xref: /third_party/mesa3d/src/util/os_time.h (revision bf215546) 
1/**************************************************************************
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27
28/**
29 * @file
30 * OS independent time-manipulation functions.
31 *
32 * @author Jose Fonseca <jfonseca@vmware.com>
33 */
34
35#ifndef _OS_TIME_H_
36#define _OS_TIME_H_
37
38#include <stdbool.h>
39#include <stdint.h>
40#include <time.h>
41
42#ifdef __cplusplus
43extern "C" {
44#endif
45
46/* must be equal to PIPE_TIMEOUT_INFINITE */
47#define OS_TIMEOUT_INFINITE 0xffffffffffffffffull
48
49/*
50 * Get the current time in nanoseconds from an unknown base.
51 */
52int64_t
53os_time_get_nano(void);
54
55
56/*
57 * Get the current time in microseconds from an unknown base.
58 */
59static inline int64_t
60os_time_get(void)
61{
62   return os_time_get_nano() / 1000;
63}
64
65
66static inline struct tm *
67os_localtime(const time_t *timer, struct tm *buf)
68{
69#ifdef _WIN32
70   return localtime_s(buf, timer) ? NULL : buf;
71#else
72   return localtime_r(timer, buf);
73#endif
74}
75
76
77/*
78 * Sleep.
79 */
80void
81os_time_sleep(int64_t usecs);
82
83
84/*
85 * Helper function for detecting time outs, taking in account overflow.
86 *
87 * Returns true if the current time has elapsed beyond the specified interval.
88 */
89static inline bool
90os_time_timeout(int64_t start,
91                int64_t end,
92                int64_t curr)
93{
94   if (start <= end)
95      return !(start <= curr && curr < end);
96   else
97      return !((start <= curr) || (curr < end));
98}
99
100
101/**
102 * Convert a relative timeout in nanoseconds into an absolute timeout,
103 * in other words, it returns current time + timeout.
104 * os_time_get_nano() must be monotonic.
105 * OS_TIMEOUT_INFINITE is passed through unchanged. If the calculation
106 * overflows, OS_TIMEOUT_INFINITE is returned.
107 */
108int64_t
109os_time_get_absolute_timeout(uint64_t timeout);
110
111
112/**
113 * Wait until the variable at the given memory location is zero.
114 *
115 * \param var           variable
116 * \param timeout       timeout in ns, can be anything from 0 (no wait) to
117 *                      OS_TIMEOUT_INFINITE (wait forever)
118 * \return     true if the variable is zero
119 */
120bool
121os_wait_until_zero(volatile int *var, uint64_t timeout);
122
123
124/**
125 * Wait until the variable at the given memory location is zero.
126 * The timeout is the absolute time when the waiting should stop. If it is
127 * less than or equal to the current time, it only returns the status and
128 * doesn't wait. OS_TIMEOUT_INFINITE waits forever. This requires that
129 * os_time_get_nano is monotonic.
130 *
131 * \param var       variable
132 * \param timeout   the time in ns when the waiting should stop
133 * \return     true if the variable is zero
134 */
135bool
136os_wait_until_zero_abs_timeout(volatile int *var, int64_t timeout);
137
138#ifdef __cplusplus
139}
140#endif
141
142#endif /* _OS_TIME_H_ */
143