f838fa820f
This PR introduces a new `ThreadPlanSingleThreadTimeout` that will be used to address potential deadlock during single-thread stepping. While debugging a target with a non-trivial number of threads (around 5000 threads in one example target), we noticed that a simple step over can take as long as 10 seconds. Enabling single-thread stepping mode significantly reduces the stepping time to around 3 seconds. However, this can introduce deadlock if we try to step over a method that depends on other threads to release a lock. To address this issue, we introduce a new `ThreadPlanSingleThreadTimeout` that can be controlled by the `target.process.thread.single-thread-plan-timeout` setting during single-thread stepping mode. The concept involves counting the elapsed time since the last internal stop to detect overall stepping progress. Once a timeout occurs, we assume the target is not making progress due to a potential deadlock, as mentioned above. We then send a new async interrupt, resume all threads, and `ThreadPlanSingleThreadTimeout` completes its task. To support this design, the major changes made in this PR are: 1. `ThreadPlanSingleThreadTimeout` is popped during every internal stop and reset (re-pushed) to the top of the stack (as a leaf node) during resume. This is achieved by always returning `true` from `ThreadPlanSingleThreadTimeout::DoPlanExplainsStop()` and `ThreadPlanSingleThreadTimeout::MischiefManaged()`. 2. A new thread-specific async interrupt stop is introduced, which can be detected/consumed by `ThreadPlanSingleThreadTimeout`. 3. The clearing of branch breakpoints in the range thread plan has been moved from `DoPlanExplainsStop()` to `ShouldStop()`, as it is not guaranteed that it will be called. The detailed design is discussed in the RFC below: [https://discourse.llvm.org/t/improve-single-thread-stepping/74599](https://discourse.llvm.org/t/improve-single-thread-stepping/74599) --------- Co-authored-by: jeffreytan81 <jeffreytan@fb.com>
5 lines
70 B
Makefile
5 lines
70 B
Makefile
ENABLE_THREADS := YES
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CXX_SOURCES := main.cpp
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include Makefile.rules
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