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| author | Max Kellermann <max@duempel.org> | 2014-01-05 01:37:22 +0100 |
|---|---|---|
| committer | Max Kellermann <max@duempel.org> | 2014-01-05 02:15:34 +0100 |
| commit | e599b86424014d469874f67594112e0a7160a336 (patch) | |
| tree | 0cda94c849fe2f4d06dba600a4cf452c87c8d576 /src/event/Loop.cxx | |
| parent | da9e5849212337f26d1fa0450ce71cd58aefc30d (diff) | |
| download | mpd-e599b86424014d469874f67594112e0a7160a336.tar.gz mpd-e599b86424014d469874f67594112e0a7160a336.tar.xz mpd-e599b86424014d469874f67594112e0a7160a336.zip | |
event/Loop: try to avoid the WakeFD when adding DeferredMonitor
Add a flag that indicates whether the EventLoop is currently "busy".
As long as that flag is set, it does not need to be woken up - we can
simply add the DeferredMonitor to the list, and it will be caught by
EventLoop very soon. This eliminates nearly all of the
DeferredMonitor overhead when compared to IdleMonitor, rendering
IdleMonitor mostly obsolete.
Diffstat (limited to 'src/event/Loop.cxx')
| -rw-r--r-- | src/event/Loop.cxx | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/src/event/Loop.cxx b/src/event/Loop.cxx index 0e76afc25..58c25e040 100644 --- a/src/event/Loop.cxx +++ b/src/event/Loop.cxx @@ -31,7 +31,7 @@ EventLoop::EventLoop(Default) :SocketMonitor(*this), now_ms(::MonotonicClockMS()), - quit(false), + quit(false), busy(true), thread(ThreadId::Null()) { SocketMonitor::Open(wake_fd.Get()); @@ -122,6 +122,7 @@ EventLoop::Run() thread = ThreadId::GetCurrent(); assert(!quit); + assert(busy); do { now_ms = ::MonotonicClockMS(); @@ -161,6 +162,13 @@ EventLoop::Run() return; } + /* try to handle DeferredMonitors without WakeFD + overhead */ + mutex.lock(); + HandleDeferred(); + busy = false; + mutex.unlock(); + if (again) /* re-evaluate timers because one of the IdleMonitors may have added a new @@ -173,6 +181,10 @@ EventLoop::Run() now_ms = ::MonotonicClockMS(); + mutex.lock(); + busy = true; + mutex.unlock(); + /* invoke sockets */ for (int i = 0; i < poll_result.GetSize(); ++i) { auto events = poll_result.GetEvents(i); @@ -190,6 +202,7 @@ EventLoop::Run() } while (!quit); #ifndef NDEBUG + assert(busy); assert(thread.IsInside()); thread = ThreadId::Null(); #endif @@ -209,10 +222,11 @@ EventLoop::AddDeferred(DeferredMonitor &d) /* we don't need to wake up the EventLoop if another DeferredMonitor has already done it */ - const bool must_wake = deferred.empty(); + const bool must_wake = !busy && deferred.empty(); d.pending = true; deferred.push_back(&d); + again = true; mutex.unlock(); if (must_wake) |