Method maybeStartPool

src/mcp/engine.ts:80–96

* Start the worker-thread query pool once a default project is open (daemon * mode only; honors `CODEGRAPH_QUERY_POOL_SIZE`). Idempotent and best-effort: * if workers can't spawn on this platform the ToolHandler keeps serving reads * in-process, so the pool can only help, never break, tool

(root: string)

   * in-process, so the pool can only help, never break, tool calls.
   */
  private maybeStartPool(root: string): void {
    if (!this.opts.queryPool || this.queryPool || this.closed) return;
    const size = resolvePoolSize(process.env.CODEGRAPH_QUERY_POOL_SIZE, os.cpus().length);
    if (size <= 0) {
      process.stderr.write('[CodeGraph MCP] Query pool disabled (CODEGRAPH_QUERY_POOL_SIZE=0); serving reads in-process.\n');
      return;
    }
    try {
      this.queryPool = new QueryPool({ root, size });
      this.toolHandler.setQueryPool(this.queryPool);
      process.stderr.write(`[CodeGraph MCP] Query pool: up to ${size} worker thread(s) for concurrent reads.\n`);
    } catch (err) {
      const msg = err instanceof Error ? err.message : String(err);
      process.stderr.write(`[CodeGraph MCP] Query pool unavailable (${msg}); serving reads in-process.\n`);
      this.queryPool = null;
    }
  }

  /**
   * Convenience for {@link MCPServer} compatibility: pre-seed an explicit