Fixing bug 318001 - Fatal hang on downloads to the desktop with Quicksilver running, implement kqueue notifications. r=smorgan, sr=mento. Camino head only.

2007-02-17 02:41:38 +00:00 · 2007-02-17 02:41:38 +00:00 · 567abc1c9e
--- a/camino/Camino.xcode/project.pbxproj
+++ b/camino/Camino.xcode/project.pbxproj
@ -4122,6 +4122,7 @@
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 				DEE9EBA50AF5C379002BC511,
 				DEB968190B0D8E0B0023F8B1,
+				DEE34A550B84F5C600BCD687,
 			);
 			isa = PBXHeadersBuildPhase;
 			runOnlyForDeploymentPostprocessing = 0;
@ -5253,6 +5254,7 @@
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 				DEE9EBA80AF5C390002BC511,
 				DEB968160B0D8DF70023F8B1,
+				DEE34A580B84F5E100BCD687,
 			);
 			isa = PBXSourcesBuildPhase;
 			runOnlyForDeploymentPostprocessing = 0;
@ -8013,6 +8015,7 @@
 				DE74F74F0AB25EBC00FD1D5B,
 				DEE9EBA40AF5C379002BC511,
 				DEB968180B0D8E0B0023F8B1,
+				DEE34A540B84F5C600BCD687,
 			);
 			isa = PBXHeadersBuildPhase;
 			runOnlyForDeploymentPostprocessing = 0;
@ -9145,6 +9148,7 @@
 				DE74F7560AB25EDA00FD1D5B,
 				DEE9EBA70AF5C390002BC511,
 				DEB968150B0D8DF70023F8B1,
+				DEE34A570B84F5E100BCD687,
 			);
 			isa = PBXSourcesBuildPhase;
 			runOnlyForDeploymentPostprocessing = 0;
@ -14191,6 +14195,50 @@
 			settings = {
 			};
 		};
+		DEE34A530B84F5C600BCD687 = {
+			fileEncoding = 30;
+			isa = PBXFileReference;
+			lastKnownFileType = sourcecode.c.h;
+			name = FileChangeWatcher.h;
+			path = src/download/FileChangeWatcher.h;
+			refType = 2;
+			sourceTree = SOURCE_ROOT;
+		};
+		DEE34A540B84F5C600BCD687 = {
+			fileRef = DEE34A530B84F5C600BCD687;
+			isa = PBXBuildFile;
+			settings = {
+			};
+		};
+		DEE34A550B84F5C600BCD687 = {
+			fileRef = DEE34A530B84F5C600BCD687;
+			isa = PBXBuildFile;
+			settings = {
+			};
+		};
+		DEE34A560B84F5E100BCD687 = {
+			fileEncoding = 30;
+			isa = PBXFileReference;
+			lastKnownFileType = sourcecode.c.objc;
+			name = FileChangeWatcher.m;
+			path = src/download/FileChangeWatcher.m;
+			refType = 2;
+			sourceTree = SOURCE_ROOT;
+		};
+		DEE34A570B84F5E100BCD687 = {
+			fileRef = DEE34A560B84F5E100BCD687;
+			isa = PBXBuildFile;
+			settings = {
+				COMPILER_FLAGS = "-fobjc-exceptions";
+			};
+		};
+		DEE34A580B84F5E100BCD687 = {
+			fileRef = DEE34A560B84F5E100BCD687;
+			isa = PBXBuildFile;
+			settings = {
+				COMPILER_FLAGS = "-fobjc-exceptions";
+			};
+		};
 		DEE9EBA30AF5C379002BC511 = {
 			fileEncoding = 30;
 			isa = PBXFileReference;
@ -14975,6 +15023,7 @@
 				F517395B020CE3740189DA0C,
 				3FC0FB7F05A0D2DC002F47DE,
 				3FC0FB8005A0D2DC002F47DE,
+				DEE34A560B84F5E100BCD687,
 			);
 			isa = PBXGroup;
 			name = Camino;
@ -15340,6 +15389,7 @@
 				F566BD1202EFA9AD01A967F3,
 				F59E9F3D0237E28401A967DF,
 				DE74F74D0AB25EBC00FD1D5B,
+				DEE34A530B84F5C600BCD687,
 				F5137A1102676B9101026D05,
 				F528E218020FD8400168DE43,
 				F5607CB5023944AD01A967DF,
--- a/camino/src/download/FileChangeWatcher.h
+++ b/camino/src/download/FileChangeWatcher.h
@ -0,0 +1,90 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* ***** 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
+* Nick Kreeger
+* Portions created by the Initial Developer are Copyright (C) 2006
+* the Initial Developer. All Rights Reserved.
+*
+* Contributor(s):
+*   Nick Kreeger <nick.kreeger@park.edu>
+*
+* 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 ***** */
+
+#import <AppKit/AppKit.h>
+
+//
+// Any object that needs a file to be polled can implement this protocol and 
+// register itself with the watch queue.
+//
+@protocol WatchedFileDelegate
+
+//
+// This method will need to return the full path of the file/folder 
+// that is being watched.
+//
+-(const char*)representedFilePath;
+
+//
+// This method gets called when the watcher recieves news that the
+// watched path has changed.
+// Note: This method will be called on a background thread.
+//
+-(void)fileDidChange;
+
+@end
+
+
+//
+// This class provides a file polling service to any object
+// that implements the |WatchedFileDelegate| protocol.
+//
+@interface FileChangeWatcher : NSObject
+{
+@private
+  NSMutableArray* mWatchedFileDelegates;     // strong ref
+  NSMutableArray* mWatchedFileDescriptors;   // strong ref
+  
+  int          mQueueFileDesc;
+  BOOL         mShouldRunThread;
+  BOOL         mThreadIsRunning;
+}
+
+//
+// Add an object implementing the |WatchedFileDelegate| to the 
+// watch queue. 
+// Note: An object will only be added once to the queue.
+//
+-(void)addWatchedFileDelegate:(id<WatchedFileDelegate>)aWatchedFileDelegate;
+
+//
+// Remove an object implementing the |WatchedFileDelegate| from the watch queue.
+//
+-(void)removeWatchedFileDelegate:(id<WatchedFileDelegate>)aWatchedFileDelegate;
+
+@end
--- a/camino/src/download/FileChangeWatcher.m
+++ b/camino/src/download/FileChangeWatcher.m
@ -0,0 +1,162 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* ***** 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
+* Nick Kreeger
+* Portions created by the Initial Developer are Copyright (C) 2006
+* the Initial Developer. All Rights Reserved.
+*
+* Contributor(s):
+*   Nick Kreeger <nick.kreeger@park.edu>
+*
+* 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 ***** */
+
+#import "FileChangeWatcher.h"
+#include <sys/types.h>
+#include <sys/event.h>
+#import "unistd.h"
+#import "fcntl.h"
+
+const int kSecondPollingInterval = 60;
+
+@interface FileChangeWatcher(Private)
+
+-(void)startPolling;
+-(void)stopPolling;
+-(void)pollWatchedDirectories;
+
+@end
+
+@implementation FileChangeWatcher
+
+-(id)init
+{
+  if ((self = [super init])) {
+    mWatchedFileDelegates = [[NSMutableArray alloc] init];
+    mWatchedFileDescriptors = [[NSMutableArray alloc] init];
+    mQueueFileDesc = kqueue();
+  }
+  
+  return self;
+}
+
+-(void)dealloc
+{
+  close(mQueueFileDesc);
+  [mWatchedFileDelegates release];
+  [mWatchedFileDescriptors release];
+  [super dealloc];
+}
+
+-(void)addWatchedFileDelegate:(id<WatchedFileDelegate>)aWatchedFileDelegate
+{  
+  if ([mWatchedFileDelegates containsObject:aWatchedFileDelegate])
+    return;
+  
+  int fileDesc = open([aWatchedFileDelegate representedFilePath], O_EVTONLY, 0);
+  if (fileDesc >= 0) {
+    struct timespec nullts = { 0, 0 };
+    struct kevent ev;
+    u_int fflags = NOTE_RENAME | NOTE_WRITE | NOTE_DELETE;
+    
+    EV_SET(&ev, fileDesc, EVFILT_VNODE, EV_ADD | EV_ENABLE | EV_CLEAR, fflags, 0, (void*)aWatchedFileDelegate);
+    
+    [mWatchedFileDelegates addObject:aWatchedFileDelegate];
+    [mWatchedFileDescriptors addObject:[NSNumber numberWithInt:fileDesc]];
+    kevent(mQueueFileDesc, &ev, 1, NULL, 0, &nullts);
+    if (!mShouldRunThread && [mWatchedFileDescriptors count] > 0)
+      [self startPolling];
+  }
+}
+
+-(void)removeWatchedFileDelegate:(id<WatchedFileDelegate>)aWatchedFileDelegate
+{
+  int index = [mWatchedFileDelegates indexOfObject:aWatchedFileDelegate];
+  if (index == NSNotFound)
+    return;
+  
+  int fileDesc = [[mWatchedFileDescriptors objectAtIndex:index] intValue];
+  [mWatchedFileDelegates removeObjectAtIndex:index];
+  [mWatchedFileDescriptors removeObjectAtIndex:index];
+  close(fileDesc);
+  
+  if (mShouldRunThread && [mWatchedFileDelegates count] == 0)
+    [self stopPolling];
+}
+
+-(void)startPolling
+{
+  @synchronized(self) {
+    mShouldRunThread = YES;
+    if (!mThreadIsRunning) {
+      mThreadIsRunning = YES;
+      [NSThread detachNewThreadSelector:@selector(pollWatchedDirectories) 
+                               toTarget:self 
+                             withObject:nil];
+    }
+  }
+}
+
+-(void)stopPolling
+{
+  @synchronized(self) {
+    mShouldRunThread = NO;
+  }
+}
+
+//
+// Portions of this method were originally written by M. Uli Kusterer.
+//
+-(void)pollWatchedDirectories
+{
+  const struct timespec timeInterval = { kSecondPollingInterval, 0 };
+
+  while (1) {
+    @synchronized(self) {
+      if (!mShouldRunThread) {
+        mThreadIsRunning = NO;
+        break;
+      }
+    }
+
+    NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
+    NS_DURING
+      struct kevent event;
+      int n = kevent(mQueueFileDesc, NULL, 0, &event, 1, &timeInterval);
+      if (n > 0 && event.filter == EVFILT_VNODE && event.fflags) {
+        [(id<WatchedFileDelegate>)event.udata fileDidChange];
+      }
+    NS_HANDLER
+      NSLog(@"Error in watcherThread: %@", localException);
+    NS_ENDHANDLER
+    
+    [pool release];
+  }
+}
+
+@end
--- a/camino/src/download/ProgressDlgController.h
+++ b/camino/src/download/ProgressDlgController.h
@ -23,6 +23,7 @@
 *   Simon Fraser <sfraser@netscape.com>
 *   Calum Robinson <calumr@mac.com>
 *   Josh Aas <josh@mozilla.com>
+ *   Nick Kreeger <nick.kreeger@park.edu>
 *
 * 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
@ -68,6 +69,7 @@

 #import "CHDownloadProgressDisplay.h"
 #import "ProgressViewController.h"
+#import "FileChangeWatcher.h"

 //
 // interface ProgressDlgController
@ -79,16 +81,18 @@

@interface ProgressDlgController : NSWindowController<CHDownloadDisplayFactory, CHStackViewDataSource>
 {
-  IBOutlet CHStackView  *mStackView;
-  IBOutlet NSScrollView *mScrollView;
+  IBOutlet CHStackView*  mStackView;
+  IBOutlet NSScrollView* mScrollView;
  
  NSSize                mDefaultWindowSize;
-  NSTimer               *mDownloadTimer;            // used for updating the status, STRONG ref
-  NSMutableArray        *mProgressViewControllers;  // the downloads we manage, STRONG ref
+  NSTimer*              mDownloadTimer;            // used for updating the status, STRONG ref
+  NSMutableArray*       mProgressViewControllers;  // the downloads we manage, STRONG ref
  int                   mNumActiveDownloads;
  int                   mSelectionPivotIndex;
  BOOL                  mShouldCloseWindow;         // true when a download completes when termination modal sheet is up
  BOOL                  mAwaitingTermination;       // true when we are waiting for users termination modal sheet
+  
+  FileChangeWatcher*    mFileChangeWatcher;         // strong ref.
 }

 +(ProgressDlgController *)sharedDownloadController;           // creates if necessary
@ -104,7 +108,7 @@

 -(int)numDownloadsInProgress;
 -(void)clearAllDownloads;
-(void)didStartDownload:(id <CHDownloadProgressDisplay>)progressDisplay;
+-(void)didStartDownload:(ProgressViewController*)progressDisplay;
 -(void)didEndDownload:(id <CHDownloadProgressDisplay>)progressDisplay withSuccess:(BOOL)completedOK statusCode:(nsresult)status;
 -(void)removeDownload:(id <CHDownloadProgressDisplay>)progressDisplay suppressRedraw:(BOOL)suppressRedraw;
 -(NSApplicationTerminateReply)allowTerminate;
@ -112,4 +116,7 @@
 -(void)saveProgressViewControllers;
 -(void)loadProgressViewControllers;

+-(void)addFileDelegateToWatchList:(id<WatchedFileDelegate>)aWatchedFileDelegate;
+-(void)removeFileDelegateFromWatchList:(id<WatchedFileDelegate>)aWatchedFileDelegate;
+
@end
--- a/camino/src/download/ProgressDlgController.mm
+++ b/camino/src/download/ProgressDlgController.mm
@ -142,6 +142,8 @@ static id gSharedProgressController = nil;
  [toolbar setAutosavesConfiguration:YES];
  [[self window] setToolbar:toolbar];    
  
+  mFileChangeWatcher = [[FileChangeWatcher alloc] init];
+  
  // load the saved instances to mProgressViewControllers array
  [self loadProgressViewControllers];
 }
@ -153,6 +155,7 @@ static id gSharedProgressController = nil;
    gSharedProgressController = nil;
  }
  [mProgressViewControllers release];
+  [mFileChangeWatcher release];
  [self killDownloadTimer];
  [super dealloc];
 }
@ -526,7 +529,7 @@ static id gSharedProgressController = nil;
  }
 }

-(void)didStartDownload:(id <CHDownloadProgressDisplay>)progressDisplay
+-(void)didStartDownload:(ProgressViewController*)progressDisplay
 {
  if (![[self window] isVisible]) {
    [self showWindow:nil]; // make sure the window is visible
@ -645,6 +648,7 @@ static id gSharedProgressController = nil;

 -(void)removeDownload:(id <CHDownloadProgressDisplay>)progressDisplay suppressRedraw:(BOOL)suppressRedraw
 {
+  [progressDisplay displayWillBeRemoved];
  [mProgressViewControllers removeObject:progressDisplay];
  
  if ([mProgressViewControllers count] == 0) {
@ -808,7 +812,8 @@ static id gSharedProgressController = nil;
    NSDictionary* downloadsDictionary;
    while((downloadsDictionary = [downloadsEnum nextObject]))
    {
-      ProgressViewController* curController = [[ProgressViewController alloc] initWithDictionary:downloadsDictionary];
+      ProgressViewController* curController = [[ProgressViewController alloc] initWithDictionary:downloadsDictionary
+                                                                             andWindowController:self];
      [mProgressViewControllers addObject:curController];
      [curController release];
    }
@ -817,6 +822,16 @@ static id gSharedProgressController = nil;
  }
 }

+-(void)addFileDelegateToWatchList:(id<WatchedFileDelegate>)aWatchedFileDelegate
+{
+  [mFileChangeWatcher addWatchedFileDelegate:aWatchedFileDelegate];
+}
+
+-(void)removeFileDelegateFromWatchList:(id<WatchedFileDelegate>)aWatchedFileDelegate
+{
+  [mFileChangeWatcher removeWatchedFileDelegate:aWatchedFileDelegate];
+}
+
 // Remove the successful downloads from the downloads list
 -(void)removeSuccessfulDownloads
 {
@ -1201,8 +1216,7 @@ static id gSharedProgressController = nil;
 */
 -(id <CHDownloadProgressDisplay>)createProgressDisplay
 {
-  ProgressViewController *newController = [[[ProgressViewController alloc] init] autorelease];
-  [newController setProgressWindowController:self];
+  ProgressViewController* newController = [[[ProgressViewController alloc] initWithWindowController:self] autorelease];
  [mProgressViewControllers addObject:newController];
  
  return newController;
--- a/camino/src/download/ProgressViewController.h
+++ b/camino/src/download/ProgressViewController.h
@ -42,6 +42,7 @@


 #import "CHDownloadProgressDisplay.h"
+#import "FileChangeWatcher.h"

 class CHDownloader;
@class ProgressDlgController;
@ -70,7 +71,7 @@ const int kRemoveUponSuccessfulDownloadPrefValue = 2;
 // well as managing the download. It holds onto two views, one for while
 // the item is downloading, the other for after it has completed.
 //
-@interface ProgressViewController : NSObject<CHDownloadProgressDisplay>
+@interface ProgressViewController : NSObject<CHDownloadProgressDisplay, WatchedFileDelegate>
 {
  IBOutlet NSProgressIndicator *mProgressBar;

@ -83,10 +84,8 @@ const int kRemoveUponSuccessfulDownloadPrefValue = 2;
  BOOL            mDownloadDone;
  BOOL            mRefreshIcon;
  BOOL            mFileExists;
+  BOOL            mFileIsWatched;
  BOOL            mIsSelected;
-  
-  FNSubscriptionRef mSubRef;
-  FNSubscriptionUPP mSubUPP;

  NSTimeInterval  mDownloadTime; // only set when done

@ -106,7 +105,10 @@ const int kRemoveUponSuccessfulDownloadPrefValue = 2;
 +(NSString *)formatFuzzyTime:(int)aSeconds;
 +(NSString *)formatBytes:(float)aBytes;

-(id)initWithDictionary:(NSDictionary*)aDict;
+-(id)initWithWindowController:(ProgressDlgController*)aWindowController;
+-(id)initWithDictionary:(NSDictionary*)aDict 
+    andWindowController:(ProgressDlgController*)aWindowController;
+
 -(ProgressView *)view;

 -(IBAction)cancel:(id)sender;
@ -132,6 +134,4 @@ const int kRemoveUponSuccessfulDownloadPrefValue = 2;

 -(NSMenu*)contextualMenu;

-(void)setProgressWindowController:(ProgressDlgController*)progressWindowController;
-
@end
--- a/camino/src/download/ProgressViewController.mm
+++ b/camino/src/download/ProgressViewController.mm
@ -59,13 +59,6 @@ enum {
  kLabelTagIcon
 };

-// Method helps set up a subscription to the download dir to listen for changes
-static void FileSystemNotificationProc(FNMessage message, OptionBits flags, void* refcon, FNSubscriptionRef subscription)
-{
-  [(ProgressViewController*)refcon checkFileExists];
-}
-
-
@interface ProgressViewController(ProgressViewControllerPrivate)

 -(void)viewDidLoad;
@ -166,10 +159,20 @@ static void FileSystemNotificationProc(FNMessage message, OptionBits flags, void
  return self;
 }

-(id)initWithDictionary:(NSDictionary*)aDict
+-(id)initWithWindowController:(ProgressDlgController*)aWindowController
+{
+  if ((self = [self init]))
+    mProgressWindowController = aWindowController;
+  
+  return self;
+}
+
+-(id)initWithDictionary:(NSDictionary*)aDict 
+    andWindowController:(ProgressDlgController*)aWindowController
 {
  if ((self = [self init]))
  {
+    mProgressWindowController = aWindowController;
    [self setProgressViewFromDictionary:aDict];
  }
  
@ -197,8 +200,6 @@ static void FileSystemNotificationProc(FNMessage message, OptionBits flags, void
  [mCompletedView setController:nil];
  [mProgressView setController:nil];
  
-  [self unsubscribeFileSystemNotification];
-  
  [mStartTime release];
  [mSourceURL release];
  [mDestPath release];
@ -250,35 +251,20 @@ static void FileSystemNotificationProc(FNMessage message, OptionBits flags, void

 -(void)setupFileSystemNotification
 {
-  // there is some update, that is why we are being called again
-  // unsubscribe the old stuff and create a fresh subscription
-  [self unsubscribeFileSystemNotification];
-  
  [self checkFileExists];
-
-  NSString *dir = [mDestPath stringByDeletingLastPathComponent];
-  if (dir)
-  {
-    mSubUPP = NewFNSubscriptionUPP(FileSystemNotificationProc);
-    OSStatus err = FNSubscribeByPath(((const UInt8*)[dir fileSystemRepresentation]), mSubUPP, (void*)self, nil, &mSubRef);
-    if (err != noErr)
-      NSLog(@"Failed to subscribe to file system notification for %@", dir);
+  if (mFileExists && !mFileIsWatched) {
+    // Adding ourselves to the watch kqueue creates an extra ref-count to our instance.
+    // We will remove ourselves from the watch kqueue on |displayWillBeRemoved|, which
+    // will remove the extra ref count from our instance.
+    [mProgressWindowController addFileDelegateToWatchList:self];
+    mFileIsWatched = YES;
  }
 }

 -(void)unsubscribeFileSystemNotification
 {
-  if (mSubRef) 
-  {
-    FNUnsubscribe(mSubRef); 
-    mSubRef = nil;
-  }
-
-  if (mSubUPP) 
-  {
-    DisposeFNSubscriptionUPP(mSubUPP);
-    mSubUPP = nil;
-  }
+  [mProgressWindowController removeFileDelegateFromWatchList:self];
+  mFileIsWatched = NO;
 }

 -(IBAction)copySourceURL:(id)sender
@ -505,11 +491,6 @@ static void FileSystemNotificationProc(FNMessage message, OptionBits flags, void
  }
 }

-(void)setProgressWindowController:(ProgressDlgController*)progressWindowController
-{
-  mProgressWindowController = progressWindowController;
-}
-
 -(BOOL)isActive
 {
  return !mDownloadDone;
@ -602,6 +583,21 @@ static void FileSystemNotificationProc(FNMessage message, OptionBits flags, void
  return dict;
 }

+-(const char*)representedFilePath
+{
+  return [mDestPath fileSystemRepresentation];
+}
+
+-(void)fileDidChange
+{
+  // This method gets called on a background thread, so switch the |checkFileExists| call to the main thread.
+  NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
+  [self performSelectorOnMainThread:@selector(checkFileExists)
+                         withObject:nil 
+                      waitUntilDone:NO];
+  [pool release];
+}
+
 -(NSMenu*)contextualMenu
 {
  NSMenu *menu = [[NSMenu alloc] init];
@ -691,6 +687,8 @@ static void FileSystemNotificationProc(FNMessage message, OptionBits flags, void

  [self downloadDidEnd];
  [mProgressWindowController didEndDownload:self withSuccess:completedOK statusCode:aStatus];
+  if (completedOK)
+    [self setupFileSystemNotification];
 }

 -(void)setProgressTo:(long long)aCurProgress ofMax:(long long)aMaxProgress
@ -775,13 +773,26 @@ static void FileSystemNotificationProc(FNMessage message, OptionBits flags, void
 {
  [mDestPath autorelease];
  mDestPath = [aDestPath copy];
-  [self setupFileSystemNotification];
+  if (mDownloadDone)
+    [self setupFileSystemNotification];
  //[self tryToSetFinderComments];
 }

- (NSString*)destinationPath
+-(NSString*)destinationPath
 {
  return mDestPath;
 }

+//
+// This method exists because of an extra ref-count to ourselves in
+// |FileChangeWatcher|. To remove this extra refcount before |dealloc|,
+// this class gets notified when the view is about to be removed.
+//
+-(void)displayWillBeRemoved
+{
+  // The file can only be watched if the download compeleted sucessfully
+  if (mFileIsWatched)
+    [self unsubscribeFileSystemNotification];
+}
+
@end
--- a/camino/src/embedding/CHDownloadProgressDisplay.h
+++ b/camino/src/embedding/CHDownloadProgressDisplay.h
@ -121,6 +121,8 @@ class CHDownloader;
 - (void)setDestinationPath:(NSString*)aDestPath;
 - (NSString*)destinationPath;

+- (void)displayWillBeRemoved;
+
@end

 // A formal protocol which is implemented by a factory of progress UI.