apps: Share common source between applications

Multiple source files in the src/apps/cam/ directory are used by cam,
qcam and lc-compliance. They are compiled separately for each
application. Move them to a new src/apps/common/ directory and compile
them in a static library to decrease the number of compilation
operations.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

1 files changed, 68 insertions, 0 deletions

diff --git a/src/apps/common/event_loop.h b/src/apps/common/event_loop.h
new file mode 100644
index 00000000..ef79e8e5
--- /dev/null
+++ b/src/apps/common/event_loop.h
@@ -0,0 +1,68 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2019, Google Inc.
+ *
+ * event_loop.h - cam - Event loop
+ */
+
+#pragma once
+
+#include <chrono>
+#include <functional>
+#include <list>
+#include <memory>
+#include <mutex>
+
+#include <event2/util.h>
+
+struct event_base;
+
+class EventLoop
+{
+public:
+	enum EventType {
+		Read = 1,
+		Write = 2,
+	};
+
+	EventLoop();
+	~EventLoop();
+
+	static EventLoop *instance();
+
+	int exec();
+	void exit(int code = 0);
+
+	void callLater(const std::function<void()> &func);
+
+	void addFdEvent(int fd, EventType type,
+			const std::function<void()> &handler);
+
+	using duration = std::chrono::steady_clock::duration;
+	void addTimerEvent(const std::chrono::microseconds period,
+			   const std::function<void()> &handler);
+
+private:
+	struct Event {
+		Event(const std::function<void()> &callback);
+		~Event();
+
+		static void dispatch(int fd, short events, void *arg);
+
+		std::function<void()> callback_;
+		struct event *event_;
+	};
+
+	static EventLoop *instance_;
+
+	struct event_base *base_;
+	int exitCode_;
+
+	std::list<std::function<void()>> calls_;
+	std::list<std::unique_ptr<Event>> events_;
+	std::mutex lock_;
+
+	static void dispatchCallback(evutil_socket_t fd, short flags,
+				     void *param);
+	void dispatchCall();
+};