Bug 637286 - Eliminate deadlocks in ReleaseZip, r=taras

modules/libjar/nsJAR.cpp

@@ -171,6 +171,7 @@ nsJAR::Open(nsIFile* zipFile)
   if (mLock) return NS_ERROR_FAILURE; // Already open!
 
   mZipFile = zipFile;
+  mOuterZipEntry.Truncate();
 
   mLock = nsAutoLock::NewLock("nsJAR::mLock");
   NS_ENSURE_TRUE(mLock, NS_ERROR_OUT_OF_MEMORY);
@@ -237,7 +238,6 @@ nsJAR::Close()
   mManifestData.Reset();
   mGlobalStatus = JAR_MANIFEST_NOT_PARSED;
   mTotalItemsInManifest = 0;
-  mOuterZipEntry.Truncate(0);
 
 #ifdef MOZ_OMNIJAR
   if (mZip == mozilla::OmnijarReader()) {
@@ -1290,31 +1290,28 @@ nsZipReaderCache::ReleaseZip(nsJAR* zip)
     mZipCacheFlushes++;
 #endif
 
-  // Clear the cache pointer in case we gave out this oldest guy while
-  // his Release call was being made. Otherwise we could nest on ReleaseZip
-  // when the second owner calls Release and we are still here in this lock.
-  oldest->SetZipReaderCache(nsnull);
-
   // remove from hashtable
   nsCAutoString uri;
   rv = oldest->GetJarPath(uri);
   if (NS_FAILED(rv))
     return rv;
 
-  if (zip->mOuterZipEntry.IsEmpty()) {
+  if (oldest->mOuterZipEntry.IsEmpty()) {
     uri.Insert(NS_LITERAL_CSTRING("file:"), 0);
   } else {
     uri.Insert(NS_LITERAL_CSTRING("jar:"), 0);
     uri.AppendLiteral("!/");
-    uri.Append(zip->mOuterZipEntry);
+    uri.Append(oldest->mOuterZipEntry);
   }
 
   nsCStringKey key(uri);
-#ifdef DEBUG
+  nsRefPtr<nsJAR> removed;
-  PRBool removed =
+  mZips.Remove(&key, (nsISupports **)removed.StartAssignment());
-#endif
-    mZips.Remove(&key);   // Releases
   NS_ASSERTION(removed, "botched");
+  NS_ASSERTION(oldest == removed, "removed wrong entry");
+
+  if (removed)
+    removed->SetZipReaderCache(nsnull);
 
   return NS_OK;
 }

modules/libjar/test/unit/test_bug637286.js

@@ -0,0 +1,60 @@
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is mozilla.org code.
+ *
+ * The Initial Developer of the Original Code is
+ * Mozilla Foundation.
+ * Portions created by the Initial Developer are Copyright (C) 2011
+ * the Initial Developer. All Rights Reserved.
+ * 
+ * Contributor(s):
+ *  Michael Wu <mwu@mozilla.com>
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+
+// Check that the zip cache can expire entries from nested jars
+var ios = Cc["@mozilla.org/network/io-service;1"].
+          getService(Ci.nsIIOService);
+
+function open_inner_zip(base, idx) {
+    var spec = "jar:" + base + "inner" + idx + ".zip!/foo";
+    var channel = ios.newChannel(spec, null, null);
+    var stream = channel.open();
+}
+
+function run_test() {
+  var file = do_get_file("data/test_bug637286.zip");
+  var outerJarBase = "jar:" + ios.newFileURI(file).spec + "!/";
+
+  for (var i = 0; i < 40; i++) {
+    open_inner_zip(outerJarBase, i);
+    gc();
+  }
+}
+