pr_atomicset.rst (751B)
1 PR_AtomicSet 2 ============ 3 4 Atomically sets a 32-bit value and return its previous contents. 5 6 7 Syntax 8 ------ 9 10 .. code:: 11 12 #include <pratom.h> 13 14 PRInt32 PR_AtomicSet( 15 PRInt32 *val, 16 PRInt32 newval); 17 18 19 Parameters 20 ~~~~~~~~~~ 21 22 The function has the following parameter: 23 24 ``val`` 25 A pointer to the value to be set. 26 ``newval`` 27 The new value to assign to the ``val`` parameter. 28 29 30 Returns 31 ~~~~~~~ 32 33 The function returns the prior value of the referenced variable. 34 35 36 Description 37 ----------- 38 39 :ref:`PR_AtomicSet` first reads the value of var, then updates it with the 40 supplied value. The returned value is the value that was read\ *before* 41 memory was updated. The memory modification is unconditional--that is, 42 it isn't a test and set operation.