ovs-thread: Make caller provide thread name when creating a thread.

Thread names are occasionally very useful for debugging, but from time to
time we've forgotten to set one.  This commit adds the new thread's name
as a parameter to the function to start a thread, to make that mistake
impossible.  This also simplifies code, since two function calls become
only one.

This makes a few other changes to the thread creation function:

    * Since it is no longer a direct wrapper around a pthread function,
      rename it to avoid giving that impression.

    * Remove 'pthread_attr_t *' param that every caller supplied as NULL.

    * Change 'pthread *' parameter into a return value, for convenience.

The system-stats code hadn't set a thread name, so this fixes that issue.

This patch is a prerequisite for making RCU report the name of a thread
that is blocking RCU synchronization, because the easiest way to do that is
for ovsrcu_quiesce_end() to record the current thread's name.
ovsrcu_quiesce_end() is called before the thread function is called, so it
won't get a name set within the thread function itself.  Setting the thread
name earlier, as in this patch, avoids the problem.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Alex Wang <alexw@nicira.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/vswitchd/system-stats.c b/vswitchd/system-stats.c
index 6c7393368..778978731 100644
--- a/vswitchd/system-stats.c
+++ b/vswitchd/system-stats.c
@@ -542,7 +542,8 @@ system_stats_enable(bool enable)
         ovs_mutex_lock(&mutex);
         if (enable) {
             if (!started) {
-                xpthread_create(NULL, NULL, system_stats_thread_func, NULL);
+                ovs_thread_create("system_stats",
+                                  system_stats_thread_func, NULL);
                 latch_init(&latch);
                 started = true;
             }