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      1 /*
      2  * Copyright (C) 2014 The Android Open Source Project
      3  * All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  *  * Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  *  * Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in
     12  *    the documentation and/or other materials provided with the
     13  *    distribution.
     14  *
     15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     16  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     17  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
     18  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
     19  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
     20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
     22  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
     25  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 
     29 #include <stdio_ext.h>
     30 
     31 #include <errno.h>
     32 #include <stdlib.h>
     33 
     34 #include <async_safe/log.h>
     35 
     36 #include "local.h"
     37 
     38 size_t __fbufsize(FILE* fp) {
     39   return fp->_bf._size;
     40 }
     41 
     42 /* For a _SRW stream, we don't know whether we last read or wrote.
     43 int __freading(FILE* fp) {
     44   return (fp->_flags & _SRD) != 0 || ...;
     45 }
     46 */
     47 
     48 /* For a _SRW stream, we don't know whether we last read or wrote.
     49 int __fwriting(FILE*) {
     50   return (fp->_flags & _SWR) != 0 || ...;
     51 }
     52 */
     53 
     54 int __freadable(FILE* fp) {
     55   return (fp->_flags & (__SRD|__SRW)) != 0;
     56 }
     57 
     58 int __fwritable(FILE* fp) {
     59   return (fp->_flags & (__SWR|__SRW)) != 0;
     60 }
     61 
     62 int __flbf(FILE* fp) {
     63   return (fp->_flags & __SLBF) != 0;
     64 }
     65 
     66 void __fpurge(FILE* fp) {
     67   fpurge(fp);
     68 }
     69 
     70 size_t __fpending(FILE* fp) {
     71   return fp->_p - fp->_bf._base;
     72 }
     73 
     74 void _flushlbf() {
     75   // If we flush all streams, we know we've flushed all the line-buffered streams.
     76   fflush(NULL);
     77 }
     78 
     79 int __fsetlocking(FILE* fp, int type) {
     80   int old_state = _EXT(fp)->_caller_handles_locking ? FSETLOCKING_BYCALLER : FSETLOCKING_INTERNAL;
     81   if (type == FSETLOCKING_QUERY) {
     82     return old_state;
     83   }
     84 
     85   if (type != FSETLOCKING_INTERNAL && type != FSETLOCKING_BYCALLER) {
     86     // The API doesn't let us report an error, so blow up.
     87     async_safe_fatal("Bad type (%d) passed to __fsetlocking", type);
     88   }
     89 
     90   _EXT(fp)->_caller_handles_locking = (type == FSETLOCKING_BYCALLER);
     91   return old_state;
     92 }
     93