xref: /third_party/mesa3d/src/util/os_time.c (revision bf215546) 
1/**************************************************************************
2 *
3 * Copyright 2008-2010 VMware, Inc.
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11 * permit persons to whom the Software is furnished to do so, subject to
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14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
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19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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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#include "os_time.h"
36#include "detect_os.h"
37
38#include "util/u_atomic.h"
39
40#if DETECT_OS_UNIX
41#  include <unistd.h> /* usleep */
42#  include <time.h> /* timeval */
43#  include <sys/time.h> /* timeval */
44#  include <sched.h> /* sched_yield */
45#  include <errno.h>
46#elif DETECT_OS_WINDOWS
47#  include <windows.h>
48#else
49#  error Unsupported OS
50#endif
51
52
53int64_t
54os_time_get_nano(void)
55{
56#if DETECT_OS_LINUX || DETECT_OS_BSD
57
58   struct timespec tv;
59   clock_gettime(CLOCK_MONOTONIC, &tv);
60   return tv.tv_nsec + tv.tv_sec*INT64_C(1000000000);
61
62#elif DETECT_OS_UNIX
63
64   struct timeval tv;
65   gettimeofday(&tv, NULL);
66   return tv.tv_usec*INT64_C(1000) + tv.tv_sec*INT64_C(1000000000);
67
68#elif DETECT_OS_WINDOWS
69
70   LARGE_INTEGER frequency;
71   LARGE_INTEGER counter;
72   int64_t secs, nanosecs;
73   QueryPerformanceFrequency(&frequency);
74   QueryPerformanceCounter(&counter);
75   /* Compute seconds and nanoseconds parts separately to
76    * reduce severity of precision loss.
77    */
78   secs = counter.QuadPart / frequency.QuadPart;
79   nanosecs = (counter.QuadPart % frequency.QuadPart) * INT64_C(1000000000)
80      / frequency.QuadPart;
81   return secs*INT64_C(1000000000) + nanosecs;
82
83#else
84
85#error Unsupported OS
86
87#endif
88}
89
90
91
92void
93os_time_sleep(int64_t usecs)
94{
95#if DETECT_OS_LINUX
96   struct timespec time;
97   time.tv_sec = usecs / 1000000;
98   time.tv_nsec = (usecs % 1000000) * 1000;
99   while (clock_nanosleep(CLOCK_MONOTONIC, 0, &time, &time) == EINTR);
100
101#elif DETECT_OS_UNIX
102   usleep(usecs);
103
104#elif DETECT_OS_WINDOWS
105   DWORD dwMilliseconds = (DWORD) ((usecs + 999) / 1000);
106   /* Avoid Sleep(O) as that would cause to sleep for an undetermined duration */
107   if (dwMilliseconds) {
108      Sleep(dwMilliseconds);
109   }
110#else
111#  error Unsupported OS
112#endif
113}
114
115
116
117int64_t
118os_time_get_absolute_timeout(uint64_t timeout)
119{
120   int64_t time, abs_timeout;
121
122   /* Also check for the type upper bound. */
123   if (timeout == OS_TIMEOUT_INFINITE || timeout > INT64_MAX)
124      return OS_TIMEOUT_INFINITE;
125
126   time = os_time_get_nano();
127   abs_timeout = time + (int64_t)timeout;
128
129   /* Check for overflow. */
130   if (abs_timeout < time)
131      return OS_TIMEOUT_INFINITE;
132
133   return abs_timeout;
134}
135
136
137bool
138os_wait_until_zero(volatile int *var, uint64_t timeout)
139{
140   if (!p_atomic_read(var))
141      return true;
142
143   if (!timeout)
144      return false;
145
146   if (timeout == OS_TIMEOUT_INFINITE) {
147      while (p_atomic_read(var)) {
148#if DETECT_OS_UNIX
149         sched_yield();
150#endif
151      }
152      return true;
153   }
154   else {
155      int64_t start_time = os_time_get_nano();
156      int64_t end_time = start_time + timeout;
157
158      while (p_atomic_read(var)) {
159         if (os_time_timeout(start_time, end_time, os_time_get_nano()))
160            return false;
161
162#if DETECT_OS_UNIX
163         sched_yield();
164#endif
165      }
166      return true;
167   }
168}
169
170
171bool
172os_wait_until_zero_abs_timeout(volatile int *var, int64_t timeout)
173{
174   if (!p_atomic_read(var))
175      return true;
176
177   if (timeout == OS_TIMEOUT_INFINITE)
178      return os_wait_until_zero(var, OS_TIMEOUT_INFINITE);
179
180   while (p_atomic_read(var)) {
181      if (os_time_get_nano() >= timeout)
182         return false;
183
184#if DETECT_OS_UNIX
185      sched_yield();
186#endif
187   }
188   return true;
189}
190