1/*
2 * Copyright (c) 2010 Apple Inc. All rights reserved.
3 *
4 * @APPLE_LICENSE_HEADER_START@
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
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9 *
10 * 1.  Redistributions of source code must retain the above copyright
11 *     notice, this list of conditions and the following disclaimer.
12 * 2.  Redistributions in binary form must reproduce the above copyright
13 *     notice, this list of conditions and the following disclaimer in the
14 *     documentation and/or other materials provided with the distribution.
15 * 3.  Neither the name of Apple Inc. ("Apple") nor the names of its
16 *     contributors may be used to endorse or promote products derived from
17 *     this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
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21 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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24 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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30 * Portions of this software have been released under the following terms:
31 *
32 * (c) Copyright 1989-1993 OPEN SOFTWARE FOUNDATION, INC.
33 * (c) Copyright 1989-1993 HEWLETT-PACKARD COMPANY
34 * (c) Copyright 1989-1993 DIGITAL EQUIPMENT CORPORATION
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36 * To anyone who acknowledges that this file is provided "AS IS"
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48 *
49 * Copyright (c) 2007, Novell, Inc. All rights reserved.
50 * Redistribution and use in source and binary forms, with or without
51 * modification, are permitted provided that the following conditions
52 * are met:
53 *
54 * 1.  Redistributions of source code must retain the above copyright
55 *     notice, this list of conditions and the following disclaimer.
56 * 2.  Redistributions in binary form must reproduce the above copyright
57 *     notice, this list of conditions and the following disclaimer in the
58 *     documentation and/or other materials provided with the distribution.
59 * 3.  Neither the name of Novell Inc. nor the names of its contributors
60 *     may be used to endorse or promote products derived from this
61 *     this software without specific prior written permission.
62 *
63 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
64 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
65 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
66 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY
67 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
68 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
69 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
70 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
71 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
72 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
73 *
74 * @APPLE_LICENSE_HEADER_END@
75 */
76
77/*
78**
79**  NAME
80**
81**      rpctimer.h
82**
83**  FACILITY:
84**
85**      Remote Procedure Call (RPC)
86**
87**  ABSTRACT:
88**
89**  Interface to NCK timer functions.
90**
91**  Suggested uasge:  These routines are tailored for the situation
92**  in which a monitor routine is needed to keep track of the state
93**  of a data structure.  In this case, one of the fields in the data
94**  structure should be a rpc_timer_t (defined below).  The user of the
95**  timer service would then call the rpc__timer_set routine with the
96**  following arguments:
97**
98**      1) the address of the rpc_timer_t variable
99**      2) the address of the routine to run
100**      3) a dce_pointer_t value to be sent to the routine when run
101**      4) the frequency with which the routine should be run
102**
103**  The pointer value used will most often be the address of the data
104**  structure being monitored.  (However, it also possible to declare
105**  a global rpc_timer_t to be used to periodically run a routine not
106**  associated with any particular data object.  N.B.  It is necessary
107**  that the rpc_timer_t variable exist during the entire time that the
108**  periodic routine is registered to run;  that is, don't declare it on
109**  the stack if the current routine will return before unregistering the
110**  periodic routine.)
111**
112**  Users of this service should not keep track of time by the frequency
113**  with which their periodic routines are run.  Aside from the lack of
114**  accuracy of user space time functions, it is also possible that the
115**  system's idea of the current time may be changed at any time.  When
116**  necessary, the routines currently err in favor of running a periodic
117**  routine too early rather than too late.  For this reason, data
118**  struture monitoring should follow this outline:
119**
120**      struct {
121**          .....
122**          rpc_clock_t        timestamp;
123**          rpc_timer_t        timer;
124**          .....
125**      } foo;
126**
127**      rpc__clock_stamp( &foo.timestamp );
128**
129**      rpc__timer_set( &foo.timer, foo_mon, &foo, rpc_timer_sec(1) );
130**          ...
131**
132**      void foo_mon( parg )
133**      dce_pointer_t parg;
134**      {
135**          if( rpc__clock_aged( parg->timestamp, rpc_timer_sec( 1 ) )
136**          {
137**            ...
138**          }
139**      }
140**
141**
142**
143*/
144
145#ifndef _RPCTIMER_H
146#define _RPCTIMER_H
147
148typedef void (*rpc_timer_proc_p_t) ( dce_pointer_t );
149
150/*
151 * This type is used to create a list of periodic functions ordered by
152 * trigger time.
153 */
154typedef struct rpc_timer_t
155{
156    struct rpc_timer_t   *next;
157    rpc_clock_t          trigger;
158    rpc_clock_t          frequency;
159    rpc_timer_proc_p_t   proc;
160    dce_pointer_t            parg;
161} rpc_timer_t, *rpc_timer_p_t;
162
163/*
164 * Initialize the timer package.
165 */
166PRIVATE void rpc__timer_init (void);
167
168/*
169 * Timer package fork handling routine
170 */
171PRIVATE void rpc__timer_fork_handler (
172    rpc_fork_stage_id_t  /*stage*/
173);
174
175/*
176 * Shutdown the timer package.
177 */
178PRIVATE void rpc__timer_shutdown (void);
179
180/*
181 * Register a routine to be run at a specific interval.
182 */
183PRIVATE void rpc__timer_set (
184    rpc_timer_p_t /*t*/,
185    rpc_timer_proc_p_t /*proc*/,
186    dce_pointer_t /*parg*/,
187    rpc_clock_t  /*freq*/
188);
189
190/*
191 * Change one or more of the characteristics of a periodic routine.
192 */
193PRIVATE void rpc__timer_adjust (
194    rpc_timer_p_t /*t*/,
195    rpc_clock_t /*freq*/
196);
197
198/*
199 * Discontinue running a previously registered periodic routine.
200 */
201PRIVATE void rpc__timer_clear (rpc_timer_p_t /*t*/);
202
203/*
204 * Run any periodic routines that are ready.  Return the amount of time
205 * until the next scheduled routine should be run.
206 */
207PRIVATE rpc_clock_t rpc__timer_callout (void);
208
209#endif /* _RPCTIMER_H */
210