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 static bool initialized;
167 public int Connection
172 public KqueueMonitor (FileSystemWatcher fsw)
179 var maxenv = Environment.GetEnvironmentVariable ("MONO_DARWIN_WATCHER_MAXFDS");
180 if (maxenv != null && Int32.TryParse (maxenv, out t))
185 public void Dispose ()
199 throw new IOException (String.Format (
200 "kqueue() error at init, error code = '{0}'", Marshal.GetLastWin32Error ()));
202 thread = new Thread (() => DoMonitor ());
203 thread.IsBackground = true;
206 startedEvent.WaitOne ();
228 // This will break the wait in Monitor ()
235 if (!thread.Join (2000))
254 foreach (int fd in fdsDict.Keys)
265 } catch (Exception e) {
272 fsw.DispatchErrorEvents (new ErrorEventArgs (exc));
278 } catch (Exception e) {
282 if (!requestStop) { // failure
285 fsw.EnableRaisingEvents = false;
288 fsw.DispatchErrorEvents (new ErrorEventArgs (exc));
295 var initialFds = new List<int> ();
297 // fsw.FullPath may end in '/', see https://bugzilla.xamarin.com/show_bug.cgi?id=5747
298 if (fsw.FullPath != "/" && fsw.FullPath.EndsWith ("/", StringComparison.Ordinal))
299 fullPathNoLastSlash = fsw.FullPath.Substring (0, fsw.FullPath.Length - 1);
301 fullPathNoLastSlash = fsw.FullPath;
303 // GetFilenameFromFd() returns the *realpath* which can be different than fsw.FullPath because symlinks.
304 // If so, introduce a fixup step.
305 int fd = open (fullPathNoLastSlash, O_EVTONLY, 0);
306 var resolvedFullPath = GetFilenameFromFd (fd);
309 if (resolvedFullPath != fullPathNoLastSlash)
310 fixupPath = resolvedFullPath;
314 Scan (fullPathNoLastSlash, false, ref initialFds);
316 var immediate_timeout = new timespec { tv_sec = (IntPtr)0, tv_usec = (IntPtr)0 };
317 var eventBuffer = new kevent[0]; // we don't want to take any events from the queue at this point
318 var changes = CreateChangeList (ref initialFds);
320 int numEvents = kevent (conn, changes, changes.Length, eventBuffer, eventBuffer.Length, ref immediate_timeout);
322 if (numEvents == -1) {
323 var errMsg = String.Format ("kevent() error at initial event registration, error code = '{0}'", Marshal.GetLastWin32Error ());
324 throw new IOException (errMsg);
328 kevent[] CreateChangeList (ref List<int> FdList)
330 if (FdList.Count == 0)
331 return emptyEventList;
333 var changes = new List<kevent> ();
334 foreach (int fd in FdList) {
335 var change = new kevent {
338 filter = EventFilter.Vnode,
339 flags = EventFlags.Add | EventFlags.Enable | EventFlags.Clear,
340 fflags = FilterFlags.VNodeDelete | FilterFlags.VNodeExtend |
341 FilterFlags.VNodeRename | FilterFlags.VNodeAttrib |
342 FilterFlags.VNodeLink | FilterFlags.VNodeRevoke |
343 FilterFlags.VNodeWrite,
348 changes.Add (change);
352 return changes.ToArray ();
357 var eventBuffer = new kevent[32];
358 var newFds = new List<int> ();
359 List<PathData> removeQueue = new List<PathData> ();
360 List<string> rescanQueue = new List<string> ();
364 while (!requestStop) {
365 var changes = CreateChangeList (ref newFds);
367 // We are calling an icall, so have to marshal manually
369 int ksize = Marshal.SizeOf<kevent> ();
370 var changesNative = Marshal.AllocHGlobal (ksize * changes.Length);
371 for (int i = 0; i < changes.Length; ++i)
372 Marshal.StructureToPtr (changes [i], changesNative + (i * ksize), false);
373 var eventBufferNative = Marshal.AllocHGlobal (ksize * eventBuffer.Length);
375 int numEvents = kevent_notimeout (ref conn, changesNative, changes.Length, eventBufferNative, eventBuffer.Length);
378 Marshal.FreeHGlobal (changesNative);
379 for (int i = 0; i < numEvents; ++i)
380 eventBuffer [i] = Marshal.PtrToStructure<kevent> (eventBufferNative + (i * ksize));
381 Marshal.FreeHGlobal (eventBufferNative);
383 if (numEvents == -1) {
384 // Stop () signals us to stop by closing the connection
388 throw new IOException (String.Format (
389 "persistent kevent() error, error code = '{0}'", Marshal.GetLastWin32Error ()));
395 for (var i = 0; i < numEvents; i++) {
396 var kevt = eventBuffer [i];
398 if (!fdsDict.ContainsKey ((int)kevt.ident))
399 // The event is for a file that was removed
402 var pathData = fdsDict [(int)kevt.ident];
404 if ((kevt.flags & EventFlags.Error) == EventFlags.Error) {
405 var errMsg = String.Format ("kevent() error watching path '{0}', error code = '{1}'", pathData.Path, kevt.data);
406 fsw.DispatchErrorEvents (new ErrorEventArgs (new IOException (errMsg)));
410 if ((kevt.fflags & FilterFlags.VNodeDelete) == FilterFlags.VNodeDelete || (kevt.fflags & FilterFlags.VNodeRevoke) == FilterFlags.VNodeRevoke) {
411 if (pathData.Path == fullPathNoLastSlash)
412 // The root path is deleted; exit silently
415 removeQueue.Add (pathData);
419 if ((kevt.fflags & FilterFlags.VNodeRename) == FilterFlags.VNodeRename) {
420 UpdatePath (pathData);
423 if ((kevt.fflags & FilterFlags.VNodeWrite) == FilterFlags.VNodeWrite) {
424 if (pathData.IsDirectory) //TODO: Check if dirs trigger Changed events on .NET
425 rescanQueue.Add (pathData.Path);
427 PostEvent (FileAction.Modified, pathData.Path);
430 if ((kevt.fflags & FilterFlags.VNodeAttrib) == FilterFlags.VNodeAttrib || (kevt.fflags & FilterFlags.VNodeExtend) == FilterFlags.VNodeExtend)
431 PostEvent (FileAction.Modified, pathData.Path);
434 removeQueue.ForEach (Remove);
435 removeQueue.Clear ();
437 rescanQueue.ForEach (path => {
438 Scan (path, true, ref newFds);
440 rescanQueue.Clear ();
444 PathData Add (string path, bool postEvents, ref List<int> fds)
447 pathsDict.TryGetValue (path, out pathData);
449 if (pathData != null)
452 if (fdsDict.Count >= maxFds)
453 throw new IOException ("kqueue() FileSystemWatcher has reached the maximum number of files to watch.");
455 var fd = open (path, O_EVTONLY, 0);
458 fsw.DispatchErrorEvents (new ErrorEventArgs (new IOException (String.Format (
459 "open() error while attempting to process path '{0}', error code = '{1}'", path, Marshal.GetLastWin32Error ()))));
466 var attrs = File.GetAttributes (path);
468 pathData = new PathData {
471 IsDirectory = (attrs & FileAttributes.Directory) == FileAttributes.Directory
474 pathsDict.Add (path, pathData);
475 fdsDict.Add (fd, pathData);
478 PostEvent (FileAction.Added, path);
481 } catch (Exception e) {
483 fsw.DispatchErrorEvents (new ErrorEventArgs (e));
489 void Remove (PathData pathData)
491 fdsDict.Remove (pathData.Fd);
492 pathsDict.Remove (pathData.Path);
494 PostEvent (FileAction.Removed, pathData.Path);
497 void RemoveTree (PathData pathData)
499 var toRemove = new List<PathData> ();
501 toRemove.Add (pathData);
503 if (pathData.IsDirectory) {
504 var prefix = pathData.Path + Path.DirectorySeparatorChar;
505 foreach (var path in pathsDict.Keys)
506 if (path.StartsWith (prefix)) {
507 toRemove.Add (pathsDict [path]);
510 toRemove.ForEach (Remove);
513 void UpdatePath (PathData pathData)
515 var newRoot = GetFilenameFromFd (pathData.Fd);
516 if (!newRoot.StartsWith (fullPathNoLastSlash)) { // moved outside of our watched path (so stop observing it)
517 RemoveTree (pathData);
521 var toRename = new List<PathData> ();
522 var oldRoot = pathData.Path;
524 toRename.Add (pathData);
526 if (pathData.IsDirectory) { // anything under the directory must have their paths updated
527 var prefix = oldRoot + Path.DirectorySeparatorChar;
528 foreach (var path in pathsDict.Keys)
529 if (path.StartsWith (prefix))
530 toRename.Add (pathsDict [path]);
533 foreach (var renaming in toRename) {
534 var oldPath = renaming.Path;
535 var newPath = newRoot + oldPath.Substring (oldRoot.Length);
537 renaming.Path = newPath;
538 pathsDict.Remove (oldPath);
540 // destination may exist in our records from a Created event, take care of it
541 if (pathsDict.ContainsKey (newPath)) {
542 var conflict = pathsDict [newPath];
543 if (GetFilenameFromFd (renaming.Fd) == GetFilenameFromFd (conflict.Fd))
546 UpdatePath (conflict);
549 pathsDict.Add (newPath, renaming);
552 PostEvent (FileAction.RenamedNewName, oldRoot, newRoot);
555 void Scan (string path, bool postEvents, ref List<int> fds)
560 var pathData = Add (path, postEvents, ref fds);
562 if (pathData == null)
565 if (!pathData.IsDirectory)
568 var dirsToProcess = new List<string> ();
569 dirsToProcess.Add (path);
571 while (dirsToProcess.Count > 0) {
572 var tmp = dirsToProcess [0];
573 dirsToProcess.RemoveAt (0);
575 var info = new DirectoryInfo (tmp);
576 FileSystemInfo[] fsInfos = null;
578 fsInfos = info.GetFileSystemInfos ();
580 } catch (IOException) {
581 // this can happen if the directory has been deleted already.
582 // that's okay, just keep processing the other dirs.
583 fsInfos = new FileSystemInfo[0];
586 foreach (var fsi in fsInfos) {
587 if ((fsi.Attributes & FileAttributes.Directory) == FileAttributes.Directory && !fsw.IncludeSubdirectories)
590 if ((fsi.Attributes & FileAttributes.Directory) != FileAttributes.Directory && !fsw.Pattern.IsMatch (fsi.FullName))
593 var currentPathData = Add (fsi.FullName, postEvents, ref fds);
595 if (currentPathData != null && currentPathData.IsDirectory)
596 dirsToProcess.Add (fsi.FullName);
601 void PostEvent (FileAction action, string path, string newPath = null)
603 RenamedEventArgs renamed = null;
605 if (requestStop || action == 0)
609 string name = path.Substring (fullPathNoLastSlash.Length + 1);
611 // only post events that match filter pattern. check both old and new paths for renames
612 if (!fsw.Pattern.IsMatch (path) && (newPath == null || !fsw.Pattern.IsMatch (newPath)))
615 if (action == FileAction.RenamedNewName) {
616 string newName = newPath.Substring (fullPathNoLastSlash.Length + 1);
617 renamed = new RenamedEventArgs (WatcherChangeTypes.Renamed, fsw.Path, newName, name);
620 fsw.DispatchEvents (action, name, ref renamed);
625 System.Threading.Monitor.PulseAll (fsw);
630 private string GetFilenameFromFd (int fd)
632 var sb = new StringBuilder (__DARWIN_MAXPATHLEN);
634 if (fcntl (fd, F_GETPATH, sb) != -1) {
635 if (fixupPath != null)
636 sb.Replace (fixupPath, fullPathNoLastSlash, 0, fixupPath.Length); // see Setup()
638 return sb.ToString ();
640 fsw.DispatchErrorEvents (new ErrorEventArgs (new IOException (String.Format (
641 "fcntl() error while attempting to get path for fd '{0}', error code = '{1}'", fd, Marshal.GetLastWin32Error ()))));
646 const int O_EVTONLY = 0x8000;
647 const int F_GETPATH = 50;
648 const int __DARWIN_MAXPATHLEN = 1024;
649 static readonly kevent[] emptyEventList = new System.IO.kevent[0];
650 int maxFds = Int32.MaxValue;
652 FileSystemWatcher fsw;
655 volatile bool requestStop = false;
656 AutoResetEvent startedEvent = new AutoResetEvent (false);
657 bool started = false;
658 bool inDispatch = false;
659 Exception exc = null;
660 object stateLock = new object ();
661 object connLock = new object ();
663 readonly Dictionary<string, PathData> pathsDict = new Dictionary<string, PathData> ();
664 readonly Dictionary<int, PathData> fdsDict = new Dictionary<int, PathData> ();
665 string fixupPath = null;
666 string fullPathNoLastSlash = null;
668 [DllImport ("libc", EntryPoint="fcntl", CharSet=CharSet.Auto, SetLastError=true)]
669 static extern int fcntl (int file_names_by_descriptor, int cmd, StringBuilder sb);
672 extern static int open (string path, int flags, int mode_t);
675 extern static int close (int fd);
678 extern static int kqueue ();
681 extern static int kevent (int kq, [In]kevent[] ev, int nchanges, [Out]kevent[] evtlist, int nevents, [In] ref timespec time);
683 [MethodImplAttribute(MethodImplOptions.InternalCall)]
684 extern static int kevent_notimeout (ref int kq, IntPtr ev, int nchanges, IntPtr evtlist, int nevents);
687 class KeventWatcher : IFileWatcher
690 static KeventWatcher instance;
691 static Hashtable watches; // <FileSystemWatcher, KqueueMonitor>
693 private KeventWatcher ()
698 public static bool GetInstance (out IFileWatcher watcher)
700 if (failed == true) {
705 if (instance != null) {
710 watches = Hashtable.Synchronized (new Hashtable ());
719 instance = new KeventWatcher ();
724 public void StartDispatching (FileSystemWatcher fsw)
726 KqueueMonitor monitor;
728 if (watches.ContainsKey (fsw)) {
729 monitor = (KqueueMonitor)watches [fsw];
731 monitor = new KqueueMonitor (fsw);
732 watches.Add (fsw, monitor);
738 public void StopDispatching (FileSystemWatcher fsw)
740 KqueueMonitor monitor = (KqueueMonitor)watches [fsw];
748 extern static int close (int fd);
751 extern static int kqueue ();