glthread: implement glGetUniformLocation without syncing

We already have the infrastructure for querying shader program properties
without syncing. This just uses it. _mesa_error_glthread_safe sets a GL
error from the producer thread.

This decreases CPU overhead for viewperf/snx.

Reviewed-by: Qiang Yu <yuq825@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/12490>

src/mapi/glapi/gen/gl_API.xml

@@ -5483,7 +5483,7 @@
         <glx ignore="true"/>
     </function>
 
-    <function name="GetUniformLocation" es2="2.0" no_error="true">
+    <function name="GetUniformLocation" es2="2.0" no_error="true" marshal="custom">
         <param name="program" type="GLuint"/>
         <param name="name" type="const GLchar *"/>
         <return type="GLint"/>

src/mesa/main/glthread_shaderobj.c

@@ -136,6 +136,17 @@ _mesa_unmarshal_GetActiveUniform(struct gl_context *ctx,
    return 0;
 }
 
+static void
+wait_for_glLinkProgram(struct gl_context *ctx)
+{
+   /* Wait for the last glLinkProgram call. */
+   int batch = p_atomic_read(&ctx->GLThread.LastProgramChangeBatch);
+   if (batch != -1) {
+      util_queue_fence_wait(&ctx->GLThread.batches[batch].fence);
+      assert(p_atomic_read(&ctx->GLThread.LastProgramChangeBatch) == -1);
+   }
+}
+
 void GLAPIENTRY
 _mesa_marshal_GetActiveUniform(GLuint program, GLuint index, GLsizei bufSize,
                                GLsizei *length, GLint *size, GLenum *type,
@@ -143,12 +154,7 @@ _mesa_marshal_GetActiveUniform(GLuint program, GLuint index, GLsizei bufSize,
 {
    GET_CURRENT_CONTEXT(ctx);
 
-   /* Wait for the last glLinkProgram call. */
-   int batch = p_atomic_read(&ctx->GLThread.LastProgramChangeBatch);
-   if (batch != -1) {
-      util_queue_fence_wait(&ctx->GLThread.batches[batch].fence);
-      assert(p_atomic_read(&ctx->GLThread.LastProgramChangeBatch) == -1);
-   }
+   wait_for_glLinkProgram(ctx);
 
    /* We can execute glGetActiveUniform without syncing if we are sync'd to
     * the last calls of glLinkProgram and glDeleteProgram because shader
@@ -160,3 +166,23 @@ _mesa_marshal_GetActiveUniform(GLuint program, GLuint index, GLsizei bufSize,
    _mesa_GetActiveUniform_impl(program, index, bufSize, length, size, type,
                                name, true);
 }
+
+uint32_t
+_mesa_unmarshal_GetUniformLocation(struct gl_context *ctx,
+                                   const struct marshal_cmd_GetUniformLocation *cmd,
+                                   const uint64_t *last)
+{
+   unreachable("never executed");
+   return 0;
+}
+
+GLint GLAPIENTRY
+_mesa_marshal_GetUniformLocation(GLuint program, const GLchar *name)
+{
+   GET_CURRENT_CONTEXT(ctx);
+
+   wait_for_glLinkProgram(ctx);
+
+   /* This is thread-safe. See the comment in _mesa_marshal_GetActiveUniform. */
+   return _mesa_GetUniformLocation_impl(program, name, true);
+}

src/mesa/main/uniforms.c

@@ -996,15 +996,16 @@ _mesa_GetUniformui64vARB(GLuint program, GLint location, GLuint64 *params)
 }
 
 
-GLint GLAPIENTRY
-_mesa_GetUniformLocation(GLuint programObj, const GLcharARB *name)
+GLint
+_mesa_GetUniformLocation_impl(GLuint programObj, const GLcharARB *name,
+                              bool glthread)
 {
    struct gl_shader_program *shProg;
 
    GET_CURRENT_CONTEXT(ctx);
 
-   shProg = _mesa_lookup_shader_program_err(ctx, programObj,
-					    "glGetUniformLocation");
+   shProg = _mesa_lookup_shader_program_err_glthread(ctx, programObj, glthread,
+                                                     "glGetUniformLocation");
    if (!shProg || !name)
       return -1;
 
@@ -1014,14 +1015,20 @@ _mesa_GetUniformLocation(GLuint programObj, const GLcharARB *name)
     *     INVALID_OPERATION is generated."
     */
    if (shProg->data->LinkStatus == LINKING_FAILURE) {
-      _mesa_error(ctx, GL_INVALID_OPERATION,
-		  "glGetUniformLocation(program not linked)");
+      _mesa_error_glthread_safe(ctx, GL_INVALID_OPERATION, glthread,
+                                "glGetUniformLocation(program not linked)");
       return -1;
    }
 
    return _mesa_program_resource_location(shProg, GL_UNIFORM, name);
 }
 
+GLint GLAPIENTRY
+_mesa_GetUniformLocation(GLuint programObj, const GLcharARB *name)
+{
+   return _mesa_GetUniformLocation_impl(programObj, name, false);
+}
+
 GLint GLAPIENTRY
 _mesa_GetUniformLocation_no_error(GLuint programObj, const GLcharARB *name)
 {

src/mesa/main/uniforms.h

@@ -222,6 +222,8 @@ void GLAPIENTRY
 _mesa_GetnUniformdvARB(GLuint, GLint, GLsizei, GLdouble *);
 void GLAPIENTRY
 _mesa_GetUniformdv(GLuint, GLint, GLdouble *);
+GLint
+_mesa_GetUniformLocation_impl(GLuint, const GLcharARB *, bool glthread);
 GLint GLAPIENTRY
 _mesa_GetUniformLocation(GLuint, const GLcharARB *);
 GLint GLAPIENTRY