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Hash : 1f5eb6b8
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Date : 2021-11-17T16:42:20
Avoid Android vkEnumerateDeviceExtensionProperties() bug This works around a race-condition during Android start-up, when ANGLE is used as the default GLES driver and when render engine (RE) is using SkiaGL (which uses ANGLE, which uses Vulkan). The race condition occassionally results in different numbers of extensions between ANGLE's first and second calls to vkEnumerateDeviceExtensionProperties(). In that case, the second call would return VK_INCOMPLETE instead of VK_SUCCESS. That caused ANGLE to fail to initialize, causing RE to fail to initialize. This change works around this problem by increasing the number of extensions asked for in the second call to vkEnumerateDeviceExtensionProperties(). Background: Surface Flinger uses Hardware Composer (HWC) for hardware-based composition (e.g. using overlays), and RE for GPU composition (e.g. rendering to combine multiple app and system windows together). SF, RE, and HWC all start about the same time. HWC sets a property if it can support display timing. This gets passed through SF to RE's Vulkan loader. The Vulkan loader uses that property to determine whether to enable the VK_GOOGLE_display_timing extension. The Vulkan loader used to make a synchronous call to SF in vkEnumerateDeviceExtensionProperties() in order to get this property. That took some number of milliseconds to complete and affected the start-up time of every Vulkan/ANGLE app. To eliminate that performance problem, the property now propogates in an asynchronous manner. At that time, it was thought that RE would always get the property in time. However, a partner's experience is that VK_INCOMPLETE is happening 0.5% of the time. ANGLE doesn't need to use the VK_GOOGLE_display_timing extension. This is because the Android EGL loader provides the related EGL_ANDROID_get_frame_timestamps extension. The issue that ANGLE is working around is that it shouldn't fail to initialize in this situation. Bug: angleproject:6715 Bug: b/206733351 Change-Id: I4eb2197cdcc9692518b1bf5984d06fc8a1a7d145 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3290506 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Tim Van Patten <timvp@google.com> Commit-Queue: Ian Elliott <ianelliott@google.com>
