Rev 1264 | Rev 1433 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 1 | jermar | 1 | /* |
| 2 | * Copyright (C) 2001-2004 Jakub Jermar |
||
| 3 | * All rights reserved. |
||
| 4 | * |
||
| 5 | * Redistribution and use in source and binary forms, with or without |
||
| 6 | * modification, are permitted provided that the following conditions |
||
| 7 | * are met: |
||
| 8 | * |
||
| 9 | * - Redistributions of source code must retain the above copyright |
||
| 10 | * notice, this list of conditions and the following disclaimer. |
||
| 11 | * - Redistributions in binary form must reproduce the above copyright |
||
| 12 | * notice, this list of conditions and the following disclaimer in the |
||
| 13 | * documentation and/or other materials provided with the distribution. |
||
| 14 | * - The name of the author may not be used to endorse or promote products |
||
| 15 | * derived from this software without specific prior written permission. |
||
| 16 | * |
||
| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
||
| 18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
||
| 19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
||
| 20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
||
| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
||
| 22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
||
| 23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
||
| 24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
||
| 25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
||
| 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
||
| 27 | */ |
||
| 28 | |||
| 1264 | jermar | 29 | /** |
| 30 | * @file clock.c |
||
| 31 | * @brief High-level clock interrupt handler. |
||
| 32 | * |
||
| 33 | * This file contains the clock() function which is the source |
||
| 34 | * of preemption. It is also responsible for executing expired |
||
| 35 | * timeouts. |
||
| 36 | */ |
||
| 37 | |||
| 1 | jermar | 38 | #include <time/clock.h> |
| 39 | #include <time/timeout.h> |
||
| 40 | #include <arch/types.h> |
||
| 41 | #include <config.h> |
||
| 42 | #include <synch/spinlock.h> |
||
| 43 | #include <synch/waitq.h> |
||
| 44 | #include <func.h> |
||
| 45 | #include <proc/scheduler.h> |
||
| 46 | #include <cpu.h> |
||
| 47 | #include <arch.h> |
||
| 788 | jermar | 48 | #include <adt/list.h> |
| 1104 | jermar | 49 | #include <atomic.h> |
| 391 | jermar | 50 | #include <proc/thread.h> |
| 1 | jermar | 51 | |
| 107 | decky | 52 | /** Clock routine |
| 53 | * |
||
| 54 | * Clock routine executed from clock interrupt handler |
||
| 413 | jermar | 55 | * (assuming interrupts_disable()'d). Runs expired timeouts |
| 107 | decky | 56 | * and preemptive scheduling. |
| 57 | * |
||
| 1 | jermar | 58 | */ |
| 59 | void clock(void) |
||
| 60 | { |
||
| 61 | link_t *l; |
||
| 62 | timeout_t *h; |
||
| 411 | jermar | 63 | timeout_handler_t f; |
| 1 | jermar | 64 | void *arg; |
| 1431 | jermar | 65 | int i; |
| 1 | jermar | 66 | |
| 67 | /* |
||
| 68 | * To avoid lock ordering problems, |
||
| 69 | * run all expired timeouts as you visit them. |
||
| 70 | */ |
||
| 1431 | jermar | 71 | for (i = 0; i < CPU->missed_clock_ticks; i++) { |
| 72 | spinlock_lock(&CPU->timeoutlock); |
||
| 73 | while ((l = CPU->timeout_active_head.next) != &CPU->timeout_active_head) { |
||
| 74 | h = list_get_instance(l, timeout_t, link); |
||
| 75 | spinlock_lock(&h->lock); |
||
| 76 | if (h->ticks-- != 0) { |
||
| 77 | spinlock_unlock(&h->lock); |
||
| 78 | break; |
||
| 79 | } |
||
| 80 | list_remove(l); |
||
| 81 | f = h->handler; |
||
| 82 | arg = h->arg; |
||
| 83 | timeout_reinitialize(h); |
||
| 84 | spinlock_unlock(&h->lock); |
||
| 85 | spinlock_unlock(&CPU->timeoutlock); |
||
| 86 | |||
| 87 | f(arg); |
||
| 88 | |||
| 89 | spinlock_lock(&CPU->timeoutlock); |
||
| 1 | jermar | 90 | } |
| 15 | jermar | 91 | spinlock_unlock(&CPU->timeoutlock); |
| 1 | jermar | 92 | } |
| 1431 | jermar | 93 | CPU->missed_clock_ticks = 0; |
| 1 | jermar | 94 | |
| 95 | /* |
||
| 15 | jermar | 96 | * Do CPU usage accounting and find out whether to preempt THREAD. |
| 1 | jermar | 97 | */ |
| 98 | |||
| 15 | jermar | 99 | if (THREAD) { |
| 221 | jermar | 100 | __u64 ticks; |
| 101 | |||
| 15 | jermar | 102 | spinlock_lock(&CPU->lock); |
| 103 | CPU->needs_relink++; |
||
| 104 | spinlock_unlock(&CPU->lock); |
||
| 1 | jermar | 105 | |
| 15 | jermar | 106 | spinlock_lock(&THREAD->lock); |
| 615 | palkovsky | 107 | if ((ticks = THREAD->ticks)) |
| 221 | jermar | 108 | THREAD->ticks--; |
| 109 | spinlock_unlock(&THREAD->lock); |
||
| 110 | |||
| 111 | if (!ticks && !PREEMPTION_DISABLED) { |
||
| 1 | jermar | 112 | scheduler(); |
| 113 | } |
||
| 114 | } |
||
| 115 | |||
| 116 | } |