diff options
Diffstat (limited to 'mysys/my_seek.c')
| -rw-r--r-- | mysys/my_seek.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/mysys/my_seek.c b/mysys/my_seek.c index a9ae68cd5f0..cb0fe75d7e5 100644 --- a/mysys/my_seek.c +++ b/mysys/my_seek.c @@ -24,7 +24,9 @@ my_off_t pos The expected position (absolute or relative) int whence A direction parameter and one of {SEEK_SET, SEEK_CUR, SEEK_END} - myf MyFlags Not used. + myf MyFlags MY_THREADSAFE must be set in case my_seek may be mixed + with my_pread/my_pwrite calls and fd is shared among + threads. DESCRIPTION The my_seek function is a wrapper around the system call lseek and @@ -51,7 +53,16 @@ my_off_t my_seek(File fd, my_off_t pos, int whence, whence, MyFlags)); DBUG_ASSERT(pos != MY_FILEPOS_ERROR); /* safety check */ - newpos=lseek(fd, pos, whence); +#if defined(THREAD) && !defined(HAVE_PREAD) + if (MyFlags & MY_THREADSAFE) + { + pthread_mutex_lock(&my_file_info[fd].mutex); + newpos= lseek(fd, pos, whence); + pthread_mutex_lock(&my_file_info[fd].mutex); + } + else +#endif + newpos= lseek(fd, pos, whence); if (newpos == (os_off_t) -1) { my_errno=errno; |