PPAPI: Make GLES2 calls resilient to bad/dead resources.

Currently, if PPB_OpenGLES2 is passed a bad resource, or if a bad resource is
set prior to OpenGLES2 calls, our code happily dereferences a NULL pointer.
This CL tries to address that by handling failure in a way that's consistent
with our other Pepper interfaces.

It also appears that the "old" approach to locking would end up locking twice
per call. Once to get the PPB_GLES2Impl, then unlocked, and then locked
again inside the LockingCommandBuffer (meaning that the PPB_GLES2Impl
might not actually be valid at the time we dereference it!!). This change
simplifies that and removes the old/hacky way of locking.

BUG=275815

Review URL: https://codereview.chromium.org/24466004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226017 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 60 insertions, 19 deletions

diff --git a/gpu/command_buffer/build_gles2_cmd_buffer.py b/gpu/command_buffer/build_gles2_cmd_buffer.py
index f4c7e5b..83700f6 100755
--- a/gpu/command_buffer/build_gles2_cmd_buffer.py
+++ b/gpu/command_buffer/build_gles2_cmd_buffer.py
@@ -1212,6 +1212,10 @@ _PEPPER_INTERFACES = [
 # valid_args:   A dictionary of argument indices to args to use in unit tests
 #               when they can not be automatically determined.
 # pepper_interface: The pepper interface that is used for this extension
+# pepper_args:  A string representing the argument list (what would appear in
+#               C/C++ between the parentheses for the function declaration)
+#               that the Pepper API expects for this function. Use this only if
+#               the stable Pepper API differs from the GLES2 argument list.
 # invalid_test: False if no invalid test needed.
 # shadowed:     True = the value is shadowed so no glGetXXX call will be made.
 # first_element_only: For PUT types, True if only the first element of an
@@ -1627,6 +1631,7 @@ _FUNCTION_INFO = {
     'cmd_args':
         'GLidProgram program, const char* name, NonImmediate GLint* location',
     'result': ['GLint'],
+    'error_return': -1, # http://www.opengl.org/sdk/docs/man/xhtml/glGetAttribLocation.xml
   },
   'GetBooleanv': {
     'type': 'GETn',
@@ -1778,6 +1783,7 @@ _FUNCTION_INFO = {
     'cmd_args':
         'GLidProgram program, const char* name, NonImmediate GLint* location',
     'result': ['GLint'],
+    'error_return': -1, # http://www.opengl.org/sdk/docs/man/xhtml/glGetUniformLocation.xml
   },
   'GetVertexAttribfv': {
     'type': 'GETn',
@@ -1941,6 +1947,8 @@ _FUNCTION_INFO = {
     'client_test': False,
     'cmd_args':
         'GLuint shader, const char* data',
+    'pepper_args':
+        'GLuint shader, GLsizei count, const char** str, const GLint* length',
   },
   'StencilMask': {
     'type': 'StateSetFrontBack',
@@ -2305,6 +2313,7 @@ _FUNCTION_INFO = {
   },
   'BindUniformLocationCHROMIUM': {
     'type': 'GLchar',
+    'extension': True,
     'bucket': True,
     'needs_size': True,
     'gl_test_func': 'DoBindUniformLocationCHROMIUM',
@@ -2313,20 +2322,24 @@ _FUNCTION_INFO = {
     'type': 'GLcharN',
     'decoder_func': 'DoInsertEventMarkerEXT',
     'expectation': False,
+    'extension': True,
   },
   'PushGroupMarkerEXT': {
     'type': 'GLcharN',
     'decoder_func': 'DoPushGroupMarkerEXT',
     'expectation': False,
+    'extension': True,
   },
   'PopGroupMarkerEXT': {
     'decoder_func': 'DoPopGroupMarkerEXT',
     'expectation': False,
+    'extension': True,
     'impl_func': False,
   },
 
   'GenVertexArraysOES': {
     'type': 'GENn',
+    'extension': True,
     'gl_test_func': 'glGenVertexArraysOES',
     'resource_type': 'VertexArray',
     'resource_types': 'VertexArrays',
@@ -2334,6 +2347,7 @@ _FUNCTION_INFO = {
   },
   'BindVertexArrayOES': {
     'type': 'Bind',
+    'extension': True,
     'gl_test_func': 'glBindVertexArrayOES',
     'decoder_func': 'DoBindVertexArrayOES',
     'gen_func': 'GenVertexArraysOES',
@@ -2342,6 +2356,7 @@ _FUNCTION_INFO = {
   },
   'DeleteVertexArraysOES': {
     'type': 'DELn',
+    'extension': True,
     'gl_test_func': 'glDeleteVertexArraysOES',
     'resource_type': 'VertexArray',
     'resource_types': 'VertexArrays',
@@ -2349,6 +2364,7 @@ _FUNCTION_INFO = {
   },
   'IsVertexArrayOES': {
     'type': 'Is',
+    'extension': True,
     'gl_test_func': 'glIsVertexArrayOES',
     'decoder_func': 'DoIsVertexArrayOES',
     'expectation': False,
@@ -6394,7 +6410,7 @@ class Function(object):
     """Gets the last original argument to this function."""
     return self.original_args[len(self.original_args) - 1]
 
-  def __GetArgList(self, arg_string, add_comma):
+  def __MaybePrependComma(self, arg_string, add_comma):
     """Adds a comma if arg_string is not empty and add_comma is true."""
     comma = ""
     if add_comma and len(arg_string):
@@ -6402,46 +6418,53 @@ class Function(object):
     return "%s%s" % (comma, arg_string)
 
   def MakeTypedOriginalArgString(self, prefix, add_comma = False):
-    """Gets a list of arguments as they arg in GL."""
+    """Gets a list of arguments as they are in GL."""
     args = self.GetOriginalArgs()
     arg_string = ", ".join(
         ["%s %s%s" % (arg.type, prefix, arg.name) for arg in args])
-    return self.__GetArgList(arg_string, add_comma)
+    return self.__MaybePrependComma(arg_string, add_comma)
 
   def MakeOriginalArgString(self, prefix, add_comma = False, separator = ", "):
     """Gets the list of arguments as they are in GL."""
     args = self.GetOriginalArgs()
     arg_string = separator.join(
         ["%s%s" % (prefix, arg.name) for arg in args])
-    return self.__GetArgList(arg_string, add_comma)
+    return self.__MaybePrependComma(arg_string, add_comma)
+
+  def MakeTypedPepperArgString(self, prefix):
+    """Gets a list of arguments as they need to be for Pepper."""
+    if self.GetInfo("pepper_args"):
+      return self.GetInfo("pepper_args")
+    else:
+      return self.MakeTypedOriginalArgString(prefix, False)
 
   def MakeTypedCmdArgString(self, prefix, add_comma = False):
     """Gets a typed list of arguments as they need to be for command buffers."""
     args = self.GetCmdArgs()
     arg_string = ", ".join(
         ["%s %s%s" % (arg.type, prefix, arg.name) for arg in args])
-    return self.__GetArgList(arg_string, add_comma)
+    return self.__MaybePrependComma(arg_string, add_comma)
 
   def MakeCmdArgString(self, prefix, add_comma = False):
     """Gets the list of arguments as they need to be for command buffers."""
     args = self.GetCmdArgs()
     arg_string = ", ".join(
         ["%s%s" % (prefix, arg.name) for arg in args])
-    return self.__GetArgList(arg_string, add_comma)
+    return self.__MaybePrependComma(arg_string, add_comma)
 
   def MakeTypedInitString(self, prefix, add_comma = False):
     """Gets a typed list of arguments as they need to be for cmd Init/Set."""
     args = self.GetInitArgs()
     arg_string = ", ".join(
         ["%s %s%s" % (arg.type, prefix, arg.name) for arg in args])
-    return self.__GetArgList(arg_string, add_comma)
+    return self.__MaybePrependComma(arg_string, add_comma)
 
   def MakeInitString(self, prefix, add_comma = False):
     """Gets the list of arguments as they need to be for cmd Init/Set."""
     args = self.GetInitArgs()
     arg_string = ", ".join(
         ["%s%s" % (prefix, arg.name) for arg in args])
-    return self.__GetArgList(arg_string, add_comma)
+    return self.__MaybePrependComma(arg_string, add_comma)
 
   def MakeLogArgString(self):
     """Makes a string of the arguments for the LOG macros"""
@@ -7593,7 +7616,7 @@ const size_t GLES2Util::enum_to_string_table_len_ =
         if not func.InPepperInterface(interface):
           continue
 
-        original_arg = func.MakeTypedOriginalArgString("")
+        original_arg = func.MakeTypedPepperArgString("")
         context_arg = "PP_Resource context"
         if len(original_arg):
           arg = context_arg + ", " + original_arg
@@ -7621,31 +7644,49 @@ const size_t GLES2Util::enum_to_string_table_len_ =
     file.Write("namespace ppapi {\n\n")
     file.Write("namespace {\n\n")
 
-    file.Write("gpu::gles2::GLES2Implementation*"
-               " GetGLES(PP_Resource context) {\n")
-    file.Write("  thunk::EnterResource<thunk::PPB_Graphics3D_API>"
-               " enter_g3d(context, false);\n")
-    file.Write("  DCHECK(enter_g3d.succeeded());\n")
-    file.Write("  return static_cast<PPB_Graphics3D_Shared*>"
-               "(enter_g3d.object())->gles2_impl();\n")
-    file.Write("}\n\n")
+    file.Write("typedef thunk::EnterResource<thunk::PPB_Graphics3D_API>"
+               " Enter3D;\n\n")
+
+    file.Write("gpu::gles2::GLES2Implementation* ToGles2Impl(Enter3D*"
+               " enter) {\n")
+    file.Write("  DCHECK(enter);\n")
+    file.Write("  DCHECK(enter->succeeded());\n")
+    file.Write("  return static_cast<PPB_Graphics3D_Shared*>(enter->object())->"
+               "gles2_impl();\n");
+    file.Write("}\n\n");
 
     for func in self.original_functions:
       if not func.InAnyPepperExtension():
         continue
 
-      original_arg = func.MakeTypedOriginalArgString("")
+      original_arg = func.MakeTypedPepperArgString("")
       context_arg = "PP_Resource context_id"
       if len(original_arg):
         arg = context_arg + ", " + original_arg
       else:
         arg = context_arg
       file.Write("%s %s(%s) {\n" % (func.return_type, func.name, arg))
+      file.Write("  Enter3D enter(context_id, true);\n")
+      file.Write("  if (enter.succeeded()) {\n")
 
       return_str = "" if func.return_type == "void" else "return "
-      file.Write("  %sGetGLES(context_id)->%s(%s);\n" %
+      file.Write("    %sToGles2Impl(&enter)->%s(%s);\n" %
                  (return_str, func.original_name,
                   func.MakeOriginalArgString("")))
+      file.Write("  }")
+      if func.return_type == "void":
+        file.Write("\n")
+      else:
+        file.Write(" else {\n")
+        error_return = "0"
+        if func.GetInfo("error_return"):
+          error_return = func.GetInfo("error_return")
+        elif func.return_type == "GLboolean":
+          error_return = "GL_FALSE"
+        elif "*" in func.return_type:
+          error_return = "NULL"
+        file.Write("    return %s;\n" % error_return)
+        file.Write("  }\n")
       file.Write("}\n\n")
 
     file.Write("}  // namespace\n")