2 // System.IO.KeventWatcher.cs: interface with osx kevent
5 // Geoff Norton (gnorton@customerdna.com)
6 // Cody Russell (cody@xamarin.com)
7 // Alexis Christoforides (lexas@xamarin.com)
9 // (c) 2004 Geoff Norton
10 // Copyright 2014 Xamarin Inc
12 // Permission is hereby granted, free of charge, to any person obtaining
13 // a copy of this software and associated documentation files (the
14 // "Software"), to deal in the Software without restriction, including
15 // without limitation the rights to use, copy, modify, merge, publish,
16 // distribute, sublicense, and/or sell copies of the Software, and to
17 // permit persons to whom the Software is furnished to do so, subject to
18 // the following conditions:
20 // The above copyright notice and this permission notice shall be
21 // included in all copies or substantial portions of the Software.
23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
27 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
28 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
29 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
33 using System.Collections;
34 using System.Collections.Generic;
35 using System.ComponentModel;
36 using System.Runtime.CompilerServices;
37 using System.Runtime.InteropServices;
39 using System.Threading;
40 using System.Reflection;
45 enum EventFlags : ushort {
57 SystemFlags = unchecked (0xf000),
64 enum EventFilter : short {
79 enum FilterFlags : uint {
80 ReadPoll = EventFlags.Flag0,
81 ReadOutOfBand = EventFlags.Flag1,
82 ReadLowWaterMark = 0x00000001,
84 WriteLowWaterMark = ReadLowWaterMark,
86 NoteTrigger = 0x01000000,
87 NoteFFNop = 0x00000000,
88 NoteFFAnd = 0x40000000,
89 NoteFFOr = 0x80000000,
90 NoteFFCopy = 0xc0000000,
91 NoteFFCtrlMask = 0xc0000000,
92 NoteFFlagsMask = 0x00ffffff,
94 VNodeDelete = 0x00000001,
95 VNodeWrite = 0x00000002,
96 VNodeExtend = 0x00000004,
97 VNodeAttrib = 0x00000008,
98 VNodeLink = 0x00000010,
99 VNodeRename = 0x00000020,
100 VNodeRevoke = 0x00000040,
101 VNodeNone = 0x00000080,
103 ProcExit = 0x80000000,
104 ProcFork = 0x40000000,
105 ProcExec = 0x20000000,
106 ProcReap = 0x10000000,
107 ProcSignal = 0x08000000,
108 ProcExitStatus = 0x04000000,
109 ProcResourceEnd = 0x02000000,
112 ProcAppactive = 0x00800000,
113 ProcAppBackground = 0x00400000,
114 ProcAppNonUI = 0x00200000,
115 ProcAppInactive = 0x00100000,
116 ProcAppAllStates = 0x00f00000,
119 ProcPDataMask = 0x000fffff,
120 ProcControlMask = 0xfff00000,
122 VMPressure = 0x80000000,
123 VMPressureTerminate = 0x40000000,
124 VMPressureSuddenTerminate = 0x20000000,
125 VMError = 0x10000000,
126 TimerSeconds = 0x00000001,
127 TimerMicroSeconds = 0x00000002,
128 TimerNanoSeconds = 0x00000004,
129 TimerAbsolute = 0x00000008,
132 [StructLayout(LayoutKind.Sequential)]
133 struct kevent : IDisposable {
134 public UIntPtr ident;
135 public EventFilter filter;
136 public EventFlags flags;
137 public FilterFlags fflags;
141 public void Dispose ()
143 if (udata != IntPtr.Zero)
144 Marshal.FreeHGlobal (udata);
150 [StructLayout(LayoutKind.Sequential)]
152 public IntPtr tv_sec;
153 public IntPtr tv_usec;
159 public bool IsDirectory;
163 class KqueueMonitor : IDisposable
165 public int Connection
170 public KqueueMonitor (FileSystemWatcher fsw)
176 public void Dispose ()
190 throw new IOException (String.Format (
191 "kqueue() error at init, error code = '{0}'", Marshal.GetLastWin32Error ()));
193 thread = new Thread (() => DoMonitor ());
194 thread.IsBackground = true;
197 startedEvent.WaitOne ();
219 // This will break the wait in Monitor ()
226 if (!thread.Join (2000))
245 foreach (int fd in fdsDict.Keys)
256 } catch (Exception e) {
263 fsw.DispatchErrorEvents (new ErrorEventArgs (exc));
269 } catch (Exception e) {
273 if (!requestStop) { // failure
276 fsw.EnableRaisingEvents = false;
280 fsw.DispatchErrorEvents (new ErrorEventArgs (exc));
287 var initialFds = new List<int> ();
289 // fsw.FullPath may end in '/', see https://bugzilla.xamarin.com/show_bug.cgi?id=5747
290 if (fsw.FullPath != "/" && fsw.FullPath.EndsWith ("/", StringComparison.Ordinal))
291 fullPathNoLastSlash = fsw.FullPath.Substring (0, fsw.FullPath.Length - 1);
293 fullPathNoLastSlash = fsw.FullPath;
295 // GetFilenameFromFd() returns the *realpath* which can be different than fsw.FullPath because symlinks.
296 // If so, introduce a fixup step.
297 int fd = open (fullPathNoLastSlash, O_EVTONLY, 0);
298 var resolvedFullPath = GetFilenameFromFd (fd);
301 if (resolvedFullPath != fullPathNoLastSlash)
302 fixupPath = resolvedFullPath;
306 Scan (fullPathNoLastSlash, false, ref initialFds);
308 var immediate_timeout = new timespec { tv_sec = (IntPtr)0, tv_usec = (IntPtr)0 };
309 var eventBuffer = new kevent[0]; // we don't want to take any events from the queue at this point
310 var changes = CreateChangeList (ref initialFds);
312 int numEvents = kevent (conn, changes, changes.Length, eventBuffer, eventBuffer.Length, ref immediate_timeout);
314 if (numEvents == -1) {
315 var errMsg = String.Format ("kevent() error at initial event registration, error code = '{0}'", Marshal.GetLastWin32Error ());
316 throw new IOException (errMsg);
320 kevent[] CreateChangeList (ref List<int> FdList)
322 if (FdList.Count == 0)
323 return emptyEventList;
325 var changes = new List<kevent> ();
326 foreach (int fd in FdList) {
327 var change = new kevent {
330 filter = EventFilter.Vnode,
331 flags = EventFlags.Add | EventFlags.Enable | EventFlags.Clear,
332 fflags = FilterFlags.VNodeDelete | FilterFlags.VNodeExtend |
333 FilterFlags.VNodeRename | FilterFlags.VNodeAttrib |
334 FilterFlags.VNodeLink | FilterFlags.VNodeRevoke |
335 FilterFlags.VNodeWrite,
340 changes.Add (change);
344 return changes.ToArray ();
349 var eventBuffer = new kevent[32];
350 var newFds = new List<int> ();
351 List<PathData> removeQueue = new List<PathData> ();
352 List<string> rescanQueue = new List<string> ();
356 while (!requestStop) {
357 var changes = CreateChangeList (ref newFds);
359 int numEvents = kevent_notimeout (conn, changes, changes.Length, eventBuffer, eventBuffer.Length, IntPtr.Zero);
361 if (numEvents == -1) {
362 // Stop () signals us to stop by closing the connection
366 throw new IOException (String.Format (
367 "persistent kevent() error, error code = '{0}'", Marshal.GetLastWin32Error ()));
374 for (var i = 0; i < numEvents; i++) {
375 var kevt = eventBuffer [i];
376 var pathData = fdsDict [(int)kevt.ident];
378 if ((kevt.flags & EventFlags.Error) == EventFlags.Error) {
379 var errMsg = String.Format ("kevent() error watching path '{0}', error code = '{1}'", pathData.Path, kevt.data);
380 fsw.DispatchErrorEvents (new ErrorEventArgs (new IOException (errMsg)));
384 if ((kevt.fflags & FilterFlags.VNodeDelete) == FilterFlags.VNodeDelete || (kevt.fflags & FilterFlags.VNodeRevoke) == FilterFlags.VNodeRevoke) {
385 removeQueue.Add (pathData);
389 if ((kevt.fflags & FilterFlags.VNodeRename) == FilterFlags.VNodeRename) {
390 UpdatePath (pathData);
393 if ((kevt.fflags & FilterFlags.VNodeWrite) == FilterFlags.VNodeWrite) {
394 if (pathData.IsDirectory) //TODO: Check if dirs trigger Changed events on .NET
395 rescanQueue.Add (pathData.Path);
397 PostEvent (FileAction.Modified, pathData.Path);
400 if ((kevt.fflags & FilterFlags.VNodeAttrib) == FilterFlags.VNodeAttrib || (kevt.fflags & FilterFlags.VNodeExtend) == FilterFlags.VNodeExtend)
401 PostEvent (FileAction.Modified, pathData.Path);
404 removeQueue.ForEach (Remove);
405 removeQueue.Clear ();
407 rescanQueue.ForEach (path => {
408 Scan (path, true, ref newFds);
410 rescanQueue.Clear ();
414 PathData Add (string path, bool postEvents, ref List<int> fds)
417 pathsDict.TryGetValue (path, out pathData);
419 if (pathData != null)
422 if (fdsDict.Count >= maxFds)
423 throw new IOException ("kqueue() FileSystemWatcher has reached the maximum number of files to watch.");
425 var fd = open (path, O_EVTONLY, 0);
428 fsw.DispatchErrorEvents (new ErrorEventArgs (new IOException (String.Format (
429 "open() error while attempting to process path '{0}', error code = '{1}'", path, Marshal.GetLastWin32Error ()))));
436 var attrs = File.GetAttributes (path);
438 pathData = new PathData {
441 IsDirectory = (attrs & FileAttributes.Directory) == FileAttributes.Directory
444 pathsDict.Add (path, pathData);
445 fdsDict.Add (fd, pathData);
448 PostEvent (FileAction.Added, path);
451 } catch (Exception e) {
453 fsw.DispatchErrorEvents (new ErrorEventArgs (e));
459 void Remove (PathData pathData)
461 fdsDict.Remove (pathData.Fd);
462 pathsDict.Remove (pathData.Path);
464 PostEvent (FileAction.Removed, pathData.Path);
467 void RemoveTree (PathData pathData)
469 var toRemove = new List<PathData> ();
471 toRemove.Add (pathData);
473 if (pathData.IsDirectory) {
474 var prefix = pathData.Path + Path.DirectorySeparatorChar;
475 foreach (var path in pathsDict.Keys)
476 if (path.StartsWith (prefix)) {
477 toRemove.Add (pathsDict [path]);
480 toRemove.ForEach (Remove);
483 void UpdatePath (PathData pathData)
485 var newRoot = GetFilenameFromFd (pathData.Fd);
486 if (!newRoot.StartsWith (fullPathNoLastSlash)) { // moved outside of our watched path (so stop observing it)
487 RemoveTree (pathData);
491 var toRename = new List<PathData> ();
492 var oldRoot = pathData.Path;
494 toRename.Add (pathData);
496 if (pathData.IsDirectory) { // anything under the directory must have their paths updated
497 var prefix = oldRoot + Path.DirectorySeparatorChar;
498 foreach (var path in pathsDict.Keys)
499 if (path.StartsWith (prefix))
500 toRename.Add (pathsDict [path]);
503 foreach (var renaming in toRename) {
504 var oldPath = renaming.Path;
505 var newPath = newRoot + oldPath.Substring (oldRoot.Length);
507 renaming.Path = newPath;
508 pathsDict.Remove (oldPath);
510 // destination may exist in our records from a Created event, take care of it
511 if (pathsDict.ContainsKey (newPath)) {
512 var conflict = pathsDict [newPath];
513 if (GetFilenameFromFd (renaming.Fd) == GetFilenameFromFd (conflict.Fd))
516 UpdatePath (conflict);
519 pathsDict.Add (newPath, renaming);
522 PostEvent (FileAction.RenamedNewName, oldRoot, newRoot);
525 void Scan (string path, bool postEvents, ref List<int> fds)
530 var pathData = Add (path, postEvents, ref fds);
532 if (pathData == null)
535 if (!pathData.IsDirectory)
538 var dirsToProcess = new List<string> ();
539 dirsToProcess.Add (path);
541 while (dirsToProcess.Count > 0) {
542 var tmp = dirsToProcess [0];
543 dirsToProcess.RemoveAt (0);
545 var info = new DirectoryInfo (tmp);
546 FileSystemInfo[] fsInfos = null;
548 fsInfos = info.GetFileSystemInfos ();
550 } catch (IOException) {
551 // this can happen if the directory has been deleted already.
552 // that's okay, just keep processing the other dirs.
553 fsInfos = new FileSystemInfo[0];
556 foreach (var fsi in fsInfos) {
557 if ((fsi.Attributes & FileAttributes.Directory) == FileAttributes.Directory && !fsw.IncludeSubdirectories)
560 if ((fsi.Attributes & FileAttributes.Directory) != FileAttributes.Directory && !fsw.Pattern.IsMatch (fsi.FullName))
563 var currentPathData = Add (fsi.FullName, postEvents, ref fds);
565 if (currentPathData != null && currentPathData.IsDirectory)
566 dirsToProcess.Add (fsi.FullName);
571 void PostEvent (FileAction action, string path, string newPath = null)
573 RenamedEventArgs renamed = null;
575 if (requestStop || action == 0)
579 string name = path.Substring (fullPathNoLastSlash.Length + 1);
581 // only post events that match filter pattern. check both old and new paths for renames
582 if (!fsw.Pattern.IsMatch (path) && (newPath == null || !fsw.Pattern.IsMatch (newPath)))
585 if (action == FileAction.RenamedNewName) {
586 string newName = newPath.Substring (fullPathNoLastSlash.Length + 1);
587 renamed = new RenamedEventArgs (WatcherChangeTypes.Renamed, fsw.Path, newName, name);
590 fsw.DispatchEvents (action, name, ref renamed);
595 System.Threading.Monitor.PulseAll (fsw);
600 private string GetFilenameFromFd (int fd)
602 var sb = new StringBuilder (__DARWIN_MAXPATHLEN);
604 if (fcntl (fd, F_GETPATH, sb) != -1) {
605 if (fixupPath != null)
606 sb.Replace (fixupPath, fullPathNoLastSlash, 0, fixupPath.Length); // see Setup()
608 return sb.ToString ();
610 fsw.DispatchErrorEvents (new ErrorEventArgs (new IOException (String.Format (
611 "fcntl() error while attempting to get path for fd '{0}', error code = '{1}'", fd, Marshal.GetLastWin32Error ()))));
616 const int O_EVTONLY = 0x8000;
617 const int F_GETPATH = 50;
618 const int __DARWIN_MAXPATHLEN = 1024;
619 static readonly kevent[] emptyEventList = new System.IO.kevent[0];
620 const int maxFds = 200;
622 FileSystemWatcher fsw;
625 volatile bool requestStop = false;
626 AutoResetEvent startedEvent = new AutoResetEvent (false);
627 bool started = false;
628 bool inDispatch = false;
629 Exception exc = null;
630 object stateLock = new object ();
631 object connLock = new object ();
633 readonly Dictionary<string, PathData> pathsDict = new Dictionary<string, PathData> ();
634 readonly Dictionary<int, PathData> fdsDict = new Dictionary<int, PathData> ();
635 string fixupPath = null;
636 string fullPathNoLastSlash = null;
638 [DllImport ("libc", EntryPoint="fcntl", CharSet=CharSet.Auto, SetLastError=true)]
639 static extern int fcntl (int file_names_by_descriptor, int cmd, StringBuilder sb);
642 extern static int open (string path, int flags, int mode_t);
645 extern static int close (int fd);
648 extern static int kqueue ();
651 extern static int kevent (int kq, [In]kevent[] ev, int nchanges, [Out]kevent[] evtlist, int nevents, [In] ref timespec time);
653 [DllImport ("libc", EntryPoint="kevent")]
654 extern static int kevent_notimeout (int kq, [In]kevent[] ev, int nchanges, [Out]kevent[] evtlist, int nevents, IntPtr ptr);
657 class KeventWatcher : IFileWatcher
660 static KeventWatcher instance;
661 static Hashtable watches; // <FileSystemWatcher, KqueueMonitor>
663 private KeventWatcher ()
668 public static bool GetInstance (out IFileWatcher watcher)
670 if (failed == true) {
675 if (instance != null) {
680 watches = Hashtable.Synchronized (new Hashtable ());
689 instance = new KeventWatcher ();
694 public void StartDispatching (FileSystemWatcher fsw)
696 KqueueMonitor monitor;
698 if (watches.ContainsKey (fsw)) {
699 monitor = (KqueueMonitor)watches [fsw];
701 monitor = new KqueueMonitor (fsw);
702 watches.Add (fsw, monitor);
708 public void StopDispatching (FileSystemWatcher fsw)
710 KqueueMonitor monitor = (KqueueMonitor)watches [fsw];
718 extern static int close (int fd);
721 extern static int kqueue ();