[Engine-devel] Switched to thread-based GWT worker factory

[Vojtech Szocs]

Hi guys,

with patch [1] merged into master, GWT compiler will now use only
thread-based GWT worker factory (ThreadedPermutationWorkerFactory)
when compiling WebAdmin & UserPortal GUI.

[1] http://gerrit.ovirt.org/#/c/25163/

In practice, this means that GWT compiler will spawn up to:

  max_worker_threads = min(localWorkers, 4)

when compiling specific permutations (i.e. browser x locale).

Note that localWorkers value can be controlled through:

  EXTRA_BUILD_FLAGS="-Dgwt.compiler.localWorkers=..."
  DEV_EXTRA_BUILD_FLAGS="-Dgwt.compiler.localWorkers=..."

Before this patch was merged, GWT compiler spawned up to:

  max_external_processes = localWorkers

i.e. using separate Java sub-process (CompilePermsServer) that
communicates with GWT compiler process via socket.

For localWorkers == 1, tests show minimal-to-zero improvement.
However, for localWorkers > 1, tests show a slight improvement
in favor of thread-based approach.

Let me know if you have any questions.

Regards,
Vojtech