reduce overhead when running in no main thread mode#1502
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November 5, 2025 13:41
Generally, post to context would not be used as SwitchToMainThread is no-op in this context. Even it is being called under certain corner cases, it would just queue the same work item to the thread pool multiple times, so better to prevent the allocation in the first place.
…s used in no main thread mode. Because IsOnMainThread is just to check the thread id, this can be turned on randomly when the code is running in the initial thread pool thread. It would turn on expensive dependency tracking graph, which is not what we expect to do.
…main thread mode.
lifengl
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AArnott
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Nov 8, 2025
This was referenced Jun 22, 2026
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The primary reason is IsOnMainThread only check the thread id matches the initial thread id, so it can be true if the task happens to start on the same thread pool thread to initialize the JoinableTaskContext in a no main thread application. It leads some unnecessary work, including marking the task main thread blocking, and tracking its dependent tasks.
All these work, including tracking nested factories seem to be unnecessary in this mode.