From 99b72dc0657875cee4a10bf4c855e99a1b1d1f9c Mon Sep 17 00:00:00 2001
From: Pierre-Marc Fournier <pierre-marc.fournier@polymtl.ca>
Date: Fri, 11 Sep 2009 15:35:21 -0400
Subject: [PATCH] make forking while tracing work correctly

---
 libinterfork/interfork.c |  1 -
 libust/tracectl.c        | 27 ++++++++++++++++++++++++---
 libust/tracer.c          |  2 +-
 libustcomm/ustcomm.c     | 17 +++++++++++++++++
 libustcomm/ustcomm.h     |  1 +
 5 files changed, 43 insertions(+), 5 deletions(-)

diff --git a/libinterfork/interfork.c b/libinterfork/interfork.c
index e57b7e5..a8db252 100644
--- a/libinterfork/interfork.c
+++ b/libinterfork/interfork.c
@@ -34,7 +34,6 @@ pid_t fork(void)
 		}
 	}
 
-	printf("IN FORK!\n");
 	retval = plibc_func();
 
 	if(retval == 0)
diff --git a/libust/tracectl.c b/libust/tracectl.c
index 412cca2..a52b208 100644
--- a/libust/tracectl.c
+++ b/libust/tracectl.c
@@ -1109,14 +1109,35 @@ static void __attribute__((destructor)) keepalive()
 
 void ust_fork(void)
 {
+	struct blocked_consumer *bc;
+	struct blocked_consumer *deletable_bc = NULL;
+	int result;
+
 	DBG("ust: forking");
 	ltt_trace_stop("auto");
 	ltt_trace_destroy("auto");
-	ltt_trace_alloc("auto");
-	ltt_trace_start("auto");
-	init_socket();
+	/* Delete all active connections */
+	ustcomm_close_all_connections(&ustcomm_app.server);
+
+	/* Delete all blocked consumers */
+	list_for_each_entry(bc, &blocked_consumers, list) {
+		free(deletable_bc);
+		deletable_bc = bc;
+		list_del(&bc->list);
+	}
+
 	have_listener = 0;
 	create_listener();
+	init_socket();
+	ltt_trace_setup("auto");
+	result = ltt_trace_set_type("auto", "ustrelay");
+	if(result < 0) {
+		ERR("ltt_trace_set_type failed");
+		return (void *)1;
+	}
+
+	ltt_trace_alloc("auto");
+	ltt_trace_start("auto");
 	inform_consumer_daemon("auto");
 }
 
diff --git a/libust/tracer.c b/libust/tracer.c
index cc1dbfd..6f19213 100644
--- a/libust/tracer.c
+++ b/libust/tracer.c
@@ -807,7 +807,7 @@ traces_error:
 //ust// }
 
 /* Must be called while sure that trace is in the list. */
-static int _ltt_trace_destroy(struct ltt_trace_struct	*trace)
+static int _ltt_trace_destroy(struct ltt_trace_struct *trace)
 {
 	int err = -EPERM;
 
diff --git a/libustcomm/ustcomm.c b/libustcomm/ustcomm.c
index 1f4bce9..e773f71 100644
--- a/libustcomm/ustcomm.c
+++ b/libustcomm/ustcomm.c
@@ -191,6 +191,23 @@ int ustcomm_send_reply(struct ustcomm_server *server, char *msg, struct ustcomm_
 	return 0;
 } 
 
+/* Called after a fork. */
+
+int ustcomm_close_all_connections(struct ustcomm_server *server)
+{
+	struct ustcomm_connection *conn;
+	struct ustcomm_connection *deletable_conn = NULL;
+
+	list_for_each_entry(conn, &server->connections, list) {
+		free(deletable_conn);
+		deletable_conn = conn;
+		close(conn->fd);
+		list_del(&conn->list);
+	}
+
+	return 0;
+}
+
 /* @timeout: max blocking time in milliseconds, -1 means infinity
  *
  * returns 1 to indicate a message was received
diff --git a/libustcomm/ustcomm.h b/libustcomm/ustcomm.h
index 7620940..b7d8839 100644
--- a/libustcomm/ustcomm.h
+++ b/libustcomm/ustcomm.h
@@ -71,6 +71,7 @@ extern int ustcomm_connect_path(const char *path, struct ustcomm_connection *con
 extern int ustcomm_send_request(struct ustcomm_connection *conn, const char *req, char **reply);
 extern int ustcomm_send_reply(struct ustcomm_server *server, char *msg, struct ustcomm_source *src);
 extern int ustcomm_disconnect(struct ustcomm_connection *conn);
+extern int ustcomm_close_all_connections(struct ustcomm_server *server);
 
 extern int nth_token_is(char *str, char *token, int tok_no);
 
-- 
2.34.1