diff options
Diffstat (limited to 'libc/bionic/flockfile.cpp')
-rw-r--r-- | libc/bionic/flockfile.cpp | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/libc/bionic/flockfile.cpp b/libc/bionic/flockfile.cpp new file mode 100644 index 0000000..3381e8e --- /dev/null +++ b/libc/bionic/flockfile.cpp @@ -0,0 +1,58 @@ +/* + * Copyright (C) 2008 The Android Open Source Project + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <errno.h> +#include <stdio.h> + +#include "local.h" + +// We can't use the OpenBSD implementation which uses kernel-specific +// APIs not available on Linux. Instead we use a pthread_mutex_t within +// struct __sfileext (see fileext.h). + +void flockfile(FILE* fp) { + if (fp != NULL) { + pthread_mutex_lock(&_FLOCK(fp)); + } +} + +int ftrylockfile(FILE* fp) { + // The specification for ftrylockfile() says it returns 0 on success, + // or non-zero on error. So return an errno code directly on error. + if (fp == NULL) { + return EINVAL; + } + + return pthread_mutex_trylock(&_FLOCK(fp)); +} + +void funlockfile(FILE* fp) { + if (fp != NULL) { + pthread_mutex_unlock(&_FLOCK(fp)); + } +} |