[Mesa-dev] [PATCH] mesa/glthread: add custom marshalling for ClearBufferfv()

[Timothy Arceri]

This is one of the main causes of syncs in Civ6.
---
 src/mapi/glapi/gen/GL3x.xml |  2 +-
 src/mesa/main/marshal.c     | 73 +++++++++++++++++++++++++++++++++++++++++++++
 src/mesa/main/marshal.h     |  9 ++++++
 3 files changed, 83 insertions(+), 1 deletion(-)

diff --git a/src/mapi/glapi/gen/GL3x.xml b/src/mapi/glapi/gen/GL3x.xml
index b603e1f..f38a287 100644
--- a/src/mapi/glapi/gen/GL3x.xml
+++ b/src/mapi/glapi/gen/GL3x.xml
@@ -122,21 +122,21 @@
     <param name="drawbuffer" type="GLint"/>
     <param name="value" type="const GLint *"/>
   </function>
 
   <function name="ClearBufferuiv" es2="3.0">
     <param name="buffer" type="GLenum"/>
     <param name="drawbuffer" type="GLint"/>
     <param name="value" type="const GLuint *"/>
   </function>
 
-  <function name="ClearBufferfv" es2="3.0">
+  <function name="ClearBufferfv" es2="3.0" marshal="custom">
     <param name="buffer" type="GLenum"/>
     <param name="drawbuffer" type="GLint"/>
     <param name="value" type="const GLfloat *"/>
   </function>
 
   <function name="ClearBufferfi" es2="3.0">
     <param name="buffer" type="GLenum"/>
     <param name="drawbuffer" type="GLint"/>
     <param name="depth" type="GLfloat"/>
     <param name="stencil" type="GLint"/>
diff --git a/src/mesa/main/marshal.c b/src/mesa/main/marshal.c
index cdc7fed..bcc6f17 100644
--- a/src/mesa/main/marshal.c
+++ b/src/mesa/main/marshal.c
@@ -20,20 +20,21 @@
  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  * IN THE SOFTWARE.
  */
 
 /** \file marshal.c
  *
  * Custom functions for marshalling GL calls from the main thread to a worker
  * thread when automatic code generation isn't appropriate.
  */
 
+#include "main/enums.h"
 #include "marshal.h"
 #include "dispatch.h"
 #include "marshal_generated.h"
 
 #ifdef HAVE_PTHREAD
 
 struct marshal_cmd_Flush
 {
    struct marshal_cmd_base cmd_base;
 };
@@ -377,11 +378,83 @@ _mesa_marshal_BufferSubData(GLenum target, GLintptr offset, GLsizeiptr size,
       memcpy(variable_data, data, size);
       variable_data += size;
       _mesa_post_marshal_hook(ctx);
    } else {
       _mesa_glthread_finish(ctx);
       CALL_BufferSubData(ctx->CurrentServerDispatch,
                          (target, offset, size, data));
    }
 }
 
+/* ClearBufferfv: marshalled asynchronously */
+struct marshal_cmd_ClearBufferfv
+{
+   struct marshal_cmd_base cmd_base;
+   GLenum buffer;
+   GLint drawbuffer;
+};
+
+void
+_mesa_unmarshal_ClearBufferfv(struct gl_context *ctx,
+                              const struct marshal_cmd_ClearBufferfv *cmd)
+{
+   const GLenum buffer = cmd->buffer;
+   const GLint drawbuffer = cmd->drawbuffer;
+   const char *variable_data = (const char *) (cmd + 1);
+   const GLfloat *value = (const GLfloat *) variable_data;
+
+   CALL_ClearBufferfv(ctx->CurrentServerDispatch,
+                      (buffer, drawbuffer, value));
+}
+
+void GLAPIENTRY
+_mesa_marshal_ClearBufferfv(GLenum buffer, GLint drawbuffer,
+                            const GLfloat *value)
+{
+   GET_CURRENT_CONTEXT(ctx);
+   debug_print_marshal("ClearBufferfv");
+
+   size_t size;
+   switch (buffer) {
+   case GL_DEPTH:
+      size = sizeof(GLfloat);
+      break;
+   case GL_COLOR:
+      size = sizeof(GLfloat) * 4;
+      break;
+   default:
+      _mesa_glthread_finish(ctx);
+
+      /* Page 498 of the PDF, section '17.4.3.1 Clearing Individual Buffers'
+       * of the OpenGL 4.5 spec states:
+       *
+       *    "An INVALID_ENUM error is generated by ClearBufferfv and
+       *     ClearNamedFramebufferfv if buffer is not COLOR or DEPTH."
+       */
+      _mesa_error(ctx, GL_INVALID_ENUM, "glClearBufferfv(buffer=%s)",
+                  _mesa_enum_to_string(buffer));
+      return;
+   }
+
+   size_t cmd_size = sizeof(struct marshal_cmd_ClearBufferfv) + size;
+   if (cmd_size <= MARSHAL_MAX_CMD_SIZE) {
+      struct marshal_cmd_ClearBufferfv *cmd =
+         _mesa_glthread_allocate_command(ctx, DISPATCH_CMD_ClearBufferfv,
+                                         cmd_size);
+      cmd->buffer = buffer;
+      cmd->drawbuffer = drawbuffer;
+      GLfloat *variable_data = (GLfloat *) (cmd + 1);
+      if (buffer == GL_COLOR)
+         COPY_4V(variable_data, value);
+      else
+         *variable_data = *value;
+
+      _mesa_post_marshal_hook(ctx);
+   } else {
+      debug_print_sync("ClearBufferfv");
+      _mesa_glthread_finish(ctx);
+      CALL_ClearBufferfv(ctx->CurrentServerDispatch,
+                         (buffer, drawbuffer, value));
+   }
+}
+
 #endif
diff --git a/src/mesa/main/marshal.h b/src/mesa/main/marshal.h
index c2ecba6..8ea303a 100644
--- a/src/mesa/main/marshal.h
+++ b/src/mesa/main/marshal.h
@@ -183,20 +183,21 @@ static inline bool
 _mesa_glthread_is_compat_bind_vertex_array(const struct gl_context *ctx)
 {
    return ctx->API != API_OPENGL_CORE;
 }
 
 struct marshal_cmd_ShaderSource;
 struct marshal_cmd_Flush;
 struct marshal_cmd_BindBuffer;
 struct marshal_cmd_BufferData;
 struct marshal_cmd_BufferSubData;
+struct marshal_cmd_ClearBufferfv;
 
 void GLAPIENTRY
 _mesa_marshal_ShaderSource(GLuint shader, GLsizei count,
                            const GLchar * const *string, const GLint *length);
 
 void
 _mesa_unmarshal_ShaderSource(struct gl_context *ctx,
                              const struct marshal_cmd_ShaderSource *cmd);
 
 void GLAPIENTRY
@@ -222,11 +223,19 @@ _mesa_marshal_BufferData(GLenum target, GLsizeiptr size, const GLvoid * data,
                          GLenum usage);
 
 void
 _mesa_unmarshal_BufferSubData(struct gl_context *ctx,
                               const struct marshal_cmd_BufferSubData *cmd);
 
 void GLAPIENTRY
 _mesa_marshal_BufferSubData(GLenum target, GLintptr offset, GLsizeiptr size,
                             const GLvoid * data);
 
+void
+_mesa_unmarshal_ClearBufferfv(struct gl_context *ctx,
+                              const struct marshal_cmd_ClearBufferfv *cmd);
+
+void GLAPIENTRY
+_mesa_marshal_ClearBufferfv(GLenum buffer, GLint drawbuffer,
+                            const GLfloat *value);
+
 #endif /* MARSHAL_H */
-- 
2.9.3