Function

GLibatomic_pointer_compare_and_exchange_full

Declaration

gboolean
g_atomic_pointer_compare_and_exchange_full (
  void* atomic,
  gpointer oldval,
  gpointer newval,
  void* preval
)

Description

Compares atomic to oldval and, if equal, sets it to newval. If atomic was not equal to oldval then no change occurs. In any case the value of atomic before this operation is stored in preval.

This compare and exchange is done atomically.

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

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

See also g_atomic_pointer_compare_and_exchange()

Available since:2.74

Parameters

atomic

Type: void*

A pointer to a #gpointer-sized value.

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

Type: gpointer

The value to compare with.

The argument can be NULL.
The data is owned by the caller of the function.
newval

Type: gpointer

The value to conditionally replace with.

The argument can be NULL.
The data is owned by the caller of the function.
preval

Type: void*

The contents of atomic before this operation.

The argument will be set by the function.

Return value

Type: gboolean

TRUE if the exchange took place.