tree 948bcb5780f0b6520ca1c61dc71d1bbfdfc0b1b7
parent 1bd45c4ffb8076b9f05ad89578cebc89682c3268
author Shahbaz Youssefi <syoussefi@chromium.org> 1692300564 -0400
committer Angle LUCI CQ <angle-scoped@luci-project-accounts.iam.gserviceaccount.com> 1692728246 +0000

Make shader recompile while parallel linking safe

Prior to this change, Program* objects held references to Shader*
objects.  This poses a problem where a shader recompile can race with a
program link, if the program link is done in parallel.

As a result, a good chunk of the link job is done serially and under the
share group lock.  After this change, that is no longer a problem, and
most of the link can be made lockless/parallelized.

This change separates out the "compiled state" from the rest of the
shader state.  This was already done for the front-end state (for the
sake of caching), but is also now done for the backends that need it.
The compiled state in turn is placed in a shared_ptr, and is shared with
the program.  When a shader is compiled, its own shared_ptr is replaced
with a new object, leaving all programs currently compiling unaffected
and using the previous compilation results.

Once a program is linked, its references to compiled shader states is
updated.

Bug: angleproject:8297
Change-Id: Iff7094a37088fbad99c6241f1c48b0bd4c820eb2
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4791065
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Charlie Lao <cclao@google.com>