Method onChildExit

src/workspaces/persistent-session.ts:171–212

* Child process exited but the session itself is sticking around. We tell * the client (lifecycle child-exit), then schedule a respawn after a short * debounce — unless the child has been crashing too often, in which case * we open the circuit breaker and dispose for real.

(
    exited: pty.IPty,
    exitCode: number,
    signalRaw: number | undefined,
  )

   * we open the circuit breaker and dispose for real.
   */
  private onChildExit(
    exited: pty.IPty,
    exitCode: number,
    signalRaw: number | undefined,
  ): void {
    if (this.disposed) return;
    // Ignore exits from an already-replaced term (paranoia).
    if (exited !== this.term) return;
    const signal = typeof signalRaw === 'number' ? signalRaw : null;
    this.log.info('session.child_exit', {
      pid: exited.pid,
      code: exitCode,
      signal,
    });
    if (this.firstExit === null) {
      this.firstExit = { code: exitCode, signal };
      for (const w of this.exitWaiters) w(this.firstExit);
      this.exitWaiters.clear();
    }
    this.sendControl({
      type: 'lifecycle',
      kind: 'child-exit',
      code: exitCode,
      signal,
    });

    const now = Date.now();
    this.respawnTimes = this.respawnTimes.filter((t) => now - t < RESPAWN_WINDOW_MS);
    this.respawnTimes.push(now);
    if (this.respawnTimes.length > RESPAWN_WINDOW_LIMIT) {
      this.log.warn('session.respawn_circuit_open', {
        recentCrashes: this.respawnTimes.length,
      });
      this.sendControl({ type: 'exit', code: exitCode, signal });
      this.dispose('respawn circuit open');
      return;
    }

    if (this.respawnTimer) clearTimeout(this.respawnTimer);
    this.respawnTimer = setTimeout(() => this.respawnNow(), RESPAWN_DEBOUNCE_MS);
    this.respawnTimer.unref();
  }

  private respawnNow(): void {
    this.respawnTimer = null;