fix: race condition in fast tx collection

yarn-project/p2p/src/client/test/p2p_client.integration_batch_txs.test.ts

@@ -22,7 +22,7 @@ import { BatchTxRequester } from '../../services/reqresp/batch-tx-requester/batc
 import type { BatchTxRequesterLibP2PService } from '../../services/reqresp/batch-tx-requester/interface.js';
 import type { IBatchRequestTxValidator } from '../../services/reqresp/batch-tx-requester/tx_validator.js';
 import type { ConnectionSampler } from '../../services/reqresp/connection-sampler/connection_sampler.js';
-import { MissingTxsTracker } from '../../services/tx_collection/missing_txs_tracker.js';
+import { RequestTracker } from '../../services/tx_collection/request_tracker.js';
 import { generatePeerIdPrivateKeys } from '../../test-helpers/generate-peer-id-private-keys.js';
 import { getPorts } from '../../test-helpers/get-ports.js';
 import { makeEnrs } from '../../test-helpers/make-enrs.js';
@@ -231,10 +231,9 @@ describe('p2p client integration batch txs', () => {
     mockP2PService.reqResp = (client0 as any).p2pService.reqresp;
 
     const requester = new BatchTxRequester(
-      MissingTxsTracker.fromArray(missingTxHashes),
+      RequestTracker.create(missingTxHashes, new Date(Date.now() + 5_000)),
       blockProposal,
       undefined, // no pinned peer
-      5_000,
       mockP2PService,
       logger,
       undefined,

yarn-project/p2p/src/client/test/tx_proposal_collector/proposal_tx_collector_worker.ts

@@ -19,7 +19,7 @@ import type { P2PConfig } from '../../../config.js';
 import { BatchTxRequesterCollector, SendBatchRequestCollector } from '../../../services/index.js';
 import type { IBatchRequestTxValidator } from '../../../services/reqresp/batch-tx-requester/tx_validator.js';
 import { RateLimitStatus } from '../../../services/reqresp/rate-limiter/rate_limiter.js';
-import { MissingTxsTracker } from '../../../services/tx_collection/missing_txs_tracker.js';
+import { RequestTracker } from '../../../services/tx_collection/request_tracker.js';
 import {
   AlwaysTrueCircuitVerifier,
   BENCHMARK_CONSTANTS,
@@ -213,10 +213,9 @@ async function runCollector(cmd: Extract<WorkerCommand, { type: 'RUN_COLLECTOR'
       const fetched = await executeTimeout(
         (_signal: AbortSignal) =>
           collector.collectTxs(
-            MissingTxsTracker.fromArray(parsedTxHashes),
+            RequestTracker.create(parsedTxHashes, new Date(Date.now() + internalTimeoutMs)),
             parsedProposal,
             pinnedPeer,
-            internalTimeoutMs,
           ),
         timeoutMs,
         () => new Error(`Collector timed out after ${timeoutMs}ms`),
@@ -231,10 +230,9 @@ async function runCollector(cmd: Extract<WorkerCommand, { type: 'RUN_COLLECTOR'
       const fetched = await executeTimeout(
         (_signal: AbortSignal) =>
           collector.collectTxs(
-            MissingTxsTracker.fromArray(parsedTxHashes),
+            RequestTracker.create(parsedTxHashes, new Date(Date.now() + internalTimeoutMs)),
             parsedProposal,
             pinnedPeer,
-            internalTimeoutMs,
           ),
         timeoutMs,
         () => new Error(`Collector timed out after ${timeoutMs}ms`),

yarn-project/p2p/src/services/reqresp/batch-tx-requester/README.md

@@ -170,6 +170,37 @@ class BlockTxsResponse {
 
 The `BitVector` is a compact representation where each bit corresponds to a transaction index in the block proposal. This allows efficient capability advertisement without repeating full hashes.
 
+## Cancellation
+
+All cancellation is managed by a single `RequestTracker` instance, shared across the entire collection
+flow. The `RequestTracker` owns the deadline, tracks which txs are still missing, and exposes a
+`cancellationToken` promise that resolves when the request should stop (deadline hit, all txs fetched,
+or external `cancel()` call).
+
+Cancellation propagates from the deepest stack level upward:
+
+```
+RequestTracker.finish()
+  ├── resolves cancellationToken promise
+  │
+  ├── BatchTxRequester workers (deepest)
+  │     ├── shouldStop() checks requestTracker.cancelled → exit loop
+  │     ├── sleepClampedToDeadline races sleep vs cancellationToken → wakes
+  │     └── semaphore.acquire races vs cancellationToken → wakes
+  │           │
+  │           ▼ workers settle → txQueue.end() → generator returns
+  │
+  ├── Node collection loops
+  │     ├── notFinished() checks requestTracker.cancelled → exit loop
+  │     └── inter-retry sleep races vs cancellationToken → wakes
+  │           │
+  │           ▼ all node loops settle
+  │
+  └── collectFast (outermost)
+        awaits Promise.allSettled([reqresp, nodes]) → settles after inner tasks
+        finally: requestTracker.cancel() (idempotent), cleanup
+```
+
 ## Key Files
 
 | File | Description |
@@ -179,15 +210,16 @@ The `BitVector` is a compact representation where each bit corresponds to a tran
 | `peer_collection.ts` | Manages peer classification (dumb/smart/bad) and rate limiting |
 | `interface.ts` | Type definitions for dependencies |
 | `../protocols/block_txs/` | Wire protocol definitions (`BlockTxsRequest`, `BlockTxsResponse`, `BitVector`) |
+| `../../tx_collection/request_tracker.ts` | Centralized deadline, missing tx tracking, and cancellation signal |
 
 ## Stopping Conditions
 
-The `BatchTxRequester` stops when any of these conditions are met:
+The `BatchTxRequester` stops when any of these conditions are met, all managed by the `RequestTracker`:
 
-1. **All transactions fetched** - Success!
-2. **Deadline exceeded** - Timeout configured by caller
-3. **Abort signal** - External cancellation
-4. **No transactions to fetch** - Nothing was missing
+1. **All transactions fetched** - `markFetched()` removes the last missing tx, triggering `finish()`
+2. **Deadline exceeded** - `setTimeout` in `RequestTracker` fires, triggering `finish()`
+3. **External cancellation** - `RequestTracker.cancel()` called (e.g., from `stop()`, `stopCollectingForBlocksUpTo`)
+4. **No transactions to fetch** - Empty hash set at construction, `RequestTracker` finishes immediately
 
 ## Configuration
 
@@ -228,11 +260,15 @@ Request to peer fails
 ## Usage Example
 
 ```typescript
+const requestTracker = RequestTracker.create(
+  missingTxHashes,                          // TxHash[] - what we need
+  new Date(Date.now() + 5_000),             // deadline
+);
+
 const requester = new BatchTxRequester(
-  missingTxHashes,      // TxHash[] - what we need
+  requestTracker,       // IRequestTracker - tracks missing txs, deadline, and cancellation
   blockTxsSource,       // BlockTxsSource - the proposal or block we need txs for
   pinnedPeer,           // PeerId | undefined - peer expected to have the txs
-  timeoutMs,            // number - how long to try
   p2pService,           // BatchTxRequesterLibP2PService
 );
 
@@ -273,6 +309,8 @@ const txs = await BatchTxRequester.collectAllTxs(requester.run());
 │  1. Try RPC nodes first (fast)    │   │  Periodic polling of RPC nodes      │
 │  2. Fall back to BatchTxRequester │   │  and peers for missing txs          │
 │                                   │   │                                     │
+│  Creates RequestTracker per       │   │                                     │
+│  request with deadline            │   │                                     │
 └───────────────────┬───────────────┘   └─────────────────────────────────────┘
                     │
                     │ For 'proposal' and 'block' requests
@@ -281,6 +319,7 @@ const txs = await BatchTxRequester.collectAllTxs(requester.run());
 │                           BatchTxRequester                                  │
 │                                                                             │
 │  Aggressive parallel fetching from multiple peers                           │
+│  Shares RequestTracker with FastTxCollection for unified cancellation       │
 │  Uses BLOCK_TXS sub-protocol for efficient batching                         │
 └───────────────────┬─────────────────────────────────────────────────────────┘
                     │