Docs » Autodocs » exec.library » ObtainSemaphoreList
ObtainSemaphoreList -- get a list of semaphores.
ObtainSemaphoreList(list)
A0
void ObtainSemaphoreList(struct List *);
Signal semaphores may be linked together into a list. This function
takes a list of these semaphores and attempts to lock all of them at
once. This call is preferable to applying ObtainSemaphore() to each
element in the list because it attempts to lock all the elements
simultaneously, and won't deadlock if someone is attempting to lock
in some other order.
This function assumes that only one task at a time will attempt to
lock the entire list of semaphores. In other words, there needs to
be a higher level lock (perhaps another signal semaphore...) that is
used before someone attempts to lock the semaphore list via
ObtainSemaphoreList().
Note that deadlocks may result if this call is used AND someone
attempts to use ObtainSemaphore() to lock more than one semaphore on
the list. If you wish to lock more than semaphore (but not all of
them) then you should obtain the higher level lock (see above)
list -- a list of signal semaphores
ObtainSemaphoreShared(), InitSemaphore(), ReleaseSemaphore(), AttemptSemaphore(), ObtainSemaphoreShared(), Procure(), Vacate()
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