xnu-792.17.14.tar.gz

[apple/xnu.git] / bsd / vfs / vfs_fsevents.c

diff --git a/bsd/vfs/vfs_fsevents.c b/bsd/vfs/vfs_fsevents.c
index 3688244efe1c06ac46ee86a50b51cde3feed8515..109a8f72e3d33ddef424a1275410883de49d7c6b 100644 (file)
--- a/bsd/vfs/vfs_fsevents.c
+++ b/bsd/vfs/vfs_fsevents.c
@@ -1,23 +1,29 @@
 /*
  * Copyright (c) 2004 Apple Computer, Inc. All rights reserved.
  *
- * @APPLE_LICENSE_HEADER_START@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License").  You may not use this file except in compliance with the
- * License.  Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
  * 
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
- * License for the specific language governing rights and limitations
- * under the License.
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
  * 
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 #include <stdarg.h>
 #include <sys/param.h>
@@ -41,6 +47,7 @@
 #include <miscfs/specfs/specdev.h>
 #include <miscfs/devfs/devfs.h>
 #include <sys/filio.h>
+#include <architecture/byte_order.h>
 #include <kern/locks.h>
 #include <libkern/OSAtomic.h>
 
@@ -87,7 +94,6 @@ typedef struct fs_event_watcher {
     int32_t      eventq_size;            // number of event pointers in queue
     int32_t      rd, wr;                 // indices to the event_queue
     int32_t      blockers;
-    int32_t      num_readers;
 } fs_event_watcher;
 
 // fs_event_watcher flags
@@ -249,7 +255,7 @@ add_fsevent(int type, vfs_context_t ctx, ...)
     kfs_event        *kfse;
     fs_event_watcher *watcher;
     va_list           ap;
-    int              error = 0, base;
+    int              error = 0;
     dev_t             dev = 0;
 
     va_start(ap, ctx);
@@ -267,9 +273,8 @@ add_fsevent(int type, vfs_context_t ctx, ...)
     //       the lock is dropped.
     lock_fs_event_buf();
     
-    base = free_event_idx;
     for(i=0; i < MAX_KFS_EVENTS; i++) {
-       if (fs_event_buf[(base + i) % MAX_KFS_EVENTS].type == FSE_INVALID) {
+       if (fs_event_buf[(free_event_idx + i) % MAX_KFS_EVENTS].type == FSE_INVALID) {
            break;
        }
     }
@@ -291,12 +296,12 @@ add_fsevent(int type, vfs_context_t ctx, ...)
        return ENOSPC;
     }
 
-    kfse = &fs_event_buf[(base + i) % MAX_KFS_EVENTS];
+    kfse = &fs_event_buf[(free_event_idx + i) % MAX_KFS_EVENTS];
 
-    free_event_idx = ((base + i) % MAX_KFS_EVENTS) + 1;
+    free_event_idx++;
     
     kfse->type     = type;
-    kfse->refcount = 1;
+    kfse->refcount = 0;
     kfse->pid      = p->p_pid;
 
     unlock_fs_event_buf();  // at this point it's safe to unlock
@@ -463,8 +468,9 @@ add_fsevent(int type, vfs_context_t ctx, ...)
     
   clean_up:
     // just in case no one was interested after all...
-    if (OSAddAtomic(-1, (SInt32 *)&kfse->refcount) == 1) {
+    if (num_deliveries == 0) {
        do_free_event(kfse);
+       free_event_idx = (int)(kfse - &fs_event_buf[0]);
     }  
 
     lck_rw_done(&fsevent_big_lock);
@@ -479,10 +485,8 @@ do_free_event(kfs_event *kfse)
     
     lock_fs_event_buf();
     
-    if (kfse->refcount > 0) {
-       panic("do_free_event: free'ing a kfsevent w/refcount == %d (kfse %p)\n",
-           kfse->refcount, kfse);
-    }
+    // mark this fsevent as invalid
+    kfse->type = FSE_INVALID;
 
     // make a copy of this so we can free things without
     // holding the fs_event_buf lock
@@ -492,9 +496,6 @@ do_free_event(kfs_event *kfse)
     // and just to be anal, set this so that there are no args
     kfse->args[0].type = FSE_ARG_DONE;
     
-    // mark this fsevent as invalid
-    kfse->type = FSE_INVALID;
-
     free_event_idx = (kfse - fs_event_buf);
 
     unlock_fs_event_buf();
@@ -547,7 +548,6 @@ add_watcher(int8_t *event_list, int32_t num_events, int32_t eventq_size, fs_even
     watcher->rd           = 0;
     watcher->wr           = 0;
     watcher->blockers     = 0;
-    watcher->num_readers  = 0;
 
     lock_watch_list();
 
@@ -656,15 +656,9 @@ fmod_watch(fs_event_watcher *watcher, struct uio *uio)
        return EINVAL;
     }
 
-    if (OSAddAtomic(1, (SInt32 *)&watcher->num_readers) != 0) {
-       // don't allow multiple threads to read from the fd at the same time
-       OSAddAtomic(-1, (SInt32 *)&watcher->num_readers);
-       return EAGAIN;
-    }
 
     if (watcher->rd == watcher->wr) {
        if (watcher->flags & WATCHER_CLOSING) {
-           OSAddAtomic(-1, (SInt32 *)&watcher->num_readers);
            return 0;
        }
        OSAddAtomic(1, (SInt32 *)&watcher->blockers);
@@ -675,7 +669,6 @@ fmod_watch(fs_event_watcher *watcher, struct uio *uio)
        OSAddAtomic(-1, (SInt32 *)&watcher->blockers);
 
        if (error != 0 || (watcher->flags & WATCHER_CLOSING)) {
-           OSAddAtomic(-1, (SInt32 *)&watcher->num_readers);
            return error;
        }
     }
@@ -694,7 +687,6 @@ fmod_watch(fs_event_watcher *watcher, struct uio *uio)
        } 
 
        if (error) {
-           OSAddAtomic(-1, (SInt32 *)&watcher->num_readers);
            return error;
        }
        
@@ -864,7 +856,6 @@ fmod_watch(fs_event_watcher *watcher, struct uio *uio)
     }
 
   get_out:
-    OSAddAtomic(-1, (SInt32 *)&watcher->num_readers);
     return error;
 }
 
@@ -917,9 +908,6 @@ fsevent_unmount(struct mount *mp)
 
                        if (vname)
                                vnode_putname(vname);
-
-                       strcpy(pathbuff, "UNKNOWN-FILE");
-                       pathbuff_len = strlen(pathbuff) + 1;
                }
 
                // switch the type of the string