From: David Goulet <dgoulet@efficios.com>
Date: Tue, 6 Nov 2012 19:35:43 +0000 (-0500)
Subject: Fix: Create default channel on add-context if none
X-Git-Tag: v2.1.0-rc7~18
X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=commitdiff_plain;h=979e618e0c03933b16cba3a83285938b25045bdc

Fix: Create default channel on add-context if none

For both kernel and UST, if no channel exists and an add-context command
is sent, the default channel0 is created and the context(es) are set.

Fixes #391

Signed-off-by: David Goulet <dgoulet@efficios.com>
---

diff --git a/src/bin/lttng-sessiond/cmd.c b/src/bin/lttng-sessiond/cmd.c
index 1404e7f33..46a758e27 100644
--- a/src/bin/lttng-sessiond/cmd.c
+++ b/src/bin/lttng-sessiond/cmd.c
@@ -939,12 +939,23 @@ error:
  * Command LTTNG_ADD_CONTEXT processed by the client thread.
  */
 int cmd_add_context(struct ltt_session *session, int domain,
-		char *channel_name, char *event_name, struct lttng_event_context *ctx)
+		char *channel_name, char *event_name, struct lttng_event_context *ctx,
+		int kwpipe)
 {
 	int ret;
 
 	switch (domain) {
 	case LTTNG_DOMAIN_KERNEL:
+		assert(session->kernel_session);
+
+		if (session->kernel_session->channel_count == 0) {
+			/* Create default channel */
+			ret = channel_kernel_create(session->kernel_session, NULL, kwpipe);
+			if (ret != LTTNG_OK) {
+				goto error;
+			}
+		}
+
 		/* Add kernel context to kernel tracer */
 		ret = context_kernel_add(session->kernel_session, ctx,
 				event_name, channel_name);
@@ -955,9 +966,28 @@ int cmd_add_context(struct ltt_session *session, int domain,
 	case LTTNG_DOMAIN_UST:
 	{
 		struct ltt_ust_session *usess = session->ust_session;
-
 		assert(usess);
 
+		unsigned int chan_count =
+			lttng_ht_get_count(usess->domain_global.channels);
+		if (chan_count == 0) {
+			struct lttng_channel *attr;
+			/* Create default channel */
+			attr = channel_new_default_attr(domain);
+			if (attr == NULL) {
+				ret = LTTNG_ERR_FATAL;
+				goto error;
+			}
+
+			ret = channel_ust_create(usess, domain, attr);
+			if (ret != LTTNG_OK) {
+				free(attr);
+				goto error;
+			}
+			free(attr);
+		}
+
+
 		ret = context_ust_add(usess, domain, ctx, event_name, channel_name);
 		if (ret != LTTNG_OK) {
 			goto error;
diff --git a/src/bin/lttng-sessiond/cmd.h b/src/bin/lttng-sessiond/cmd.h
index a95cb994e..20fc84a93 100644
--- a/src/bin/lttng-sessiond/cmd.h
+++ b/src/bin/lttng-sessiond/cmd.h
@@ -45,7 +45,8 @@ int cmd_disable_event(struct ltt_session *session, int domain,
 int cmd_disable_event_all(struct ltt_session *session, int domain,
 		char *channel_name);
 int cmd_add_context(struct ltt_session *session, int domain,
-		char *channel_name, char *event_name, struct lttng_event_context *ctx);
+		char *channel_name, char *event_name, struct lttng_event_context *ctx,
+		int kwpipe);
 int cmd_set_filter(struct ltt_session *session, int domain,
 		char *channel_name, char *event_name,
 		struct lttng_filter_bytecode *bytecode);
diff --git a/src/bin/lttng-sessiond/main.c b/src/bin/lttng-sessiond/main.c
index 6bc8b00e9..ce2213c1b 100644
--- a/src/bin/lttng-sessiond/main.c
+++ b/src/bin/lttng-sessiond/main.c
@@ -2408,7 +2408,7 @@ skip_domain:
 		ret = cmd_add_context(cmd_ctx->session, cmd_ctx->lsm->domain.type,
 				cmd_ctx->lsm->u.context.channel_name,
 				cmd_ctx->lsm->u.context.event_name,
-				&cmd_ctx->lsm->u.context.ctx);
+				&cmd_ctx->lsm->u.context.ctx, kernel_poll_pipe[1]);
 		break;
 	}
 	case LTTNG_DISABLE_CHANNEL: