From 986e4c6f1cfdb2ce8d28f3d0a81c354df7930155 Mon Sep 17 00:00:00 2001
From: rswindell <>
Date: Tue, 8 Apr 2003 23:47:58 +0000
Subject: [PATCH] Eliminated lockf-version of lock/unlock on Unix (lockf is
just a wrapper for fcntl). lock/unlock/sopen for Unix now use both lockf and
fcntl mechanisms Replaced C++ comments with C comments.
---
src/xpdev/filewrap.c | 72 ++++++++++++--------------------------------
1 file changed, 19 insertions(+), 53 deletions(-)
diff --git a/src/xpdev/filewrap.c b/src/xpdev/filewrap.c
index 92884a989b..810271f990 100644
--- a/src/xpdev/filewrap.c
+++ b/src/xpdev/filewrap.c
@@ -80,42 +80,6 @@ long DLLCALL filelength(int fd)
return(st.st_size);
}
-#ifdef USE_LOCKF
-
-/* Sets a lock on a portion of a file */
-int DLLCALL lock(int file, long offset, int len)
-{
- int i;
- long pos;
-
- pos=tell(file);
- if(offset!=pos)
- lseek(file, offset, SEEK_SET);
- i=lockf(file,F_TLOCK,len);
- if(offset!=pos)
- lseek(file, pos, SEEK_SET);
-
- return(i);
-}
-
-/* Removes a lock from a file record */
-int DLLCALL unlock(int file, long offset, int len)
-{
- int i;
- long pos;
-
- pos=tell(file);
- if(offset!=pos)
- lseek(file, offset, SEEK_SET);
- i=lockf(file,F_ULOCK,len);
- if(offset!=pos)
- lseek(file, pos, SEEK_SET);
-
- return(i);
-}
-
-#else /* use fcntl */
-
/* Sets a lock on a portion of a file */
int DLLCALL lock(int fd, long pos, int len)
{
@@ -126,15 +90,20 @@ int DLLCALL lock(int fd, long pos, int len)
return -1;
if(flags==O_RDONLY)
- alock.l_type = F_RDLCK; // set read lock to prevent writes
+ alock.l_type = F_RDLCK; /* set read lock to prevent writes */
else
- alock.l_type = F_WRLCK; // set write lock to prevent all access
- alock.l_whence = L_SET; // SEEK_SET
+ alock.l_type = F_WRLCK; /* set write lock to prevent all access */
+ alock.l_whence = L_SET; /* SEEK_SET */
alock.l_start = pos;
alock.l_len = len;
if(fcntl(fd, F_SETLK, &alock)==-1)
return(-1);
+
+ /* use flock (doesn't work over NFS) */
+ if(flock(fd,LOCK_EX|LOCK_NB)!=0)
+ return(-1);
+
return(0);
}
@@ -143,35 +112,34 @@ int DLLCALL unlock(int fd, long pos, int len)
{
struct flock alock;
- alock.l_type = F_UNLCK; // remove the lock
+ alock.l_type = F_UNLCK; /* remove the lock */
alock.l_whence = L_SET;
alock.l_start = pos;
alock.l_len = len;
if(fcntl(fd, F_SETLK, &alock)==-1)
return(-1);
+
+ /* use flock (doesn't work over NFS) */
+ if(flock(fd,LOCK_UN|LOCK_NB)!=0)
+ return(-1);
+
return(0);
}
-#endif
-
/* Opens a file in specified sharing (file-locking) mode */
int DLLCALL sopen(char *fn, int access, int share)
{
int fd;
-#ifdef USE_FLOCK /* use flock */
int flock_op=LOCK_NB; /* non-blocking */
-#else
struct flock alock;
-#endif
if ((fd = open(fn, access, S_IREAD|S_IWRITE)) < 0)
return -1;
- if (share == SH_DENYNO)
- // no lock needed
+ if (share == SH_DENYNO) /* no lock needed */
return fd;
-#ifdef USE_FLOCK /* use flock */
+ /* use flock (doesn't work over NFS) */
if(share==SH_DENYRW)
flock_op|=LOCK_EX;
else /* SH_DENYWR */
@@ -183,18 +151,16 @@ int DLLCALL sopen(char *fn, int access, int share)
return(-1);
}
-#else /* use fcntl */
-
+ /* use fcntl (doesn't work correctly with threads) */
alock.l_type = share;
alock.l_whence = L_SET;
alock.l_start = 0;
- alock.l_len = 0; // lock to EOF
+ alock.l_len = 0; /* lock to EOF */
- if (fcntl(fd, F_SETLK, &alock) == -1) {
+ if(fcntl(fd, F_SETLK, &alock)==-1) {
close(fd);
return -1;
}
-#endif
return fd;
}
--
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