mesa/st: use a lock to protect access to variants when updating them
Multiple threads may access st_update_* function at same time. Issues
happen when the threads modify lists managed by shader compiler.
Issues were found with script that runs multithread tests 1000 times in
a row with MESA_GLSL_CACHE_DISABLE=1 set. Problems start when 2
simultaneous st_create_[vp|fp]_variant calls start to compile a new
shader variant for the same program and various nir passes use and
modify same exec_lists.
Example failure:
deqp-egl: ../src/compiler/glsl/list.h:575: exec_list_validate: Assertion `node->next->prev == node' failed.
v2: instead of introducing new mutex, lock shared state
Signed-off-by: Tapani Pälli <tapani.palli@intel.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7418>
diff --git a/src/mesa/state_tracker/st_atom_shader.c b/src/mesa/state_tracker/st_atom_shader.c
index 18acc30..ec55e33 100644
--- a/src/mesa/state_tracker/st_atom_shader.c
+++ b/src/mesa/state_tracker/st_atom_shader.c
@@ -160,7 +160,9 @@
key.external = st_get_external_sampler_key(st, &stfp->Base);
+ simple_mtx_lock(&st->ctx->Shared->Mutex);
shader = st_get_fp_variant(st, stfp, &key)->base.driver_shader;
+ simple_mtx_unlock(&st->ctx->Shared->Mutex);
}
st_reference_prog(st, &st->fp, stfp);
@@ -232,7 +234,9 @@
!st->ctx->GeometryProgram._Current)
key.lower_ucp = st->ctx->Transform.ClipPlanesEnabled;
+ simple_mtx_lock(&st->ctx->Shared->Mutex);
st->vp_variant = st_get_vp_variant(st, stvp, &key);
+ simple_mtx_unlock(&st->ctx->Shared->Mutex);
}
st_reference_prog(st, &st->vp, stvp);
@@ -291,7 +295,11 @@
key.lower_ucp = st->ctx->Transform.ClipPlanesEnabled;
}
- return st_get_common_variant(st, stp, &key)->driver_shader;
+ simple_mtx_lock(&st->ctx->Shared->Mutex);
+ void *result = st_get_common_variant(st, stp, &key)->driver_shader;
+ simple_mtx_unlock(&st->ctx->Shared->Mutex);
+
+ return result;
}