/* reccondition.h - condition variables, w/ recursive mutex Copyright (C) Lumiera.org 2008, Christian Thaeter This program is free 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 2 of the License, or (at your option) any later version. 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., 675 Mass Ave, Cambridge, MA 02139, USA. */ #ifndef LUMIERA_RECCONDITION_H #define LUMIERA_RECCONDITION_H #include "lib/error.h" #include "lib/mutex.h" /** * @file * Reccondition variables. Same as Conditon variables but using a recursive mutex for locking. */ /** * Reccondition section. * Locks the reccondition mutex, one can then use LUMIERA_RECCONDITION_WAIT to wait for signals or * LUMIERA_RECCONDITION_SIGNAL or LUMIERA_RECCONDITION_BROADCAST to wake waiting threads * @param nobugflag NoBug flag used to log actions on the reccondition * @param rcnd Reccondition variable to be locked */ #define LUMIERA_RECCONDITION_SECTION(nobugflag, rcnd) \ for (lumiera_recconditionacquirer NOBUG_CLEANUP(lumiera_recconditionacquirer_ensureunlocked) \ lumiera_reccondition_section_ = {(LumieraReccondition)1}; \ lumiera_reccondition_section_.reccondition;) \ for ( \ ({ \ lumiera_reccondition_section_.reccondition = (rcnd); \ NOBUG_IF(NOBUG_MODE_ALPHA, lumiera_reccondition_section_.flag = &NOBUG_FLAG(nobugflag)); \ NOBUG_RESOURCE_HANDLE_INIT (lumiera_reccondition_section_.rh); \ RESOURCE_ENTER (nobugflag, (rcnd)->rh, "acquire reccondition", &lumiera_reccondition_section_, \ NOBUG_RESOURCE_RECURSIVE, lumiera_reccondition_section_.rh); \ if (pthread_mutex_lock (&(rcnd)->mutex)) LUMIERA_DIE (MUTEX_LOCK); \ }); \ lumiera_reccondition_section_.reccondition; \ ({ \ LUMIERA_RECCONDITION_UNLOCK(nobugflag) \ })) /** * Explicit mutex unlock for a reccondition variable * One can early unlock the mutex of a condition variable prior leaving a RECCONDITION_SECTION. * The RECCONDITION_WAIT, RECCONDITION_SIGNAL and RECCONDITION_BROADCAST macros must not be used after the mutex * got unlocked. * @param nobugflag NoBug flag used to log actions on the reccondition */ #define LUMIERA_RECCONDITION_UNLOCK \ if (lumiera_reccondition_section_.reccondition) \ { \ pthread_mutex_unlock (&lumiera_reccondition_section_.reccondition->mutex); \ lumiera_reccondition_section_.reccondition = NULL; \ RESOURCE_LEAVE(nobugflag, lumiera_reccondition_section_.rh); \ } /** * Wait for a reccondition. * Must be used inside a RECCONDITION_SECTION. * @param expr Recconditon which must become true, else the reccondition variable goes back into sleep */ #define LUMIERA_RECCONDITION_WAIT(expr) \ do { \ ENSURE (lumiera_reccondition_section_.reccondition, "Reccondition mutex not locked"); \ NOBUG_RESOURCE_STATE_RAW (lumiera_reccondition_section_.flag, lumiera_reccondition_section_.rh, NOBUG_RESOURCE_WAITING); \ pthread_cond_wait (&lumiera_reccondition_section_.reccondition->cond, &lumiera_reccondition_section_.reccondition->mutex); \ NOBUG_RESOURCE_STATE_RAW (lumiera_reccondition_section_.flag, lumiera_reccondition_section_.rh, NOBUG_RESOURCE_RECURSIVE); \ } while (!(expr)) /** * Signal a reccondition variable * Must be used inside a RECCONDITION_SECTION. * Wakes one thread waiting on the condition variable */ #define LUMIERA_RECCONDITION_SIGNAL \ do { \ ENSURE (lumiera_reccondition_section_.reccondition, "Reccondition mutex not locked"); \ NOBUG_IF(NOBUG_MODE_ALPHA, TRACE(lumiera_reccondition_section_.flag, "Signaling")); \ pthread_cond_signal (&lumiera_reccondition_section_.reccondition->cond); \ } while (0) /** * Broadcast a reccondition variable * Must be used inside a RECCONDITION_SECTION. * Wakes all threads waiting on the reccondition variable */ #define LUMIERA_RECCONDITION_BROADCAST \ do { \ ENSURE (lumiera_reccondition_section_.reccondition, "Reccondition mutex not locked"); \ NOBUG_IF(NOBUG_MODE_ALPHA, TRACE(lumiera_reccondition_section_.flag, "Broadcasting"));\ pthread_cond_broadcast (&lumiera_reccondition_section_.reccondition->cond); \ } while (0) /** * Reccondition variables. * */ struct lumiera_reccondition_struct { pthread_cond_t cond; pthread_mutex_t mutex; RESOURCE_HANDLE (rh); }; typedef struct lumiera_reccondition_struct lumiera_reccondition; typedef lumiera_reccondition* LumieraReccondition; /** * Initialize a reccondition variable * @param self is a pointer to the reccondition variable to be initialized * @return self as given */ LumieraReccondition lumiera_reccondition_init (LumieraReccondition self, const char* purpose, struct nobug_flag* flag); /** * Destroy a reccondition variable * @param self is a pointer to the reccondition variable to be destroyed * @return self as given */ LumieraReccondition lumiera_reccondition_destroy (LumieraReccondition self, struct nobug_flag* flag); /** * recconditionacquirer used to manage the state of a reccondition variable. */ struct lumiera_recconditionacquirer_struct { LumieraReccondition reccondition; NOBUG_IF(NOBUG_MODE_ALPHA, struct nobug_flag* flag); RESOURCE_HANDLE (rh); }; typedef struct lumiera_recconditionacquirer_struct lumiera_recconditionacquirer; typedef struct lumiera_recconditionacquirer_struct* LumieraRecconditionacquirer; /* helper function for nobug */ static inline void lumiera_recconditionacquirer_ensureunlocked (LumieraRecconditionacquirer self) { ENSURE (!self->reccondition, "forgot to unlock reccondition variable"); } #endif /* // Local Variables: // mode: C // c-file-style: "gnu" // indent-tabs-mode: nil // End: */