src: add debug check for inspector uv_async_t - #25777
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Add a check to make sure start_io_thread_async is not accidentally re-used or used when uninitialized. (This is a bit of an odd check imo, but it helped me figure out a real issue and it might do so again, so… why not?)
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Add a check to make sure start_io_thread_async is not accidentally re-used or used when uninitialized. (This is a bit of an odd check imo, but it helped me figure out a real issue and it might do so again, so… why not?) PR-URL: #25777 Reviewed-By: Eugene Ostroukhov <eostroukhov@google.com> Reviewed-By: Minwoo Jung <minwoo@nodesource.com> Reviewed-By: James M Snell <jasnell@gmail.com>
addaleax
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Add a check to make sure start_io_thread_async is not accidentally re-used or used when uninitialized. (This is a bit of an odd check imo, but it helped me figure out a real issue and it might do so again, so… why not?) PR-URL: #25777 Reviewed-By: Eugene Ostroukhov <eostroukhov@google.com> Reviewed-By: Minwoo Jung <minwoo@nodesource.com> Reviewed-By: James M Snell <jasnell@gmail.com>
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Two Environments with default flags alive at the same time (for example the embedding.md example run on two threads, or two `CommonEnvironmentSetup`s) aborted the process: `Agent::Start()` bound one file-level static `uv_async_t` to the current Environment's loop for every Environment with `kOwnsInspector`, which `kDefaultFlags` implies, and CHECKed that nobody else had. Environments created one after another did not abort, but each ran `StartDebugSignalHandler()` again, which re-initialized the semaphore the watchdog waits on and spawned another detached watchdog thread, leaking one thread per Environment. Give every Agent that asks for the debug signal handler its own async handle, keep those Agents in a mutex-protected list that the watchdog (or the Windows remote thread) walks, and set the watchdog up once per process while still unblocking SIGUSR1 on each Environment's thread. The handle is heap-allocated, closed by the cleanup hook or `~Agent()`, whichever runs first, and freed by its close callback. A SIGUSR1 now reaches every Environment that asked for the handler, and no longer starts the inspector of one that passed `kNoStartDebugSignalHandler`. Refs: nodejs#25777 Signed-off-by: Shelley Vohr <shelley.vohr@gmail.com>
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Two Environments with default flags alive at the same time (for example the embedding.md example run on two threads, or two `CommonEnvironmentSetup`s) aborted the process: `Agent::Start()` bound one file-level static `uv_async_t` to the current Environment's loop for every Environment with `kOwnsInspector`, which `kDefaultFlags` implies, and CHECKed that nobody else had. Environments created one after another did not abort, but each ran `StartDebugSignalHandler()` again, which re-initialized the semaphore the watchdog waits on and spawned another detached watchdog thread, leaking one thread per Environment. Give every Agent that asks for the debug signal handler its own async handle, keep those Agents in a mutex-protected list that the watchdog (or the Windows remote thread) walks, and set the watchdog up once per process while still unblocking SIGUSR1 on each Environment's thread. The handle is heap-allocated, closed by the cleanup hook or `~Agent()`, whichever runs first, and freed by its close callback. A SIGUSR1 now reaches every Environment that asked for the handler, and no longer starts the inspector of one that passed `kNoStartDebugSignalHandler`. Refs: nodejs#25777 Signed-off-by: Shelley Vohr <shelley.vohr@gmail.com>
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Add a check to make sure start_io_thread_async is not
accidentally re-used or used when uninitialized.
(This is a bit of an odd check imo, but it helped me figure
out a real issue and it might do so again, so… why not?)
Checklist
make -j4 test(UNIX), orvcbuild test(Windows) passes