http://en.wikipedia.org/wiki/Semaphore_(programming)
http://www.tin.org/bin/man.cgi?section=3&topic=sem_init
You initialise the semaphore to some N
You're allowed to call sem_wait() N times in succession before blocking.
At some point, there will be N sem_post() calls to return the semaphore to it's initial state.
Are you saying you want to change N after you've created it?
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
If at first you don't succeed, try writing your phone number on the exam paper.
yes, what i want is to have the semaphore locked, and then change the value to N, being N the number of children, so that all of them start accessing the memory.
Seems i will have to use N sem_post. not in one instruction how i hoped, but it works
Thank You all
