debian-packages/eventcore
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

Fix possible race condition in PosixEventDriverEvents.trigger.

Browse source 
Accessing the event slot should only be done from the owner thread, since the chunk index of the ChoppedVector could be updated at any time. Instead of a triggerAll field, this flag is now propagated through the underlying eventfd/socket pair.
This commit is contained in:
Sönke Ludwig 2019-04-13 16:57:04 +02:00
parent 1bbe244196
commit 48d083b20f
1 changed files with 14 additions and 21 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

35
source/eventcore/drivers/posix/events.d
View file

@ -48,7 +48,7 @@ final class PosixEventDriverEvents(Loop : PosixEventLoop, Sockets : EventDriverS
auto id = cast(EventID)eid;
// FIXME: avoid dynamic memory allocation for the queue
m_loop.initFD(id, FDFlags.internal,
EventSlot(mallocT!(ConsumableQueue!EventCallback), false, is_internal));
EventSlot(mallocT!(ConsumableQueue!EventCallback), is_internal));
m_loop.registerFD(id, EventMask.read);
m_loop.setNotifyCallback!(EventType.read)(id, &onEvent);
releaseRef(id); // setNotifyCallback increments the reference count, but we need a value of 1 upon return
@ -106,7 +106,7 @@ final class PosixEventDriverEvents(Loop : PosixEventLoop, Sockets : EventDriverS
catch (Exception e) assert(false, e.msg);
// FIXME: avoid dynamic memory allocation for the queue
m_loop.initFD(id, FDFlags.internal,
EventSlot(mallocT!(ConsumableQueue!EventCallback), false, is_internal, s));
EventSlot(mallocT!(ConsumableQueue!EventCallback), is_internal, s));
assert(getRC(id) == 1);
return id;
}
@ -133,13 +133,10 @@ final class PosixEventDriverEvents(Loop : PosixEventLoop, Sockets : EventDriverS
final override void trigger(EventID event, bool notify_all)
shared @trusted @nogc {
import core.atomic : atomicStore;
auto thisus = cast(PosixEventDriverEvents)this;
assert(event < thisus.m_loop.m_fds.length, "Invalid event ID passed to shared triggerEvent.");
long one = 1;
long count = notify_all ? long.max : 1;
//log("emitting for all threads");
if (notify_all) atomicStore(thisus.getSlot(event).triggerAll, true);
version (Posix) .write(cast(int)event, &one, one.sizeof);
else assert(send(cast(int)event, cast(const(ubyte*))&one, one.sizeof, 0) == one.sizeof);
version (Posix) .write(cast(int)event, &count, count.sizeof);
else assert(send(cast(int)event, cast(const(ubyte*))&count, count.sizeof, 0) == count.sizeof);
}
final override void wait(EventID event, EventCallback on_event)
@ -157,26 +154,23 @@ final class PosixEventDriverEvents(Loop : PosixEventLoop, Sockets : EventDriverS
getSlot(event).waiters.removePending(on_event);
}
private void onEvent(FD fd)
@trusted {
EventID event = cast(EventID)fd;
version (linux) {
version (linux) {
private void onEvent(FD fd)
@trusted {
EventID event = cast(EventID)fd;
ulong cnt;
() @trusted { .read(cast(int)event, &cnt, cnt.sizeof); } ();
trigger(event, cnt > 0);
}
import core.atomic : cas;
auto all = cas(&getSlot(event).triggerAll, true, false);
trigger(event, all);
}
version (linux) {}
else {
} else {
private void onSocketData(DatagramSocketFD s, IOStatus, size_t, scope RefAddress)
@nogc {
m_sockets.receiveNoGC(s, m_buf, IOMode.once, &onSocketData);
try {
EventID evt = m_sockets.userData!EventID(s);
scope doit = { onEvent(evt); }; // cast to nogc
scope doit = {
trigger(evt, (cast(long[])m_buf)[0] > 1);
}; // cast to nogc
() @trusted { (cast(void delegate() @nogc)doit)(); } ();
} catch (Exception e) assert(false, e.msg);
}
@ -238,7 +232,6 @@ final class PosixEventDriverEvents(Loop : PosixEventLoop, Sockets : EventDriverS
package struct EventSlot {
alias Handle = EventID;
ConsumableQueue!EventCallback waiters;
shared bool triggerAll;
bool isInternal;
version (linux) {}
else {