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;
279 fsw.DispatchErrorEvents (new ErrorEventArgs (exc));
286 var initialFds = new List<int> ();
288 // fsw.FullPath may end in '/', see https://bugzilla.xamarin.com/show_bug.cgi?id=5747
289 if (fsw.FullPath != "/" && fsw.FullPath.EndsWith ("/", StringComparison.Ordinal))
290 fullPathNoLastSlash = fsw.FullPath.Substring (0, fsw.FullPath.Length - 1);
292 fullPathNoLastSlash = fsw.FullPath;
294 // GetFilenameFromFd() returns the *realpath* which can be different than fsw.FullPath because symlinks.
295 // If so, introduce a fixup step.
296 int fd = open (fullPathNoLastSlash, O_EVTONLY, 0);
297 var resolvedFullPath = GetFilenameFromFd (fd);
300 if (resolvedFullPath != fullPathNoLastSlash)
301 fixupPath = resolvedFullPath;
305 Scan (fullPathNoLastSlash, false, ref initialFds);
307 var immediate_timeout = new timespec { tv_sec = (IntPtr)0, tv_usec = (IntPtr)0 };
308 var eventBuffer = new kevent[0]; // we don't want to take any events from the queue at this point
309 var changes = CreateChangeList (ref initialFds);
311 int numEvents = kevent (conn, changes, changes.Length, eventBuffer, eventBuffer.Length, ref immediate_timeout);
313 if (numEvents == -1) {
314 var errMsg = String.Format ("kevent() error at initial event registration, error code = '{0}'", Marshal.GetLastWin32Error ());
315 throw new IOException (errMsg);
319 kevent[] CreateChangeList (ref List<int> FdList)
321 if (FdList.Count == 0)
322 return emptyEventList;
324 var changes = new List<kevent> ();
325 foreach (int fd in FdList) {
326 var change = new kevent {
329 filter = EventFilter.Vnode,
330 flags = EventFlags.Add | EventFlags.Enable | EventFlags.Clear,
331 fflags = FilterFlags.VNodeDelete | FilterFlags.VNodeExtend |
332 FilterFlags.VNodeRename | FilterFlags.VNodeAttrib |
333 FilterFlags.VNodeLink | FilterFlags.VNodeRevoke |
334 FilterFlags.VNodeWrite,
339 changes.Add (change);
343 return changes.ToArray ();
348 var eventBuffer = new kevent[32];
349 var newFds = new List<int> ();
350 List<PathData> removeQueue = new List<PathData> ();
351 List<string> rescanQueue = new List<string> ();
355 while (!requestStop) {
356 var changes = CreateChangeList (ref newFds);
358 // We are calling an icall, so have to marshal manually
360 int ksize = Marshal.SizeOf<kevent> ();
361 var changesNative = Marshal.AllocHGlobal (ksize * changes.Length);
362 for (int i = 0; i < changes.Length; ++i)
363 Marshal.StructureToPtr (changes [i], changesNative + (i * ksize), false);
364 var eventBufferNative = Marshal.AllocHGlobal (ksize * eventBuffer.Length);
366 int numEvents = kevent_notimeout (ref conn, changesNative, changes.Length, eventBufferNative, eventBuffer.Length);
369 Marshal.FreeHGlobal (changesNative);
370 for (int i = 0; i < numEvents; ++i)
371 eventBuffer [i] = Marshal.PtrToStructure<kevent> (eventBufferNative + (i * ksize));
372 Marshal.FreeHGlobal (eventBufferNative);
374 if (numEvents == -1) {
375 // Stop () signals us to stop by closing the connection
379 throw new IOException (String.Format (
380 "persistent kevent() error, error code = '{0}'", Marshal.GetLastWin32Error ()));
386 for (var i = 0; i < numEvents; i++) {
387 var kevt = eventBuffer [i];
389 if (!fdsDict.ContainsKey ((int)kevt.ident))
390 // The event is for a file that was removed
393 var pathData = fdsDict [(int)kevt.ident];
395 if ((kevt.flags & EventFlags.Error) == EventFlags.Error) {
396 var errMsg = String.Format ("kevent() error watching path '{0}', error code = '{1}'", pathData.Path, kevt.data);
397 fsw.DispatchErrorEvents (new ErrorEventArgs (new IOException (errMsg)));
401 if ((kevt.fflags & FilterFlags.VNodeDelete) == FilterFlags.VNodeDelete || (kevt.fflags & FilterFlags.VNodeRevoke) == FilterFlags.VNodeRevoke) {
402 if (pathData.Path == fullPathNoLastSlash)
403 // The root path is deleted; exit silently
406 removeQueue.Add (pathData);
410 if ((kevt.fflags & FilterFlags.VNodeRename) == FilterFlags.VNodeRename) {
411 UpdatePath (pathData);
414 if ((kevt.fflags & FilterFlags.VNodeWrite) == FilterFlags.VNodeWrite) {
415 if (pathData.IsDirectory) //TODO: Check if dirs trigger Changed events on .NET
416 rescanQueue.Add (pathData.Path);
418 PostEvent (FileAction.Modified, pathData.Path);
421 if ((kevt.fflags & FilterFlags.VNodeAttrib) == FilterFlags.VNodeAttrib || (kevt.fflags & FilterFlags.VNodeExtend) == FilterFlags.VNodeExtend)
422 PostEvent (FileAction.Modified, pathData.Path);
425 removeQueue.ForEach (Remove);
426 removeQueue.Clear ();
428 rescanQueue.ForEach (path => {
429 Scan (path, true, ref newFds);
431 rescanQueue.Clear ();
435 PathData Add (string path, bool postEvents, ref List<int> fds)
438 pathsDict.TryGetValue (path, out pathData);
440 if (pathData != null)
443 if (fdsDict.Count >= maxFds)
444 throw new IOException ("kqueue() FileSystemWatcher has reached the maximum number of files to watch.");
446 var fd = open (path, O_EVTONLY, 0);
449 fsw.DispatchErrorEvents (new ErrorEventArgs (new IOException (String.Format (
450 "open() error while attempting to process path '{0}', error code = '{1}'", path, Marshal.GetLastWin32Error ()))));
457 var attrs = File.GetAttributes (path);
459 pathData = new PathData {
462 IsDirectory = (attrs & FileAttributes.Directory) == FileAttributes.Directory
465 pathsDict.Add (path, pathData);
466 fdsDict.Add (fd, pathData);
469 PostEvent (FileAction.Added, path);
472 } catch (Exception e) {
474 fsw.DispatchErrorEvents (new ErrorEventArgs (e));
480 void Remove (PathData pathData)
482 fdsDict.Remove (pathData.Fd);
483 pathsDict.Remove (pathData.Path);
485 PostEvent (FileAction.Removed, pathData.Path);
488 void RemoveTree (PathData pathData)
490 var toRemove = new List<PathData> ();
492 toRemove.Add (pathData);
494 if (pathData.IsDirectory) {
495 var prefix = pathData.Path + Path.DirectorySeparatorChar;
496 foreach (var path in pathsDict.Keys)
497 if (path.StartsWith (prefix)) {
498 toRemove.Add (pathsDict [path]);
501 toRemove.ForEach (Remove);
504 void UpdatePath (PathData pathData)
506 var newRoot = GetFilenameFromFd (pathData.Fd);
507 if (!newRoot.StartsWith (fullPathNoLastSlash)) { // moved outside of our watched path (so stop observing it)
508 RemoveTree (pathData);
512 var toRename = new List<PathData> ();
513 var oldRoot = pathData.Path;
515 toRename.Add (pathData);
517 if (pathData.IsDirectory) { // anything under the directory must have their paths updated
518 var prefix = oldRoot + Path.DirectorySeparatorChar;
519 foreach (var path in pathsDict.Keys)
520 if (path.StartsWith (prefix))
521 toRename.Add (pathsDict [path]);
524 foreach (var renaming in toRename) {
525 var oldPath = renaming.Path;
526 var newPath = newRoot + oldPath.Substring (oldRoot.Length);
528 renaming.Path = newPath;
529 pathsDict.Remove (oldPath);
531 // destination may exist in our records from a Created event, take care of it
532 if (pathsDict.ContainsKey (newPath)) {
533 var conflict = pathsDict [newPath];
534 if (GetFilenameFromFd (renaming.Fd) == GetFilenameFromFd (conflict.Fd))
537 UpdatePath (conflict);
540 pathsDict.Add (newPath, renaming);
543 PostEvent (FileAction.RenamedNewName, oldRoot, newRoot);
546 void Scan (string path, bool postEvents, ref List<int> fds)
551 var pathData = Add (path, postEvents, ref fds);
553 if (pathData == null)
556 if (!pathData.IsDirectory)
559 var dirsToProcess = new List<string> ();
560 dirsToProcess.Add (path);
562 while (dirsToProcess.Count > 0) {
563 var tmp = dirsToProcess [0];
564 dirsToProcess.RemoveAt (0);
566 var info = new DirectoryInfo (tmp);
567 FileSystemInfo[] fsInfos = null;
569 fsInfos = info.GetFileSystemInfos ();
571 } catch (IOException) {
572 // this can happen if the directory has been deleted already.
573 // that's okay, just keep processing the other dirs.
574 fsInfos = new FileSystemInfo[0];
577 foreach (var fsi in fsInfos) {
578 if ((fsi.Attributes & FileAttributes.Directory) == FileAttributes.Directory && !fsw.IncludeSubdirectories)
581 if ((fsi.Attributes & FileAttributes.Directory) != FileAttributes.Directory && !fsw.Pattern.IsMatch (fsi.FullName))
584 var currentPathData = Add (fsi.FullName, postEvents, ref fds);
586 if (currentPathData != null && currentPathData.IsDirectory)
587 dirsToProcess.Add (fsi.FullName);
592 void PostEvent (FileAction action, string path, string newPath = null)
594 RenamedEventArgs renamed = null;
596 if (requestStop || action == 0)
600 string name = path.Substring (fullPathNoLastSlash.Length + 1);
602 // only post events that match filter pattern. check both old and new paths for renames
603 if (!fsw.Pattern.IsMatch (path) && (newPath == null || !fsw.Pattern.IsMatch (newPath)))
606 if (action == FileAction.RenamedNewName) {
607 string newName = newPath.Substring (fullPathNoLastSlash.Length + 1);
608 renamed = new RenamedEventArgs (WatcherChangeTypes.Renamed, fsw.Path, newName, name);
611 fsw.DispatchEvents (action, name, ref renamed);
616 System.Threading.Monitor.PulseAll (fsw);
621 private string GetFilenameFromFd (int fd)
623 var sb = new StringBuilder (__DARWIN_MAXPATHLEN);
625 if (fcntl (fd, F_GETPATH, sb) != -1) {
626 if (fixupPath != null)
627 sb.Replace (fixupPath, fullPathNoLastSlash, 0, fixupPath.Length); // see Setup()
629 return sb.ToString ();
631 fsw.DispatchErrorEvents (new ErrorEventArgs (new IOException (String.Format (
632 "fcntl() error while attempting to get path for fd '{0}', error code = '{1}'", fd, Marshal.GetLastWin32Error ()))));
637 const int O_EVTONLY = 0x8000;
638 const int F_GETPATH = 50;
639 const int __DARWIN_MAXPATHLEN = 1024;
640 static readonly kevent[] emptyEventList = new System.IO.kevent[0];
641 const int maxFds = 200;
643 FileSystemWatcher fsw;
646 volatile bool requestStop = false;
647 AutoResetEvent startedEvent = new AutoResetEvent (false);
648 bool started = false;
649 bool inDispatch = false;
650 Exception exc = null;
651 object stateLock = new object ();
652 object connLock = new object ();
654 readonly Dictionary<string, PathData> pathsDict = new Dictionary<string, PathData> ();
655 readonly Dictionary<int, PathData> fdsDict = new Dictionary<int, PathData> ();
656 string fixupPath = null;
657 string fullPathNoLastSlash = null;
659 [DllImport ("libc", EntryPoint="fcntl", CharSet=CharSet.Auto, SetLastError=true)]
660 static extern int fcntl (int file_names_by_descriptor, int cmd, StringBuilder sb);
663 extern static int open (string path, int flags, int mode_t);
666 extern static int close (int fd);
669 extern static int kqueue ();
672 extern static int kevent (int kq, [In]kevent[] ev, int nchanges, [Out]kevent[] evtlist, int nevents, [In] ref timespec time);
674 [MethodImplAttribute(MethodImplOptions.InternalCall)]
675 extern static int kevent_notimeout (ref int kq, IntPtr ev, int nchanges, IntPtr evtlist, int nevents);
678 class KeventWatcher : IFileWatcher
681 static KeventWatcher instance;
682 static Hashtable watches; // <FileSystemWatcher, KqueueMonitor>
684 private KeventWatcher ()
689 public static bool GetInstance (out IFileWatcher watcher)
691 if (failed == true) {
696 if (instance != null) {
701 watches = Hashtable.Synchronized (new Hashtable ());
710 instance = new KeventWatcher ();
715 public void StartDispatching (FileSystemWatcher fsw)
717 KqueueMonitor monitor;
719 if (watches.ContainsKey (fsw)) {
720 monitor = (KqueueMonitor)watches [fsw];
722 monitor = new KqueueMonitor (fsw);
723 watches.Add (fsw, monitor);
729 public void StopDispatching (FileSystemWatcher fsw)
731 KqueueMonitor monitor = (KqueueMonitor)watches [fsw];
739 extern static int close (int fd);
742 extern static int kqueue ();