xnu-1228.tar.gz

[apple/xnu.git] / iokit / IOKit / IOLib.h

diff --git a/iokit/IOKit/IOLib.h b/iokit/IOKit/IOLib.h
index ccbf5554c4f43045c92e11091feb9d831fd64e60..dc85274ae5612bbafb273317ca8fa7e0e2fe5010 100644 (file)
--- a/iokit/IOKit/IOLib.h
+++ b/iokit/IOKit/IOLib.h
@@ -1,23 +1,29 @@
 /*
  * Copyright (c) 1998-2000 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@
  */
 /*
  * Copyright (c) 1998 Apple Computer, Inc.  All rights reserved. 
@@ -248,7 +254,7 @@ IOReturn IOFlushProcessorCache( task_t task, IOVirtualAddress address,
 
 /*! @function IOCreateThread
     @abstract Create a kernel thread.
-    @discussion This function creates a kernel thread, and passes the caller supplied argument to the new thread.
+    @discussion This function creates a kernel thread, and passes the caller supplied argument to the new thread.  Warning: the value returned by this function is not 100% reliable.  There is a race condition where it is possible that the new thread has already terminated before this call returns.  Under that circumstance the IOThread returned will be invalid.  In general there is little that can be done with this value except compare it against 0.  The thread itself can call IOThreadSelf() 100% reliably and that is the prefered mechanism to manipulate the IOThreads state.
     @param function A C-function pointer where the thread will begin execution.
     @param argument Caller specified data to be passed to the new thread.
     @result An IOThread identifier for the new thread, equivalent to an osfmk thread_t. */
@@ -275,6 +281,13 @@ void IOSleep(unsigned milliseconds);
 
 void IODelay(unsigned microseconds);
 
+/*! @function IOPause
+    @abstract Spin delay for a number of nanoseconds.
+    @discussion This function spins to delay for at least the number of specified nanoseconds. Since the CPU is busy spinning no time is made available to other processes; this method of delay should be used only for short periods.
+    @param microseconds The integer number of nanoseconds to spin wait. */
+
+void IOPause(unsigned nanoseconds);
+
 /*! @function IOLog
     @abstract Log a message to console in text mode, and /var/log/system.log.
     @discussion This function allows a driver to log diagnostic information to the screen during verbose boots, and to a log file found at /var/log/system.log. IOLog should not be called from interrupt context.