diff -r 000000000000 -r 6474c204b198 js/src/gc/Memory.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/gc/Memory.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,56 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef gc_Memory_h
+#define gc_Memory_h
+
+#include <stddef.h>
+
+struct JSRuntime;
+
+namespace js {
+namespace gc {
+
+// Sanity check that our compiled configuration matches the currently running
+// instance and initialize any runtime data needed for allocation.
+void
+InitMemorySubsystem(JSRuntime *rt);
+
+// Allocate or deallocate pages from the system with the given alignment.
+void *
+MapAlignedPages(JSRuntime *rt, size_t size, size_t alignment);
+
+void
+UnmapPages(JSRuntime *rt, void *p, size_t size);
+
+// Tell the OS that the given pages are not in use, so they should not
+// be written to a paging file. This may be a no-op on some platforms.
+bool
+MarkPagesUnused(JSRuntime *rt, void *p, size_t size);
+
+// Undo |MarkPagesUnused|: tell the OS that the given pages are of interest
+// and should be paged in and out normally. This may be a no-op on some
+// platforms.
+bool
+MarkPagesInUse(JSRuntime *rt, void *p, size_t size);
+
+// Returns #(hard faults) + #(soft faults)
+size_t
+GetPageFaultCount();
+
+// Allocate memory mapped content.
+// The offset must be aligned according to alignment requirement.
+void *
+AllocateMappedContent(int fd, size_t offset, size_t length, size_t alignment);
+
+// Deallocate memory mapped content.
+void
+DeallocateMappedContent(void *p, size_t length);
+
+} // namespace gc
+} // namespace js
+
+#endif /* gc_Memory_h */