commit 648d7112609dd19c38131b3e71c37bcbbd19d11e
author Dave Allison <dallison@google.com> Fri Jul 25 16:15:27 2014 -0700
committer Dave Allison <dallison@google.com> Wed Aug 13 09:01:41 2014 -0700
tree 54062831327c660acb309e877e8d8df9ba0c2d5d
parent 99c251bbd225dd97d0deece29559a430b12a0b66

Reduce stack usage for overflow checks

This reduces the stack space reserved for overflow checks to 12K, split
into an 8K gap and a 4K protected region.  GC needs over 8K when running
in a stack overflow situation.

Also prevents signal runaway by detecting a signal inside code that
resulted from a signal handler invokation.  And adds a max signal count to
the SignalTest to prevent it running forever.

Also reduces the number of iterations for the InterfaceTest as this was
taking (almost) forever with the --trace option on run-test.

Bug: 15435566

Change-Id: Id4fd46f22d52d42a9eb431ca07948673e8fda694

runtime/entrypoints/entrypoint_utils.cc

diff --git a/runtime/entrypoints/entrypoint_utils.cc b/runtime/entrypoints/entrypoint_utils.cc
index 4755b9e..a0e35f8 100644
--- a/runtime/entrypoints/entrypoint_utils.cc
+++ b/runtime/entrypoints/entrypoint_utils.cc
@@ -212,6 +212,11 @@
 
   bool explicit_overflow_check = Runtime::Current()->ExplicitStackOverflowChecks();
   self->ResetDefaultStackEnd(!explicit_overflow_check);  // Return to default stack size.
+
+  // And restore protection if implicit checks are on.
+  if (!explicit_overflow_check) {
+    self->ProtectStack();
+  }
 }
 
 void CheckReferenceResult(mirror::Object* o, Thread* self) {

runtime/entrypoints/quick/quick_throw_entrypoints.cc

diff --git a/runtime/entrypoints/quick/quick_throw_entrypoints.cc b/runtime/entrypoints/quick/quick_throw_entrypoints.cc
index 879010e..13decc8 100644
--- a/runtime/entrypoints/quick/quick_throw_entrypoints.cc
+++ b/runtime/entrypoints/quick/quick_throw_entrypoints.cc
@@ -58,8 +58,10 @@
                                                      StackReference<mirror::ArtMethod>* sp)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   FinishCalleeSaveFrameSetup(self, sp, Runtime::kSaveAll);
+  self->NoteSignalBeingHandled();
   ThrowLocation throw_location = self->GetCurrentLocationForThrow();
   ThrowNullPointerExceptionFromDexPC(throw_location);
+  self->NoteSignalHandlerDone();
   self->QuickDeliverException();
 }
 
@@ -83,7 +85,9 @@
 extern "C" void artThrowStackOverflowFromCode(Thread* self, StackReference<mirror::ArtMethod>* sp)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   FinishCalleeSaveFrameSetup(self, sp, Runtime::kSaveAll);
+  self->NoteSignalBeingHandled();
   ThrowStackOverflowError(self);
+  self->NoteSignalHandlerDone();
   self->QuickDeliverException();
 }