DO NOT MERGE: Optimize IndirectRefTable.
Removed unused debugging code that maintained pointers to the
4 previous objects in each slot.
Promoted the serial number property of a slot to be first class.
This is a sufficiently cheap and useful check to perform that we
might as well always do it.
Changed get() and remove() so they check the validity of the
references at the same time as they retrieve them. They're
also a bit smarter about checking the reference kind given
that they can assume that the table will only contain references
of one kind. The checks are now much more consistent.
For example, remove() used to check whether an index was
stale only in the case where it was not removing the top entry
(now it always checks).
Made add() return NULL instead of dvmAbort()'ing in the case
where the table overflowed and ensure we don't blow away the
table in that cases. This change resolves an issue with
TestIndirectRefTable.cpp which deliberately overflows the table
and expects add() to return NULL (as documented!). As it
happens, the add() method is called in exactly 3 places in
Jni.cpp. In each of those cases, the code was written to
handle a NULL result and only in the case of adding a weak
global reference did it not abort. Fixed the weak global
reference case to be consistent with the others.
Changed the signature of contains() to take an Object* since
that's what we're actually looking for inside the table.
Added a couple of calls to dump() in TestIndirectRefTable.cpp
for visual inspection of its correctness.
Performance as measured by TestIndirectRefTable on same hardware.
Old implementation:
- Add/remove 100 objects FIFO order, 100000 iterations, 0.023ms / iteration
- Add/remove 100 objects LIFO order, 100000 iterations, 0.020ms / iteration
- Get 100 objects, 100000 iterations, 0.009ms / iteration
New implementation:
- Add/remove 100 objects FIFO order, 100000 iterations, 0.010ms / iteration
- Add/remove 100 objects LIFO order, 100000 iterations, 0.009ms / iteration
- Get 100 objects, 100000 iterations, 0.002ms / iteration
Cherry-pick from master.
Conflicts:
vm/IndirectRefTable.cpp
Change-Id: I157f3c1ba598137222878b8e6a5890efb744fe76
4 files changed