getc_unlocked, getchar_unlocked, putc_unlocked, putchar_unlocked Subroutines

Purpose

stdio with explicit client locking.

Library

Standard Library (libc.a)

Syntax

#include <stdio.h>

int getc_unlocked (FILE * stream);
int getchar_unlocked (void);
int putc_unlocked (int c, FILE * stream);
int putchar_unlocked (int c);

Description

Versions of the functions getc, getchar, putc, and putchar respectively named getc_unlocked, getchar_unlocked, putc_unlocked, and putchar_unlocked are provided which are functionally identical to the original versions with the exception that they are not required to be implemented in a thread-safe manner. They may only safely be used within a scope protected by flockfile (or ftrylockfile ) and funlockfile. These functions may safely be used in a multi-threaded program if and only if they are called while the invoking thread owns the (FILE*) object, as is the case after a successful call of the flockfile or ftrylockfile functions.

Return Values

See getc, getchar, putc, and putchar.