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RE: slapadd hang in bdb_tool_entry_close / ldap_pvt_thread_cond_wait
> The cond_signal calls are all contained within one big mutex_lock.
Sorry, I missed the fact that ldap_pvt_thread_cond_wait() inside bdb_tool_trickle_task() will unlock the bdb_tool_trickle_mutex.
But then, I think the author of the trickle task function has also forgotten this, because later on:
bdb_tool_trickle_active = 0;
ldap_pvt_thread_cond_signal( &bdb_tool_trickle_cond_end );
ldap_pvt_thread_mutex_unlock( &bdb_tool_trickle_mutex );
Why even try to unlock the mutex when the earlier call to ldap_pvt_thread_cond_wait() will have done that already? Perhaps the intention was for the ldap_pvt_thread_cond_signal() to be called when the mutex was locked?
Actually, that might explain things, because the previous line:
bdb_tool_trickle_active = 0;
... is being called without holding the mutex, whereas bdb_tool_entry_close() is testing for !bdb_tool_trickle_active after acquiring the mutex. I think the fix is probably to do another mutex_lock() inside bdb_tool_trickle_task() prior to setting bdb_tool_trickle_active to 0. Like this:
--- servers/slapd/back-bdb/tools.c.orig 2012-02-29 17:37:09.000000000 +0000
+++ servers/slapd/back-bdb/tools.c 2016-05-27 12:35:31.285728000 +0100
@@ -1283,6 +1283,7 @@
break;
env->memp_trickle( env, 30, &wrote );
}
+ ldap_pvt_thread_mutex_lock( &bdb_tool_trickle_mutex );
bdb_tool_trickle_active = 0;
ldap_pvt_thread_cond_signal( &bdb_tool_trickle_cond_end );
ldap_pvt_thread_mutex_unlock( &bdb_tool_trickle_mutex );
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