diff options
Diffstat (limited to 'libc/stdio/_stdio.c')
| -rw-r--r-- | libc/stdio/_stdio.c | 432 |
1 files changed, 432 insertions, 0 deletions
diff --git a/libc/stdio/_stdio.c b/libc/stdio/_stdio.c new file mode 100644 index 000000000..4aae3c418 --- /dev/null +++ b/libc/stdio/_stdio.c @@ -0,0 +1,432 @@ +/* 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" + +/* This is pretty much straight from uClibc, but with one important + * difference. + * + * We now initialize the locking flag to user locking instead of + * auto locking (i.e. FSETLOCKING_BYCALLER vs FSETLOCKING_INTERNAL). + * This greatly benefits non-threading applications linked to a + * shared thread-enabled library. In threading applications, we + * walk the stdio open file list and reset the locking mode + * appropriately when the thread subsystem is initialized. + */ + +/**********************************************************************/ + +#ifdef __UCLIBC_HAS_WCHAR__ +#define __STDIO_FILE_INIT_WUNGOT { 0, 0 }, +#else +#define __STDIO_FILE_INIT_WUNGOT +#endif + +#ifdef __STDIO_GETC_MACRO +# define __STDIO_FILE_INIT_BUFGETC(x) x, +#else +# define __STDIO_FILE_INIT_BUFGETC(x) +#endif + +#ifdef __STDIO_PUTC_MACRO +# define __STDIO_FILE_INIT_BUFPUTC(x) x, +#else +# define __STDIO_FILE_INIT_BUFPUTC(x) +#endif + +#ifdef __STDIO_HAS_OPENLIST +#define __STDIO_FILE_INIT_NEXT(next) (next), +#else +#define __STDIO_FILE_INIT_NEXT(next) +#endif + +#ifdef __STDIO_BUFFERS +#define __STDIO_FILE_INIT_BUFFERS(buf,bufsize) \ + (buf), (buf)+(bufsize), (buf), (buf), +#else +#define __STDIO_FILE_INIT_BUFFERS(buf,bufsize) +#endif + +#ifdef __UCLIBC_HAS_GLIBC_CUSTOM_STREAMS__ +#define __STDIO_FILE_INIT_CUSTOM_STREAM(stream) \ + &((stream).__filedes), { _cs_read, _cs_write, _cs_seek, _cs_close }, +#else +#define __STDIO_FILE_INIT_CUSTOM_STREAM(stream) +#endif + +#ifdef __STDIO_MBSTATE +#define __STDIO_FILE_INIT_MBSTATE \ + { 0, 0 }, +#else +#define __STDIO_FILE_INIT_MBSTATE +#endif + +#ifdef __UCLIBC_HAS_XLOCALE__ +#define __STDIO_FILE_INIT_UNUSED \ + NULL, +#else +#define __STDIO_FILE_INIT_UNUSED +#endif + +#ifdef __UCLIBC_HAS_THREADS__ +#define __STDIO_FILE_INIT_THREADSAFE \ + 2, PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP, +#else +#define __STDIO_FILE_INIT_THREADSAFE +#endif + +#define __STDIO_INIT_FILE_STRUCT(stream, flags, filedes, next, buf, bufsize) \ + { (flags), \ + { 0, 0 }, /* ungot[2] (no wchar) or ungot_width[2] (wchar)*/ \ + (filedes), \ + __STDIO_FILE_INIT_BUFFERS(buf,bufsize) \ + __STDIO_FILE_INIT_BUFGETC((buf)) \ + __STDIO_FILE_INIT_BUFPUTC((buf)) \ + __STDIO_FILE_INIT_NEXT(next) \ + __STDIO_FILE_INIT_CUSTOM_STREAM(stream) \ + __STDIO_FILE_INIT_WUNGOT \ + __STDIO_FILE_INIT_MBSTATE \ + __STDIO_FILE_INIT_UNUSED \ + __STDIO_FILE_INIT_THREADSAFE \ +} /* TODO: builtin buf */ + +/**********************************************************************/ +/* First we need the standard files. */ + +#ifdef __STDIO_BUFFERS +static unsigned char _fixed_buffers[2 * BUFSIZ]; +#endif + +static FILE _stdio_streams[] = { + __STDIO_INIT_FILE_STRUCT(_stdio_streams[0], \ + __FLAG_LBF|__FLAG_READONLY, \ + 0, \ + _stdio_streams + 1, \ + _fixed_buffers, \ + BUFSIZ ), + __STDIO_INIT_FILE_STRUCT(_stdio_streams[1], \ + __FLAG_LBF|__FLAG_WRITEONLY, \ + 1, \ + _stdio_streams + 2, \ + _fixed_buffers + BUFSIZ, \ + BUFSIZ ), + __STDIO_INIT_FILE_STRUCT(_stdio_streams[2], \ + __FLAG_NBF|__FLAG_WRITEONLY, \ + 2, \ + NULL, \ + NULL, \ + 0 ) +}; + +FILE *stdin = _stdio_streams; +FILE *stdout = _stdio_streams + 1; +FILE *stderr = _stdio_streams + 2; + +#ifdef __STDIO_GETC_MACRO +FILE *__stdin = _stdio_streams; /* For getchar() macro. */ +#endif +#ifdef __STDIO_PUTC_MACRO +FILE *__stdout = _stdio_streams + 1; /* For putchar() macro. */ +/* FILE *__stderr = _stdio_streams + 2; */ +#endif + +/**********************************************************************/ +#ifdef __STDIO_HAS_OPENLIST + +/* In certain configurations, we need to keep a list of open files. + * 1) buffering enabled - We need to initialize the buffering mode + * (full or line buffering) of stdin and stdout. We also + * need to flush all write buffers prior to normal termination. + * 2) custom streams - Even if we aren't buffering in the library + * itself, we need to fclose() all custom streams when terminating + * so that any special cleanup is done. + * 3) threads enabled - We need to be able to reset the locking mode + * of all open streams when the threading system is initialized. + */ + +FILE *_stdio_openlist = _stdio_streams; + +# ifdef __UCLIBC_HAS_THREADS__ +pthread_mutex_t _stdio_openlist_lock = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP; +int _stdio_openlist_delflag = 0; +# endif + +#endif +/**********************************************************************/ +#ifdef __UCLIBC_HAS_THREADS__ + +/* 2 if threading not initialized and 0 otherwise; */ +int _stdio_user_locking = 2; + +void __stdio_init_mutex(pthread_mutex_t *m) +{ + static const pthread_mutex_t __stdio_mutex_initializer + = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP; + + memcpy(m, &__stdio_mutex_initializer, sizeof(__stdio_mutex_initializer)); +} + +#endif +/**********************************************************************/ + +/* We assume here that we are the only remaining thread. */ +void _stdio_term(void) +{ +#if defined(__STDIO_BUFFERS) || defined(__UCLIBC_HAS_GLIBC_CUSTOM_STREAMS__) + register FILE *ptr; + +#ifdef __UCLIBC_HAS_THREADS__ + /* First, make sure the open file list is unlocked. If it was + * locked, then I suppose there is a chance that a pointer in the + * chain might be corrupt due to a partial store. + */ + __stdio_init_mutex(&_stdio_openlist_lock); + + /* Next we need to worry about the streams themselves. If a stream + * is currently locked, then it may be in an invalid state. So we + * 'disable' it in case a custom stream is stacked on top of it. + * Then we reinitialize the locks. + */ + for (ptr = _stdio_openlist ; ptr ; ptr = ptr->__nextopen ) { + if (__STDIO_ALWAYS_THREADTRYLOCK(ptr)) { + /* The stream is already locked, so we don't want to touch it. + * However, if we have custom streams, we can't just close it + * or leave it locked since a custom stream may be stacked + * on top of it. So we do unlock it, while also disabling it. + */ + ptr->__modeflags = (__FLAG_READONLY|__FLAG_WRITEONLY); + __STDIO_STREAM_DISABLE_GETC(ptr); + __STDIO_STREAM_DISABLE_PUTC(ptr); + __STDIO_STREAM_INIT_BUFREAD_BUFPOS(ptr); + } + + ptr->__user_locking = 1; /* Set locking mode to "by caller". */ + __stdio_init_mutex(&ptr->__lock); /* Shouldn't be necessary, but... */ + } +#endif + + /* Finally, flush all writing streams and shut down all custom streams. + * NOTE: We assume that any stacking by custom streams is done on top + * of streams previously allocated, and hence further down the + * list. Otherwise we have no way of knowing the order in which + * to shut them down. + * Remember that freopen() counts as a new allocation here, even + * though the stream is reused. That's because it moves the + * stream to the head of the list. + */ + for (ptr = _stdio_openlist ; ptr ; ptr = ptr->__nextopen ) { +#ifdef __STDIO_BUFFERS + /* Write any pending buffered chars. */ + if (__STDIO_STREAM_IS_WRITING(ptr)) { + __STDIO_COMMIT_WRITE_BUFFER(ptr); + } +#endif +#ifdef __UCLIBC_HAS_GLIBC_CUSTOM_STREAMS__ + /* Actually close all custom streams to perform any special cleanup. */ + if (ptr->__cookie != &ptr->__filedes) { + __CLOSE(ptr); + } +#endif + } + +#endif +} + +void _stdio_init(void) +{ +#ifdef __STDIO_BUFFERS + int old_errno = errno; + /* stdin and stdout uses line buffering when connected to a tty. */ + _stdio_streams[0].__modeflags ^= (1-isatty(0)) * __FLAG_LBF; + _stdio_streams[1].__modeflags ^= (1-isatty(1)) * __FLAG_LBF; + __set_errno(old_errno); +#endif +#ifndef __UCLIBC__ + /* _stdio_term is done automatically when exiting if stdio is used. + * See misc/internals/__uClibc_main.c and and stdlib/atexit.c. */ + atexit(_stdio_term); +#endif /* __UCLIBC__ */ +} + +/**********************************************************************/ + +#if !(__MASK_READING & __FLAG_UNGOT) +#error Assumption violated about __MASK_READING and __FLAG_UNGOT +#endif + +#ifdef __UCLIBC_HAS_THREADS__ +#include <pthread.h> +#endif + +#ifndef NDEBUG + +void _stdio_validate_FILE(const FILE *stream) +{ +#ifdef __UCLIBC_HAS_THREADS__ + assert(((unsigned int)(stream->__user_locking)) <= 2); +#endif + +#warning Define a constant for minimum possible valid __filedes? + assert(stream->__filedes >= -3); + + if (stream->__filedes < 0) { +/* assert((stream->__filedes != -1) */ +/* #ifdef __UCLIBC_HAS_GLIBC_CUSTOM_STREAMS__ */ +/* || (stream->__cookie == &stream->__filedes) /\* custom *\/ */ +/* #endif */ +/* ); */ +/* assert((stream->__filedes == -1) || __STDIO_STREAM_IS_FBF(stream)); */ + + assert(!__STDIO_STREAM_IS_FAKE_VSNPRINTF(stream) + || __STDIO_STREAM_IS_NARROW(stream)); + assert(!__STDIO_STREAM_IS_FAKE_VSSCANF(stream) + || __STDIO_STREAM_IS_NARROW(stream)); +#ifdef __STDIO_STREAM_IS_FAKE_VSWPRINTF + assert(!__STDIO_STREAM_IS_FAKE_VSWPRINTF(stream) + || __STDIO_STREAM_IS_WIDE(stream)); +#endif +#ifdef __STDIO_STREAM_IS_FAKE_VSWSCANF + assert(!__STDIO_STREAM_IS_FAKE_VSWSCANF(stream) + || __STDIO_STREAM_IS_WIDE(stream)); +#endif + } + +#ifdef __UCLIBC_HAS_GLIBC_CUSTOM_STREAMS__ + if (stream->__cookie != &stream->__filedes) { /* custom */ + assert(stream->__filedes == -1); + } +#endif + + /* Can not be both narrow and wide oriented at the same time. */ + assert(!(__STDIO_STREAM_IS_NARROW(stream) + && __STDIO_STREAM_IS_WIDE(stream))); + + + /* The following impossible case is used to disable a stream. */ + if ((stream->__modeflags & (__FLAG_READONLY|__FLAG_WRITEONLY)) + == (__FLAG_READONLY|__FLAG_WRITEONLY) + ) { + assert(stream->__modeflags == (__FLAG_READONLY|__FLAG_WRITEONLY)); + assert(stream->__filedes == -1); +#ifdef __STDIO_BUFFERS + assert(stream->__bufpos == stream->__bufstart); + assert(stream->__bufread == stream->__bufstart); +# ifdef __UCLIBC_HAS_STDIO_PUTC_MACRO__ + assert(stream->__bufputc_u == stream->__bufstart); +# endif +# ifdef __UCLIBC_HAS_STDIO_GETC_MACRO__ + assert(stream->__bufgetc_u == stream->__bufstart); +# endif +#endif + } + + if (__STDIO_STREAM_IS_READONLY(stream)) { +/* assert(!__STDIO_STREAM_IS_WRITEONLY(stream)); */ + assert(!__STDIO_STREAM_IS_WRITING(stream)); + if (stream->__modeflags & __FLAG_UNGOT) { + assert(((unsigned)(stream->__ungot[1])) <= 1); + assert(!__FEOF_UNLOCKED(stream)); + } + } + + if (__STDIO_STREAM_IS_WRITEONLY(stream)) { +/* assert(!__STDIO_STREAM_IS_READONLY(stream)); */ + assert(!__STDIO_STREAM_IS_READING(stream)); + assert(!(stream->__modeflags & __FLAG_UNGOT)); + } + + if (__STDIO_STREAM_IS_NBF(stream)) { + /* We require that all non buffered streams have no buffer. */ + assert(!__STDIO_STREAM_BUFFER_SIZE(stream)); + } + + assert((stream->__modeflags & __MASK_BUFMODE) <= __FLAG_NBF); + +#ifdef __STDIO_BUFFERS + /* Ensure __bufstart <= __bufpos <= __bufend. */ + assert(stream->__bufpos >= stream->__bufstart); + assert(stream->__bufpos <= stream->__bufend); + /* Ensure __bufstart <= __bufread <= __bufend. */ + assert(stream->__bufread >= stream->__bufstart); + assert(stream->__bufread <= stream->__bufend); +#endif + + /* If EOF, then we must have no buffered readable or ungots. */ + if (__FEOF_UNLOCKED(stream)) { +#ifdef __STDIO_BUFFERS + assert(stream->__bufpos == stream->__bufread); +#endif + assert(!(stream->__modeflags & __FLAG_UNGOT)); + } + + + if (!__STDIO_STREAM_IS_WRITING(stream)) { +#ifdef __STDIO_BUFFERS + /* If not writing, then putc macro must be disabled. */ +# ifdef __UCLIBC_HAS_STDIO_PUTC_MACRO__ + assert(stream->__bufputc_u == stream->__bufstart); +# endif +#endif + } + + if (!__STDIO_STREAM_IS_READING(stream)) { + /* If not reading, then can not have ungots. */ + assert(!(stream->__modeflags & __FLAG_UNGOT)); +#ifdef __STDIO_BUFFERS + /* Ensure __bufread == __bufstart. */ + assert(stream->__bufread == stream->__bufstart); + /* If not reading, then getc macro must be disabled. */ +# ifdef __UCLIBC_HAS_STDIO_GETC_MACRO__ + assert(stream->__bufgetc_u == stream->__bufstart); +# endif +#endif + } + + if (__STDIO_STREAM_IS_READING(stream)) { + assert(!__STDIO_STREAM_IS_WRITING(stream)); +#ifdef __STDIO_BUFFERS + /* Ensure __bufpos <= __bufread. */ + assert(stream->__bufpos <= stream->__bufread); + + /* Ensure __bufgetc_u is valid. */ +# ifdef __UCLIBC_HAS_STDIO_GETC_MACRO__ + assert(stream->__bufgetc_u >= stream->__bufstart); + assert(stream->__bufgetc_u <= stream->__bufread); +# endif + +#endif + } + + if (__STDIO_STREAM_IS_WRITING(stream)) { + assert(!__STDIO_STREAM_IS_READING(stream)); +#ifdef __STDIO_BUFFERS +# ifdef __UCLIBC_HAS_STDIO_PUTC_MACRO__ + assert(stream->__bufputc_u >= stream->__bufstart); + assert(stream->__bufputc_u <= stream->__bufend); +# endif +#endif + } + + /* If have an ungotten char, then getc (and putc) must be disabled. */ + /* Also, wide streams must have the getc/putc macros disabled. */ + if ((stream->__modeflags & __FLAG_UNGOT) + || __STDIO_STREAM_IS_WIDE(stream) + ) { +#ifdef __STDIO_BUFFERS +# ifdef __UCLIBC_HAS_STDIO_PUTC_MACRO__ + assert(stream->__bufputc_u == stream->__bufstart); +# endif +# ifdef __UCLIBC_HAS_STDIO_GETC_MACRO__ + assert(stream->__bufgetc_u == stream->__bufstart); +# endif +#endif + } + + /* TODO -- filepos? ungot_width? filedes? nextopen? */ +} + +#endif |