Re: Threading in tux modules

Jason Borden <[email protected]> Thu, 11 Apr 2002 13:04:43 -0600

Newsgroups	gmane.network.tux
Organization	Sorenson Media
Message-ID	<[email protected]>

Here's a patch for tux-2.2.5 that implements the optional TUXAPI_init_postfork 
call.  I'm not sure if I've implemented it the most efficient way or not, but 
it's a start.

Jason

On Monday 08 April 2002 05:41 am, Ingo Molnar wrote:
> On Fri, 5 Apr 2002, Jason Borden wrote:
> > I have a project I'm working on that caches data received from an ldap
> > directory and runs a background thread to refresh the cache when the
> > data changes. I've run into some issues with running threads inside of a
> > tux module, but have found a way to make it work. For some reason, I am
> > unable to make the thread work if it is created at the TUXAPI_init
> > stage, [...]
>
> TUXAPI_init is executed before the main TUX processes are forked - those
> processes have a separate VM so the threads created in TUXAPI_init wont
> work as expected.
>
> perhaps there should be an optional TUXAPI_init_postfork call as well?
>
> 	Ingo
>
>
>
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postfork.patch (text/x-diff, 3.1 KB)

*** tux-2.2.5/tux.c	Thu Feb  7 10:27:43 2002
--- tux-2.2.5-jb/tux.c	Thu Apr 11 12:49:42 2002
***************
*** 63,68 ****
--- 63,69 ----
  
  static int max_module_idx = 1;
  static int (**handle_events_array) (user_req_t *req);
+ static void (**postfork_array) (void);
  char **TUXAPI_modulename_array;
  
  void die(int exitcode, char *format, ...) {
***************
*** 442,449 ****
  		const char *modulename;
  
  		handle_events_array = malloc(sizeof(*handle_events_array) * (argc-3));
  		TUXAPI_modulename_array = malloc(sizeof(*TUXAPI_modulename_array) * (argc-3));
! 		if (!handle_events_array || !TUXAPI_modulename_array) {
  			tux_stop_date_timer(timer);
  			die(1, "%s: no RAM", strerror(errno));
  		}
--- 443,451 ----
  		const char *modulename;
  
  		handle_events_array = malloc(sizeof(*handle_events_array) * (argc-3));
+         postfork_array = calloc(sizeof(*postfork_array) * (argc-3), 1);
  		TUXAPI_modulename_array = malloc(sizeof(*TUXAPI_modulename_array) * (argc-3));
! 		if (!handle_events_array || !TUXAPI_modulename_array || !postfork_array) {
  			tux_stop_date_timer(timer);
  			die(1, "%s: no RAM", strerror(errno));
  		}
***************
*** 452,457 ****
--- 454,460 ----
  			user_req_t req;
  			int (*mod_handle_events) (user_req_t *req);
  			void (*mod_init) (void);
+             void (*mod_init_postfork) (void);
  			char *libname;
  			unsigned int modulename_len = strlen(modulename);
  
***************
*** 476,485 ****
  				die(1, "%s: TUXAPI_handle_events() function missing", strerror(errno));
  			}
  			mod_init = dlsym(handle, "TUXAPI_init");
  
  			printf ("TUXAPI_init: %p\n", mod_init);
  			printf ("TUXAPI_handle_events: %p\n", mod_handle_events);
! 
  			memset(&req, 0, sizeof(req));
  			req.module_index = mod_idx;
  			strcpy(req.objectname, modulename);
--- 479,490 ----
  				die(1, "%s: TUXAPI_handle_events() function missing", strerror(errno));
  			}
  			mod_init = dlsym(handle, "TUXAPI_init");
+             mod_init_postfork = dlsym(handle, "TUXAPI_init_postfork");
  
  			printf ("TUXAPI_init: %p\n", mod_init);
+             printf ("TUXAPI_init_postfork: %p\n", mod_init_postfork);
  			printf ("TUXAPI_handle_events: %p\n", mod_handle_events);
!             
  			memset(&req, 0, sizeof(req));
  			req.module_index = mod_idx;
  			strcpy(req.objectname, modulename);
***************
*** 491,496 ****
--- 496,502 ----
  			printf("register {%s} - TUX returned %d...\n", req.objectname, ret);
  
  			handle_events_array[mod_idx] = mod_handle_events;
+             postfork_array[mod_idx] = mod_init_postfork;
  			TUXAPI_modulename_array[mod_idx] = malloc(strlen(modulename)+1);
  			if (!TUXAPI_modulename_array[mod_idx]) {
  				tux_stop_date_timer(timer);
***************
*** 529,534 ****
--- 534,547 ----
  		if (pid[i])
  			continue;
  
+         if (i == 0) {
+             for (mod_idx = 0; mod_idx < max_module_idx; mod_idx++) {
+                 if (postfork_array[mod_idx])
+                     postfork_array[mod_idx]();
+             }   
+             free(postfork_array);
+         }
+ 
  		sprintf(commandline, "[TUX worker %d]", i);
  		replace_commandline(argc, argv, commandline);