From 110027ec9f78941fcf8cc5f36b7055e17a206af6 Mon Sep 17 00:00:00 2001 From: Mattias Andrée Date: Tue, 28 Apr 2015 12:57:30 +0200 Subject: add BUS_SEMAPHORES_ARE_SYNCHRONOUS + explain some syntax in doc/protocol MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Mattias Andrée --- src/bus.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) (limited to 'src') diff --git a/src/bus.c b/src/bus.c index 614f7ad..5737fd7 100644 --- a/src/bus.c +++ b/src/bus.c @@ -623,22 +623,31 @@ fail: int bus_write(const bus_t *bus, const char *message, int flags /* TODO document in man page */) { - int state = 0, saved_errno; + int saved_errno; +#ifndef BUS_SEMAPHORES_ARE_SYNCHRONOUS + int state = 0; +#endif if (acquire_semaphore(bus, X, SEM_UNDO | F(BUS_NOWAIT, IPC_NOWAIT)) == -1) return -1; t(zero_semaphore(bus, W, 0)); write_shared_memory(bus, message); +#ifndef BUS_SEMAPHORES_ARE_SYNCHRONOUS t(release_semaphore(bus, N, SEM_UNDO)); state++; +#endif t(write_semaphore(bus, Q, 0)); t(zero_semaphore(bus, S, 0)); +#ifndef BUS_SEMAPHORES_ARE_SYNCHRONOUS t(acquire_semaphore(bus, N, SEM_UNDO)); state--; +#endif t(release_semaphore(bus, X, SEM_UNDO)); return 0; fail: saved_errno = errno; +#ifndef BUS_SEMAPHORES_ARE_SYNCHRONOUS if (state > 0) acquire_semaphore(bus, N, SEM_UNDO); +#endif release_semaphore(bus, X, SEM_UNDO); errno = saved_errno; return -1; -- cgit v1.2.3-70-g09d2