@@ -151,31 +182,8 @@ void EventDispatcherPoll::processEvents()
 			<< timeout.tv_nsec;
 	}
 
-	/* Wait for events and process notifiers and timers. */
-	ret = ppoll(pollfds.data(), pollfds.size(),
-		    nextTimer ? &timeout : nullptr, nullptr);
-	if (ret < 0) {
-		ret = -errno;
-		LOG(Event, Warning) << "poll() failed with " << strerror(-ret);
-	} else if (ret > 0) {
-		processNotifiers(pollfds);
-	}
-
-	processTimers();
-}
-
-short EventDispatcherPoll::EventNotifierSetPoll::events() const
-{
-	short events = 0;
-
-	if (notifiers[EventNotifier::Read])
-		events |= POLLIN;
-	if (notifiers[EventNotifier::Write])
-		events |= POLLOUT;
-	if (notifiers[EventNotifier::Exception])
-		events |= POLLPRI;
-
-	return events;
+	return ppoll(pollfds->data(), pollfds->size(),
+		     nextTimer ? &timeout : nullptr, nullptr);
 }
 
 void EventDispatcherPoll::processNotifiers(const std::vector<struct pollfd> &pollfds)
diff --git a/src/libcamera/include/event_dispatcher_poll.h b/src/libcamera/include/event_dispatcher_poll.h
index a41926e11..ac3efde08 100644
--- a/src/libcamera/include/event_dispatcher_poll.h
+++ b/src/libcamera/include/event_dispatcher_poll.h
@@ -41,6 +41,7 @@ private:
 	std::map<int, EventNotifierSetPoll> notifiers_;
 	std::list<Timer *> timers_;
 
+	int poll(std::vector<struct pollfd> *pollfds);
 	void processNotifiers(const std::vector<struct pollfd> &pollfds);
 	void processTimers();
 };