2322. [port] MacOS: work around the limitation of setrlimit()

			for RLIMIT_NOFILE. [RT #17526]

diff --git a/CHANGES b/CHANGES
index b32f6d4b5de496c7102735fb375705c9b5541810..9dba18d7017b8dd93d38a141964abb5afbe1b933 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+2322.  [port]          MacOS: work around the limitation of setrlimit()
+                       for RLIMIT_NOFILE. [RT #17526]
+
 2320.  [func]          Make statistics couters thread-safe for platforms
                        that support certain atomic operations. [RT #17466]
 

diff --git a/lib/isc/unix/resource.c b/lib/isc/unix/resource.c
index 73f47bf92adf444ce0246bbb3c8dece7e9c7d215..babc60b2acddcb17127c3d00788e8dfa8da575bb 100644 (file)
--- a/lib/isc/unix/resource.c
+++ b/lib/isc/unix/resource.c
@@ -15,7 +15,7 @@
  * PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: resource.c,v 1.14 2007/06/19 23:47:18 tbox Exp $ */
+/* $Id: resource.c,v 1.14.128.1 2008/01/25 23:48:17 jinmei Exp $ */
 
 #include <config.h>
 
@@ -132,58 +132,27 @@ isc_resource_setlimit(isc_resource_t resource, isc_resourcevalue_t value) {
                rlim_value = value;
        }
 
-       /*
-        * The BIND 8 documentation reports:
-        *
-        *      Note: on some operating systems the server cannot set an
-        *      unlimited value and cannot determine the maximum number of
-        *      open files the kernel can support. On such systems, choosing
-        *      unlimited will cause the server to use the larger of the
-        *      rlim_max for RLIMIT_NOFILE and the value returned by
-        *      sysconf(_SC_OPEN_MAX). If the actual kernel limit is larger
-        *      than this value, use limit files to specify the limit
-        *      explicitly.
-        *
-        * The CHANGES for 8.1.2-T3A also mention:
-        *
-        *      352. [bug] Because of problems with setting an infinite
-        *      rlim_max for RLIMIT_NOFILE on some systems, previous versions
-        *      of the server implemented "limit files unlimited" by setting
-        *      the limit to the value returned by sysconf(_SC_OPEN_MAX).  The
-        *      server will now use RLIM_INFINITY on systems which allow it.
-        *
-        * At some point the BIND 8 server stopped using SC_OPEN_MAX for this
-        * purpose at all, but it isn't clear to me when or why, as my access
-        * to the CVS archive is limited at the time of this writing.  What
-        * BIND 8 *does* do is to set RLIMIT_NOFILE to either RLIMIT_INFINITY
-        * on a half dozen operating systems or to FD_SETSIZE on the rest,
-        * the latter of which is probably fewer than the real limit.  (Note
-        * that libisc's socket module will have problems with any fd over
-        * FD_SETSIZE.  This should be fixed in the socket module, not a
-        * limitation here.  BIND 8's eventlib also has a problem, making
-        * its RLIMIT_INFINITY setting useless, because it closes and ignores
-        * any fd over FD_SETSIZE.)
-        *
-        * More troubling is the reference to some operating systems not being
-        * able to set an unlimited value for the number of open files.  I'd
-        * hate to put in code that is really only there to support archaic
-        * systems that the rest of libisc won't work on anyway.  So what this
-        * extremely verbose comment is here to say is the following:
-        *
-        *   I'm aware there might be an issue with not limiting the value
-        *   for RLIMIT_NOFILE on some systems, but since I don't know yet
-        *   what those systems are and what the best workaround is (use
-        *   sysconf()?  rlim_max from getrlimit()?  FD_SETSIZE?) so nothing
-        *   is currently being done to clamp the value for open files.
-        */
-
        rl.rlim_cur = rl.rlim_max = rlim_value;
        unixresult = setrlimit(unixresource, &rl);
 
        if (unixresult == 0)
                return (ISC_R_SUCCESS);
-       else
-               return (isc__errno2result(errno));
+
+#if defined(OPEN_MAX) && defined(__APPLE___)
+       /*
+        * The Darwin kernel doesn't accept RLIM_INFINITY for rlim_cur; the
+        * maximum possible value is OPEN_MAX.  BIND8 used to use
+        * sysconf(_SC_OPEN_MAX) for such a case, but this value is much
+        * smaller than OPEN_MAX and is not really effective.
+        */
+       if (resource == isc_resource_openfiles && rlim_value == RLIM_INFINITY) {
+               rl.rlim_cur = OPEN_MAX;
+               unixresult = setrlimit(unixresource, &rl);
+               if (unixresult == 0)
+                       return (ISC_R_SUCCESS);
+       }
+#endif
+       return (isc__errno2result(errno));
 }
 
 isc_result_t