libcfs/include/libcfs/libcfs_prim.h

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * GPL HEADER START
   5  *
   6  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 only,
  10  * as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License version 2 for more details (a copy is included
  16  * in the LICENSE file that accompanied this code).
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * version 2 along with this program; If not, see
  20  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  21  *
  22  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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  24  * have any questions.
  25  *
  26  * GPL HEADER END
  27  */
  28 /*
  29  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  30  * Use is subject to license terms.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  *
  36  * libcfs/include/libcfs/libcfs_prim.h
  37  *
  38  * General primitives.
  39  *
  40  */
  41
  42 #ifndef __LIBCFS_PRIM_H__
  43 #define __LIBCFS_PRIM_H__
  44
  45 #ifndef CFS_EXPORT_SYMBOL
  46 # define CFS_EXPORT_SYMBOL(s)
  47 #endif
  48
  49 /*
  50  * Schedule
  51  */
  52 void cfs_schedule_timeout_and_set_state(cfs_task_state_t state,
  53                                         int64_t timeout);
  54 void cfs_schedule_timeout(int64_t timeout);
  55 void cfs_schedule(void);
  56 void cfs_pause(cfs_duration_t ticks);
  57 int  cfs_need_resched(void);
  58 void cfs_cond_resched(void);
  59
  60 /*
  61  * Wait Queues
  62  */
  63 void cfs_waitq_init(cfs_waitq_t *waitq);
  64 void cfs_waitlink_init(cfs_waitlink_t *link);
  65 void cfs_waitq_add(cfs_waitq_t *waitq, cfs_waitlink_t *link);
  66 void cfs_waitq_add_exclusive(cfs_waitq_t *waitq,
  67                              cfs_waitlink_t *link);
  68 void cfs_waitq_add_exclusive_head(cfs_waitq_t *waitq,
  69                                   cfs_waitlink_t *link);
  70 void cfs_waitq_del(cfs_waitq_t *waitq, cfs_waitlink_t *link);
  71 int  cfs_waitq_active(cfs_waitq_t *waitq);
  72 void cfs_waitq_signal(cfs_waitq_t *waitq);
  73 void cfs_waitq_signal_nr(cfs_waitq_t *waitq, int nr);
  74 void cfs_waitq_broadcast(cfs_waitq_t *waitq);
  75 void cfs_waitq_wait(cfs_waitlink_t *link, cfs_task_state_t state);
  76 int64_t cfs_waitq_timedwait(cfs_waitlink_t *link, cfs_task_state_t state,
  77                             int64_t timeout);
  78
  79 /*
  80  * Timer
  81  */
  82 typedef  void (cfs_timer_func_t)(ulong_ptr_t);
  83
  84 void cfs_init_timer(cfs_timer_t *t);
  85 void cfs_timer_init(cfs_timer_t *t, cfs_timer_func_t *func, void *arg);
  86 void cfs_timer_done(cfs_timer_t *t);
  87 void cfs_timer_arm(cfs_timer_t *t, cfs_time_t deadline);
  88 void cfs_timer_disarm(cfs_timer_t *t);
  89 int  cfs_timer_is_armed(cfs_timer_t *t);
  90 cfs_time_t cfs_timer_deadline(cfs_timer_t *t);
  91
  92 /*
  93  * Memory
  94  */
  95 #ifndef cfs_memory_pressure_get
  96 #define cfs_memory_pressure_get() (0)
  97 #endif
  98 #ifndef cfs_memory_pressure_set
  99 #define cfs_memory_pressure_set() do {} while (0)
 100 #endif
 101 #ifndef cfs_memory_pressure_clr
 102 #define cfs_memory_pressure_clr() do {} while (0)
 103 #endif
 104
 105 static inline int cfs_memory_pressure_get_and_set(void)
 106 {
 107         int old = cfs_memory_pressure_get();
 108
 109         if (!old)
 110                 cfs_memory_pressure_set();
 111         return old;
 112 }
 113
 114 static inline void cfs_memory_pressure_restore(int old)
 115 {
 116         if (old)
 117                 cfs_memory_pressure_set();
 118         else
 119                 cfs_memory_pressure_clr();
 120         return;
 121 }
 122 #endif