0
The sem_wait() function locks the semaphore referenced by sem by performing a semaphore lock operation on that semaphore. If the semaphore value is currently zero, then the calling thread will not return from the call to sem_wait()until it either locks the semaphore or the call is interrupted by a signal.
Upon successful return, the state of the semaphore is locked and remains locked until the sem_post() function is executed and returns successfully. The sem_wait() function is interruptible by the delivery of a signal.
The sem_post() function unlocks the semaphore referenced by sem by performing a semaphore unlock operation on that semaphore.
If the semaphore value resulting from this operation is positive, then no threads were blocked waiting for the semaphore to become unlocked; the semaphore value is simply incremented.
If the value of the semaphore resulting from this operation is zero, then one of the threads blocked waiting for the semaphore will be allowed to return successfully from its call to sem_wait(). If the symbol _POSIX_PRIORITY_SCHEDULING is defined, the thread to be unblocked will be chosen in a manner appropriate to the scheduling policies and parameters in effect for the blocked threads. In the case of the schedulers SCHED_FIFO and SCHED_RR, the highest priority waiting thread will be unblocked, and if there is more than one highest priority thread blocked waiting for the semaphore, then the highest priority thread that has been waiting the longest will be unblocked. If the symbol _POSIX_PRIORITY_SCHEDULING is not defined, the choice of a thread to unblock is unspecified.
The sem_post() interface is reentrant with respect to signals and may be invoked from a signal-catching function.
What else can I help you with?
Bca first sem syllabus in mdu?
1st sem sllyabus of bca
Power sem for be student in rgtu?
What is the process of power sem in be ? Plz sent the details...
Rgpv Time table of be third sem?
i want be 3rd sem timetable of cs branch 2013
Bca 5th sem datesheet?
madarchod sale 5 sem ka time table de bahanchod
What is SEM used for?
SEM is an abbreviation. The person above ghave another mewaning, but I have instantly thoiugh about search engine marketing - one of the practices that is used in online marketing.
What is the date for post ume examination?
i want to gave date of b com sem 3 examination only
How much the tuition fee of sped post grad course in university of santo Tomas?
around PhP30,000 per sem i think
Bsc it ist sem and 2nd sem model questions?
Click the link below, it may help you. http://hiddencomputertricks.blogspot.com/2009/09/tybsc-it-sem-5-question-papers-mumbai.html
Identify possible actors and use cases involved in the post office functions at hertford post office?
hertford has a typical small town post office that sell stamps ,rents post office boxes, and delivery mail to postal customer .identify possible actor and use cases involved in the post office functions
What are the different function performed by post?
To post data of form to another form. there are two functions available post and get. get can carry string of data but post can carry package of data.
How can you get off of Tumblr post limit?
There's no way of bypassing the post limit, you'll have to wait 24 hours.
The be third sem and 4th sem time table for ex students?
timetable of be 3rd sem ex
Ba second sem and 4th sem time table?
i want BA 2nd sem time table
What is a SEM microscope?
A SEM microscope is a scanning electron microscope
When was Sem Sæland born?
Sem Sæland was born in 1874.
When did Sem Sæland die?
Sem Sæland died in 1940.
When did Sem Dresden die?
Sem Dresden died in 1957.
