putchar_unlocked

Synopsis

#include <stdio.h>

int getc_unlocked(FILE *stream);

int getchar_unlocked(void);

int putc_unlocked(int c, FILE *stream);

int putchar_unlocked(int c);

Status

Partially implemented

Conformance

IEEE Std 1003.1-2017

Description

Versions of the functions getc(), getchar(), putc(), and putchar() respectively named getc_unlocked(), getchar_unlocked(),putc_unlocked(), and putchar_unlocked() shall be provided which are functionally equivalent to the original versions, with the exception that they are not required to be implemented in a fully thread-safe manner. They shall be thread-safe when used within a scope protected by flockfile() (or ftrylockfile()) and funlockfile().

These functions can safely be used in a multithreaded program if and only if they are called while the invoking thread owns the ( FILE *) object, as is the case after a successful call to the flockfile() or ftrylockfile() functions.

If getc_unlocked() or putc_unlocked() are implemented as macros they may evaluate stream more than once, so the stream argument should never be an expression with side effects.

Return value

See getc(), getchar(), putc(), and putchar().

Errors

See getc(), getchar(), putc(), and putchar().

Tests

Untested

Known bugs

None