e9af4bc0b1cc30cea75d6ad4aa2fde97d985e9beJohn Beck * Copyright (c) 2003-2004, 2007, 2009 Sendmail, Inc. and its suppliers.
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck * All rights reserved.
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck * By using this file, you agree to the terms and conditions set
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck * forth in the LICENSE file which can be found at the top level of
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck * the sendmail distribution.
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck * Contributed by Jose Marcio Martins da Cruz - Ecole des Mines de Paris
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck * Jose-Marcio.Martins@ensmp.fr
e9af4bc0b1cc30cea75d6ad4aa2fde97d985e9beJohn BeckSM_RCSID("@(#)$Id: worker.c,v 8.17 2009/06/15 15:34:54 ca Exp $")
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck long tm_signature; /* has the controller been initialized */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck smfi_hd_T tm_ctx_head; /* head of the linked list of contexts */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck int tm_nb_workers; /* number of workers in the pool */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck "Error writing to event pipe: %s", \
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck } while (0)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck#endif /* USE_PIPE_WAKE_POLL */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck/* poll check periodicity (default 10000 - 10 s) */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck/* worker conditional wait timeout (default 10 s) */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck/* functions */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** periodicity of cleaning up old sessions (timedout)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** sessions list will be checked to find old inactive
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** sessions each DT_CHECK_OLD_SESSIONS sec
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck#endif /* OLD_SESSION_TIMEOUT */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck/* session states - with respect to the pool of workers */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck#define WKST_READY_TO_RUN 1 /* command ready do be read */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck#define WKST_RUNNING 2 /* session running on a worker */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck#define WKST_READY_TO_WAIT 3 /* session just finished by a worker */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck# define MIN_WORKERS 2 /* minimum number of threads to keep around */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck#define MIN_IDLE 1 /* minimum number of idle threads */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** Macros for threads and mutex management
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck } while (0)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck } while (0)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck scond_timedwait(&Tskmgr.tm_w_cond, &Tskmgr.tm_w_mutex, COND_TIMEOUT)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck } while (0)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck } while (0)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck } while (0)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck#else /* POOL_DEBUG */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck#endif /* POOL_DEBUG */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** MI_START_SESSION -- Start a session in the pool of workers
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** Parameters:
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** ctx -- context structure
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck POOL_LEV_DPRINTF(4, ("PIPE r=[%d] w=[%d]", RD_PIPE, WR_PIPE));
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck /* if there is an idle worker, signal it, otherwise start new worker */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** MI_CLOSE_SESSION -- Close a session and clean up data structures
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** Parameters:
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** ctx -- context structure
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** MI_POOL_CONTROLER_INIT -- Launch the worker pool controller
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** Must be called before starting sessions.
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** Parameters:
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck /* Launch the pool controller */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck if ((r = thread_create(&tid, mi_pool_controller, (void *) NULL)) != 0)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck smi_log(SMI_LOG_ERR, "can't create controller thread: %s",
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck /* Create the pool of workers */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck for (i = 0; i < MIN_WORKERS; i++)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck if ((r = thread_create(&tid, mi_worker, (void *) NULL)) != 0)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** MI_POOL_CONTROLLER -- manage the pool of workers
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** This thread must be running when listener begins
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** starting sessions
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** Parameters:
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** arg -- unused
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** Control flow:
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** Look for timed out sessions
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** Select sessions to wait for sendmail command
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** Poll set of file descriptors
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** if timeout
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** For each file descriptor ready
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** launch new thread if no worker available
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** signal waiting worker
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck/* Poll structure array (pollfd) size step */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeckstatic void *
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck smi_log(SMI_LOG_ERR, "Failed to detach pool controller thread");
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck pfd = (struct pollfd *) malloc(PFD_STEP * sizeof(struct pollfd));
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck smi_log(SMI_LOG_ERR, "Failed to malloc pollfd array: %s",
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck /* check for timed out sessions? */
e9af4bc0b1cc30cea75d6ad4aa2fde97d985e9beJohn Beck /* if session timed out, close it */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck ("Closing old connection: sd=%d id=%d",
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck ** Initialize poll set.
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck ** Insert into the poll set the file descriptors of
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck ** all sessions waiting for a command from sendmail.
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck /* begin with worker pipe */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck ** update ctx_wait - start of wait moment -
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck ** for timeout
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck /* add the session to the pollfd array? */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck ** Resize the pollfd array if it
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck ** isn't large enough.
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck "Failed to realloc pollfd array:%s",
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck /* add the session to pollfd array */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck /* Everything is ready, let's wait for an event */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck POOL_LEV_DPRINTF(4, ("%s returned: at epoch %d value %d",
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck /* timeout */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck /* error */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck "%s() failed (%s), %s",
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck /* something happened */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck for (i = 0; i < nfd; i++)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck /* has a worker signaled an end of task ? */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck ("PIPE WILL READ evt = %08X %08X",
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck if (r == sizeof(evt))
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck /* Do nothing */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck ("PIPE DONE READ i=[%d] fd=[%d] r=[%d] evt=[%d]",
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck /* Exception handling */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck /* no ! sendmail wants to send a command */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck ("Checking context sd=%d - fd=%d ",
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck ("TASK: found %d for fd[%d]=%d",
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck ("TASK %s FOUND - Checking PIPE for fd[%d]",
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** Look for a task ready to run.
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** Value of ctx is NULL or a pointer to a task ready to run.
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** MI_WORKER -- worker thread
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** executes tasks distributed by the mi_pool_controller
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** or by mi_start_session
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** Parameters:
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** arg -- pointer to context structure
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** NULL pointer
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeckstatic void *
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck smi_log(SMI_LOG_ERR, "Failed to detach worker thread");
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck /* let's handle next task... */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck ("worker %d: new task -> let's handle it",
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck ** Delete context from linked list of
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck ** sessions and close session.
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck ("writing to event pipe..."));
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck ** Signal task controller to add new session
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck ** to poll set.
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck /* check if there is any task waiting to be served */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck /* Got a task? */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck ** if not, let's check if there is enough idle workers
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck ** if yes: quit
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck POOL_LEV_DPRINTF(4, ("worker %d: checking ... %d %d", t_id,
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck POOL_LEV_DPRINTF(4, ("worker %d: quitting... ", t_id));
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck ** if no task ready to run, wait for another one
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck /* look for a task */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** MI_LIST_ADD_CTX -- add new session to linked list
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** Parameters:
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** ctx -- context structure
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** MI_LIST_DEL_CTX -- remove session from linked list when finished
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** Parameters:
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck** ctx -- context structure
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck#endif /* _FFR_WORKERS_POOL */