[serializer] Add API to warm up startup snapshot with an additional script.

[serializer] Add API to warm up startup snapshot with an additional script.

A startup snapshot is considered cold when it does not contain any
function code. We can now create a warm startup snapshot from a cold one
by running a warm-up script. Functions exercised by the warm-up script
are compiled and its code included in the warm startup snapshot. Side
effects caused by the warm-up script does not persist.

R=vogelheim@chromium.org
BUG=v8:4836
LOG=Y

Committed: https://crrev.com/f507bc1c7242d338b04d6bba5ea78cbb42cf0e13
Cr-Commit-Position: refs/heads/master@{#34849}

[Yang, 2016-03-16 12:17:57]

yangguo@chromium.org changed reviewers:
+ ulan@chromium.org

[Yang, 2016-03-16 12:17:57]

Daniel, please take a look.

Ulan, please review src/heap.

Jay, FYI.

[vogelheim, 2016-03-16 14:52:36]

lgtm

Nice. I like the tests in test-serialize.

The shell param thing is a nitpick; I'm not sure if it's worth the effort to
fix.

https://codereview.chromium.org/1805903002/diff/1/src/api.cc
File src/api.cc (right):

https://codereview.chromium.org/1805903002/diff/1/src/api.cc#newcode486
src/api.cc:486: //  - Create a new context. This context will not be unpolluted.
s/not// ?

https://codereview.chromium.org/1805903002/diff/1/src/snapshot/mksnapshot.cc
File src/snapshot/mksnapshot.cc (right):

https://codereview.chromium.org/1805903002/diff/1/src/snapshot/mksnapshot.cc#...
src/snapshot/mksnapshot.cc:114: if (strcmp(filename, "-") == 0) return NULL;
Why?

I think "-" is often used to designate stdin as input, which probably doesn't
make sense in this context. But then: Why silently discard instead of running
into an error?

https://codereview.chromium.org/1805903002/diff/1/test/cctest/test-serialize.cc
File test/cctest/test-serialize.cc (right):

https://codereview.chromium.org/1805903002/diff/1/test/cctest/test-serialize....
test/cctest/test-serialize.cc:804: CHECK(CompileRun("Math.sin")->IsFunction());
Just for my understanding: You garble Math.sin in the warmup script, and this
checks that the actual, original Math.sin is still in the snapshot?

https://codereview.chromium.org/1805903002/diff/1/tools/gyp/v8.gyp
File tools/gyp/v8.gyp (right):

https://codereview.chromium.org/1805903002/diff/1/tools/gyp/v8.gyp#newcode35
tools/gyp/v8.gyp:35: 'warmup_script%': "-",
Oh, that's why...

As far as the shell is concerned, an empty string ("") should work as well if
you want an "empty" positional parameter. Not sure if gyp/GN will get in the
way, though. But I guess the real solution is to have 'proper' parameters if the
need to be set independently.

[Yang, 2016-03-16 15:05:39]

https://codereview.chromium.org/1805903002/diff/1/test/cctest/test-serialize.cc
File test/cctest/test-serialize.cc (right):

https://codereview.chromium.org/1805903002/diff/1/test/cctest/test-serialize....
test/cctest/test-serialize.cc:804: CHECK(CompileRun("Math.sin")->IsFunction());
On 2016/03/16 14:52:36, vogelheim wrote:
> Just for my understanding: You garble Math.sin in the warmup script, and this
> checks that the actual, original Math.sin is still in the snapshot?

exactly.

https://codereview.chromium.org/1805903002/diff/1/tools/gyp/v8.gyp
File tools/gyp/v8.gyp (right):

https://codereview.chromium.org/1805903002/diff/1/tools/gyp/v8.gyp#newcode35
tools/gyp/v8.gyp:35: 'warmup_script%': "-",
On 2016/03/16 14:52:36, vogelheim wrote:
> Oh, that's why...
> 
> As far as the shell is concerned, an empty string ("") should work as well if
> you want an "empty" positional parameter. Not sure if gyp/GN will get in the
> way, though. But I guess the real solution is to have 'proper' parameters if
the
> need to be set independently.

I havent been able to make empty string work, and I'm too lazy to properly
implement optional arguments :p

This is just for a corner use case, so I think this is fine for now.

[Yang, 2016-03-16 15:06:26]

The CQ bit was checked by yangguo@chromium.org

[commit-bot: I haz the power, 2016-03-16 15:06:37]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1805903002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1805903002/1

[commit-bot: I haz the power, 2016-03-16 15:40:26]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-03-16 15:40:27]

Try jobs failed on following builders:
  v8_presubmit on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_presubmit/builds/12452)

[Hannes Payer (out of office), 2016-03-17 09:21:14]

hpayer@chromium.org changed reviewers:
+ hpayer@chromium.org

[Hannes Payer (out of office), 2016-03-17 09:21:15]

heap lgtm

[Yang, 2016-03-17 09:58:36]

The CQ bit was checked by yangguo@chromium.org

[Yang, 2016-03-17 09:58:37]

The patchset sent to the CQ was uploaded after l-g-t-m from hpayer@chromium.org,
vogelheim@chromium.org
Link to the patchset: https://codereview.chromium.org/1805903002/#ps20001
(title: "fix comment")

[commit-bot: I haz the power, 2016-03-17 09:58:48]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1805903002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1805903002/20001

[commit-bot: I haz the power, 2016-03-17 10:32:43]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-03-17 10:34:22]

Description was changed from

==========
[serializer] Add API to warm up startup snapshot with an additional script.

A startup snapshot is considered cold when it does not contain any
function code. We can now create a warm startup snapshot from a cold one
by running a warm-up script. Functions exercised by the warm-up script
are compiled and its code included in the warm startup snapshot. Side
effects caused by the warm-up script does not persist.


R=vogelheim@chromium.org
BUG=v8:4836
LOG=Y
==========

to

==========
[serializer] Add API to warm up startup snapshot with an additional script.

A startup snapshot is considered cold when it does not contain any
function code. We can now create a warm startup snapshot from a cold one
by running a warm-up script. Functions exercised by the warm-up script
are compiled and its code included in the warm startup snapshot. Side
effects caused by the warm-up script does not persist.

R=vogelheim@chromium.org
BUG=v8:4836
LOG=Y

Committed: https://crrev.com/f507bc1c7242d338b04d6bba5ea78cbb42cf0e13
Cr-Commit-Position: refs/heads/master@{#34849}
==========

[commit-bot: I haz the power, 2016-03-17 10:34:23]

Patchset 2 (id:??) landed as
https://crrev.com/f507bc1c7242d338b04d6bba5ea78cbb42cf0e13
Cr-Commit-Position: refs/heads/master@{#34849}