Pthread Mutex Init Error Code

- operations on mutexes Synopsis #include #include pthread_mutex_t fastmutex = PTHREAD_MUTEX_INITIALIZER; pthread_mutex_t recmutex = PTHREAD_RECURSIVE_MUTEX_INITIALIZER; pthread_mutex_t errchkmutex = PTHREAD_ERRORCHECK_MUTEX_INITIALIZER; pthread_mutex_t recmutex = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP; pthread_mutex_t errchkmutex = PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP; pthread mutex example int pthread_mutex_init(pthread_mutex_t *mutex, const pthread_mutexattr_t *mutexattr); int pthread_mutex_lock(pthread_mutex_t *mutex);

Pthread Mutex Attributes

int pthread_mutex_trylock(pthread_mutex_t *mutex); int pthread_mutex_timedlock(pthread_mutex_t *mutex, const struct timespec *abs_timeout); int pthread_mutex_unlock(pthread_mutex_t *mutex); int pthread_mutex_consistent(pthread_mutex_t pthread cond init *mutex); int pthread_mutex_destroy(pthread_mutex_t *mutex); Description A mutex is a MUTual EXclusion device, and is useful for protecting shared data structures from concurrent modifications, and

Pthread Mutex Init Example

implementing critical sections and monitors. A mutex has two possible states: unlocked (not owned by any thread), and locked (owned by one thread). A mutex can never be owned by two different threads simultaneously. A thread attempting to lock a mutex that is already locked by another thread is pthread mutex lock suspended until the owning thread unlocks the mutex first. pthread_mutex_init initializes the mutex object pointed to by mutex according to the mutex attributes specified in mutexattr. If mutexattr is NULL, default attributes are used instead. The type of a mutex determines whether it can be locked again by a thread that already owns it. The default type is “normal�. See pthread_mutexattr_init(3) for more information on mutex attributes. Variables of type pthread_mutex_t can also be initialized statically, using the constants PTHREAD_MUTEX_INITIALIZER (for normal “fast� mutexes), PTHREAD_RECURSIVE_MUTEX_INITIALIZER (for recursive mutexes), and PTHREAD_ERRORCHECK_MUTEX_INITIALIZER (for error checking mutexes). In the Pthreads-w32 implementation, an application should still call pthread_mutex_destroy at some point to ensure that any resources consumed by the mutex are released. Any mutex type can be initialized as a robust mutex. See pthread_mutexattr_init(3) for more information as well as the section Robust Mutexes below. pthread_mutex_lock locks the gi

here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company Business http://stackoverflow.com/questions/383293/pthread-mutex-t-init-error Learn more about hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation https://docs.oracle.com/cd/E19455-01/806-5257/sync-112/index.html Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 6.2 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up pthread_mutex_t init error up vote 4 down vote favorite I am using xcode 2.4.1 on tiger. When i do below everything is ok. when pthread mutex i do pthread_mutex_t mute; ImageMan() { dibSize=0; mute = PTHREAD_MUTEX_INITIALIZER; } I get these two errors error: expected primary-expression before '{' token error: expected `;' before '{' token I dont know why. However if i do pthread_mutex_t mute = PTHREAD_MUTEX_INITIALIZER; it works fine. Why? -edit- I havent ran it but this seems to compile. Why? huh? pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER; mute = mutex; initialization pthreads mutex share|improve this question asked Dec 20 '08 at 13:04 pthread mutex init acidzombie24 43k137456818 add a comment| 2 Answers 2 active oldest votes up vote 15 down vote accepted PTHREAD_MUTEX_INITIALIZER is a constant initializer, valid when in initialization only. It is a macro that doesn't necessarily expand to an integral type. Your mute=mutex; is invalid- instead you should use: pthread_mutex_init(&mute, NULL); or if you're allocating mutexes dynamically: m = malloc(sizeof(pthread_mutex_t))); pthread_mutex_init(m, NULL); share|improve this answer answered Dec 20 '08 at 13:54 geocar 7,0891730 add a comment| up vote 0 down vote mute = (pthread_mutex_t)PTHREAD_MUTEX_INITIALIZER; This is an another solution for this error. share|improve this answer answered Jul 10 '15 at 6:11 raja ashok 3,726103761 Always try to give some explanation of answer. –serenesat Jul 10 '15 at 19:34 add a comment| Your Answer draft saved draft discarded Sign up or log in Sign up using Google Sign up using Facebook Sign up using Email and Password Post as a guest Name Email Post as a guest Name Email discard By posting your answer, you agree to the privacy policy and terms of service. Not the answer you're looking for? Browse other questions tagged initialization pthreads mutex or ask your own question. asked 7 years ago viewed 8817 times active 1 year ago Blog Stack Overflow Podcast #92 - The Guerilla Guide to Interviewing Related 2Pthreads : Segmentation fault error3Using one pthread_mutex_t an

Mutex ConsistentInitialize a Mutex pthread_mutex_init(3THR) Use pthread_mutex_init(3THR) to initialize the mutex pointed at by mp to its default value (mattr is NULL), or to specify mutex attributes that have already been set with pthread_mutexattr_init(). (For Solaris threads, see "mutex_init(3THR)".) Prototype: int pthread_mutex_init(pthread_mutex_t *mp, const pthread_mutexattr_t *mattr); #include pthread_mutex_t mp = PTHREAD_MUTEX_INITIALIZER; pthread_mutexattr_t mattr; int ret; /* initialize a mutex to its default value */ ret = pthread_mutex_init(&mp, NULL); /* initialize a mutex */ ret = pthread_mutex_init(&mp, &mattr); When the mutex is initialized, it is in an unlocked state. The mutex can be in memory shared between processes or in memory private to a process. Note - The mutex memory must be cleared to zero before initialization. The effect of mattr being NULL is the same as passing the address of a default mutex attribute object, but without the memory overhead. Statically defined mutexes can be initialized directly to have default attributes with the macro PTHREAD_MUTEX_INITIALIZER. A mutex lock must not be reinitialized or destroyed while other threads might be using it. Program failure will result if either action is not done correctly. If a mutex is reinitialized or destroyed, the application must be sure the mutex is not currently in use. Return Values pthread_mutex_init() returns zero after completing successfully. Any other returned value indicates that an error occurred. When any of the following conditions occurs, the function fails and returns the corresponding value. EBUSY The implementation has detected an attempt to reinitialize the object referenced by mp (a previously initialized, but not yet destroyed mutex). EINVAL The mattr attribute value is invalid. The mutex has not been modified. EFAULT The address for the mutex pointed at by mp is invalid. Previous: Mutual Exclusion Lock AttributesNext: Make Mutex Consistent © 2010, Oracle Corporation and/or its affiliates