Function acquireProcessLock

packages/server/src/process-lock.ts:90–164

(opts: {
  lockName: LockName;
  lockDir: string;
  metadata: {
    port: number;
    worktreeRoot: string;
    kind?: LockKind;
    parentPid?: number;
    capabilities?: string[];
    protocolVersion?: number;
    runtimeVersion?: string;
  };
})

}

export function acquireProcessLock(opts: {
  lockName: LockName;
  lockDir: string;
  metadata: {
    port: number;
    worktreeRoot: string;
    kind?: LockKind;
    parentPid?: number;
    capabilities?: string[];
    protocolVersion?: number;
    runtimeVersion?: string;
  };
}): ProcessLockHandle {
  const { lockName, lockDir, metadata: init } = opts;
  const logPrefix = `[${lockName}-lock]`;

  mkdirSync(lockDir, { recursive: true });
  const lockPath = lockFilePath(lockDir, lockName);

  const record: ProcessLockMetadata = {
    pid: process.pid,
    hostname: hostname(),
    port: init.port,
    startedAt: new Date().toISOString(),
    worktreeRoot: init.worktreeRoot,
    ...(init.kind !== undefined && { kind: init.kind }),
    ...(init.parentPid !== undefined && { parentPid: init.parentPid }),
    ...(init.capabilities !== undefined && { capabilities: init.capabilities }),
    protocolVersion: init.protocolVersion ?? PROTOCOL_VERSION,
    runtimeVersion: init.runtimeVersion ?? RUNTIME_VERSION,
  };
  const payload = JSON.stringify(record, null, 2);

  const MAX_ATTEMPTS = 3;
  for (let attempt = 0; attempt < MAX_ATTEMPTS; attempt++) {
    if (!existsSync(lockPath)) {
      try {
        const fd = openSync(lockPath, 'wx', 0o600);
        try {
          writeSync(fd, payload);
        } finally {
          closeSync(fd);
        }
        bumpActiveLockRef(lockPath);
        return buildHandle({ lockName, lockDir, lockPath });
      } catch (err) {
        if ((err as NodeJS.ErrnoException).code !== 'EEXIST') throw err;
      }
    }

    const existing = parseLock(lockPath, logPrefix);
    if (existing) {
      const sameHost = existing.hostname === hostname();
      if (sameHost && existing.pid === process.pid) {
        writeFileSync(lockPath, payload, { encoding: 'utf-8', mode: 0o600 });
        bumpActiveLockRef(lockPath);
        return buildHandle({ lockName, lockDir, lockPath });
      }