call_once once_flag ONCE_FLAG_INIT p99_call_once P99_DECLARE_INIT_ONCE P99_DECLARE_ONCE_CHAIN P99_DEFINE_ONCE_CHAIN P99_INIT_CHAIN P99_INIT_ONCE P99_MUTUAL_EXCLUDE p99_once_flag thrd2str THRD2STR thrd_t_destroy thrd_t_init

p99_call_once #define p99_call_once (   FLAG,   FUNC,   ARG  ) Call a function FUNC exactly once, optionally providing it with argument ARG. This is an extension of the standard function call_once. If ARG is given, it must be compatible with type void* and is passed to FUNC as an argument. In this case FUNC must have the prototype void FUNC(void*). If ARG is omitted FUNC should have the prototype void FUNC(void), i.e not take any argument. If the field p00_init is initialized with an appropriate function, the FUNC can also be omitted and p00_init is then called instead. Remarks The FLAG is only protected by an ::atomic_flag. Therefore the functions that are passed to this should be nice and short. These functions are protected against recursion and should not deadlock when they are confronted with cyclic dependencies. But obviously, the order in which such a cycle is taken is not predictable. See also p99_once_flag Definition at line 202 of file p99_threads.h.