commit 4e6a31eb97f22f4480827474b30b9e64f396eace
author Mathieu Chartier <mathieuc@google.com> Thu Oct 31 10:35:05 2013 -0700
committer Mathieu Chartier <mathieuc@google.com> Thu Oct 31 13:33:51 2013 -0700
tree 3afe222c60314a22be8bb8de61cb245e1af2dc92
parent 1b8cb967143d5c46db1db8ac940a73d111be3628

Lazily compute object identity hash codes.

Before, we computed identity hashcodes whenever we inflated a monitor.
This caused issues since it meant that we would have all of these
hash codes in the image, causing locks to excessively inflate during
application run time.

This change makes it so that we lazily compute hash codes. When a
thin lock gets inflated, we assign a hash code of 0 assigned to it.
This value signifies no hash code. When we try to get the identity
hash code of an object with an inflated monitor, it gets computed if
it is 0.

Change-Id: Iae6acd1960515a36e74644e5b1323ff336731806

runtime/arch/arm/quick_entrypoints_arm.S

diff --git a/runtime/arch/arm/quick_entrypoints_arm.S b/runtime/arch/arm/quick_entrypoints_arm.S
index 50a5176..9a853d0 100644
--- a/runtime/arch/arm/quick_entrypoints_arm.S
+++ b/runtime/arch/arm/quick_entrypoints_arm.S
@@ -325,7 +325,7 @@
 ENTRY art_quick_lock_object
     cbz    r0, slow_lock
 retry_lock:
-    ldrt   r2, [r9, #THREAD_ID_OFFSET]
+    ldr    r2, [r9, #THREAD_ID_OFFSET]
     ldrex  r1, [r0, #LOCK_WORD_OFFSET]
     cbnz   r1, not_unlocked           @ already thin locked
     @ unlocked case - r2 holds thread id with count of 0