Change executable pages to be read/execute but not writable by default.
All pages are made temporarily writable just before a full GC, because both
the mark and sweep phases write to the pages. When allocating in a page and
when patching code, the pages are made temporarily writable.
The order of allocation of Code and Instructions objects is changed so that
a GC will not occur after Instructions is allocated. (A full GC would
render the Instructions unwritable.) A scoped object is used to make memory
protection simpler.
Original CL: https://codereview.chromium.org/106593002/
I added a cc test that is expected to crash.
R=srdjan@google.com
Review URL: https://codereview.chromium.org//136563002
git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@32493 260f80e4-7a28-3924-810f-c04153c831b5
The code can be patched if it should not be executed any longer.
The code can be now patched at other location than at entry, the requirement is still that patching code does not overwrite an inlined object.
Intrinsic methods that do not have a fall through cannot be patched.
Review URL: https://codereview.chromium.org//11783066
git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@16897 260f80e4-7a28-3924-810f-c04153c831b5
fschneider@google.com