platform_system_core/include/cutils/fs.h
Jeff Sharkey ddb1733944 Wrap system calls in TEMP_FAILURE_RETRY.
fs_prepare_dir() is used heavily during Zygote init, and can easily
run into EINTR.

Bug: 7151474
Change-Id: I7aac43a43483d55db47ca20456fff68ce51bbc46
2012-09-13 15:02:53 -07:00

62 lines
1.8 KiB
C

/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef __CUTILS_FS_H
#define __CUTILS_FS_H
#include <sys/types.h>
/*
* TEMP_FAILURE_RETRY is defined by some, but not all, versions of
* <unistd.h>. (Alas, it is not as standard as we'd hoped!) So, if it's
* not already defined, then define it here.
*/
#ifndef TEMP_FAILURE_RETRY
/* Used to retry syscalls that can return EINTR. */
#define TEMP_FAILURE_RETRY(exp) ({ \
typeof (exp) _rc; \
do { \
_rc = (exp); \
} while (_rc == -1 && errno == EINTR); \
_rc; })
#endif
#ifdef __cplusplus
extern "C" {
#endif
/*
* Ensure that directory exists with given mode and owners.
*/
extern int fs_prepare_dir(const char* path, mode_t mode, uid_t uid, gid_t gid);
/*
* Read single plaintext integer from given file, correctly handling files
* partially written with fs_write_atomic_int().
*/
extern int fs_read_atomic_int(const char* path, int* value);
/*
* Write single plaintext integer to given file, creating backup while
* in progress.
*/
extern int fs_write_atomic_int(const char* path, int value);
#ifdef __cplusplus
}
#endif
#endif /* __CUTILS_FS_H */