From c72435ad89dc397f89a30faea35274074fbb3047 Mon Sep 17 00:00:00 2001 From: =?utf8?q?J=C3=A9r=C3=A9mie=20Galarneau?= Date: Fri, 5 May 2017 00:14:02 -0400 Subject: [PATCH] Add non_block version of functions to UNIX socket wrapper MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Signed-off-by: Jérémie Galarneau --- src/common/unix.c | 113 ++++++++++++++++++++++++++++++++++++++++++---- src/common/unix.h | 4 ++ 2 files changed, 109 insertions(+), 8 deletions(-) diff --git a/src/common/unix.c b/src/common/unix.c index 11c30781b..2f4df68e6 100644 --- a/src/common/unix.c +++ b/src/common/unix.c @@ -216,6 +216,48 @@ ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len) return ret; } +/* + * Receive data of size len in put that data into the buf param. Using recvmsg + * API. Only use with sockets set in non-blocking mode. + * + * Return the size of received data. + */ +LTTNG_HIDDEN +ssize_t lttcomm_recv_unix_sock_non_block(int sock, void *buf, size_t len) +{ + struct msghdr msg; + struct iovec iov[1]; + ssize_t ret; + + memset(&msg, 0, sizeof(msg)); + + iov[0].iov_base = buf; + iov[0].iov_len = len; + msg.msg_iov = iov; + msg.msg_iovlen = 1; + +retry: + ret = lttng_recvmsg_nosigpipe(sock, &msg); + if (ret < 0) { + if (errno == EINTR) { + goto retry; + } else { + /* + * Only warn about EPIPE when quiet mode is + * deactivated. + * We consider EPIPE as expected. + */ + if (errno != EPIPE || !lttng_opt_quiet) { + PERROR("recvmsg"); + } + goto end; + } + } + ret = len; +end: + return ret; +} + /* * Send buf data of size len. Using sendmsg API. * @@ -226,7 +268,54 @@ ssize_t lttcomm_send_unix_sock(int sock, const void *buf, size_t len) { struct msghdr msg; struct iovec iov[1]; - ssize_t ret = -1; + ssize_t ret; + + memset(&msg, 0, sizeof(msg)); + + iov[0].iov_base = (void *) buf; + iov[0].iov_len = len; + msg.msg_iov = iov; + msg.msg_iovlen = 1; + + while (iov[0].iov_len) { + ret = sendmsg(sock, &msg, 0); + if (ret < 0) { + if (errno == EINTR) { + continue; + } else { + /* + * Only warn about EPIPE when quiet mode is + * deactivated. + * We consider EPIPE as expected. + */ + if (errno != EPIPE || !lttng_opt_quiet) { + PERROR("sendmsg"); + } + goto end; + } + } + iov[0].iov_len -= ret; + iov[0].iov_base += ret; + } + ret = len; +end: + return ret; +} + +/* + * Send buf data of size len. Using sendmsg API. + * Only use with non-blocking sockets. The difference with the blocking version + * of the function is that this one does not retry to send on partial sends, + * except if the interruption was caused by a signal (EINTR). + * + * Return the size of sent data. + */ +LTTNG_HIDDEN +ssize_t lttcomm_send_unix_sock_non_block(int sock, const void *buf, size_t len) +{ + struct msghdr msg; + struct iovec iov[1]; + ssize_t ret; memset(&msg, 0, sizeof(msg)); @@ -235,17 +324,25 @@ ssize_t lttcomm_send_unix_sock(int sock, const void *buf, size_t len) msg.msg_iov = iov; msg.msg_iovlen = 1; +retry: ret = sendmsg(sock, &msg, 0); if (ret < 0) { - /* - * Only warn about EPIPE when quiet mode is deactivated. - * We consider EPIPE as expected. - */ - if (errno != EPIPE || !lttng_opt_quiet) { - PERROR("sendmsg"); + if (errno == EINTR) { + goto retry; + } else { + /* + * Only warn about EPIPE when quiet mode is + * deactivated. + * We consider EPIPE as expected. + */ + if (errno != EPIPE || !lttng_opt_quiet) { + PERROR("sendmsg"); + } + goto end; } } - + ret = len; +end: return ret; } diff --git a/src/common/unix.h b/src/common/unix.h index 643512116..886b40e73 100644 --- a/src/common/unix.h +++ b/src/common/unix.h @@ -47,7 +47,11 @@ ssize_t lttcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd); LTTNG_HIDDEN ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len); LTTNG_HIDDEN +ssize_t lttcomm_recv_unix_sock_non_block(int sock, void *buf, size_t len); +LTTNG_HIDDEN ssize_t lttcomm_send_unix_sock(int sock, const void *buf, size_t len); +LTTNG_HIDDEN +ssize_t lttcomm_send_unix_sock_non_block(int sock, const void *buf, size_t len); LTTNG_HIDDEN ssize_t lttcomm_send_creds_unix_sock(int sock, void *buf, size_t len); -- 2.34.1