Be more vigilant with deferred loading.

Be more vigilant with deferred loading.
Abort background compilation if deferred loading occurs during parsing, since the code generated would not match the saved ICData (deopt-id assignments change, since LibraryPrefix.is_loaded changes in mutator thread while compiling in background)

BUG=
R=rmacnak@google.com

Committed: https://github.com/dart-lang/sdk/commit/8fb38ee2b4cadcc9029c0071bb98247ad8fc1b5d

[srdjan, 2016-03-24 18:11:22]

srdjan@google.com changed reviewers:
+ rmacnak@google.com

[rmacnak, 2016-03-24 18:18:19]

lgtm

https://chromiumcodereview.appspot.com/1830283002/diff/1/runtime/vm/compiler.cc
File runtime/vm/compiler.cc (right):

https://chromiumcodereview.appspot.com/1830283002/diff/1/runtime/vm/compiler....
runtime/vm/compiler.cc:1175:
Compiler::AbortBackgroundCompilation(Thread::kNoDeoptId);
Add comment here that we need to abort because the deopt-ids may have changed.

[srdjan, 2016-03-24 18:22:09]

https://chromiumcodereview.appspot.com/1830283002/diff/1/runtime/vm/compiler.cc
File runtime/vm/compiler.cc (right):

https://chromiumcodereview.appspot.com/1830283002/diff/1/runtime/vm/compiler....
runtime/vm/compiler.cc:1175:
Compiler::AbortBackgroundCompilation(Thread::kNoDeoptId);
On 2016/03/24 18:18:19, rmacnak wrote:
> Add comment here that we need to abort because the deopt-ids may have changed.

Done.

[srdjan, 2016-03-24 18:27:30]

Description was changed from

==========
Be more vigilant with deferred loading.
Abort background compilation if deferred loading occurs during parsing, since
the code generated would not match the saved ICData (deopt-id assignments
change, since LibraryPrefix.is_loaded changes in mutator thread while compiling
in background)

BUG=
==========

to

==========
Be more vigilant with deferred loading.
Abort background compilation if deferred loading occurs during parsing, since
the code generated would not match the saved ICData (deopt-id assignments
change, since LibraryPrefix.is_loaded changes in mutator thread while compiling
in background)

BUG=
R=rmacnak@google.com

Committed:
https://github.com/dart-lang/sdk/commit/8fb38ee2b4cadcc9029c0071bb98247ad8fc1b5d
==========

[srdjan, 2016-03-24 18:27:32]

Committed patchset #2 (id:20001) manually as
8fb38ee2b4cadcc9029c0071bb98247ad8fc1b5d (presubmit successful).

[hausner, 2016-03-25 15:24:00]

hausner@google.com changed reviewers:
+ hausner@google.com

[hausner, 2016-03-25 15:24:01]

DBC: The deferred prefix generation count is incremented once the prefex is
marked as loaded. What happens if a background compilation starts while a load
request is issued, but it doesn't terminate (increase the generation count)
before the background compilation is finished? In that case, the generation
count would not yet be incremented when the background compilation ends.

[srdjan, 2016-03-25 16:37:51]

On 2016/03/25 15:24:01, hausner wrote:
> DBC: The deferred prefix generation count is incremented once the prefex is
> marked as loaded. What happens if a background compilation starts while a load
> request is issued, but it doesn't terminate (increase the generation count)
> before the background compilation is finished? In that case, the generation
> count would not yet be incremented when the background compilation ends.

That is a valid point, I hope to be addressing that in :

https://codereview.chromium.org/1834763004/