Add non_block version of functions to UNIX socket wrapper
authorJérémie Galarneau <jeremie.galarneau@efficios.com>
Fri, 5 May 2017 04:14:02 +0000 (00:14 -0400)
committerJérémie Galarneau <jeremie.galarneau@efficios.com>
Fri, 5 May 2017 04:15:01 +0000 (00:15 -0400)
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
src/common/unix.c
src/common/unix.h

index 11c30781ba02ea5fa81f84e7f7400e15bb4436ce..2f4df68e627bd37a0f6fc84fdfb868cc02de6bc1 100644 (file)
@@ -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;
 }
 
index 643512116c85d1fd04eaa461d576d680eb998c14..886b40e73fb320536b2d91cab6fa73ce164947dd 100644 (file)
@@ -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);
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