arangodb-java-driver-shaded.7.1.0.source-code.netty_unix_util.c Maven / Gradle / Ivy
/*
* Copyright 2016 The Netty Project
*
* The Netty Project licenses this file to you under the Apache License,
* version 2.0 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at:
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/
#include
#include
#include
#include "netty_unix_util.h"
static const uint64_t NETTY_BILLION = 1000000000L;
#ifdef NETTY_USE_MACH_INSTEAD_OF_CLOCK
#include
#include
#endif /* NETTY_USE_MACH_INSTEAD_OF_CLOCK */
// util methods
uint64_t netty_unix_util_timespec_elapsed_ns(const struct timespec* begin, const struct timespec* end) {
return NETTY_BILLION * (end->tv_sec - begin->tv_sec) + (end->tv_nsec - begin->tv_nsec);
}
jboolean netty_unix_util_timespec_subtract_ns(struct timespec* ts, uint64_t nanos) {
const uint64_t seconds = nanos / NETTY_BILLION;
nanos -= seconds * NETTY_BILLION;
// If there are too many nanos we steal from seconds to avoid underflow on nanos. This way we
// only have to worry about underflow on tv_sec.
if (nanos > ts->tv_nsec) {
--(ts->tv_sec);
ts->tv_nsec += NETTY_BILLION;
}
const jboolean underflow = ts->tv_sec < seconds;
ts->tv_sec -= seconds;
ts->tv_nsec -= nanos;
return underflow;
}
int netty_unix_util_clock_gettime(clockid_t clockId, struct timespec* tp) {
#ifdef NETTY_USE_MACH_INSTEAD_OF_CLOCK
uint64_t timeNs;
switch (clockId) {
case CLOCK_MONOTONIC_COARSE:
timeNs = mach_approximate_time();
break;
case CLOCK_MONOTONIC:
timeNs = mach_absolute_time();
break;
default:
errno = EINVAL;
return -1;
}
// NOTE: this could overflow if time_t is backed by a 32 bit number.
tp->tv_sec = timeNs / NETTY_BILLION;
tp->tv_nsec = timeNs - tp->tv_sec * NETTY_BILLION; // avoid using modulo if not necessary
return 0;
#else
return clock_gettime(clockId, tp);
#endif /* NETTY_USE_MACH_INSTEAD_OF_CLOCK */
}
jboolean netty_unix_util_initialize_wait_clock(clockid_t* clockId) {
struct timespec ts;
// First try to get a monotonic clock, as we effectively measure execution time and don't want the underlying clock
// moving unexpectedly/abruptly.
#ifdef CLOCK_MONOTONIC_COARSE
*clockId = CLOCK_MONOTONIC_COARSE;
if (netty_unix_util_clock_gettime(*clockId, &ts) == 0) {
return JNI_TRUE;
}
#endif
#ifdef CLOCK_MONOTONIC_RAW
*clockId = CLOCK_MONOTONIC_RAW;
if (netty_unix_util_clock_gettime(*clockId, &ts) == 0) {
return JNI_TRUE;
}
#endif
#ifdef CLOCK_MONOTONIC
*clockId = CLOCK_MONOTONIC;
if (netty_unix_util_clock_gettime(*clockId, &ts) == 0) {
return JNI_TRUE;
}
#endif
// Fallback to realtime ... in this case we are subject to clock movements on the system.
#ifdef CLOCK_REALTIME_COARSE
*clockId = CLOCK_REALTIME_COARSE;
if (netty_unix_util_clock_gettime(*clockId, &ts) == 0) {
return JNI_TRUE;
}
#endif
#ifdef CLOCK_REALTIME
*clockId = CLOCK_REALTIME;
if (netty_unix_util_clock_gettime(*clockId, &ts) == 0) {
return JNI_TRUE;
}
#endif
return JNI_FALSE;
}