Export consumer ABI, implement ring buffer modifications for consumer

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

diff --git a/libust/lttng-ust-comm.c b/libust/lttng-ust-comm.c
index 9400b6b8ff9f6fdb74e4461aa6d6e1cf464e0b59..2e7e1a3515abd1f6b46024364ddb1747057e8a4f 100644 (file)
--- a/libust/lttng-ust-comm.c
+++ b/libust/lttng-ust-comm.c
@@ -217,6 +217,9 @@ int handle_register_done(struct sock_info *sock_info)
        if (sock_info->constructor_sem_posted)
                return 0;
        sock_info->constructor_sem_posted = 1;
+       if (uatomic_read(&sem_count) <= 0) {
+               return 0;
+       }
        ret = uatomic_add_return(&sem_count, -1);
        if (ret == 0) {
                ret = sem_post(&constructor_wait);
@@ -232,6 +235,7 @@ int handle_message(struct sock_info *sock_info,
        int ret = 0;
        const struct objd_ops *ops;
        struct lttcomm_ust_reply lur;
+       int shm_fd, wait_fd;
 
        ust_lock();
 
@@ -277,10 +281,50 @@ end:
        if (ret >= 0) {
                lur.ret_code = LTTCOMM_OK;
        } else {
-               lur.ret_code = LTTCOMM_SESSION_FAIL;
+               //lur.ret_code = LTTCOMM_SESSION_FAIL;
+               lur.ret_code = ret;
+       }
+       switch (lum->cmd) {
+       case LTTNG_UST_STREAM:
+               /*
+                * Special-case reply to send stream info.
+                * Use lum.u output.
+                */
+               lur.u.stream.memory_map_size = lum->u.stream.memory_map_size;
+               shm_fd = lum->u.stream.shm_fd;
+               wait_fd = lum->u.stream.wait_fd;
+               break;
+       case LTTNG_UST_CHANNEL:
+               lur.u.channel.memory_map_size = lum->u.channel.memory_map_size;
+               shm_fd = lum->u.channel.shm_fd;
+               wait_fd = lum->u.channel.wait_fd;
+               break;
        }
        ret = send_reply(sock, &lur);
+       if (ret < 0) {
+               perror("error sending reply");
+               goto error;
+       }
 
+       if ((lum->cmd == LTTNG_UST_STREAM || lum->cmd == LTTNG_UST_CHANNEL)
+                       && lur.ret_code == LTTCOMM_OK) {
+               /* we also need to send the file descriptors. */
+               ret = lttcomm_send_fds_unix_sock(sock,
+                       &shm_fd, &shm_fd,
+                       1, sizeof(int));
+               if (ret < 0) {
+                       perror("send shm_fd");
+                       goto error;
+               }
+               ret = lttcomm_send_fds_unix_sock(sock,
+                       &wait_fd, &wait_fd,
+                       1, sizeof(int));
+               if (ret < 0) {
+                       perror("send wait_fd");
+                       goto error;
+               }
+       }
+error:
        ust_unlock();
        return ret;
 }