cvsema(D3X)

NAME
     cvsema - conditionally perform a "V" or wait semaphore operation

SYNOPSIS
     #include "sys/types.h"
     #include "sys/sema.h"

     cvsema(sema_t *semap);

   Arguments
     semap
          Expects a pointer to the semaphore you want to conditionally.

DESCRIPTION
     cvsema routine conditionally performs a "V" operation depending on the
     current value of the semaphore. If the semaphore value is strictly less
     than 0, cvsema increments the semaphore value by 1 and wakes up a
     sleeping process.  Otherwise, cvsema simply returns. cvsema effectively
     performs a "V" operation if there is a process asleep on the semaphore;
     otherwise, it does nothing. To initialize semaphores before you use them,
     call initnsema(D3X) or initnsema_mutex(D3X).

   Return Values
     cvsema returns 1 if the semaphore value is less than 0 and a process is
     awakened. Otherwise cvsema returns 0.

   See Also
     initnsema(D3X), initnsema_mutex(D3X), vsema(D3X)