putchar_unlocked—non-thread-safe version of putchar (macro)Description
putchar_unlocked is a non-thread-safe version of putchar
declared in stdio.h. putchar_unlocked 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 to the
flockfile() or ftrylockfile() functions. If threads are disabled,
then putchar_unlocked is equivalent to putchar.
Returns
See putchar.
Portability
POSIX 1003.1 requires putchar_unlocked. putchar_unlocked may
be implemented as a macro.
Supporting OS subroutines required: close, fstat, isatty,
lseek, read, sbrk, write.