diff options
Diffstat (limited to 'libc/stdio/fflush.c')
| -rw-r--r-- | libc/stdio/fflush.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/libc/stdio/fflush.c b/libc/stdio/fflush.c new file mode 100644 index 000000000..6baa0ec82 --- /dev/null +++ b/libc/stdio/fflush.c @@ -0,0 +1,161 @@ +/* Copyright (C) 2004 Manuel Novoa III <mjn3@codepoet.org> + * + * GNU Library General Public License (LGPL) version 2 or later. + * + * Dedicated to Toni. See uClibc/DEDICATION.mjn3 for details. + */ + +#include "_stdio.h" + +extern int __fflush_unlocked(register FILE *stream); + +#ifdef __DO_UNLOCKED + +#ifdef __UCLIBC_MJN3_ONLY__ +#warning WISHLIST: Add option to test for undefined behavior of fflush. +#endif /* __UCLIBC_MJN3_ONLY__ */ + +weak_alias(__fflush_unlocked,fflush_unlocked); +#ifndef __UCLIBC_HAS_THREADS__ +weak_alias(__fflush_unlocked,fflush); +#endif + +#ifdef __UCLIBC_HAS_THREADS__ +/* Even if the stream is set to user-locking, we still need to lock + * when all (lbf) writing streams are flushed. */ +#define MY_STDIO_THREADLOCK(STREAM) \ + if (_stdio_user_locking != 2) { \ + __STDIO_ALWAYS_THREADLOCK(STREAM); \ + } + +#define MY_STDIO_THREADUNLOCK(STREAM) \ + if (_stdio_user_locking != 2) { \ + __STDIO_ALWAYS_THREADUNLOCK(STREAM); \ + } +#else +#define MY_STDIO_THREADLOCK(STREAM) ((void)0) +#define MY_STDIO_THREADUNLOCK(STREAM) ((void)0) +#endif + + +int __fflush_unlocked(register FILE *stream) +{ +#ifdef __STDIO_BUFFERS + + int retval = 0; +#ifdef __UCLIBC_MJN3_ONLY__ +#warning REMINDER: should probably define a modeflags type +#endif + unsigned short bufmask = __FLAG_LBF; + +#ifndef NDEBUG + if ((stream != NULL) && (stream != (FILE *) &_stdio_openlist)) { + __STDIO_STREAM_VALIDATE(stream); /* debugging only */ + } +#endif + + if (stream == (FILE *) &_stdio_openlist) { /* Flush all lbf streams. */ + stream = NULL; + bufmask = 0; + } + + if (!stream) { /* Flush all (lbf) writing streams. */ + __STDIO_THREADLOCK_OPENLIST; + for (stream = _stdio_openlist; stream ; stream = stream->__nextopen) { + MY_STDIO_THREADLOCK(stream); + if (!(((stream->__modeflags | bufmask) + ^ (__FLAG_WRITING|__FLAG_LBF) + ) & (__FLAG_WRITING|__MASK_BUFMODE)) + ) { + if (!__STDIO_COMMIT_WRITE_BUFFER(stream)) { + __STDIO_STREAM_DISABLE_PUTC(stream); + __STDIO_STREAM_CLEAR_WRITING(stream); + } else { + retval = EOF; + } + } + MY_STDIO_THREADUNLOCK(stream); + } + __STDIO_THREADUNLOCK_OPENLIST; + } else if (__STDIO_STREAM_IS_WRITING(stream)) { + if (!__STDIO_COMMIT_WRITE_BUFFER(stream)) { + __STDIO_STREAM_DISABLE_PUTC(stream); + __STDIO_STREAM_CLEAR_WRITING(stream); + } else { + retval = EOF; + } + } +#if 0 + else if (stream->__modeflags & (__MASK_READING|__FLAG_READONLY)) { + /* ANSI/ISO says behavior in this case is undefined but also says you + * shouldn't flush a stream you were reading from. As usual, glibc + * caters to broken programs and simply ignores this. */ + __UNDEFINED_OR_NONPORTABLE; + __STDIO_STREAM_SET_ERROR(stream); + __set_errno(EBADF); + retval = EOF; + } +#endif + +#ifndef NDEBUG + if ((stream != NULL) && (stream != (FILE *) &_stdio_openlist)) { + __STDIO_STREAM_VALIDATE(stream); /* debugging only */ + } +#endif + + return retval; + +#else /* __STDIO_BUFFERS --------------------------------------- */ + +#ifndef NDEBUG + if ((stream != NULL) +#ifdef __STDIO_HAS_OPENLIST + && (stream != (FILE *) &_stdio_openlist) +#endif + ) { + __STDIO_STREAM_VALIDATE(stream); /* debugging only */ + } +#endif + +#if 0 + if (stream && (stream->__modeflags & (__MASK_READING|__FLAG_READONLY))) { + /* ANSI/ISO says behavior in this case is undefined but also says you + * shouldn't flush a stream you were reading from. As usual, glibc + * caters to broken programs and simply ignores this. */ + __UNDEFINED_OR_NONPORTABLE; + __STDIO_STREAM_SET_ERROR(stream); + __set_errno(EBADF); + return EOF; + } +#endif + + return 0; +#endif /* __STDIO_BUFFERS */ +} + +#elif defined __UCLIBC_HAS_THREADS__ + +int fflush(register FILE *stream) +{ + int retval; + __STDIO_AUTO_THREADLOCK_VAR; + + if (stream +#ifdef __STDIO_HAS_OPENLIST + && (stream != (FILE *) &_stdio_openlist) +#endif + ) { + + __STDIO_AUTO_THREADLOCK(stream); + + retval = __fflush_unlocked(stream); + + __STDIO_AUTO_THREADUNLOCK(stream); + } else { + retval = __fflush_unlocked(stream); + } + + return retval; +} + +#endif |