Upsie, usleep is 10^6 times smaller than sleep

[citadel.git] / citadel / threads.c

diff --git a/citadel/threads.c b/citadel/threads.c
index cb216febefa00d24a3339a419c103a46564dd358..4a4fe5163ec2260335ca7e537e1a39ea7cf2f601 100644 (file)
--- a/citadel/threads.c
+++ b/citadel/threads.c
@@ -4,18 +4,12 @@
  * Copyright (c) 1987-2011 by the citadel.org team
  *
  * This program is open source software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 3 of the License, or
- * (at your option) any later version.
+ * it under the terms of the GNU General Public License, version 3.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  */
 
 #include <stdlib.h>
@@ -62,22 +56,12 @@
 #include "event_client.h"
 
 
-/*
- * To create a thread you must call one of the create thread functions.
- * You must pass it the address of (a pointer to a CtdlThreadNode initialised to NULL) like this
- * struct CtdlThreadNode *node = NULL;
- * pass in &node
- * If the thread is created *node will point to the thread control structure for the created thread.
- * If the thread creation fails *node remains NULL
- * Do not free the memory pointed to by *node, it doesn't belong to you.
- * This new interface duplicates much of the eCrash stuff. We should go for closer integration since that would
- * remove the need for the calls to eCrashRegisterThread and friends
- */
-
-static int num_threads = 0;                    /* Current number of threads */
+int num_workers = 0;                           /* Current number of worker threads */
+int active_workers = 0;                                /* Number of ACTIVE worker threads */
 pthread_key_t ThreadKey;
 pthread_mutex_t Critters[MAX_SEMAPHORES];      /* Things needing locking */
 struct thread_tsd masterTSD;
+int server_shutting_down = 0;                  /* set to nonzero during shutdown */
 
 
 
@@ -139,27 +123,6 @@ void end_critical_section(int which_one)
 }
 
 
-/*
- * A function to tell all threads to exit
- */
-void CtdlThreadStopAll(void)
-{
-       terminate_all_sessions();               /* close all client sockets */
-       CtdlShutdownServiceHooks();             /* close all listener sockets to prevent new connections */
-       PerformSessionHooks(EVT_SHUTDOWN);      /* run any registered shutdown hooks */
-}
-
-
-/*
- * A function for a thread to check if it has been asked to stop
- */
-int CtdlThreadCheckStop(void)
-{
-
-       /* FIXME this needs to do something useful.  moar code pls ! */
-
-       return 0;
-}
 
 
 /*
@@ -188,6 +151,7 @@ void *CTC_backend(void *supplied_start_routine)
 
        start_routine(NULL);
 
+       free(mytsd);
        return(NULL);
 }
 
@@ -206,8 +170,6 @@ void CtdlThreadCreate(void *(*start_routine)(void*))
        ret = pthread_attr_setstacksize(&attr, THREADSTACKSIZE);
        ret = pthread_create(&thread, &attr, CTC_backend, (void *)start_routine);
        if (ret != 0) syslog(LOG_EMERG, "pthread_create() : %s", strerror(errno));
-
-       ++num_threads;
 }
 
 
@@ -215,7 +177,10 @@ void InitializeMasterTSD(void) {
        memset(&masterTSD, 0, sizeof(struct thread_tsd));
 }
 
+extern void ShutDownEventQueues(void);
 
+int EventQShuttingDown = 0;
+int EVQShutDown = 0;
 /*
  * Initialize the thread system
  */
@@ -229,25 +194,38 @@ void go_threading(void)
        /* Second call to module init functions now that threading is up */
        initialise_modules(1);
 
-       CtdlThreadCreate(select_on_master);
-
-       /* FIXME temporary fixed size pool of worker threads */
-       CtdlThreadCreate(worker_thread);
-       CtdlThreadCreate(worker_thread);
-       CtdlThreadCreate(worker_thread);
-       CtdlThreadCreate(worker_thread);
-       CtdlThreadCreate(worker_thread);
-       CtdlThreadCreate(worker_thread);
-       CtdlThreadCreate(worker_thread);
+       /* Begin with one worker thread.  We will expand the pool if necessary */
        CtdlThreadCreate(worker_thread);
 
-       /* At this point I am a union worker and therefore serve no useful purpose. */
+       /* The supervisor thread monitors worker threads and spawns more of them if it finds that
+        * they are all in use.  FIXME make the 256 max threads a configurable value.
+        */
+       while (!server_shutting_down) {
+               if ((active_workers == num_workers) && (num_workers < 256)) {
+                       CtdlThreadCreate(worker_thread);
+               }
+               usleep(1000000);
+       }
 
-       while(!CtdlThreadCheckStop()) {
-               sleep(3);
+       /* When we get to this point we are getting ready to shut down our Citadel server */
+       if (!EventQShuttingDown)
+       {
+               EventQShuttingDown = 1;
+               ShutDownEventQueues();
        }
+       while (!EVQShutDown)
+               usleep(1000000);
 
-       /* Shut down */
-       CtdlThreadStopAll();
-       exit(0);
+
+       terminate_all_sessions();               /* close all client sockets */
+       CtdlShutdownServiceHooks();             /* close all listener sockets to prevent new connections */
+       PerformSessionHooks(EVT_SHUTDOWN);      /* run any registered shutdown hooks */
+
+       int countdown = 30;
+       while ( (num_workers > 0) && (countdown-- > 0)) {
+               syslog(LOG_DEBUG, "Waiting %d seconds for %d worker threads to exit",
+                       countdown, num_workers
+               );
+               usleep(1000000);
+       }
 }