From: Peter Meerwald <[email protected]> pa_write() knows two types of operation: calling send() and calling write()
there is a flag (a pointer to an int) passed to pa_write() which can remember which write type was successful if the pointer is NULL or the int is 0, send() is tried first, with a fallback to write() if send() resulted in ENOTSOCK pa_fdsem_post() calls pa_write() with a NULL pointer; unfortunately (at least with HAVE_SYS_EVENTFD_H #define'd) send() always fails here and write() is called -- causing an extra syscall quite frequently strace: send(17, "\1\0\0\0\0\0\0\0", 8, MSG_NOSIGNAL) = -1 ENOTSOCK (Socket operation on non-socket) write(17, "\1\0\0\0\0\0\0\0", 8) = 8 the patch adds a write_type field to pa_fdsem to the successful pa_write() type can be remembered and unnecessary send() calls are avoided Signed-off-by: Peter Meerwald <[email protected]> --- src/pulsecore/fdsem.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/src/pulsecore/fdsem.c b/src/pulsecore/fdsem.c index 14fcbd6..1d3d44a 100644 --- a/src/pulsecore/fdsem.c +++ b/src/pulsecore/fdsem.c @@ -52,7 +52,7 @@ struct pa_fdsem { #ifdef HAVE_SYS_EVENTFD_H int efd; #endif - + int write_type; pa_fdsem_data *data; }; @@ -196,7 +196,7 @@ void pa_fdsem_post(pa_fdsem *f) { if (f->efd >= 0) { uint64_t u = 1; - if ((r = pa_write(f->efd, &u, sizeof(u), NULL)) != sizeof(u)) { + if ((r = pa_write(f->efd, &u, sizeof(u), &f->write_type)) != sizeof(u)) { if (r >= 0 || errno != EINTR) { pa_log_error("Invalid write to eventfd: %s", r < 0 ? pa_cstrerror(errno) : "EOF"); pa_assert_not_reached(); @@ -207,7 +207,7 @@ void pa_fdsem_post(pa_fdsem *f) { } else #endif - if ((r = pa_write(f->fds[1], &x, 1, NULL)) != 1) { + if ((r = pa_write(f->fds[1], &x, 1, &f->write_type)) != 1) { if (r >= 0 || errno != EINTR) { pa_log_error("Invalid write to pipe: %s", r < 0 ? pa_cstrerror(errno) : "EOF"); pa_assert_not_reached(); -- 1.7.9.5 _______________________________________________ pulseaudio-discuss mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/pulseaudio-discuss
