gpu: Defer reads from default framebuffer when needed.

gpu/command_buffer/build_gles2_cmd_buffer.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """code generator for GLES2 command buffers."""
 
 import itertools
 import os
 import os.path
@@ skipping 1166 matching lines @@
     'decoder_func': 'DoBindTexture',
     'gen_func': 'GenTextures',
     # TODO(gman): remove this once client side caching works.
     'client_test': False,
   },
   'BlitFramebufferEXT': {
     'decoder_func': 'DoBlitFramebufferEXT',
     'unit_test': False,
     'extension': True,
     'pepper_interface': 'FramebufferBlit',
+    'defer_reads': True,
+    'defer_draws': True,
   },
   'BufferData': {
     'type': 'Manual',
     'immediate': True,
     'client_test': False,
   },
   'BufferSubData': {
     'type': 'Data',
     'client_test': False,
     'decoder_func': 'DoBufferSubData',
   },
   'CheckFramebufferStatus': {
     'type': 'Is',
     'decoder_func': 'DoCheckFramebufferStatus',
     'gl_test_func': 'glCheckFramebufferStatusEXT',
     'error_value': 'GL_FRAMEBUFFER_UNSUPPORTED',
     'result': ['GLenum'],
   },
   'Clear': {
-    'type': 'Manual',
-    'cmd_args': 'GLbitfield mask'
+    'decoder_func': 'DoClear',
+    'defer_draws': True,
   },
   'ClearColor': {
     'type': 'StateSet',
     'state': 'ClearColor',
   },
   'ClearDepthf': {
     'type': 'StateSet',
     'state': 'ClearDepthf',
     'decoder_func': 'glClearDepth',
     'gl_test_func': 'glClearDepth',
@@ skipping 38 matching lines @@
     'bucket': True,
   },
   'CompressedTexSubImage2D': {
     'type': 'Data',
     'bucket': True,
     'decoder_func': 'DoCompressedTexSubImage2D',
   },
   'CopyTexImage2D': {
     'decoder_func': 'DoCopyTexImage2D',
     'unit_test': False,
+    'defer_reads': True,
   },
   'CopyTexSubImage2D': {
     'decoder_func': 'DoCopyTexSubImage2D',
+    'defer_reads': True,
   },
   'CreateProgram': {
     'type': 'Create',
     'client_test': False,
   },
   'CreateShader': {
     'type': 'Create',
     'client_test': False,
   },
   'BlendColor': {
@@ skipping 110 matching lines @@
     'impl_func': False,
     'client_test': False,
   },
   'DisableVertexAttribArray': {
     'decoder_func': 'DoDisableVertexAttribArray',
     'impl_decl': False,
   },
   'DrawArrays': {
     'type': 'Manual',
     'cmd_args': 'GLenumDrawMode mode, GLint first, GLsizei count',
+    'defer_draws': True,
   },
   'DrawElements': {
     'type': 'Manual',
     'cmd_args': 'GLenumDrawMode mode, GLsizei count, '
                 'GLenumIndexType type, GLuint index_offset',
-    'client_test': False
+    'client_test': False,
+    'defer_draws': True,
   },
   'Enable': {
     'decoder_func': 'DoEnable',
     'impl_func': False,
     'client_test': False,
   },
   'EnableVertexAttribArray': {
     'decoder_func': 'DoEnableVertexAttribArray',
     'impl_decl': False,
   },
@@ skipping 372 matching lines @@
     'type': 'Custom',
     'immediate': False,
     'impl_func': False,
     'client_test': False,
     'cmd_args':
         'GLint x, GLint y, GLsizei width, GLsizei height, '
         'GLenumReadPixelFormat format, GLenumReadPixelType type, '
         'uint32 pixels_shm_id, uint32 pixels_shm_offset, '
         'uint32 result_shm_id, uint32 result_shm_offset',
     'result': ['uint32'],
+    'defer_reads': True,
   },
   'RegisterSharedIdsCHROMIUM': {
     'type': 'Custom',
     'decoder_func': 'DoRegisterSharedIdsCHROMIUM',
     'impl_func': False,
     'expectation': False,
     'immediate': False,
     'extension': True,
     'chromium': True,
   },
@@ skipping 283 matching lines @@
     'extension': True,
     'decoder_func': 'DoTexStorage2DEXT',
   },
   'DrawArraysInstancedANGLE': {
     'type': 'Manual',
     'cmd_args': 'GLenumDrawMode mode, GLint first, GLsizei count, '
                 'GLsizei primcount',
     'extension': True,
     'unit_test': False,
     'pepper_interface': 'InstancedArrays',
+    'defer_draws': True,
   },
   'DrawElementsInstancedANGLE': {
     'type': 'Manual',
     'cmd_args': 'GLenumDrawMode mode, GLsizei count, '
                 'GLenumIndexType type, GLuint index_offset, GLsizei primcount',
     'extension': True,
     'unit_test': False,
     'client_test': False,
     'pepper_interface': 'InstancedArrays',
+    'defer_draws': True,
   },
   'VertexAttribDivisorANGLE': {
     'type': 'Manual',
     'cmd_args': 'GLuint index, GLuint divisor',
     'extension': True,
     'unit_test': False,
     'pepper_interface': 'InstancedArrays',
   },
   'GenQueriesEXT': {
     'type': 'GENn',
@@ skipping 440 matching lines @@
     """Writes the handler impl for the bucket version of a command."""
     file.Write("  %s(%s);\n" %
                (func.GetGLFunctionName(), func.MakeOriginalArgString("")))
 
   def WriteServiceImplementation(self, func, file):
     """Writes the service implementation for a command."""
     file.Write(
         "error::Error GLES2DecoderImpl::Handle%s(\n" % func.name)
     file.Write(
         "    uint32 immediate_data_size, const gles2::%s& c) {\n" % func.name)
+    self.WriteHandlerDeferReadWrite(func, file);
     if len(func.GetOriginalArgs()) > 0:
       last_arg = func.GetLastOriginalArg()
       all_but_last_arg = func.GetOriginalArgs()[:-1]
       for arg in all_but_last_arg:
         arg.WriteGetCode(file)
       self.WriteGetDataSizeCode(func, file)
       last_arg.WriteGetCode(file)
     func.WriteHandlerValidation(file)
     func.WriteHandlerImplementation(file)
     file.Write("  return error::kNoError;\n")
     file.Write("}\n")
     file.Write("\n")
 
   def WriteImmediateServiceImplementation(self, func, file):
     """Writes the service implementation for an immediate version of command."""
     file.Write(
         "error::Error GLES2DecoderImpl::Handle%s(\n" % func.name)
     file.Write(
         "    uint32 immediate_data_size, const gles2::%s& c) {\n" % func.name)
+    self.WriteHandlerDeferReadWrite(func, file);
     last_arg = func.GetLastOriginalArg()
     all_but_last_arg = func.GetOriginalArgs()[:-1]
     for arg in all_but_last_arg:
       arg.WriteGetCode(file)
     self.WriteGetDataSizeCode(func, file)
     last_arg.WriteGetCode(file)
     func.WriteHandlerValidation(file)
     func.WriteHandlerImplementation(file)
     file.Write("  return error::kNoError;\n")
     file.Write("}\n")
     file.Write("\n")
 
   def WriteBucketServiceImplementation(self, func, file):
     """Writes the service implementation for a bucket version of command."""
     file.Write(
         "error::Error GLES2DecoderImpl::Handle%s(\n" % func.name)
     file.Write(
         "    uint32 immediate_data_size, const gles2::%s& c) {\n" % func.name)
+    self.WriteHandlerDeferReadWrite(func, file);
     last_arg = func.GetLastOriginalArg()
     all_but_last_arg = func.GetOriginalArgs()[:-1]
     for arg in all_but_last_arg:
       arg.WriteGetCode(file)
     self.WriteGetDataSizeCode(func, file)
     last_arg.WriteGetCode(file)
     func.WriteHandlerValidation(file)
     func.WriteHandlerImplementation(file)
     file.Write("  return error::kNoError;\n")
     file.Write("}\n")
     file.Write("\n")
 
+  def WriteHandlerDeferReadWrite(self, func, file):
+    """Writes the code to handle deferring reads or writes."""
+    defer_reads = func.GetInfo('defer_reads')
+    defer_draws = func.GetInfo('defer_draws')
+    conditions = []
+    if defer_draws:
+      conditions.append('ShouldDeferDraws()');
+    if defer_reads:
+      conditions.append('ShouldDeferReads()');
+    if not conditions:
+      return
+    file.Write("  if (%s)\n" % ' || '.join(conditions))
+    file.Write("    return error::kDeferCommandUntilLater;\n")
+
   def WriteValidUnitTest(self, func, file, test, extra = {}):
     """Writes a valid unit test."""
     if func.GetInfo('expectation') == False:
       test = self._remove_expected_call_re.sub('', test)
     name = func.name
     arg_strings = []
     for count, arg in enumerate(func.GetOriginalArgs()):
       arg_strings.append(arg.GetValidArg(func, count, 0))
     gl_arg_strings = []
     for count, arg in enumerate(func.GetOriginalArgs()):
@@ skipping 4797 matching lines @@
     gen.WriteGLES2Header("../../third_party/khronos/GLES2/gl2chromium.h")
 
   if gen.errors > 0:
     print "%d errors" % gen.errors
     return 1
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))