aboutsummaryrefslogtreecommitdiffhomepage
path: root/src/core/lib/support/time_posix.c
blob: fcfab2f2fab821ea7f1b797c3fd2c5a7cd72f033 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
/*
 *
 * Copyright 2015-2016, Google Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include <grpc/support/port_platform.h>
#include "src/core/lib/support/time_precise.h"

#ifdef GPR_POSIX_TIME

#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#ifdef __linux__
#include <sys/syscall.h>
#endif
#include <grpc/support/log.h>
#include <grpc/support/time.h>
#include "src/core/lib/support/block_annotate.h"

static struct timespec timespec_from_gpr(gpr_timespec gts) {
  struct timespec rv;
  if (sizeof(time_t) < sizeof(int64_t)) {
    /* fine to assert, as this is only used in gpr_sleep_until */
    GPR_ASSERT(gts.tv_sec <= INT32_MAX && gts.tv_sec >= INT32_MIN);
  }
  rv.tv_sec = (time_t)gts.tv_sec;
  rv.tv_nsec = gts.tv_nsec;
  return rv;
}

#if _POSIX_TIMERS > 0
static gpr_timespec gpr_from_timespec(struct timespec ts,
                                      gpr_clock_type clock_type) {
  /*
   * timespec.tv_sec can have smaller size than gpr_timespec.tv_sec,
   * but we are only using this function to implement gpr_now
   * so there's no need to handle "infinity" values.
   */
  gpr_timespec rv;
  rv.tv_sec = ts.tv_sec;
  rv.tv_nsec = (int32_t)ts.tv_nsec;
  rv.clock_type = clock_type;
  return rv;
}

/** maps gpr_clock_type --> clockid_t for clock_gettime */
static const clockid_t clockid_for_gpr_clock[] = {CLOCK_MONOTONIC,
                                                  CLOCK_REALTIME};

void gpr_time_init(void) { gpr_precise_clock_init(); }

gpr_timespec gpr_now(gpr_clock_type clock_type) {
  struct timespec now;
  GPR_ASSERT(clock_type != GPR_TIMESPAN);
  if (clock_type == GPR_CLOCK_PRECISE) {
    gpr_timespec ret;
    gpr_precise_clock_now(&ret);
    return ret;
  } else {
#if defined(GPR_BACKWARDS_COMPATIBILITY_MODE) && defined(__linux__)
    /* avoid ABI problems by invoking syscalls directly */
    syscall(SYS_clock_gettime, clockid_for_gpr_clock[clock_type], &now);
#else
    clock_gettime(clockid_for_gpr_clock[clock_type], &now);
#endif
    return gpr_from_timespec(now, clock_type);
  }
}
#else
/* For some reason Apple's OSes haven't implemented clock_gettime. */

#include <mach/mach.h>
#include <mach/mach_time.h>
#include <sys/time.h>

static double g_time_scale;
static uint64_t g_time_start;

void gpr_time_init(void) {
  mach_timebase_info_data_t tb = {0, 1};
  gpr_precise_clock_init();
  mach_timebase_info(&tb);
  g_time_scale = tb.numer;
  g_time_scale /= tb.denom;
  g_time_start = mach_absolute_time();
}

gpr_timespec gpr_now(gpr_clock_type clock) {
  gpr_timespec now;
  struct timeval now_tv;
  double now_dbl;

  now.clock_type = clock;
  switch (clock) {
    case GPR_CLOCK_REALTIME:
      gettimeofday(&now_tv, NULL);
      now.tv_sec = now_tv.tv_sec;
      now.tv_nsec = now_tv.tv_usec * 1000;
      break;
    case GPR_CLOCK_MONOTONIC:
      now_dbl = (mach_absolute_time() - g_time_start) * g_time_scale;
      now.tv_sec = (int64_t)(now_dbl * 1e-9);
      now.tv_nsec = (int32_t)(now_dbl - ((double)now.tv_sec) * 1e9);
      break;
    case GPR_CLOCK_PRECISE:
      gpr_precise_clock_now(&now);
      break;
    case GPR_TIMESPAN:
      abort();
  }

  return now;
}
#endif

void gpr_sleep_until(gpr_timespec until) {
  gpr_timespec now;
  gpr_timespec delta;
  struct timespec delta_ts;
  int ns_result;

  for (;;) {
    /* We could simplify by using clock_nanosleep instead, but it might be
     * slightly less portable. */
    now = gpr_now(until.clock_type);
    if (gpr_time_cmp(until, now) <= 0) {
      return;
    }

    delta = gpr_time_sub(until, now);
    delta_ts = timespec_from_gpr(delta);
    GRPC_SCHEDULING_START_BLOCKING_REGION;
    ns_result = nanosleep(&delta_ts, NULL);
    GRPC_SCHEDULING_END_BLOCKING_REGION;
    if (ns_result == 0) {
      break;
    }
  }
}

#endif /* GPR_POSIX_TIME */