Refresh cache before reading contents of bundle

packages/core/core/src/requests/WriteBundleRequest.js

@@ -47,6 +47,7 @@ type WriteBundleRequestInput = {|
   bundle: Bundle,
   info: BundleInfo,
   hashRefToNameHash: Map<string, string>,
+  shouldResetReadCtx: boolean,
 |};
 
 type RunInput<TResult> = {|
@@ -129,6 +130,16 @@ async function run({input, options, api}) {
   if (info.isLargeBlob) {
     contentStream = options.cache.getStream(cacheKeys.content);
   } else {
+    // Force a refresh of the cache to avoid a race condition
+    // between threaded reads and writes that can result in an LMDB cache miss:
+    //   1. Thread A has read some value from cache, necessitating a read transaction.
+    //   2. Concurrently, Thread B finishes a packaging request.
+    //   3. Subsequently, Thread A is tasked with this request, but fails because the read transaction is stale.
+    // This only occurs if the reading thread has a transaction that was created before the writing thread committed,
+    // and the transaction is still live when the reading thread attempts to get the written value.
+    // See https://github.com/parcel-bundler/parcel/issues/9121
+    options.cache.refresh();
+
     contentStream = blobToStream(
       await options.cache.getBlob(cacheKeys.content),
     );