Issue 22191. Grab the document lock before positionsLock to prevent deadlock.

Issue 22191. Grab the document lock before positionsLock to prevent deadlock.

R=paulberry@google.com
BUG= https://code.google.com/p/dart/issues/detail?id=22191

Committed: https://code.google.com/p/dart/source/detail?r=43251

[Paul Berry, 2015-01-28 18:30:22]

lgtm

https://codereview.chromium.org/885653005/diff/1/editor/tools/plugins/com.goo...
File
editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/editor/SemanticHighlightingManager_NEW.java
(right):

https://codereview.chromium.org/885653005/diff/1/editor/tools/plugins/com.goo...
editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/editor/SemanticHighlightingManager_NEW.java:339:
synchronized (getDocumentLockObject()) {
It would be nice to have a comment here explaining why we've had to do this,
e.g. something like "when the ServerResponseReaderThread handles a highlights
notification, it grabs the document lock before the positions lock.  To avoid a
deadlock, we must grab the locks in the same order."

[scheglov, 2015-01-28 18:33:23]

Committed patchset #1 (id:1) manually as 43251 (presubmit successful).

[scheglov, 2015-01-28 18:33:41]

https://codereview.chromium.org/885653005/diff/1/editor/tools/plugins/com.goo...
File
editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/editor/SemanticHighlightingManager_NEW.java
(right):

https://codereview.chromium.org/885653005/diff/1/editor/tools/plugins/com.goo...
editor/tools/plugins/com.google.dart.tools.ui/src/com/google/dart/tools/ui/internal/text/editor/SemanticHighlightingManager_NEW.java:339:
synchronized (getDocumentLockObject()) {
On 2015/01/28 18:30:22, Paul Berry wrote:
> It would be nice to have a comment here explaining why we've had to do this,
> e.g. something like "when the ServerResponseReaderThread handles a highlights
> notification, it grabs the document lock before the positions lock.  To avoid
a
> deadlock, we must grab the locks in the same order."

Done.