| 17,19 → 17,32 |
|---|
| |
| /* |
| FUNCTION |
| <<fflush>>---flush buffered file output |
| <<fflush>>, <<fflush_unlocked>>---flush buffered file output |
| |
| INDEX |
| fflush |
| INDEX |
| fflush_unlocked |
| INDEX |
| _fflush_r |
| INDEX |
| _fflush_unlocked_r |
| |
| ANSI_SYNOPSIS |
| #include <stdio.h> |
| int fflush(FILE *<[fp]>); |
| |
| #define _BSD_SOURCE |
| #include <stdio.h> |
| int fflush_unlocked(FILE *<[fp]>); |
| |
| #include <stdio.h> |
| int _fflush_r(struct _reent *<[reent]>, FILE *<[fp]>); |
| |
| #define _BSD_SOURCE |
| #include <stdio.h> |
| int _fflush_unlocked_r(struct _reent *<[reent]>, FILE *<[fp]>); |
| |
| DESCRIPTION |
| The <<stdio>> output functions can buffer output before delivering it |
| to the host system, in order to minimize the overhead of system calls. |
| 45,10 → 58,19 |
|---|
| unread byte, useful for obeying POSIX semantics when ending a process |
| without consuming all input from the stream. |
| |
| The alternate function <<_fflush_r>> is a reentrant version, where the |
| extra argument <[reent]> is a pointer to a reentrancy structure, and |
| <[fp]> must not be NULL. |
| <<fflush_unlocked>> is a non-thread-safe version of <<fflush>>. |
| <<fflush_unlocked>> may only safely be used within a scope |
| protected by flockfile() (or ftrylockfile()) and funlockfile(). This |
| function 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 |
| <<fflush_unlocked>> is equivalent to <<fflush>>. |
| |
| The alternate functions <<_fflush_r>> and <<_fflush_unlocked_r>> are |
| reentrant versions, where the extra argument <[reent]> is a pointer to |
| a reentrancy structure, and <[fp]> must not be NULL. |
| |
| RETURNS |
| <<fflush>> returns <<0>> unless it encounters a write error; in that |
| situation, it returns <<EOF>>. |
| 57,6 → 79,8 |
|---|
| ANSI C requires <<fflush>>. The behavior on input streams is only |
| specified by POSIX, and not all implementations follow POSIX rules. |
| |
| <<fflush_unlocked>> is a BSD extension also provided by GNU libc. |
| |
| No supporting OS subroutines are required. |
| */ |
| |
| 65,6 → 89,12 |
|---|
| #include <errno.h> |
| #include "local.h" |
| |
| #ifdef __IMPL_UNLOCKED__ |
| #define _fflush_r _fflush_unlocked_r |
| #define fflush fflush_unlocked |
| #endif |
| |
| #ifndef __IMPL_UNLOCKED__ |
| /* Flush a single file, or (if fp is NULL) all files. */ |
| |
| /* Core function which does not lock file pointer. This gets called |
| 204,7 → 234,22 |
|---|
| return 0; |
| } |
| |
| #ifdef _STDIO_BSD_SEMANTICS |
| /* Called from _cleanup_r. At exit time, we don't need file locking, |
| and we don't want to move the underlying file pointer unless we're |
| writing. */ |
| int |
| _DEFUN(__sflushw_r, (ptr, fp), |
| struct _reent *ptr _AND |
| register FILE *fp) |
| { |
| return (fp->_flags & __SWR) ? __sflush_r (ptr, fp) : 0; |
| } |
| #endif |
| |
| #endif /* __IMPL_UNLOCKED__ */ |
| |
| int |
| _DEFUN(_fflush_r, (ptr, fp), |
| struct _reent *ptr _AND |
| register FILE * fp) |