Fix Bug in RingBuffer

gpu/command_buffer/client/gles2_implementation.cc

 // Copyright (c) 2009 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.
 
 // A class to emluate GLES2 over command buffers.
 
 #include "../client/gles2_implementation.h"
 #include "../common/gles2_cmd_utils.h"
 
 namespace gpu {
@@ skipping 626 matching lines @@
     GLsizei length) {
   if (n < 0) {
     SetGLError(GL_INVALID_VALUE, "glShaderBinary n < 0.");
     return;
   }
   if (length < 0) {
     SetGLError(GL_INVALID_VALUE, "glShaderBinary length < 0.");
     return;
   }
   GLsizei shader_id_size = n * sizeof(*shaders);
-  void* shader_ids = transfer_buffer_.Alloc(shader_id_size);
-  void* shader_data = transfer_buffer_.Alloc(length);
+  char* buffer = transfer_buffer_.AllocTyped<char>(shader_id_size + length);

[apatrick_chromium, 2010/04/29 22:26:51]

char -> int8

+  void* shader_ids = buffer;
+  void* shader_data = buffer + shader_id_size;
   memcpy(shader_ids, shaders, shader_id_size);
   memcpy(shader_data, binary, length);
   helper_->ShaderBinary(
       n,
       transfer_buffer_id_, transfer_buffer_.GetOffset(shader_ids),
       binaryformat,
       transfer_buffer_id_, transfer_buffer_.GetOffset(shader_data),
       length);
-  int32 token = helper_->InsertToken();
-  transfer_buffer_.FreePendingToken(shader_ids, token);
-  transfer_buffer_.FreePendingToken(shader_data, token);
+  transfer_buffer_.FreePendingToken(buffer, helper_->InsertToken());
 }
 
 void GLES2Implementation::PixelStorei(GLenum pname, GLint param) {
   switch (pname) {
   case GL_PACK_ALIGNMENT:
       pack_alignment_ = param;
       break;
   case GL_UNPACK_ALIGNMENT:
       unpack_alignment_ = param;
       break;
@@ skipping 468 matching lines @@
       // include padding.
       GLsizeiptr part_size =
           unpadded_row_size + (padded_row_size * std::max(num_rows - 1, 0));
       void* buffer = transfer_buffer_.Alloc(part_size);
       *result = 0;  // mark as failed.
       helper_->ReadPixels(
           xoffset, yoffset, width, num_rows, format, type,
           transfer_buffer_id_, transfer_buffer_.GetOffset(buffer),
           result_shm_id(), result_shm_offset());
       WaitForCmd();
+      if (*result != 0) {
+        // We have to copy 1 row at a time to avoid writing pad bytes.
+        const int8* src = static_cast<const int8*>(buffer);
+        for (GLint yy = 0; yy < num_rows; ++yy) {
+          memcpy(dest, src, unpadded_row_size);
+          dest += padded_row_size;
+          src += padded_row_size;
+        }
+      }
+      transfer_buffer_.FreePendingToken(buffer, helper_->InsertToken());
       // If it was not marked as successful exit.
       if (*result == 0) {
         return;
       }
-      // We have to copy 1 row at a time to avoid writing pad bytes.
-      const int8* src = static_cast<const int8*>(buffer);
-      for (GLint yy = 0; yy < num_rows; ++yy) {
-        memcpy(dest, src, unpadded_row_size);
-        dest += padded_row_size;
-        src += padded_row_size;
-      }
-      transfer_buffer_.FreePendingToken(buffer, helper_->InsertToken());
       yoffset += num_rows;
       height -= num_rows;
     }
   } else {
     // Transfer by sub rows. Beacuse GL has no maximum texture dimensions.
     GLES2Util::ComputeImageDataSize(
        1, 1, format, type, pack_alignment_, &temp_size);
     GLsizeiptr element_size = temp_size;
     max_size -= max_size % element_size;
     GLint max_sub_row_pixels = max_size / element_size;
     for (; height; --height) {
       GLint temp_width = width;
       GLint temp_xoffset = xoffset;
       int8* row_dest = dest;
       while (temp_width) {
         GLint num_pixels = std::min(width, max_sub_row_pixels);
         GLsizeiptr part_size = num_pixels * element_size;
         void* buffer = transfer_buffer_.Alloc(part_size);
         *result = 0;  // mark as failed.
         helper_->ReadPixels(
             temp_xoffset, yoffset, temp_width, 1, format, type,
             transfer_buffer_id_, transfer_buffer_.GetOffset(buffer),
             result_shm_id(), result_shm_offset());
         WaitForCmd();
+        if (*result != 0) {
+          memcpy(row_dest, buffer, part_size);
+        }
+        transfer_buffer_.FreePendingToken(buffer, helper_->InsertToken());
         // If it was not marked as successful exit.
         if (*result == 0) {
           return;
         }
-        memcpy(row_dest, buffer, part_size);
-        transfer_buffer_.FreePendingToken(buffer, helper_->InsertToken());
         row_dest += part_size;
         temp_xoffset += num_pixels;
         temp_width -= num_pixels;
       }
       ++yoffset;
       dest += padded_row_size;
     }
   }
 }
 
@@ skipping 145 matching lines @@
   helper_->GetVertexAttribiv(
       index, pname, result_shm_id(), result_shm_offset());
   WaitForCmd();
   result->CopyResult(params);
 }
 
 #endif  // defined(GLES2_SUPPORT_CLIENT_SIDE_BUFFERS)
 
 }  // namespace gles2
 }  // namespace gpu