mesa/compiler: rework tear down of builtin/types

The issue we're running into when running CTS is that glsl types are
deleted while builtins depending on them are not.

This happens because on one hand we have glsl types ref counted, but
builtins are not. Instead builtins are destroyed when unloading libGL
or explicitly calling glReleaseShaderCompiler().

This change removes almost entirely any dealing with glsl types
ref/unref by letting the builtins deal with it instead. In turn we
introduce a builtin ref count mechanism. Each GL context takes a
reference on the builtins when compiling a shader for the first time.
It releases the reference when the context is destroyed. It can also
explicitly release those when glReleaseShaderCompiler() is called.

Finally we also take a reference on the glsl types when loading libGL
to avoid recreating glsl types too often.

v2: Ensure we take a reference if we don't have one in link step (Lionel)

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=110796
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Tapani Pälli <tapani.palli@intel.com>

src/compiler/glsl/ast_function.cpp

@@ -664,7 +664,6 @@ match_function_by_name(const char *name,
    }
 
    /* Local shader has no exact candidates; check the built-ins. */
-   _mesa_glsl_initialize_builtin_functions();
    sig = _mesa_glsl_find_builtin_function(state, name, actual_parameters);
 
    /* if _mesa_glsl_find_builtin_function failed, fall back to the result

src/compiler/glsl/ast_to_hir.cpp

@@ -6043,7 +6043,6 @@ ast_function::hir(exec_list *instructions,
     */
    if (state->es_shader) {
       /* Local shader has no exact candidates; check the built-ins. */
-      _mesa_glsl_initialize_builtin_functions();
       if (state->language_version >= 300 &&
           _mesa_glsl_has_builtin_function(state, name)) {
          YYLTYPE loc = this->get_location();

src/compiler/glsl/builtin_functions.cpp

@@ -1254,6 +1254,8 @@ builtin_builder::initialize()
    if (mem_ctx != NULL)
       return;
 
+   glsl_type_singleton_init_or_ref();
+
    mem_ctx = ralloc_context(NULL);
    create_shader();
    create_intrinsics();
@@ -1268,6 +1270,8 @@ builtin_builder::release()
 
    ralloc_free(shader);
    shader = NULL;
+
+   glsl_type_singleton_decref();
 }
 
 void
@@ -7277,24 +7281,28 @@ builtin_builder::_vote(const char *intrinsic_name,
 /* The singleton instance of builtin_builder. */
 static builtin_builder builtins;
 static mtx_t builtins_lock = _MTX_INITIALIZER_NP;
+static uint32_t builtin_users = 0;
 
 /**
  * External API (exposing the built-in module to the rest of the compiler):
  *  @{
  */
-void
-_mesa_glsl_initialize_builtin_functions()
+extern "C" void
+_mesa_glsl_builtin_functions_init_or_ref()
 {
    mtx_lock(&builtins_lock);
-   builtins.initialize();
+   if (builtin_users++ == 0)
+      builtins.initialize();
    mtx_unlock(&builtins_lock);
 }
 
-void
-_mesa_glsl_release_builtin_functions()
+extern "C" void
+_mesa_glsl_builtin_functions_decref()
 {
    mtx_lock(&builtins_lock);
-   builtins.release();
+   assert(builtin_users != 0);
+   if (--builtin_users == 0)
+      builtins.release();
    mtx_unlock(&builtins_lock);
 }
 

src/compiler/glsl/builtin_functions.h

@@ -26,8 +26,19 @@
 
 struct gl_shader;
 
-extern void
-_mesa_glsl_initialize_builtin_functions();
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void
+_mesa_glsl_builtin_functions_init_or_ref();
+
+void
+_mesa_glsl_builtin_functions_decref(void);
+
+#ifdef __cplusplus
+
+} /* extern "C" */
 
 extern ir_function_signature *
 _mesa_glsl_find_builtin_function(_mesa_glsl_parse_state *state,
@@ -43,9 +54,6 @@ _mesa_glsl_get_builtin_function_shader(void);
 extern ir_function_signature *
 _mesa_get_main_function_signature(glsl_symbol_table *symbols);
 
-extern void
-_mesa_glsl_release_builtin_functions(void);
-
 namespace generate_ir {
 
 ir_function_signature *
@@ -71,4 +79,6 @@ udivmod64(void *mem_ctx, builtin_available_predicate avail);
 
 }
 
+#endif /* __cplusplus */
+
 #endif /* BULITIN_FUNCTIONS_H */

src/compiler/glsl/glsl_parser_extras.cpp

@@ -2326,49 +2326,3 @@ do_common_optimization(exec_list *ir, bool linked,
 
    return progress;
 }
-
-extern "C" {
-
-/**
- * To be called at GL context ctor.
- */
-void
-_mesa_init_shader_compiler_types(void)
-{
-   glsl_type_singleton_init_or_ref();
-}
-
-/**
- * To be called at GL context dtor.
- */
-void
-_mesa_destroy_shader_compiler_types(void)
-{
-   glsl_type_singleton_decref();
-}
-
-/**
- * To be called at GL teardown time, this frees compiler datastructures.
- *
- * After calling this, any previously compiled shaders and shader
- * programs would be invalid.  So this should happen at approximately
- * program exit.
- */
-void
-_mesa_destroy_shader_compiler(void)
-{
-   _mesa_destroy_shader_compiler_caches();
-}
-
-/**
- * Releases compiler caches to trade off performance for memory.
- *
- * Intended to be used with glReleaseShaderCompiler().
- */
-void
-_mesa_destroy_shader_compiler_caches(void)
-{
-   _mesa_glsl_release_builtin_functions();
-}
-
-}

src/compiler/glsl/glsl_parser_extras.h

@@ -1024,11 +1024,6 @@ extern int glcpp_preprocess(void *ctx, const char **shader, char **info_log,
                             struct _mesa_glsl_parse_state *state,
                             struct gl_context *gl_ctx);
 
-extern void _mesa_init_shader_compiler_types(void);
-extern void _mesa_destroy_shader_compiler_types(void);
-extern void _mesa_destroy_shader_compiler(void);
-extern void _mesa_destroy_shader_compiler_caches(void);
-
 extern void
 _mesa_glsl_copy_symbols_from_table(struct exec_list *shader_ir,
                                    struct glsl_symbol_table *src,

src/compiler/glsl/standalone.cpp

@@ -134,7 +134,7 @@ static void
 initialize_context(struct gl_context *ctx, gl_api api)
 {
    initialize_context_to_defaults(ctx, api);
-   glsl_type_singleton_init_or_ref();
+   _mesa_glsl_builtin_functions_init_or_ref();
 
    /* The standalone compiler needs to claim support for almost
     * everything in order to compile the built-in functions.
@@ -620,6 +620,5 @@ standalone_compiler_cleanup(struct gl_shader_program *whole_program)
    delete whole_program->FragDataIndexBindings;
 
    ralloc_free(whole_program);
-   glsl_type_singleton_decref();
-   _mesa_glsl_release_builtin_functions();
+   _mesa_glsl_builtin_functions_decref();
 }

src/mesa/main/context.c

@@ -149,6 +149,7 @@
 #endif
 
 #include "compiler/glsl_types.h"
+#include "compiler/glsl/builtin_functions.h"
 #include "compiler/glsl/glsl_parser_extras.h"
 #include <stdbool.h>
 
@@ -360,7 +361,7 @@ mtx_t OneTimeLock = _MTX_INITIALIZER_NP;
 static void
 one_time_fini(void)
 {
-   _mesa_destroy_shader_compiler();
+   glsl_type_singleton_decref();
    _mesa_locale_fini();
 }
 
@@ -408,6 +409,11 @@ one_time_init( struct gl_context *ctx )
          _mesa_debug(ctx, "Mesa " PACKAGE_VERSION " DEBUG build" MESA_GIT_SHA1 "\n");
       }
 #endif
+
+      /* Take a glsl type reference for the duration of libGL's life to avoid
+       * unecessary creation/destruction of glsl types.
+       */
+      glsl_type_singleton_init_or_ref();
    }
 
    /* per-API one-time init */
@@ -1205,8 +1211,6 @@ _mesa_initialize_context(struct gl_context *ctx,
    /* misc one-time initializations */
    one_time_init(ctx);
 
-   _mesa_init_shader_compiler_types();
-
    /* Plug in driver functions and context pointer here.
     * This is important because when we call alloc_shared_state() below
     * we'll call ctx->Driver.NewTextureObject() to create the default
@@ -1394,9 +1398,6 @@ _mesa_free_context_data(struct gl_context *ctx, bool destroy_compiler_types)
 
    free(ctx->VersionString);
 
-   if (destroy_compiler_types)
-      _mesa_destroy_shader_compiler_types();
-
    ralloc_free(ctx->SoftFP64);
 
    /* unbind the context if it's currently bound */
@@ -1404,6 +1405,12 @@ _mesa_free_context_data(struct gl_context *ctx, bool destroy_compiler_types)
       _mesa_make_current(NULL, NULL, NULL);
    }
 
+   /* Do this after unbinding context to ensure any thread is finished. */
+   if (ctx->shader_builtin_ref) {
+      _mesa_glsl_builtin_functions_decref();
+      ctx->shader_builtin_ref = false;
+   }
+
    free(ctx->Const.SpirVExtensions);
 }
 

src/mesa/main/mtypes.h

@@ -5174,6 +5174,8 @@ struct gl_context
    struct hash_table_u64 *ResidentTextureHandles;
    struct hash_table_u64 *ResidentImageHandles;
    /*@}*/
+
+   bool shader_builtin_ref;
 };
 
 /**

src/mesa/main/shaderapi.c

@@ -48,6 +48,7 @@
 #include "main/state.h"
 #include "main/transformfeedback.h"
 #include "main/uniforms.h"
+#include "compiler/glsl/builtin_functions.h"
 #include "compiler/glsl/glsl_parser_extras.h"
 #include "compiler/glsl/ir.h"
 #include "compiler/glsl/ir_uniform.h"
@@ -1155,6 +1156,14 @@ set_shader_source(struct gl_shader *sh, const GLchar *source)
 #endif
 }
 
+static void
+ensure_builtin_types(struct gl_context *ctx)
+{
+   if (!ctx->shader_builtin_ref) {
+      _mesa_glsl_builtin_functions_init_or_ref();
+      ctx->shader_builtin_ref = true;
+   }
+}
 
 /**
  * Compile a shader.
@@ -1189,6 +1198,8 @@ _mesa_compile_shader(struct gl_context *ctx, struct gl_shader *sh)
          _mesa_log("%s\n", sh->Source);
       }
 
+      ensure_builtin_types(ctx);
+
       /* this call will set the shader->CompileStatus field to indicate if
        * compilation was successful.
        */
@@ -1266,6 +1277,8 @@ link_program(struct gl_context *ctx, struct gl_shader_program *shProg,
          }
    }
 
+   ensure_builtin_types(ctx);
+
    FLUSH_VERTICES(ctx, 0);
    _mesa_glsl_link_shader(ctx, shProg);
 
@@ -2245,7 +2258,12 @@ _mesa_GetShaderPrecisionFormat(GLenum shadertype, GLenum precisiontype,
 void GLAPIENTRY
 _mesa_ReleaseShaderCompiler(void)
 {
-   _mesa_destroy_shader_compiler_caches();
+   GET_CURRENT_CONTEXT(ctx);
+
+   if (ctx->shader_builtin_ref) {
+      _mesa_glsl_builtin_functions_decref();
+      ctx->shader_builtin_ref = false;
+   }
 }
 
 

src/mesa/state_tracker/st_context.c

@@ -1036,11 +1036,6 @@ st_destroy_context(struct st_context *st)
    st_destroy_context_priv(st, true);
    st = NULL;
 
-   /* This must be called after st_destroy_context_priv() to avoid a race
-    * condition between any shader compiler threads and context destruction.
-    */
-   _mesa_destroy_shader_compiler_types();
-
    free(ctx);
 
    if (save_ctx == ctx) {