libzmq/doc/zmq_atomic_counter_dec.txt
Pieter Hintjens 2de940b422 Problem: need atomic reference counting in several projects
Solution: as libzmq already provides this across all platforms,
expose an atomic counter API. I've not wrapped atomic pointers,
though someone who needs this may want to do so.
2014-12-23 01:14:38 +01:00

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zmq_atomic_counter_dec(3)
=========================
NAME
----
zmq_atomic_counter_dec - decrement an atomic counter
SYNOPSIS
--------
*bool zmq_atomic_counter_dec (void *counter);*
DESCRIPTION
-----------
The _zmq_atomic_counter_dec_ function decrements an atomic counter in
a threadsafe fashion. This function uses platform specific atomic
operations.
RETURN VALUE
------------
The _zmq_atomic_counter_dec()_ function returns true if the counter is
greater than zero after decrementing, or false if the counter reached
zero.
EXAMPLE
-------
.Test code for atomic counters
----
void *counter = zmq_atomic_counter_new ();
assert (zmq_atomic_counter_value (counter) == 0);
assert (zmq_atomic_counter_inc (counter) == 0);
assert (zmq_atomic_counter_inc (counter) == 1);
assert (zmq_atomic_counter_inc (counter) == 2);
assert (zmq_atomic_counter_value (counter) == 3);
assert (zmq_atomic_counter_dec (counter) == true);
assert (zmq_atomic_counter_dec (counter) == true);
assert (zmq_atomic_counter_dec (counter) == false);
zmq_atomic_counter_set (counter, 2);
assert (zmq_atomic_counter_dec (counter) == true);
assert (zmq_atomic_counter_dec (counter) == false);
zmq_atomic_counter_destroy (&counter);
----
SEE ALSO
--------
linkzmq:zmq_atomic_counter_new[3]
linkzmq:zmq_atomic_counter_set[3]
linkzmq:zmq_atomic_counter_inc[3]
linkzmq:zmq_atomic_counter_value[3]
linkzmq:zmq_atomic_counter_destroy[3]
AUTHORS
-------
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read the 0MQ Contribution Policy at <http://www.zeromq.org/docs:contributing>.