From 4f3ab6ee347964379eefc57f41f8a381965b4316 Mon Sep 17 00:00:00 2001 From: David Goulet Date: Mon, 21 Jan 2013 11:25:09 -0500 Subject: [PATCH] Add a create_ust_stream function in ust-app.c This helps by having a single callsite for ustctl_create_stream and removes the need for the caller to handle FD reservation. On success, the function sets the returned handle to the given stream. Signed-off-by: David Goulet --- src/bin/lttng-sessiond/ust-app.c | 61 +++++++++++++++++++++++++------- 1 file changed, 48 insertions(+), 13 deletions(-) diff --git a/src/bin/lttng-sessiond/ust-app.c b/src/bin/lttng-sessiond/ust-app.c index 22b395773..8f7db8f2c 100644 --- a/src/bin/lttng-sessiond/ust-app.c +++ b/src/bin/lttng-sessiond/ust-app.c @@ -748,6 +748,52 @@ error: return ret; } +/* + * Create stream onto the UST tracer for a given channel. + * + * Return -ENOENT if no more stream is available for this channel. + * On success, return 0. + * On error, return a negative value. + */ +static int create_ust_stream(struct ust_app *app, + struct ust_app_channel *ua_chan, struct ltt_ust_stream *stream) +{ + int ret; + + assert(app); + assert(ua_chan); + assert(ua_chan->obj); + assert(stream); + + health_code_update(&health_thread_cmd); + + /* We are going to receive 2 fds, we need to reserve them. */ + ret = lttng_fd_get(LTTNG_FD_APPS, 2); + if (ret < 0) { + ERR("Exhausted number of available FD on stream creation"); + /* Just to make sure we never return -ENOENT. */ + ret = -1; + goto error; + } + + ret = ustctl_create_stream(app->sock, ua_chan->obj, &stream->obj); + if (ret < 0) { + lttng_fd_put(LTTNG_FD_APPS, 2); + /* Indicates that there is no more stream for that channel. */ + if (ret != -ENOENT) { + ERR("UST create metadata stream failed (ret: %d)", ret); + } + goto error; + } + + /* Set stream handle with the returned value. */ + stream->handle = stream->obj->handle; + +error: + health_code_update(&health_thread_cmd); + return ret; +} + /* * Create the specified channel onto the UST tracer for a UST session. */ @@ -2307,22 +2353,12 @@ int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app) goto error_rcu_unlock; } - /* We are going to receive 2 fds, we need to reserve them. */ - ret = lttng_fd_get(LTTNG_FD_APPS, 2); - if (ret < 0) { - ERR("Exhausted number of available FD upon stream create"); - free(ustream); - goto error_rcu_unlock; - } - health_code_update(&health_thread_cmd); - ret = ustctl_create_stream(app->sock, ua_chan->obj, - &ustream->obj); + ret = create_ust_stream(app, ua_chan, ustream); if (ret < 0) { - /* Free unused memory and reset FD states. */ + /* Free unused memory after this point. */ free(ustream); - lttng_fd_put(LTTNG_FD_APPS, 2); if (ret == -ENOENT) { /* Got all streams. Continue normal execution. */ break; @@ -2331,7 +2367,6 @@ int ust_app_start_trace(struct ltt_ust_session *usess, struct ust_app *app) ret = LTTNG_ERR_UST_STREAM_FAIL; goto error_rcu_unlock; } - ustream->handle = ustream->obj->handle; health_code_update(&health_thread_cmd); -- 2.34.1