Add some (commented out) page poisoning code, for debugging use-after-free.

diff --git a/pbo_frame_allocator.cpp b/pbo_frame_allocator.cpp
index 3d4f8cf09321230a39c471164e9740fa99a92e84..0020ba484878ee70a0a560b885a58c9493bda9e9 100644 (file)
--- a/pbo_frame_allocator.cpp
+++ b/pbo_frame_allocator.cpp
@@ -126,6 +126,35 @@ void PBOFrameAllocator::release_frame(Frame frame)
                printf("%d bytes overflow after last (PBO) frame\n", int(frame.overflow));
        }
 
+#if 0
+       // Poison the page. (Note that this might be bogus if you don't have an OpenGL context.)
+       memset(frame.data, 0, frame.size);
+       Userdata *userdata = (Userdata *)frame.userdata;
+       for (unsigned field = 0; field < 2; ++field) {
+               glBindTexture(GL_TEXTURE_2D, userdata->tex_y[field]);
+               check_error();
+               glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+               check_error();
+               glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+               check_error();
+               glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+               check_error();
+               glTexImage2D(GL_TEXTURE_2D, 0, GL_R8, userdata->last_width[field], userdata->last_height[field], 0, GL_RED, GL_UNSIGNED_BYTE, NULL);
+               check_error();
+
+               glBindTexture(GL_TEXTURE_2D, userdata->tex_cbcr[field]);
+               check_error();
+               glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+               check_error();
+               glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+               check_error();
+               glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+               check_error();
+               glTexImage2D(GL_TEXTURE_2D, 0, GL_RG8, userdata->last_width[field] / 2, userdata->last_height[field], 0, GL_RED, GL_UNSIGNED_BYTE, NULL);
+               check_error();
+       }
+#endif
+
        unique_lock<mutex> lock(freelist_mutex);
        freelist.push(frame);
        //--sumsum;