Remove hard limit from mirrors accessor caches.

Remove hard limit from mirrors accessor caches.

Avoids treadmilling the cache when the working set is larger than the cache size, such as the observe loop of a very large Angular app.

BUG=http://dartbug.com/20196
R=iposva@google.com

Committed: https://code.google.com/p/dart/source/detail?r=39057

[Ivan Posva, 2014-08-06 23:05:15]

https://codereview.chromium.org/420713008/diff/40001/runtime/lib/mirrors_impl...
File runtime/lib/mirrors_impl.dart (right):

https://codereview.chromium.org/420713008/diff/40001/runtime/lib/mirrors_impl...
runtime/lib/mirrors_impl.dart:324: return (_getFieldClosures[unwrapped] =
_createGetterClosure(unwrapped))(r);
Long line?

https://codereview.chromium.org/420713008/diff/40001/sdk/lib/internal/cache.dart
File sdk/lib/internal/cache.dart (right):

https://codereview.chromium.org/420713008/diff/40001/sdk/lib/internal/cache.d...
sdk/lib/internal/cache.dart:7: class CacheAssociation<K,V> {
Why <K,V>?

https://codereview.chromium.org/420713008/diff/40001/sdk/lib/internal/cache.d...
sdk/lib/internal/cache.dart:57: throw new Exception("Internal error: LRUMap
table full");
LRUMap?

https://codereview.chromium.org/420713008/diff/40001/sdk/lib/internal/cache.d...
sdk/lib/internal/cache.dart:71: throw new Exception("Internal error: LRUMap
table full");
ditto

https://codereview.chromium.org/420713008/diff/40001/sdk/lib/internal/cache.d...
sdk/lib/internal/cache.dart:77: while (null != (assoc = _table[index])) {
Assignment in condition?

https://codereview.chromium.org/420713008/diff/40001/sdk/lib/internal/cache.d...
sdk/lib/internal/cache.dart:131: index = _scanFor(key);
assert(table[index] == null);

https://codereview.chromium.org/420713008/diff/40001/sdk/lib/internal/cache.d...
sdk/lib/internal/cache.dart:138: }
What is missing here is the deletion of an entry if the value is being set to
null. Alternatively you could put that into _tryToShrinkOtherwiseGrow, by
deleting the associations with null values during that step.

[rmacnak, 2014-08-07 20:05:25]

Removed generics, moved into vm mirrors, assert free slot after shrinkOrGrow

https://codereview.chromium.org/420713008/diff/40001/sdk/lib/internal/cache.dart
File sdk/lib/internal/cache.dart (right):

https://codereview.chromium.org/420713008/diff/40001/sdk/lib/internal/cache.d...
sdk/lib/internal/cache.dart:77: while (null != (assoc = _table[index])) {
On 2014/08/06 23:05:14, Ivan Posva wrote:
> Assignment in condition?

Yes, Dart doesn't have sequence expressions to write

while (assoc = _table[index], assoc != null)

or better yet

[assoc:: table at: index. assoc isNil] whileFalse: [...]

https://codereview.chromium.org/420713008/diff/40001/sdk/lib/internal/cache.d...
sdk/lib/internal/cache.dart:138: }
On 2014/08/06 23:05:14, Ivan Posva wrote:
> What is missing here is the deletion of an entry if the value is being set to
> null. Alternatively you could put that into _tryToShrinkOtherwiseGrow, by
> deleting the associations with null values during that step.

This doesn't occur in practice, but added the logic to
_tryToShrinkOtherwiseGrow.

[Ivan Posva, 2014-08-08 19:09:36]

https://codereview.chromium.org/420713008/diff/80001/runtime/lib/mirrors_impl...
File runtime/lib/mirrors_impl.dart (right):

https://codereview.chromium.org/420713008/diff/80001/runtime/lib/mirrors_impl...
runtime/lib/mirrors_impl.dart:95: bool usedSinceGrowth = false;
Allocating a new association marks it immediately accessed.

https://codereview.chromium.org/420713008/diff/80001/runtime/lib/mirrors_impl...
runtime/lib/mirrors_impl.dart:212: var newAssoc = new
_AccessorCacheAssociation();
var newAssoc = new _AccessorCacheAssociation(key, value);

https://codereview.chromium.org/420713008/diff/80001/runtime/lib/mirrors_impl...
runtime/lib/mirrors_impl.dart:221: newAssoc.usedSinceGrowth = true;
These three lines can be move to the constructor.

[rmacnak, 2014-08-08 20:31:40]

Moved association initialization to constructor.

[Ivan Posva, 2014-08-08 21:05:27]

LGTM with the changes we discussed.

-Ivan

[rmacnak, 2014-08-08 22:20:45]

Committed patchset #7 manually as 39057 (presubmit successful).