1 files changed, 41 insertions, 17 deletions

diff --git a/src/event/Loop.hxx b/src/event/Loop.hxx
index 62e733747..029d01245 100644
--- a/src/event/Loop.hxx
+++ b/src/event/Loop.hxx
@@ -24,8 +24,8 @@
 #include "thread/Id.hxx"
 #include "Compiler.h"
 
-#ifdef USE_EPOLL
-#include "system/EPollFD.hxx"
+#ifdef USE_INTERNAL_EVENTLOOP
+#include "PollGroup.hxx"
 #include "thread/Mutex.hxx"
 #include "WakeFD.hxx"
 #include "SocketMonitor.hxx"
@@ -33,11 +33,13 @@
 #include <functional>
 #include <list>
 #include <set>
-#else
+#endif
+
+#ifdef USE_GLIB_EVENTLOOP
 #include <glib.h>
 #endif
 
-#ifdef USE_EPOLL
+#ifdef USE_INTERNAL_EVENTLOOP
 class TimeoutMonitor;
 class IdleMonitor;
 class SocketMonitor;
@@ -45,12 +47,21 @@ class SocketMonitor;
 
 #include <assert.h>
 
+/**
+ * An event loop that polls for events on file/socket descriptors.
+ *
+ * This class is not thread-safe, all methods must be called from the
+ * thread that runs it, except where explicitly documented as
+ * thread-safe.
+ *
+ * @see SocketMonitor, MultiSocketMonitor, TimeoutMonitor, IdleMonitor
+ */
 class EventLoop final
-#ifdef USE_EPOLL
+#ifdef USE_INTERNAL_EVENTLOOP
 	: private SocketMonitor
 #endif
 {
-#ifdef USE_EPOLL
+#ifdef USE_INTERNAL_EVENTLOOP
 	struct TimerRecord {
 		/**
 		 * Projected monotonic_clock_ms() value when this
@@ -73,8 +84,6 @@ class EventLoop final
 		}
 	};
 
-	EPollFD epoll;
-
 	WakeFD wake_fd;
 
 	std::multiset<TimerRecord> timers;
@@ -87,10 +96,11 @@ class EventLoop final
 
 	bool quit;
 
-	static constexpr unsigned MAX_EVENTS = 16;
-	unsigned n_events;
-	epoll_event events[MAX_EVENTS];
-#else
+	PollGroup poll_group;
+	PollResult poll_result;
+#endif
+
+#ifdef USE_GLIB_EVENTLOOP
 	GMainContext *context;
 	GMainLoop *loop;
 #endif
@@ -101,24 +111,32 @@ class EventLoop final
 	ThreadId thread;
 
 public:
-#ifdef USE_EPOLL
+#ifdef USE_INTERNAL_EVENTLOOP
 	struct Default {};
 
 	EventLoop(Default dummy=Default());
 	~EventLoop();
 
+	/**
+	 * A caching wrapper for MonotonicClockMS().
+	 */
 	unsigned GetTimeMS() const {
 		return now_ms;
 	}
 
+	/**
+	 * Stop execution of this #EventLoop at the next chance.  This
+	 * method is thread-safe and non-blocking: after returning, it
+	 * is not guaranteed that the EventLoop has really stopped.
+	 */
 	void Break();
 
 	bool AddFD(int _fd, unsigned flags, SocketMonitor &m) {
-		return epoll.Add(_fd, flags, &m);
+		return poll_group.Add(_fd, flags, &m);
 	}
 
 	bool ModifyFD(int _fd, unsigned flags, SocketMonitor &m) {
-		return epoll.Modify(_fd, flags, &m);
+		return poll_group.Modify(_fd, flags, &m);
 	}
 
 	/**
@@ -126,7 +144,7 @@ public:
 	 * has been closed.  This is like RemoveFD(), but does not
 	 * attempt to use #EPOLL_CTL_DEL.
 	 */
-	void Abandon(SocketMonitor &m);
+	bool Abandon(int fd, SocketMonitor &m);
 
 	bool RemoveFD(int fd, SocketMonitor &m);
 
@@ -138,13 +156,19 @@ public:
 
 	void AddCall(std::function<void()> &&f);
 
+	/**
+	 * The main function of this class.  It will loop until
+	 * Break() gets called.  Can be called only once.
+	 */
 	void Run();
 
 private:
 	virtual bool OnSocketReady(unsigned flags) override;
 
 public:
-#else
+#endif
+
+#ifdef USE_GLIB_EVENTLOOP
 	EventLoop()
 		:context(g_main_context_new()),
 		 loop(g_main_loop_new(context, false)),