/* rwlock.h - read/write locks 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_RWLOCK_H #define LUMIERA_RWLOCK_H #ifndef _GNU_SOURCE #error "This header must be included with _GNU_SOURCE or _POSIX_C_SOURCE >= 200112L defined" #endif #include "lib/sectionlock.h" #include "lib/lockerror.h" #include #include #include /** * @file * Read/write locks, header. */ /** * Read locked section. * readlocks may fail when there are too much readers, one has to check the error afterwards! */ #define LUMIERA_RDLOCK_SECTION(nobugflag, rwlck) \ for (lumiera_sectionlock NOBUG_CLEANUP(lumiera_sectionlock_ensureunlocked) \ lumiera_lock_section_ = { \ rwlck, (lumiera_sectionlock_unlock_fn) lumiera_rwlock_unlock \ NOBUG_ALPHA_COMMA(&NOBUG_FLAG(nobugflag)) NOBUG_ALPHA_COMMA_NULL}; \ ({ \ if (lumiera_lock_section_.lock) \ lumiera_lock_section_.lock = \ lumiera_rwlock_rdlock (rwlck, &NOBUG_FLAG(nobugflag), \ &lumiera_lock_section_.rh, NOBUG_CONTEXT); \ lumiera_lock_section_.lock; \ }); \ ({ \ LUMIERA_RWLOCK_SECTION_UNLOCK; \ })) #define LUMIERA_RDLOCK_SECTION_CHAIN(nobugflag, rwlck) \ for (lumiera_sectionlock *lumiera_lock_section_old_ = &lumiera_lock_section_, \ NOBUG_CLEANUP(lumiera_sectionlock_ensureunlocked) lumiera_lock_section_ = { \ rwlck, (lumiera_sectionlock_unlock_fn) lumiera_rwlock_unlock \ NOBUG_ALPHA_COMMA(&NOBUG_FLAG(nobugflag)) NOBUG_ALPHA_COMMA_NULL}; \ ({ \ if (lumiera_lock_section_.lock) \ { \ REQUIRE (lumiera_lock_section_old_->lock, "section prematurely unlocked"); \ lumiera_lock_section_.lock = \ lumiera_rwlock_rdlock (rwlck, &NOBUG_FLAG(nobugflag), \ lumiera_lock_section_.rh, NOBUG_CONTEXT); \ LUMIERA_SECTION_UNLOCK_(lumiera_lock_section_old_); \ } \ lumiera_lock_section_.lock; \ }); \ ({ \ LUMIERA_RWLOCK_SECTION_UNLOCK; \ })) /** * Write locked section. */ #define LUMIERA_WRLOCK_SECTION(nobugflag, rwlck) \ for (lumiera_sectionlock NOBUG_CLEANUP(lumiera_sectionlock_ensureunlocked) \ lumiera_lock_section_ = { \ rwlck, (lumiera_sectionlock_unlock_fn) lumiera_rwlock_unlock \ NOBUG_ALPHA_COMMA(&NOBUG_FLAG(nobugflag)) NOBUG_ALPHA_COMMA_NULL}; \ ({ \ if (lumiera_lock_section_.lock) \ lumiera_lock_section_.lock = \ lumiera_rwlock_wrlock (rwlck, &NOBUG_FLAG(nobugflag), \ &lumiera_lock_section_.rh, NOBUG_CONTEXT); \ lumiera_lock_section_.lock; \ }); \ ({ \ LUMIERA_RWLOCK_SECTION_UNLOCK; \ })) #define LUMIERA_WRLOCK_SECTION_CHAIN(nobugflag, rwlck) \ for (lumiera_sectionlock *lumiera_lock_section_old_ = &lumiera_lock_section_, \ NOBUG_CLEANUP(lumiera_sectionlock_ensureunlocked) lumiera_lock_section_ = { \ rwlck, (lumiera_sectionlock_unlock_fn) lumiera_rwlock_unlock \ NOBUG_ALPHA_COMMA(&NOBUG_FLAG(nobugflag)) NOBUG_ALPHA_COMMA_NULL}; \ ({ \ if (lumiera_lock_section_.lock) \ { \ REQUIRE (lumiera_lock_section_old_->lock, "section prematurely unlocked"); \ lumiera_lock_section_.lock = \ lumiera_rwlock_wrlock (rwlck, &NOBUG_FLAG(nobugflag), \ lumiera_lock_section_.rh, NOBUG_CONTEXT); \ LUMIERA_SECTION_UNLOCK_(lumiera_lock_section_old_); \ } \ lumiera_lock_section_.lock; \ }); \ ({ \ LUMIERA_RWLOCK_SECTION_UNLOCK; \ })) #define LUMIERA_RWLOCK_SECTION_UNLOCK \ LUMIERA_SECTION_UNLOCK_(&lumiera_lock_section_) /** * RWLock. * */ struct lumiera_rwlock_struct { pthread_rwlock_t rwlock; RESOURCE_HANDLE (rh); }; typedef struct lumiera_rwlock_struct lumiera_rwlock; typedef lumiera_rwlock* LumieraRWLock; /** * Initialize a rwlock * @param self is a pointer to the rwlock to be initialised * @return self as given */ LumieraRWLock lumiera_rwlock_init (LumieraRWLock self, const char* purpose, struct nobug_flag* flag, const struct nobug_context ctx); /** * destroy a rwlock * @param self is a pointer to the rwlock to be initialised * @return self on success or NULL at error */ LumieraRWLock lumiera_rwlock_destroy (LumieraRWLock self, struct nobug_flag* flag, const struct nobug_context ctx); static inline LumieraRWLock lumiera_rwlock_rdlock (LumieraRWLock self, struct nobug_flag* flag, struct nobug_resource_user** handle, const struct nobug_context ctx) { if (self) { NOBUG_RESOURCE_WAIT_CTX (NOBUG_FLAG_RAW(flag), self->rh, "acquire rwlock for reading", *handle, ctx) { int err = pthread_rwlock_rdlock (&self->rwlock); if (!err) { NOBUG_RESOURCE_STATE_CTX (NOBUG_FLAG_RAW(flag), NOBUG_RESOURCE_SHARED, *handle, ctx) /*{}*/; } else { NOBUG_RESOURCE_LEAVE_RAW_CTX (flag, *handle, ctx) /*{}*/; lumiera_lockerror_set (err, flag, ctx); self = NULL; } } } return self; } static inline LumieraRWLock lumiera_rwlock_tryrdlock (LumieraRWLock self, struct nobug_flag* flag, struct nobug_resource_user** handle, const struct nobug_context ctx) { if (self) { NOBUG_RESOURCE_TRY_CTX (NOBUG_FLAG_RAW(flag), self->rh, "try acquire rwlock for reading", *handle, ctx) { int err = pthread_rwlock_tryrdlock (&self->rwlock); if (!err) { NOBUG_RESOURCE_STATE_CTX (NOBUG_FLAG_RAW(flag), NOBUG_RESOURCE_SHARED, *handle, ctx) /*{}*/; } else { NOBUG_RESOURCE_LEAVE_RAW_CTX (flag, *handle, ctx) /*{}*/; lumiera_lockerror_set (err, flag, ctx); self = NULL; } } } return self; } static inline LumieraRWLock lumiera_rwlock_timedrdlock (LumieraRWLock self, const struct timespec* timeout, struct nobug_flag* flag, struct nobug_resource_user** handle, const struct nobug_context ctx) { if (self) { NOBUG_RESOURCE_TRY_CTX (NOBUG_FLAG_RAW(flag), self->rh, "timed acquire rwlock for reading", *handle, ctx) { int err = pthread_rwlock_timedrdlock (&self->rwlock, timeout); if (!err) { NOBUG_RESOURCE_STATE_CTX (NOBUG_FLAG_RAW(flag), NOBUG_RESOURCE_SHARED, *handle, ctx) /*{}*/; } else { NOBUG_RESOURCE_LEAVE_RAW_CTX (flag, *handle, ctx) /*{}*/; lumiera_lockerror_set (err, flag, ctx); self = NULL; } } } return self; } static inline LumieraRWLock lumiera_rwlock_wrlock (LumieraRWLock self, struct nobug_flag* flag, struct nobug_resource_user** handle, const struct nobug_context ctx) { if (self) { NOBUG_RESOURCE_WAIT_CTX (NOBUG_FLAG_RAW(flag), self->rh, "acquire rwlock for writing", *handle, ctx) { if (pthread_rwlock_wrlock (&self->rwlock)) LUMIERA_DIE (LOCK_ACQUIRE); /* never reached (in a correct program) */ NOBUG_RESOURCE_STATE_CTX (NOBUG_FLAG_RAW(flag), NOBUG_RESOURCE_EXCLUSIVE, *handle, ctx) /*{}*/; } } return self; } static inline LumieraRWLock lumiera_rwlock_trywrlock (LumieraRWLock self, struct nobug_flag* flag, struct nobug_resource_user** handle, const struct nobug_context ctx) { if (self) { NOBUG_RESOURCE_TRY_CTX (NOBUG_FLAG_RAW(flag), self->rh, "try acquire rwlock for writing", *handle, ctx) { int err = pthread_rwlock_trywrlock (&self->rwlock); if (!err) { NOBUG_RESOURCE_STATE_CTX (NOBUG_FLAG_RAW(flag), NOBUG_RESOURCE_EXCLUSIVE, *handle, ctx) /*{}*/; } else { NOBUG_RESOURCE_LEAVE_RAW_CTX (flag, *handle, ctx) /*{}*/; lumiera_lockerror_set (err, flag, ctx); self = NULL; } } } return self; } static inline LumieraRWLock lumiera_rwlock_timedwrlock (LumieraRWLock self, const struct timespec* timeout, struct nobug_flag* flag, struct nobug_resource_user** handle, const struct nobug_context ctx) { if (self) { NOBUG_RESOURCE_TRY_CTX (NOBUG_FLAG_RAW(flag), self->rh, "timed acquire rwlock for writing", *handle, ctx) { int err = pthread_rwlock_timedwrlock (&self->rwlock, timeout); if (!err) { NOBUG_RESOURCE_STATE_CTX (NOBUG_FLAG_RAW(flag), NOBUG_RESOURCE_EXCLUSIVE, *handle, ctx) /*{}*/; } else { NOBUG_RESOURCE_LEAVE_RAW_CTX (flag, *handle, ctx) /*{}*/; lumiera_lockerror_set (err, flag, ctx); self = NULL; } } } return self; } static inline void lumiera_rwlock_unlock (LumieraRWLock self, struct nobug_flag* flag, struct nobug_resource_user** handle, const struct nobug_context ctx) { NOBUG_REQUIRE_CTX (self, ctx); NOBUG_RESOURCE_LEAVE_RAW_CTX (flag, *handle, ctx) { if (pthread_rwlock_unlock (&self->rwlock)) LUMIERA_DIE (LOCK_RELEASE); /* never reached (in a correct program) */ } } #endif /* // Local Variables: // mode: C // c-file-style: "gnu" // indent-tabs-mode: nil // End: */