Initial import of the CDE 2.1.30 sources from the Open Group.

cde/lib/tt/mini_isam/isfcbwatchfd.c

@@ -0,0 +1,127 @@
+/*%%  (c) Copyright 1993, 1994 Hewlett-Packard Company			 */
+/*%%  (c) Copyright 1993, 1994 International Business Machines Corp.	 */
+/*%%  (c) Copyright 1993, 1994 Sun Microsystems, Inc.			 */
+/*%%  (c) Copyright 1993, 1994 Novell, Inc. 				 */
+/*%%  $XConsortium: isfcbwatchfd.c /main/3 1995/10/23 11:38:51 rswiston $ 			 				 */
+#ifndef lint
+static char sccsid[] = "@(#)isfcbwatchfd.c	1.8 93/09/07 Copyr 1988-1993 Sun Microsystems, Inc";
+#endif
+/*
+ * Copyright (c) 1988 by Sun Microsystems, Inc.
+ */
+
+/*
+ * isfcbwatchfd.c
+ *
+ * Description:
+ *	Watch the limit on UNIX file descriptors used by the FCB module.
+ */
+
+#if defined(_AIX)
+#define _POSIX_SYSCONF
+#endif 
+
+#if defined(_AIX)
+#define _POSIX_SYSCONF
+#endif 
+
+#include "isam_impl.h"
+#include <sys/time.h>
+#include <sys/resource.h>
+#ifdef _POSIX_SYSCONF
+#include <unistd.h>
+#endif /* _POSIX_SYSCONF */
+
+static int _limit = MAXFCB_UNIXFD;	     /* Imposed limit */
+static int _in_use = 0;			     /* Current number of 
+					      * open file descriptors
+					      */
+
+/*
+ * _watchfd_incr(n)
+ *
+ * Register that n additional UNIX file descriptors were open.
+ *
+ * Return the new number of open file descriptors.
+ */
+
+int
+_watchfd_incr(n)
+{
+    _in_use += n;
+    assert(_in_use <= _limit);
+    return (_in_use);
+}
+
+
+/*
+ * _watch_decr(n)
+ *
+ * Register that n open file descriptors were closed.
+ *
+ * Return the new number of open file descriptors.
+ */
+
+int
+_watchfd_decr(n)
+{
+    _in_use -= n;
+    assert(_in_use >= 0);
+    return (_in_use);
+}
+
+
+/*
+ * _watch_check()
+ *
+ * Return number of fd that are still available.
+ */
+
+int
+_watchfd_check()
+{
+    return (_limit - _in_use);
+}
+
+
+/*
+ * _watchfd_max_set(n)
+ *
+ * Set the maximum number of UNIX fds that may be comsumed by ISAM files.
+ */
+
+int
+_watchfd_max_set(n)
+    int		n;
+{
+    int		oldlimit = _limit;
+
+#ifdef _POSIX_SYSCONF
+    if (n < 3 || n > sysconf(_SC_OPEN_MAX)) {
+#else
+    int dtab_size = 0;
+    struct rlimit rl;
+    if (getrlimit(RLIMIT_NOFILE, &rl) == 0)
+      dtab_size = rl.rlim_cur;
+
+    if (n < 3 || n > dtab_size) {
+#endif
+	_setiserrno2(EBADARG, '9', '0');
+	return (ISERROR);
+    }
+
+    _limit = n;
+    return (oldlimit);
+}
+
+/*
+ * _watchfd_max_get()
+ *
+ * Get the maximum number of UNIX fds that may be comsumed by ISAM files.
+ */
+
+int
+_watchfd_max_get()
+{
+    return (_limit);
+}