Release mutex when facing AbandonedMutexException (PowerShell#2867)

Author: daxian-dbw

PSReadLine/History.cs

@@ -313,15 +313,24 @@ private bool WithHistoryFileMutexDo(int timeout, Action action)
  _historyFileMutex.ReleaseMutex();
  }
  }
+
+ // Consider it a failure if we timed out on the mutex.
+ return false;
  }
  catch (AbandonedMutexException)
  {
  retryCount += 1;
+
+ // We acquired the mutex object that was abandoned by another powershell process.
+ // Now, since we own it, we must release it before retry, otherwise, we will miss
+ // a release and keep holding the mutex, in which case the 'WaitOne' calls from
+ // all other powershell processes will time out.
+ _historyFileMutex.ReleaseMutex();
  }
  } while (retryCount > 0 && retryCount < 3);
 
- // No errors to report, so consider it a success even if we timed out on the mutex.
- return true;
+ // If we reach here, that means we've done the retries but always got the 'AbandonedMutexException'.
+ return false;
  }
 
  private void WriteHistoryRange(int start, int end, bool overwritten)
@@ -427,18 +436,16 @@ private bool MaybeReadHistoryFile()
 
  private void ReadHistoryFile()
  {
- WithHistoryFileMutexDo(1000, () =>
+ if (File.Exists(Options.HistorySavePath))
  {
- if (!File.Exists(Options.HistorySavePath))
+ WithHistoryFileMutexDo(1000, () =>
  {
- return;
- }
-
- var historyLines = File.ReadAllLines(Options.HistorySavePath);
- UpdateHistoryFromFile(historyLines, fromDifferentSession: false, fromInitialRead: true);
- var fileInfo = new FileInfo(Options.HistorySavePath);
- _historyFileLastSavedSize = fileInfo.Length;
- });
+ var historyLines = File.ReadAllLines(Options.HistorySavePath);
+ UpdateHistoryFromFile(historyLines, fromDifferentSession: false, fromInitialRead: true);
+ var fileInfo = new FileInfo(Options.HistorySavePath);
+ _historyFileLastSavedSize = fileInfo.Length;
+ });
+ }
  }
 
  void UpdateHistoryFromFile(IEnumerable<string> historyLines, bool fromDifferentSession, bool fromInitialRead)