/* * Server-side change notification management * * Copyright (C) 1998 Alexandre Julliard * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include "config.h" #include "wine/port.h" #include #include #include #include #include #include #include "ntstatus.h" #define WIN32_NO_STATUS #include "windef.h" #include "file.h" #include "handle.h" #include "thread.h" #include "request.h" #include "winternl.h" #ifdef linux #ifndef F_NOTIFY #define F_NOTIFY 1026 #define DN_ACCESS 0x00000001 /* File accessed */ #define DN_MODIFY 0x00000002 /* File modified */ #define DN_CREATE 0x00000004 /* File created */ #define DN_DELETE 0x00000008 /* File removed */ #define DN_RENAME 0x00000010 /* File renamed */ #define DN_ATTRIB 0x00000020 /* File changed attibutes */ #define DN_MULTISHOT 0x80000000 /* Don't remove notifier */ #endif #endif struct change { struct object obj; /* object header */ struct fd *fd; /* file descriptor to the directory */ struct list entry; /* entry in global change notifications list */ int subtree; /* watch all the subtree */ unsigned int filter; /* notification filter */ int notified; /* SIGIO counter */ long signaled; /* the file changed */ }; static void change_dump( struct object *obj, int verbose ); static int change_signaled( struct object *obj, struct thread *thread ); static void change_destroy( struct object *obj ); static const struct object_ops change_ops = { sizeof(struct change), /* size */ change_dump, /* dump */ add_queue, /* add_queue */ remove_queue, /* remove_queue */ change_signaled, /* signaled */ no_satisfied, /* satisfied */ no_signal, /* signal */ no_get_fd, /* get_fd */ no_lookup_name, /* lookup_name */ no_close_handle, /* close_handle */ change_destroy /* destroy */ }; static struct list change_list = LIST_INIT(change_list); static void adjust_changes( int fd, unsigned int filter ) { #if defined(F_SETSIG) && defined(F_NOTIFY) unsigned int val; if ( 0 > fcntl( fd, F_SETSIG, SIGIO) ) return; val = DN_MULTISHOT; if (filter & FILE_NOTIFY_CHANGE_FILE_NAME) val |= DN_RENAME | DN_DELETE | DN_CREATE; if (filter & FILE_NOTIFY_CHANGE_DIR_NAME) val |= DN_RENAME | DN_DELETE | DN_CREATE; if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES) val |= DN_ATTRIB; if (filter & FILE_NOTIFY_CHANGE_SIZE) val |= DN_MODIFY; if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE) val |= DN_MODIFY; if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS) val |= DN_ACCESS; if (filter & FILE_NOTIFY_CHANGE_CREATION) val |= DN_CREATE; if (filter & FILE_NOTIFY_CHANGE_SECURITY) val |= DN_ATTRIB; fcntl( fd, F_NOTIFY, val ); #endif } /* insert change in the global list */ static inline void insert_change( struct change *change ) { sigset_t sigset; sigemptyset( &sigset ); sigaddset( &sigset, SIGIO ); sigprocmask( SIG_BLOCK, &sigset, NULL ); list_add_head( &change_list, &change->entry ); sigprocmask( SIG_UNBLOCK, &sigset, NULL ); } /* remove change from the global list */ static inline void remove_change( struct change *change ) { sigset_t sigset; sigemptyset( &sigset ); sigaddset( &sigset, SIGIO ); sigprocmask( SIG_BLOCK, &sigset, NULL ); list_remove( &change->entry ); sigprocmask( SIG_UNBLOCK, &sigset, NULL ); } static struct change *create_change_notification( struct fd *fd, int subtree, unsigned int filter ) { struct change *change; struct stat st; int unix_fd = get_unix_fd( fd ); if (unix_fd == -1) return NULL; if (fstat( unix_fd, &st ) == -1 || !S_ISDIR(st.st_mode)) { set_error( STATUS_NOT_A_DIRECTORY ); return NULL; } if ((change = alloc_object( &change_ops ))) { change->fd = (struct fd *)grab_object( fd ); change->subtree = subtree; change->filter = filter; change->notified = 0; change->signaled = 0; insert_change( change ); adjust_changes( unix_fd, filter ); } return change; } static void change_dump( struct object *obj, int verbose ) { struct change *change = (struct change *)obj; assert( obj->ops == &change_ops ); fprintf( stderr, "Change notification fd=%p sub=%d filter=%08x\n", change->fd, change->subtree, change->filter ); } static int change_signaled( struct object *obj, struct thread *thread ) { struct change *change = (struct change *)obj; return change->signaled != 0; } static void change_destroy( struct object *obj ) { struct change *change = (struct change *)obj; release_object( change->fd ); remove_change( change ); } /* enter here directly from SIGIO signal handler */ void do_change_notify( int unix_fd ) { struct list *ptr; /* FIXME: this is O(n) ... probably can be improved */ LIST_FOR_EACH( ptr, &change_list ) { struct change *change = LIST_ENTRY( ptr, struct change, entry ); if (get_unix_fd( change->fd ) != unix_fd) continue; interlocked_xchg_add( &change->notified, 1 ); break; } } /* SIGIO callback, called synchronously with the poll loop */ void sigio_callback(void) { struct list *ptr; LIST_FOR_EACH( ptr, &change_list ) { struct change *change = LIST_ENTRY( ptr, struct change, entry ); long count = interlocked_xchg( &change->notified, 0 ); if (count) { change->signaled += count; if (change->signaled == count) /* was it 0? */ wake_up( &change->obj, 0 ); } } } /* create a change notification */ DECL_HANDLER(create_change_notification) { struct change *change; struct file *file; struct fd *fd; if (!(file = get_file_obj( current->process, req->handle, 0 ))) return; fd = get_obj_fd( (struct object *)file ); release_object( file ); if (!fd) return; if ((change = create_change_notification( fd, req->subtree, req->filter ))) { reply->handle = alloc_handle( current->process, change, STANDARD_RIGHTS_REQUIRED|SYNCHRONIZE, 0 ); release_object( change ); } release_object( fd ); } /* move to the next change notification */ DECL_HANDLER(next_change_notification) { struct change *change; if ((change = (struct change *)get_handle_obj( current->process, req->handle, 0, &change_ops ))) { if (change->signaled > 0) change->signaled--; release_object( change ); } }