fix nightly build (#3049)

Author: msyyc

.chronus/changes/fix-nightly-2025-2-3-17-27-31.md

@@ -0,0 +1,7 @@
+---
+changeKind: internal
+packages:
+  - "@azure-tools/typespec-python"
+---
+
+add task pool for regeneration

packages/typespec-python/scripts/eng/regenerate.ts

@@ -281,6 +281,20 @@ function _getCmdList(spec: string, flags: RegenerateFlags): TspCommand[] {
     });
 }
 
+async function runTaskPool(tasks: Array<() => Promise<void>>, poolLimit: number): Promise<void> {
+    let currentIndex = 0;
+
+    async function worker() {
+        while (currentIndex < tasks.length) {
+            const index = currentIndex++;
+            await tasks[index]();
+        }
+    }
+
+    const workers = new Array(Math.min(poolLimit, tasks.length)).fill(null).map(() => worker());
+    await Promise.all(workers);
+}
+
 async function regenerate(flags: RegenerateFlagsInput): Promise<void> {
     if (flags.flavor === undefined) {
         await regenerate({ ...flags, flavor: "azure" });
@@ -296,8 +310,14 @@ async function regenerate(flags: RegenerateFlagsInput): Promise<void> {
         const cmdList: TspCommand[] = subdirectories.flatMap((subdirectory) =>
             _getCmdList(subdirectory, flagsResolved),
         );
-        const PromiseCommands = cmdList.map((tspCommand) => executeCommand(tspCommand));
-        await Promise.all(PromiseCommands);
+
+        // Create tasks as functions for the pool
+        const tasks: Array<() => Promise<void>> = cmdList.map((tspCommand) => {
+            return () => executeCommand(tspCommand);
+        });
+
+        // Run tasks with a concurrency limit
+        await runTaskPool(tasks, 30);
     }
 }
 
@@ -319,6 +339,7 @@ const argv = yargs(hideBin(process.argv))
         description: "Specify filename if you only want to generate a subset",
     }).argv;
 
+const start = performance.now();
 regenerate(argv as RegenerateFlags)
-    .then(() => console.log("Regeneration successful"))
+    .then(() => console.log(`Regeneration successful, time taken: ${Math.round((performance.now() - start) / 1000)} s`))
     .catch((error) => console.error(`Regeneration failed: ${error.message}`));