- Each isolate starts off with a 'Default' UserTag set.
- A null tag cannot be set.
- Calls to clearCurrentTag() should be replaced with a call to UserTag.defaultTag.makeCurrent().
- makeCurrent returns the previously current tag.
This allows for the following pattern to work:
callee() {
var old = calleeTag.makeCurrent();
...
old.makeCurrent();
}
caller() {
var old = callerTag.makeCurrent();
...
callee();
assert(getCurrentTag() == callerTag);
...
old.makeCurrent();
}
R=iposva@google.com, zra@google.com
Review URL: https://codereview.chromium.org//266913010
git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@35810 260f80e4-7a28-3924-810f-c04153c831b5
asiva@google.com