1 files changed, 125 insertions, 0 deletions
diff --git a/APACHE_1_3_42/src/lib/sdbm/sdbm_lock.c b/APACHE_1_3_42/src/lib/sdbm/sdbm_lock.c
new file mode 100644
index 0000000000..2ebb2a9b54
--- /dev/null
+++ b/APACHE_1_3_42/src/lib/sdbm/sdbm_lock.c
@@ -0,0 +1,125 @@
+/*
+** File locking
+**
+** Snarfed from mod_rewrite.c. Munged up for our use.
+*/
+
+#include "ap_config.h"
+#include "sdbm_tune.h"   /* include the prototypes */
+
+    /* The locking support:
+     * Try to determine whether we should use fcntl() or flock().
+     * Would be better ap_config.h could provide this... :-(
+     * Small monkey business to ensure that fcntl is preferred,
+     * unless we specified USE_FLOCK_SERIALIZED_ACCEPT during compile.
+     */
+#if defined(HAVE_FCNTL_SERIALIZED_ACCEPT) && !defined(USE_FLOCK_SERIALIZED_ACCEPT)
+#define USE_FCNTL 1
+#include <fcntl.h>
+#elif defined(HAVE_FLOCK_SERIALIZED_ACCEPT)
+#define USE_FLOCK 1
+#include <sys/file.h>
+#endif
+#if !defined(USE_FCNTL) && !defined(USE_FLOCK)
+#define USE_FLOCK 1
+#if !defined(MPE) && !defined(WIN32) && !defined(NETWARE)
+#include <sys/file.h>
+#endif
+#ifndef LOCK_UN
+#undef USE_FLOCK
+#define USE_FCNTL 1
+#include <fcntl.h>
+#endif
+#endif
+#ifdef AIX
+#undef USE_FLOCK
+#define USE_FCNTL 1
+#include <fcntl.h>
+#endif
+#ifdef WIN32
+#undef USE_FCNTL
+#define USE_LOCKING
+#include <sys/locking.h>
+#endif
+#ifdef NETWARE
+#undef USE_FCNTL
+#define USE_SEM_LOCKING
+#include <nwsemaph.h>
+LONG locking_sem = 0;
+#endif
+
+
+#ifdef USE_FCNTL
+/* ugly interface requires this structure to be "live" for a while */
+static struct flock   lock_it;
+static struct flock unlock_it;
+#endif
+
+/* NOTE: this function blocks until it acquires the lock */
+int sdbm_fd_lock(int fd, int readonly)
+{
+    int rc;
+
+#ifdef USE_FCNTL
+    lock_it.l_whence = SEEK_SET; /* from current point */
+    lock_it.l_start  = 0;        /* -"- */
+    lock_it.l_len    = 0;        /* until end of file */
+    lock_it.l_type   = readonly ? F_RDLCK : F_WRLCK;  /* set lock type */
+    lock_it.l_pid    = 0;        /* pid not actually interesting */
+
+    while (   ((rc = fcntl(fd, F_SETLKW, &lock_it)) < 0)
+              && (errno == EINTR)                               ) {
+        continue;
+    }
+#endif
+#ifdef USE_FLOCK
+    while (   ((rc = flock(fd, readonly ? LOCK_SH : LOCK_EX)) < 0)
+              && (errno == EINTR)               ) {
+        continue;
+    }
+#endif
+#ifdef USE_LOCKING
+    /* ### this doesn't allow simultaneous reads! */
+    /* ### this doesn't block forever */
+    /* Lock the first byte */
+    lseek(fd, 0, SEEK_SET);
+    rc = _locking(fd, _LK_LOCK, 1);
+#endif
+#ifdef USE_SEM_LOCKING
+	if ((locking_sem != 0) && (TimedWaitOnLocalSemaphore (locking_sem, 10000) != 0))
+		rc = -1;
+	else
+		rc = 1;
+#endif
+
+    return rc;
+}
+
+int sdbm_fd_unlock(int fd)
+{
+    int rc;
+
+#ifdef USE_FCNTL
+    unlock_it.l_whence = SEEK_SET; /* from current point */
+    unlock_it.l_start  = 0;        /* -"- */
+    unlock_it.l_len    = 0;        /* until end of file */
+    unlock_it.l_type   = F_UNLCK;  /* unlock */
+    unlock_it.l_pid    = 0;        /* pid not actually interesting */
+
+    rc = fcntl(fd, F_SETLKW, &unlock_it);
+#endif
+#ifdef USE_FLOCK
+    rc = flock(fd, LOCK_UN);
+#endif
+#ifdef USE_LOCKING
+    lseek(fd, 0, SEEK_SET);
+    rc = _locking(fd, _LK_UNLCK, 1);
+#endif
+#ifdef USE_SEM_LOCKING
+	if (locking_sem)
+		SignalLocalSemaphore (locking_sem);
+	rc = 1;
+#endif
+
+    return rc;
+}