wait_event_interruptible_exclusive_locked_irq(9) [centos man page]

WAIT_EVENT_INTERRUPT(9) 					   Driver Basics					   WAIT_EVENT_INTERRUPT(9)

NAME

       wait_event_interruptible_exclusive_locked_irq - sleep until a condition gets true

SYNOPSIS

       wait_event_interruptible_exclusive_locked_irq(wq, condition);

ARGUMENTS

       wq
	   the waitqueue to wait on

       condition
	   a C expression for the event to wait for

DESCRIPTION

       The process is put to sleep (TASK_INTERRUPTIBLE) until the condition evaluates to true or a signal is received. The condition is checked
       each time the waitqueue wq is woken up.

       It must be called with wq.lock being held. This spinlock is unlocked while sleeping but condition testing is done while lock is held and
       when this macro exits the lock is held.

       The lock is locked/unlocked using spin_lock_irq/spin_unlock_irq functions which must match the way they are locked/unlocked outside of this
       macro.

       The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag set thus when other process waits process on the list if this process
       is awaken further processes are not considered.

       wake_up_locked has to be called after changing any variable that could change the result of the wait condition.

       The function will return -ERESTARTSYS if it was interrupted by a signal and 0 if condition evaluated to true.

COPYRIGHT

Kernel Hackers Manual 3.10					     June 2014						   WAIT_EVENT_INTERRUPT(9)

msem_lock(2)							System Calls Manual						      msem_lock(2)

NAME

       msem_lock() - lock a semaphore

SYNOPSIS


DESCRIPTION

       attempts to lock a binary semaphore.

       sem points to an structure which specifies the semaphore to be locked.

       If the semaphore is not currently locked, it becomes locked and the function returns successfully.

       If  the	semaphore is currently locked, and condition is then the function returns with an error.  If the semaphore is currently locked and
       condition is zero, the function does not return until either the calling process is able to successfully lock the semaphore,  or  an  error
       condition occurs.

       All calls to and by multiple processes sharing a common structure behave as if the calls were serialized.

       If  the	structure  contains any value not resulting from a call to followed by a (possibly empty) sequence of calls to and the results are
       undefined.  The address of an uniquely identifies the semaphore.  If the structure contains any value copied from an structure at a differ-
       ent address, the result is undefined.

IMPLEMENTATION NOTES

       If blocked on a locked semaphore, suspends the calling process at a priority such that the process can be interrupted by a signal.

       The system attempts to ignore or recover from invalid values written to the structure, but this is not guaranteed for all cases.

       successfully acquires a semaphore that is locked by a process that has exited.

RETURN VALUE

       returns one of the following values:

	      Success.

	      Failure.
		     is set to indicate the error.

ERRORS

       sets to one of the following values if the corresponding condition is encountered.

	      was specified and the semaphore was already locked.

	      sem	     points to an structure that has been removed, or condition is invalid.

	      was interrupted by a signal that was caught.

	      The semaphore is currently locked,
			     condition is zero, and waiting to lock the semaphore would create a deadlock.

	      sem	     is not a properly aligned address or is otherwise an invalid pointer.

AUTHOR

       was developed by HP and OSF.

SEE ALSO

       msem_init(2), msem_remove(2), msem_unlock(2), mman(5).

STANDARDS CONFORMANCE

																      msem_lock(2)