Add a README.cygwin detailing Cygwin specific build/install instructions

[lttng-ust.git] / liblttng-ust-comm / lttng-ust-comm.c

diff --git a/liblttng-ust-comm/lttng-ust-comm.c b/liblttng-ust-comm/lttng-ust-comm.c
index 7e55cff556c6ced0314329401fdbe866480cf160..3138016569e8d0c11d2036e2c2fb97225efc399a 100644 (file)
--- a/liblttng-ust-comm/lttng-ust-comm.c
+++ b/liblttng-ust-comm/lttng-ust-comm.c
@@ -255,8 +255,10 @@ ssize_t ustcomm_recv_unix_sock(int sock, void *buf, size_t len)
        msg.msg_iov = iov;
        msg.msg_iovlen = 1;
 
-       ret = recvmsg(sock, &msg, 0);
-       if (ret < 0) {
+       do {
+               ret = recvmsg(sock, &msg, 0);
+       } while (ret < 0 && errno == EINTR);
+       if (ret < 0 && errno != EPIPE) {
                perror("recvmsg");
        }
 
@@ -289,8 +291,10 @@ ssize_t ustcomm_send_unix_sock(int sock, void *buf, size_t len)
         * by ignoring SIGPIPE, but we don't have this luxury on the
         * libust side.
         */
-       ret = sendmsg(sock, &msg, MSG_NOSIGNAL);
-       if (ret < 0) {
+       do {
+               ret = sendmsg(sock, &msg, MSG_NOSIGNAL);
+       } while (ret < 0 && errno == EINTR);
+       if (ret < 0 && errno != EPIPE) {
                perror("sendmsg");
        }
 
@@ -306,10 +310,9 @@ int ustcomm_close_unix_sock(int sock)
 {
        int ret;
 
-       /* Shutdown receptions and transmissions */
-       ret = shutdown(sock, SHUT_RDWR);
+       ret = close(sock);
        if (ret < 0) {
-               perror("shutdown");
+               perror("close");
        }
 
        return ret;
@@ -353,8 +356,10 @@ ssize_t ustcomm_send_fds_unix_sock(int sock, void *buf, int *fds, size_t nb_fd,
        msg.msg_iov = iov;
        msg.msg_iovlen = 1;
 
-       ret = sendmsg(sock, &msg, 0);
-       if (ret < 0) {
+       do {
+               ret = sendmsg(sock, &msg, MSG_NOSIGNAL);
+       } while (ret < 0 && errno == EINTR);
+       if (ret < 0 && errno != EPIPE) {
                perror("sendmsg");
        }
 
@@ -469,8 +474,13 @@ int ustcomm_recv_fd(int sock)
        msg.msg_control = recv_fd;
        msg.msg_controllen = sizeof(recv_fd);
 
-       if ((ret = recvmsg(sock, &msg, 0)) < 0) {
-               perror("recvmsg");
+       do {
+               ret = recvmsg(sock, &msg, 0);
+       } while (ret < 0 && errno == EINTR);
+       if (ret < 0) {
+               if (errno != EPIPE) {
+                       perror("recvmsg");
+               }
                goto end;
        }
        if (ret != sizeof(data_fd)) {
@@ -499,3 +509,85 @@ int ustcomm_recv_fd(int sock)
 end:
        return ret;
 }
+
+ssize_t ustcomm_send_string(int sock, char *str, size_t len)
+{
+       ssize_t slen, ret = -1;
+
+       if (!str) {
+               goto end;
+       }
+
+       /* Send string len first */
+       slen = ustcomm_send_unix_sock(sock, &len, sizeof(len));
+
+       if (slen != sizeof(len)) {
+               fprintf(stderr,
+                       "Unexpected sent size. Expected %zu got %zu\n",
+                       sizeof(len), slen);
+               ret = -1;
+               goto end;
+       }
+
+       /* Send the actual string */
+       slen = ustcomm_send_unix_sock(sock, str, len);
+       if (slen != len) {
+               fprintf(stderr,
+                       "Unexpected sent size. Expected %zu got %zu\n",
+                       len, slen);
+               ret = -1;
+               goto end;
+       }
+
+       ret = slen;
+
+end:
+       return ret;
+}
+
+/*
+ * Allocate and return the received string.
+ * Return NULL on error.
+ * Caller is responsible of freeing the allocated string.
+ */
+char *ustcomm_recv_string(int sock)
+{
+       ssize_t rlen;
+       size_t len;
+       char *ret;
+
+       /* Get the string len first */
+       rlen = ustcomm_recv_unix_sock(sock, &len, sizeof(len));
+
+       if (rlen != sizeof(len)) {
+               fprintf(stderr,
+                       "Unexpected received size. Expected %zu got %zu\n",
+                       sizeof(len), rlen);
+               ret = NULL;
+               goto end;
+       }
+
+       /* Account for the NULL byte */
+       ret = malloc(len + 1);
+       if (!ret) {
+               ret = NULL;
+               goto end;
+       }
+
+       /* Get the actual string */
+       rlen = ustcomm_recv_unix_sock(sock, ret, len);
+       if (rlen != len) {
+               fprintf(stderr,
+                       "Unexpected received size. Expected %zu got %zu\n",
+                       len, rlen);
+               free(ret);
+               ret = NULL;
+               goto end;
+       }
+
+       /* Set terminating NULL byte */
+       ret[len] = '\0';
+
+end:
+       return ret;
+}