Line data Source code
1 : /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 : /* This Source Code Form is subject to the terms of the Mozilla Public
3 : * License, v. 2.0. If a copy of the MPL was not distributed with this
4 : * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
5 :
6 : /*
7 : ** File: prinrval.h
8 : ** Description: API to interval timing functions of NSPR.
9 : **
10 : **
11 : ** NSPR provides interval times that are independent of network time
12 : ** of day values. Interval times are (in theory) accurate regardless
13 : ** of host processing requirements and also very cheap to acquire. It
14 : ** is expected that getting an interval time while in a synchronized
15 : ** function (holding one's lock).
16 : **/
17 :
18 : #if !defined(prinrval_h)
19 : #define prinrval_h
20 :
21 : #include "prtypes.h"
22 :
23 : PR_BEGIN_EXTERN_C
24 :
25 : /**********************************************************************/
26 : /************************* TYPES AND CONSTANTS ************************/
27 : /**********************************************************************/
28 :
29 : typedef PRUint32 PRIntervalTime;
30 :
31 : /***********************************************************************
32 : ** DEFINES: PR_INTERVAL_MIN
33 : ** PR_INTERVAL_MAX
34 : ** DESCRIPTION:
35 : ** These two constants define the range (in ticks / second) of the
36 : ** platform dependent type, PRIntervalTime. These constants bound both
37 : ** the period and the resolution of a PRIntervalTime.
38 : ***********************************************************************/
39 : #define PR_INTERVAL_MIN 1000UL
40 : #define PR_INTERVAL_MAX 100000UL
41 :
42 : /***********************************************************************
43 : ** DEFINES: PR_INTERVAL_NO_WAIT
44 : ** PR_INTERVAL_NO_TIMEOUT
45 : ** DESCRIPTION:
46 : ** Two reserved constants are defined in the PRIntervalTime namespace.
47 : ** They are used to indicate that the process should wait no time (return
48 : ** immediately) or wait forever (never time out), respectively.
49 : ** Note: PR_INTERVAL_NO_TIMEOUT passed as input to PR_Connect is
50 : ** interpreted as use the OS's connect timeout.
51 : **
52 : ***********************************************************************/
53 : #define PR_INTERVAL_NO_WAIT 0UL
54 : #define PR_INTERVAL_NO_TIMEOUT 0xffffffffUL
55 :
56 : /**********************************************************************/
57 : /****************************** FUNCTIONS *****************************/
58 : /**********************************************************************/
59 :
60 : /***********************************************************************
61 : ** FUNCTION: PR_IntervalNow
62 : ** DESCRIPTION:
63 : ** Return the value of NSPR's free running interval timer. That timer
64 : ** can be used to establish epochs and determine intervals (be computing
65 : ** the difference between two times).
66 : ** INPUTS: void
67 : ** OUTPUTS: void
68 : ** RETURN: PRIntervalTime
69 : **
70 : ** SIDE EFFECTS:
71 : ** None
72 : ** RESTRICTIONS:
73 : ** The units of PRIntervalTime are platform dependent. They are chosen
74 : ** such that they are appropriate for the host OS, yet provide sufficient
75 : ** resolution and period to be useful to clients.
76 : ** MEMORY: N/A
77 : ** ALGORITHM: Platform dependent
78 : ***********************************************************************/
79 4527 : NSPR_API(PRIntervalTime) PR_IntervalNow(void);
80 :
81 : /***********************************************************************
82 : ** FUNCTION: PR_TicksPerSecond
83 : ** DESCRIPTION:
84 : ** Return the number of ticks per second for PR_IntervalNow's clock.
85 : ** The value will be in the range [PR_INTERVAL_MIN..PR_INTERVAL_MAX].
86 : ** INPUTS: void
87 : ** OUTPUTS: void
88 : ** RETURN: PRUint32
89 : **
90 : ** SIDE EFFECTS:
91 : ** None
92 : ** RESTRICTIONS:
93 : ** None
94 : ** MEMORY: N/A
95 : ** ALGORITHM: N/A
96 : ***********************************************************************/
97 2052 : NSPR_API(PRUint32) PR_TicksPerSecond(void);
98 :
99 : /***********************************************************************
100 : ** FUNCTION: PR_SecondsToInterval
101 : ** PR_MillisecondsToInterval
102 : ** PR_MicrosecondsToInterval
103 : ** DESCRIPTION:
104 : ** Convert standard clock units to platform dependent intervals.
105 : ** INPUTS: PRUint32
106 : ** OUTPUTS: void
107 : ** RETURN: PRIntervalTime
108 : **
109 : ** SIDE EFFECTS:
110 : ** None
111 : ** RESTRICTIONS:
112 : ** Conversion may cause overflow, which is not reported.
113 : ** MEMORY: N/A
114 : ** ALGORITHM: N/A
115 : ***********************************************************************/
116 42 : NSPR_API(PRIntervalTime) PR_SecondsToInterval(PRUint32 seconds);
117 1323 : NSPR_API(PRIntervalTime) PR_MillisecondsToInterval(PRUint32 milli);
118 384 : NSPR_API(PRIntervalTime) PR_MicrosecondsToInterval(PRUint32 micro);
119 :
120 : /***********************************************************************
121 : ** FUNCTION: PR_IntervalToSeconds
122 : ** PR_IntervalToMilliseconds
123 : ** PR_IntervalToMicroseconds
124 : ** DESCRIPTION:
125 : ** Convert platform dependent intervals to standard clock units.
126 : ** INPUTS: PRIntervalTime
127 : ** OUTPUTS: void
128 : ** RETURN: PRUint32
129 : **
130 : ** SIDE EFFECTS:
131 : ** None
132 : ** RESTRICTIONS:
133 : ** Conversion may cause overflow, which is not reported.
134 : ** MEMORY: N/A
135 : ** ALGORITHM: N/A
136 : ***********************************************************************/
137 60 : NSPR_API(PRUint32) PR_IntervalToSeconds(PRIntervalTime ticks);
138 14 : NSPR_API(PRUint32) PR_IntervalToMilliseconds(PRIntervalTime ticks);
139 162 : NSPR_API(PRUint32) PR_IntervalToMicroseconds(PRIntervalTime ticks);
140 :
141 : PR_END_EXTERN_C
142 :
143 :
144 : #endif /* !defined(prinrval_h) */
145 :
146 : /* prinrval.h */
|
