From 76ddb43454d12be81d31c1fae9bf10a90379c2f9 Mon Sep 17 00:00:00 2001
From: Konstantin Shcheglov <scheglov@google.com>
Date: Wed, 17 Nov 2021 23:26:21 +0000
Subject: [PATCH] Try to work around invalidation exceptions.

We have a spike in exceptions internally, and I suspect that it was
caused by https://dart-review.googlesource.com/c/sdk/+/219942

But I was unable to understand why it happens.
So, this workaround is the best I can think of now.

Change-Id: I714eb6666706aad457b72e066978aa2d734fb89f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/220640
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
---
 .../lib/src/dart/analysis/driver.dart         |  5 +++++
 .../lib/src/dart/analysis/file_state.dart     | 19 +++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/pkg/analyzer/lib/src/dart/analysis/driver.dart b/pkg/analyzer/lib/src/dart/analysis/driver.dart
index 98ff8fb7caa..686137d2638 100644
--- a/pkg/analyzer/lib/src/dart/analysis/driver.dart
+++ b/pkg/analyzer/lib/src/dart/analysis/driver.dart
@@ -1783,6 +1783,11 @@ class AnalysisDriver implements AnalysisDriverGeneric {
   void _removePotentiallyAffectedLibraries(String path) {
     var affected = <FileState>{};
     _fsState.collectAffected(path, affected);
+
+    for (var file in affected) {
+      file.invalidateLibraryCycle();
+    }
+
     _libraryContext?.elementFactory.removeLibraries(
       affected.map((e) => e.uriStr).toSet(),
     );
diff --git a/pkg/analyzer/lib/src/dart/analysis/file_state.dart b/pkg/analyzer/lib/src/dart/analysis/file_state.dart
index 433d6e37ffd..a275ba243fb 100644
--- a/pkg/analyzer/lib/src/dart/analysis/file_state.dart
+++ b/pkg/analyzer/lib/src/dart/analysis/file_state.dart
@@ -352,6 +352,11 @@ class FileState {
     _libraryCycle = cycle;
   }
 
+  void invalidateLibraryCycle() {
+    _libraryCycle?.invalidate();
+    _libraryCycle = null;
+  }
+
   /// Return a new parsed unresolved [CompilationUnit].
   CompilationUnitImpl parse([AnalysisErrorListener? errorListener]) {
     errorListener ??= AnalysisErrorListener.NULL_LISTENER;
@@ -765,6 +770,20 @@ class FileSystemState {
   /// Collected files that transitively reference a file with the [path].
   /// These files are potentially affected by the change.
   void collectAffected(String path, Set<FileState> affected) {
+    // TODO(scheglov) This should not be necessary.
+    // We use affected files to remove library elements, and we can only get
+    // these library elements when we link or load them, using library cycles.
+    // And we get library cycles by asking `directReferencedFiles`.
+    while (true) {
+      final knownFiles = this.knownFiles.toList();
+      for (var file in knownFiles.toList()) {
+        file.directReferencedFiles;
+      }
+      if (this.knownFiles.length == knownFiles.length) {
+        break;
+      }
+    }
+
     collectAffected(FileState file) {
       if (affected.add(file)) {
         for (var other in file.referencingFiles) {