1/**************************************************************************
2 *
3 * Copyright 2008-2010 VMware, Inc.
4 * All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
16 * of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
21 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
22 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
23 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
24 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25 *
26 **************************************************************************/
27
28/**
29 * @file
30 * OS independent time-manipulation functions.
31 *
32 * @author Jose Fonseca <jfonseca@vmware.com>
33 */
34
35
36#include "pipe/p_defines.h"
37#include "util/u_atomic.h"
38
39#if defined(PIPE_OS_UNIX)
40#  include <time.h> /* timeval */
41#  include <sys/time.h> /* timeval */
42#  include <sched.h> /* sched_yield */
43#  include <errno.h>
44#elif defined(PIPE_SUBSYSTEM_WINDOWS_USER)
45#  include <windows.h>
46#else
47#  error Unsupported OS
48#endif
49
50#include "os_time.h"
51
52
53int64_t
54os_time_get_nano(void)
55{
56#if defined(PIPE_OS_LINUX)
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 defined(PIPE_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 defined(PIPE_SUBSYSTEM_WINDOWS_USER)
69
70   static LARGE_INTEGER frequency;
71   LARGE_INTEGER counter;
72   if(!frequency.QuadPart)
73      QueryPerformanceFrequency(&frequency);
74   QueryPerformanceCounter(&counter);
75   return counter.QuadPart*INT64_C(1000000000)/frequency.QuadPart;
76
77#else
78
79#error Unsupported OS
80
81#endif
82}
83
84
85
86void
87os_time_sleep(int64_t usecs)
88{
89#if defined(PIPE_OS_LINUX)
90   struct timespec time;
91   time.tv_sec = usecs / 1000000;
92   time.tv_nsec = (usecs % 1000000) * 1000;
93   while (clock_nanosleep(CLOCK_MONOTONIC, 0, &time, &time) == EINTR);
94
95#elif defined(PIPE_OS_UNIX)
96   usleep(usecs);
97
98#elif defined(PIPE_SUBSYSTEM_WINDOWS_USER)
99   DWORD dwMilliseconds = (DWORD) ((usecs + 999) / 1000);
100   /* Avoid Sleep(O) as that would cause to sleep for an undetermined duration */
101   if (dwMilliseconds) {
102      Sleep(dwMilliseconds);
103   }
104#else
105#  error Unsupported OS
106#endif
107}
108
109
110
111int64_t
112os_time_get_absolute_timeout(uint64_t timeout)
113{
114   int64_t time, abs_timeout;
115
116   /* Also check for the type upper bound. */
117   if (timeout == PIPE_TIMEOUT_INFINITE || timeout > INT64_MAX)
118      return PIPE_TIMEOUT_INFINITE;
119
120   time = os_time_get_nano();
121   abs_timeout = time + (int64_t)timeout;
122
123   /* Check for overflow. */
124   if (abs_timeout < time)
125      return PIPE_TIMEOUT_INFINITE;
126
127   return abs_timeout;
128}
129
130
131bool
132os_wait_until_zero(volatile int *var, uint64_t timeout)
133{
134   if (!p_atomic_read(var))
135      return true;
136
137   if (!timeout)
138      return false;
139
140   if (timeout == PIPE_TIMEOUT_INFINITE) {
141      while (p_atomic_read(var)) {
142#if defined(PIPE_OS_UNIX)
143         sched_yield();
144#endif
145      }
146      return true;
147   }
148   else {
149      int64_t start_time = os_time_get_nano();
150      int64_t end_time = start_time + timeout;
151
152      while (p_atomic_read(var)) {
153         if (os_time_timeout(start_time, end_time, os_time_get_nano()))
154            return false;
155
156#if defined(PIPE_OS_UNIX)
157         sched_yield();
158#endif
159      }
160      return true;
161   }
162}
163
164
165bool
166os_wait_until_zero_abs_timeout(volatile int *var, int64_t timeout)
167{
168   if (!p_atomic_read(var))
169      return true;
170
171   if (timeout == PIPE_TIMEOUT_INFINITE)
172      return os_wait_until_zero(var, PIPE_TIMEOUT_INFINITE);
173
174   while (p_atomic_read(var)) {
175      if (os_time_get_nano() >= timeout)
176         return false;
177
178#if defined(PIPE_OS_UNIX)
179      sched_yield();
180#endif
181   }
182   return true;
183}
184