[Mesa-dev] [PATCH] glsl: builtin: always return clones of the builtins

[Lionel Landwerlin]

Builtins are created once and allocated using their own private ralloc
context. When reparenting IR that includes builtins, we might be steal
bits of builtins. This is problematic because these builtins might now
be freed when the shader that includes then last is disposed. This
might also lead to inconsistent ralloc trees/lists if shaders are
created on multiple threads.

Rather than including builtins directly into a shader's IR, we should
include clones of them in the ralloc context of the shader that
requires them. This fixes double free issues we've been seeing when
running shader-db on a big multicore (72 threads) server.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
---
 src/compiler/glsl/ast_to_hir.cpp        |  2 +-
 src/compiler/glsl/builtin_functions.cpp | 28 +++++++++++++++++++++++++---
 src/compiler/glsl/builtin_functions.h   |  3 ++-
 3 files changed, 28 insertions(+), 5 deletions(-)

diff --git a/src/compiler/glsl/ast_to_hir.cpp b/src/compiler/glsl/ast_to_hir.cpp
index 59d03c9c96..1bcc59b695 100644
--- a/src/compiler/glsl/ast_to_hir.cpp
+++ b/src/compiler/glsl/ast_to_hir.cpp
@@ -5653,7 +5653,7 @@ ast_function::hir(exec_list *instructions,
    if (state->es_shader && state->language_version >= 300) {
       /* Local shader has no exact candidates; check the built-ins. */
       _mesa_glsl_initialize_builtin_functions();
-      if (_mesa_glsl_find_builtin_function_by_name(name)) {
+      if (_mesa_glsl_find_builtin_function_by_name(state, name)) {
          YYLTYPE loc = this->get_location();
          _mesa_glsl_error(& loc, state,
                           "A shader cannot redefine or overload built-in "
diff --git a/src/compiler/glsl/builtin_functions.cpp b/src/compiler/glsl/builtin_functions.cpp
index e03a50c843..329e35aad2 100644
--- a/src/compiler/glsl/builtin_functions.cpp
+++ b/src/compiler/glsl/builtin_functions.cpp
@@ -62,6 +62,7 @@
 #include "program/prog_instruction.h"
 #include <math.h>
 #include "builtin_functions.h"
+#include "util/hash_table.h"
 
 #define M_PIf   ((float) M_PI)
 #define M_PI_2f ((float) M_PI_2)
@@ -6002,20 +6003,41 @@ ir_function_signature *
 _mesa_glsl_find_builtin_function(_mesa_glsl_parse_state *state,
                                  const char *name, exec_list *actual_parameters)
 {
-   ir_function_signature * s;
+   ir_function_signature *s;
    mtx_lock(&builtins_lock);
    s = builtins.find(state, name, actual_parameters);
    mtx_unlock(&builtins_lock);
-   return s;
+
+   if (s == NULL)
+      return NULL;
+
+   struct hash_table *ht =
+      _mesa_hash_table_create(NULL, _mesa_hash_pointer, _mesa_key_pointer_equal);
+   void *ctx = state;
+   ir_function *f = s->function()->clone(ctx, ht);
+   _mesa_hash_table_destroy(ht, NULL);
+
+   return f->matching_signature(state, actual_parameters, true);
 }
 
 ir_function *
-_mesa_glsl_find_builtin_function_by_name(const char *name)
+_mesa_glsl_find_builtin_function_by_name(_mesa_glsl_parse_state *state,
+                                         const char *name)
 {
    ir_function *f;
    mtx_lock(&builtins_lock);
    f = builtins.shader->symbols->get_function(name);
    mtx_unlock(&builtins_lock);
+
+   if (f == NULL)
+      return NULL;
+
+   struct hash_table *ht =
+      _mesa_hash_table_create(NULL, _mesa_hash_pointer, _mesa_key_pointer_equal);
+   void *ctx = state;
+   f = f->clone(ctx, ht);
+   _mesa_hash_table_destroy(ht, NULL);
+
    return f;
 }
 
diff --git a/src/compiler/glsl/builtin_functions.h b/src/compiler/glsl/builtin_functions.h
index 7ae211b48a..b609e4c342 100644
--- a/src/compiler/glsl/builtin_functions.h
+++ b/src/compiler/glsl/builtin_functions.h
@@ -32,7 +32,8 @@ _mesa_glsl_find_builtin_function(_mesa_glsl_parse_state *state,
                                  const char *name, exec_list *actual_parameters);
 
 extern ir_function *
-_mesa_glsl_find_builtin_function_by_name(const char *name);
+_mesa_glsl_find_builtin_function_by_name(_mesa_glsl_parse_state *state,
+                                         const char *name);
 
 extern gl_shader *
 _mesa_glsl_get_builtin_function_shader(void);
-- 
2.11.0