4223. [func] Add support for setting max-cache-size to percentage

of available physical memory, set default to 90%.
			[RT #38442]

lib/isc/include/isc/meminfo.h

@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2015 Internet Systems Consortium, Inc. ("ISC")
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef ISC_MEMINFO_H
+#define ISC_MEMINFO_H 1
+
+#include <isc/types.h>
+
+#include <isc/lang.h>
+
+ISC_LANG_BEGINDECLS
+
+isc_uint64_t
+isc_meminfo_totalphys(void);
+/*%<
+ * Return total available physical memory in bytes, or 0 if this cannot 
+ * be determined
+*/
+
+ISC_LANG_ENDDECLS
+
+#endif /* ISC_MEMINFO_H */