[libvirt] [PATCH v2 3/6] fdstream: Emit stream abort callback even if poll() doesnt.

This patch causes the fdstream driver to call the stream event callback if virStreamAbort() is issued on a stream using this driver. This prohibited to abort streams from the daemon, as the daemon remote handler installs a callback to watch for stream errors as the only mean of detecting changes in the stream. * src/fdstream.c: - modify close function to call stream event callback --- src/fdstream.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++------ 1 files changed, 50 insertions(+), 6 deletions(-) diff --git a/src/fdstream.c b/src/fdstream.c index 841f979..35f5135 100644 --- a/src/fdstream.c +++ b/src/fdstream.c @@ -1,5 +1,5 @@ /* - * fdstream.h: generic streams impl for file descriptors + * fdstream.c: generic streams impl for file descriptors * * Copyright (C) 2009-2011 Red Hat, Inc. * @@ -55,6 +55,7 @@ struct virFDStreamData { unsigned long long length; int watch; + int events; /* events the stream callback is subscribed for */ bool cbRemoved; bool dispatching; bool closed; @@ -62,6 +63,10 @@ struct virFDStreamData { void *opaque; virFreeCallback ff; + /* don't call the abort callback more than once */ + bool abortCallbackCalled; + bool abortCallbackDispatching; + virMutex lock; }; @@ -92,6 +97,7 @@ static int virFDStreamRemoveCallback(virStreamPtr stream) fdst->watch = 0; fdst->ff = NULL; fdst->cb = NULL; + fdst->events = 0; fdst->opaque = NULL; ret = 0; @@ -120,6 +126,7 @@ static int virFDStreamUpdateCallback(virStreamPtr stream, int events) } virEventUpdateHandle(fdst->watch, events); + fdst->events = events; ret = 0; @@ -214,6 +221,8 @@ virFDStreamAddCallback(virStreamPtr st, fdst->cb = cb; fdst->opaque = opaque; fdst->ff = ff; + fdst->events = events; + fdst->abortCallbackCalled = false; virStreamRef(st); ret = 0; @@ -223,20 +232,43 @@ cleanup: return ret; } - static int -virFDStreamClose(virStreamPtr st) +virFDStreamCloseInt(virStreamPtr st, bool streamAbort) { - struct virFDStreamData *fdst = st->privateData; + struct virFDStreamData *fdst; int ret; VIR_DEBUG("st=%p", st); - if (!fdst) + if (!st || !(fdst = st->privateData) || fdst->abortCallbackDispatching) return 0; virMutexLock(&fdst->lock); + /* aborting the stream, ensure the callback is called if it's + * registered for stream error event */ + if (streamAbort && + fdst->cb && + (fdst->events & (VIR_STREAM_EVENT_READABLE | + VIR_STREAM_EVENT_WRITABLE))) { + /* don't enter this function accidentaly from the callback again */ + if (fdst->abortCallbackCalled) { + virMutexUnlock(&fdst->lock); + return 0; + } + + fdst->abortCallbackCalled = true; + fdst->abortCallbackDispatching = true; + virMutexUnlock(&fdst->lock); + + /* call failure callback, poll does report nothing on closed fd */ + (fdst->cb)(st, VIR_STREAM_EVENT_ERROR, fdst->opaque); + + virMutexLock(&fdst->lock); + fdst->abortCallbackDispatching = false; + } + + /* mutex locked */ ret = VIR_CLOSE(fdst->fd); if (fdst->cmd) { char buf[1024]; @@ -286,6 +318,18 @@ virFDStreamClose(virStreamPtr st) return ret; } +static int +virFDStreamClose(virStreamPtr st) +{ + return virFDStreamCloseInt(st, false); +} + +static int +virFDStreamAbort(virStreamPtr st) +{ + return virFDStreamCloseInt(st, true); +} + static int virFDStreamWrite(virStreamPtr st, const char *bytes, size_t nbytes) { struct virFDStreamData *fdst = st->privateData; @@ -392,7 +436,7 @@ static virStreamDriver virFDStreamDrv = { .streamSend = virFDStreamWrite, .streamRecv = virFDStreamRead, .streamFinish = virFDStreamClose, - .streamAbort = virFDStreamClose, + .streamAbort = virFDStreamAbort, .streamAddCallback = virFDStreamAddCallback, .streamUpdateCallback = virFDStreamUpdateCallback, .streamRemoveCallback = virFDStreamRemoveCallback -- 1.7.3.4