# HG changeset patch
# User James Le Cuirot <chewi@gentoo.org>
# Date 1441543564 -3600
#      Sun Sep 06 13:46:04 2015 +0100
# Node ID d0224f4490d6694e77dcb0ff7eae8e2297b822bf
# Parent  e215e36be9fc2b7dfe43ff10ec1afe639b289aa5
Dynamically set the maximum heap size on Linux

diff -r e215e36be9fc -r d0224f4490d6 src/vm/vm.cpp
--- cacao/cacao/src/vm/vm.cpp	Mon Feb 11 19:31:28 2013 +0100
+++ cacao/cacao/src/vm/vm.cpp	Sun Sep 06 13:46:04 2015 +0100
@@ -33,6 +33,10 @@
 #include <errno.h>
 #include <stdlib.h>
 
+#if defined(__LINUX__)
+#include <unistd.h>
+#endif
+
 #include "vm/types.h"
 
 #include "arch.h"
@@ -702,6 +706,19 @@
 	opt_heapstartsize = HEAP_STARTSIZE;
 	opt_stacksize     = STACK_SIZE;
 
+#if defined(__LINUX__)
+	// Calculate 1/4 of the physical memory.
+	uint64_t qmem = sysconf(_SC_PHYS_PAGES) * sysconf(_SC_PAGESIZE) / 4;
+
+	if (qmem > INT32_MAX) {
+		// More than 2GB will overflow so cap it.
+		opt_heapmaxsize = 2047 * 1024 * 1024;
+	} else if (qmem > HEAP_MAXSIZE) {
+		// Otherwise use this if greater than default (128MB).
+		opt_heapmaxsize = (s4) qmem;
+	}
+#endif
+
 	// First of all, parse the -XX options.
 
 #if defined(ENABLE_VMLOG)