`forkpty` calls `fork()` underneath. `fork()` in a multithreaded process is unsafe: only the calling thread survives in the child, but libc locks held by other threads remain "locked forever." With the multi-threaded Dart VM as parent, ~5% of spawns deadlocked in the child before `execve` (forensic probe: child stuck in S state with comm=`DartWorker`, master fd never sees POLLIN). `posix_spawn` uses `vfork` on glibc/musl/macOS, keeping the parent suspended until execve completes — no Dart code runs in the child. Pty pair built via the POSIX-standard `posix_openpt` / `grantpt` / `unlockpt` / `ptsname` sequence. Probed: zero hangs in 300 sequential spawns vs ~5% before. Behavior change: missing executable / missing workingDirectory now surface as a `PtyException` thrown by `NativePty.start` rather than a diagnostic written from the child to the slave PTY. Cleaner error path for callers. Side benefit: drops the `libutil.so.1` dynamic-library dependency. PTY now resolves entirely against libc via `DynamicLibrary.process()`. Splits the library-level `@Tags(['forkpty'])` on session_test.dart into a per-test tag, so the now-runnable-under-flutter-test cases contribute to coverage. `dart_test.yaml` declares the tag so the exclude-tags filters honor it. Drops the `retry: 2` workaround from the formerly-flaky registry test. D-5 amended. Trims session-introduced CHANGELOG entries that were over-verbose for the Keep-a-Changelog format. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
11 lines
537 B
YAML
11 lines
537 B
YAML
# Declares tags used by inline `test('...', tags: [...], ...)` calls so
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# that `flutter test --exclude-tags <name>` and `dart test --tags <name>`
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# both honor them. Undeclared tags are ignored by the runners, which
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# silently breaks selective excludes.
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tags:
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# Tests that call `forkpty()` via Dart FFI. Must run under `dart test`,
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# not `flutter test` — the latter's runner hosts a multi-threaded
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# Flutter engine in which forkpty produces a master fd that never
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# delivers output. See `test/pty/session_test.dart`.
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forkpty:
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