106 lines
2.9 KiB
C++
106 lines
2.9 KiB
C++
/*
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Copyright (c) 2005-2020 Intel Corporation
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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#ifndef __TBB_machine_H
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#error Do not #include this internal file directly; use public TBB headers instead.
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#endif
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#include <sched.h>
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#define __TBB_Yield() sched_yield()
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#include <unistd.h>
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/* Futex definitions */
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#include <sys/syscall.h>
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#if defined(SYS_futex)
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/* This header file is included for Linux and some other systems that may support futexes.*/
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#define __TBB_USE_FUTEX 1
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#if defined(__has_include)
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#define __TBB_has_include __has_include
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#else
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#define __TBB_has_include(x) 0
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#endif
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/*
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If available, use typical headers where futex API is defined. While Linux and OpenBSD
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are known to provide such headers, other systems might have them as well.
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*/
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#if defined(__linux__) || __TBB_has_include(<linux/futex.h>)
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#include <linux/futex.h>
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#elif defined(__OpenBSD__) || __TBB_has_include(<sys/futex.h>)
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#include <sys/futex.h>
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#endif
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#include <limits.h>
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#include <errno.h>
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/*
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Some systems might not define the macros or use different names. In such case we expect
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the actual parameter values to match Linux: 0 for wait, 1 for wake.
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*/
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#if defined(FUTEX_WAIT_PRIVATE)
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#define __TBB_FUTEX_WAIT FUTEX_WAIT_PRIVATE
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#elif defined(FUTEX_WAIT)
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#define __TBB_FUTEX_WAIT FUTEX_WAIT
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#else
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#define __TBB_FUTEX_WAIT 0
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#endif
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#if defined(FUTEX_WAKE_PRIVATE)
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#define __TBB_FUTEX_WAKE FUTEX_WAKE_PRIVATE
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#elif defined(FUTEX_WAKE)
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#define __TBB_FUTEX_WAKE FUTEX_WAKE
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#else
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#define __TBB_FUTEX_WAKE 1
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#endif
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#ifndef __TBB_ASSERT
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#error machine specific headers must be included after tbb_stddef.h
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#endif
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namespace tbb {
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namespace internal {
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inline int futex_wait( void *futex, int comparand ) {
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int r = syscall( SYS_futex,futex,__TBB_FUTEX_WAIT,comparand,NULL,NULL,0 );
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#if TBB_USE_ASSERT
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int e = errno;
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__TBB_ASSERT( r==0||r==EWOULDBLOCK||(r==-1&&(e==EAGAIN||e==EINTR)), "futex_wait failed." );
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#endif /* TBB_USE_ASSERT */
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return r;
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}
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inline int futex_wakeup_one( void *futex ) {
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int r = ::syscall( SYS_futex,futex,__TBB_FUTEX_WAKE,1,NULL,NULL,0 );
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__TBB_ASSERT( r==0||r==1, "futex_wakeup_one: more than one thread woken up?" );
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return r;
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}
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inline int futex_wakeup_all( void *futex ) {
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int r = ::syscall( SYS_futex,futex,__TBB_FUTEX_WAKE,INT_MAX,NULL,NULL,0 );
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__TBB_ASSERT( r>=0, "futex_wakeup_all: error in waking up threads" );
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return r;
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}
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} /* namespace internal */
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} /* namespace tbb */
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#endif /* SYS_futex */
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