Files
filament/libs/utils/src/linux/futex.h
Mathias Agopian bc3aee118a code size and performance optimizations (#472)
* Clean-up EntityManager a bit

- use tsl::robin_set instead of std::set (which should have been unordered::set
  anyways).

- getListeners() now returns a vector which avoids to traverse a set twice.
  Turns out that copying the set wasn't as efficient as I thought.

* Improve jobsystem a bit

We recently added a job reference counting mechanism, but we were a bit
too aggressive about taking/release references.

Also make the API more complete by adding explicit retain/release,
which is needed to allow several threads to wait on the same job.

Also improve futex code by inlining it.
2018-11-12 14:11:31 -08:00

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1.8 KiB
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/*
* Copyright (C) 2016 The Android Open Source Project
*
* Licensed 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
*
* http://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.
*/
#ifndef UTILS_LINUX_FUTEX_H
#define UTILS_LINUX_FUTEX_H
#include <linux/futex.h>
#include <sys/syscall.h>
#include <unistd.h>
#include <stdbool.h>
struct timespec;
namespace utils {
namespace linuxutil {
inline int futex(volatile void* ftx, int op, int value,
const struct timespec* timeout, int bitset) {
return (int)syscall(__NR_futex, ftx, op, value, timeout, nullptr, bitset);
}
inline int futex_wake(volatile void* ftx, int count) {
return futex(ftx, FUTEX_WAKE, count, nullptr, 0);
}
inline int futex_wake_ex(volatile void* ftx, bool shared, int count) {
return futex(ftx, shared ? FUTEX_WAKE : FUTEX_WAKE_PRIVATE, count, nullptr, 0);
}
inline int futex_wait(volatile void* ftx, int value, const struct timespec* timeout) {
return futex(ftx, FUTEX_WAIT, value, timeout, 0);
}
inline int futex_wait_ex(volatile void* ftx, bool shared, int value,
bool use_realtime_clock, const struct timespec* abs_timeout) {
return futex(ftx, (shared ? FUTEX_WAIT_BITSET : FUTEX_WAIT_BITSET_PRIVATE) |
(use_realtime_clock ? FUTEX_CLOCK_REALTIME : 0), value, abs_timeout,
FUTEX_BITSET_MATCH_ANY);
}
} // namespace linuxutil
} // namespace utils
#endif // UTILS_LINUX_FUTEX_H