Declaration [src]

g_atomic_pointer_compare_and_exchange (
  void* atomic,
  gpointer oldval,
  gpointer newval

Description [src]

Compares atomic to oldval and, if equal, sets it to newval. If atomic was not equal to oldval then no change occurs.

This compare and exchange is done atomically.

Think of this operation as an atomic version of { if (*atomic == oldval) { *atomic = newval; return TRUE; } else return FALSE; }.

This call acts as a full compiler and hardware memory barrier.

While atomic has a volatile qualifier, this is a historical artifact and the pointer passed to it should not be volatile.

Available since:2.4


atomic void*

A pointer to a #gpointer-sized value.

 The data is owned by the caller of the function.
oldval gpointer

The value to compare with.

newval gpointer

The value to conditionally replace with.

Return value

Returns: gboolean

TRUE if the exchange took place.