diff options
Diffstat (limited to 'ghc/lib/std/cbits/lockFile.c')
-rw-r--r-- | ghc/lib/std/cbits/lockFile.c | 128 |
1 files changed, 0 insertions, 128 deletions
diff --git a/ghc/lib/std/cbits/lockFile.c b/ghc/lib/std/cbits/lockFile.c deleted file mode 100644 index f6a9aea4ad..0000000000 --- a/ghc/lib/std/cbits/lockFile.c +++ /dev/null @@ -1,128 +0,0 @@ -/* - * (c) The GRASP/AQUA Project, Glasgow University, 1994-1998 - * - * $Id: lockFile.c,v 1.2 2001/05/21 11:02:15 simonmar Exp $ - * - * stdin/stout/stderr Runtime Support - */ - -#include "HsStd.h" - -#ifndef FD_SETSIZE -#define FD_SETSIZE 256 -#endif - -typedef struct { - dev_t device; - ino_t inode; - int fd; -} Lock; - -static Lock readLock[FD_SETSIZE]; -static Lock writeLock[FD_SETSIZE]; - -static int readLocks = 0; -static int writeLocks = 0; - -int -lockFile(int fd, int for_writing, int exclusive) -{ - struct stat sb; - int i; - - while (fstat(fd, &sb) < 0) { - if (errno != EINTR) { -#ifndef _WIN32 - return -1; -#else - /* fstat()ing socket fd's seems to fail with CRT's fstat(), - so let's just silently return and hope for the best.. - */ - return 0; -#endif - } - } - - if (for_writing) { - /* opening a file for writing, check to see whether - we don't have any read locks on it already.. */ - for (i = 0; i < readLocks; i++) { - if (readLock[i].inode == sb.st_ino && readLock[i].device == sb.st_dev) { -#ifndef __MINGW32__ - return -1; -#else - break; -#endif - } - } - /* If we're determined that there is only a single - writer to the file, check to see whether the file - hasn't already been opened for writing.. - */ - if (exclusive) { - for (i = 0; i < writeLocks; i++) { - if (writeLock[i].inode == sb.st_ino && writeLock[i].device == sb.st_dev) { -#ifndef __MINGW32__ - return -1; -#else - break; -#endif - } - } - } - /* OK, everything is cool lock-wise, record it and leave. */ - i = writeLocks++; - writeLock[i].device = sb.st_dev; - writeLock[i].inode = sb.st_ino; - writeLock[i].fd = fd; - return 0; - } else { - /* For reading, it's simpler - just check to see - that there's no-one writing to the underlying file. */ - for (i = 0; i < writeLocks; i++) { - if (writeLock[i].inode == sb.st_ino && writeLock[i].device == sb.st_dev) { -#ifndef __MINGW32__ - return -1; -#else - break; -#endif - } - } - /* Fit in new entry, reusing an existing table entry, if possible. */ - for (i = 0; i < readLocks; i++) { - if (readLock[i].inode == sb.st_ino && readLock[i].device == sb.st_dev) { - return 0; - } - } - i = readLocks++; - readLock[i].device = sb.st_dev; - readLock[i].inode = sb.st_ino; - readLock[i].fd = fd; - return 0; - } - -} - -int -unlockFile(int fd) -{ - int i; - - for (i = 0; i < readLocks; i++) - if (readLock[i].fd == fd) { - while (++i < readLocks) - readLock[i - 1] = readLock[i]; - readLocks--; - return 0; - } - - for (i = 0; i < writeLocks; i++) - if (writeLock[i].fd == fd) { - while (++i < writeLocks) - writeLock[i - 1] = writeLock[i]; - writeLocks--; - return 0; - } - /* Signal that we did not find an entry */ - return 1; -} |