[Mesa-dev] [PATCH 65/87] i965: handle incompatiable binaries in shader-cache

[Timothy Arceri]

Remove incompatiable binaries of a program before attempting
to store a new one.

A previous commit already handles deleting an incompatiable
binary for shader variants this handles the case for an initial
shader compile. Without this a variant would delete the binary
then fallback to a full recompile but would skip recreating state
that would otherwise normally already exist already and crash.
---
 src/mesa/drivers/dri/i965/brw_shader_cache.c | 49 ++++++++++++++++++++--------
 1 file changed, 36 insertions(+), 13 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_shader_cache.c b/src/mesa/drivers/dri/i965/brw_shader_cache.c
index 8b6cc62..2893d8d 100644
--- a/src/mesa/drivers/dri/i965/brw_shader_cache.c
+++ b/src/mesa/drivers/dri/i965/brw_shader_cache.c
@@ -468,6 +468,40 @@ write_program_data(struct gl_shader_program *prog, struct blob *binary,
    }
 }
 
+static void
+cache_binary(struct brw_context *brw, struct blob *binary,
+             struct program_cache *cache, unsigned char *sha1)
+{
+   char buf[41];
+   size_t size;
+   uint8_t *buffer = cache_get(cache, sha1, &size);
+
+   if (buffer) {
+      struct blob_reader read_b;
+      blob_reader_init(&read_b, buffer, size);
+
+      char *version_string = blob_read_string(&read_b);
+      if (strcmp(brw->ctx.VersionString, version_string) != 0) {
+         /* The cached version of the program was created with a different
+          * version of Mesa so remove it.
+          */
+         if (brw->ctx._Shader->Flags & GLSL_CACHE_INFO) {
+            fprintf(stderr, "removing binary created with incompatible mesa "
+                    "version\n");
+         }
+         cache_remove(cache, sha1);
+      }
+      free(buffer);
+   }
+
+   if (brw->ctx._Shader->Flags & GLSL_CACHE_INFO) {
+      fprintf(stderr, "putting binary in cache: %s\n",
+              _mesa_sha1_format(buf, sha1));
+   }
+
+   cache_put(cache, sha1, binary->data, binary->size);
+}
+
 void
 write_cached_program(struct brw_context *brw)
 {
@@ -476,7 +510,6 @@ write_cached_program(struct brw_context *brw)
    size_t program_size;
    struct gl_shader_program *prog;
    struct program_cache *cache;
-   char buf[41];
 
    cache = brw->ctx.Cache;
    if (cache == NULL)
@@ -523,12 +556,7 @@ write_cached_program(struct brw_context *brw)
       write_program_data(prog, binary, &brw->vs.prog_data->base.base,
                          MESA_SHADER_VERTEX);
 
-      if (brw->ctx._Shader->Flags & GLSL_CACHE_INFO) {
-         fprintf(stderr, "putting binary in cache: %s\n",
-                 _mesa_sha1_format(buf, vs_sha1));
-      }
-
-      cache_put(cache, vs_sha1, binary->data, binary->size);
+      cache_binary(brw, binary, cache, vs_sha1);
       ralloc_free (binary);
    }
 
@@ -560,12 +588,7 @@ write_cached_program(struct brw_context *brw)
       write_program_data(prog, binary, &brw->wm.prog_data->base,
                          MESA_SHADER_FRAGMENT);
 
-      if (brw->ctx._Shader->Flags & GLSL_CACHE_INFO) {
-         fprintf(stderr, "putting binary in cache: %s\n",
-                 _mesa_sha1_format(buf, wm_sha1));
-      }
-
-      cache_put(cache, wm_sha1, binary->data, binary->size);
+      cache_binary(brw, binary, cache, wm_sha1);
       ralloc_free (binary);
    }
 
-- 
2.7.4