/* * Copyright (c) 2000-2007 Apple Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * * 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. * * 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, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* * @OSF_COPYRIGHT@ */ /* * Mach Operating System * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University * All Rights Reserved. * * Permission to use, copy, modify and distribute this software and its * documentation is hereby granted, provided that both the copyright * notice and this permission notice appear in all copies of the * software, derivative works or modified versions, and any portions * thereof, and that both notices appear in supporting documentation. * * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. * * Carnegie Mellon requests users of this software to return to * * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU * School of Computer Science * Carnegie Mellon University * Pittsburgh PA 15213-3890 * * any improvements or extensions that they make and grant Carnegie Mellon * the rights to redistribute these changes. */ /* */ #ifndef _KERN_TIMER_H_ #define _KERN_TIMER_H_ #include <kern/kern_types.h> /* * Some platforms have very expensive timebase routines. An optimization * is to avoid switching timers on kernel exit/entry, which results in all * time billed to the system timer. However, when exposed to userspace, * we report as user time to indicate that work was done on behalf of * userspace. * * Although this policy is implemented as a global variable, we snapshot it * at key points in the thread structure (when the thread is locked and * executing in the kernel) to avoid imbalances. */ extern int precise_user_kernel_time; /* * thread must be locked, or be the current executing thread, so that * it doesn't transition from user to kernel while updating the * thread-local value (or in kernel debugger context). In the future, * we make take into account task-level or thread-level policy. */ #define use_precise_user_kernel_time(thread) (precise_user_kernel_time) /* * Definitions for high resolution timers. */ #if __LP64__ #define TIMER_ALIGNMENT #else #define TIMER_ALIGNMENT __attribute__((packed, aligned(4))) #endif struct timer { uint64_t tstamp; #if defined(__LP64__) uint64_t all_bits; #else /* defined(__LP64__) */ /* A check word on the high portion allows atomic updates. */ uint32_t low_bits; uint32_t high_bits; uint32_t high_bits_check; #endif /* !defined(__LP64__) */ } TIMER_ALIGNMENT; typedef struct timer timer_data_t, *timer_t; /* * Initialize the `timer`. */ void timer_init(timer_t timer); /* * Start the `timer` at time `tstamp`. */ void timer_start(timer_t timer, uint64_t tstamp); /* * Stop the `timer` and update it with time `tstamp`. */ void timer_stop(timer_t timer, uint64_t tstamp); /* * Update the `timer` at time `tstamp`, leaving it running. */ void timer_update(timer_t timer, uint64_t tstamp); /* * Update the `timer` with time `tstamp` and start `new_timer`. */ void timer_switch(timer_t timer, uint64_t tstamp, timer_t new_timer); /* * Update the thread timer at an "event," like a context switch, at time * `tstamp`. This stops the current timer and starts the `new_timer` running. * * Must be called with interrupts disabled. */ void processor_timer_switch_thread(uint64_t tstamp, timer_t new_timer); /* * Return the difference between the `timer` and a previous value pointed to by * `prev_in_cur_out`. Store the current value of the timer to * `prev_in_cur_out`. */ uint64_t timer_delta(timer_t timer, uint64_t *prev_in_cur_out); /* * Read the accumulated time of `timer`. */ #if defined(__LP64__) static inline uint64_t timer_grab(timer_t timer) { return timer->all_bits; } #else /* defined(__LP64__) */ uint64_t timer_grab(timer_t timer); #endif /* !defined(__LP64__) */ #endif /* _KERN_TIMER_H_ */