| 1 | //===-- Implementation of pthread_spin_init function ----------------------===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | |
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| 9 | #include "src/pthread/pthread_spin_init.h" |
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| 10 | #include "hdr/errno_macros.h" |
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| 11 | #include "src/__support/CPP/new.h" |
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| 12 | #include "src/__support/common.h" |
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| 13 | #include "src/__support/threads/spin_lock.h" |
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| 14 | #include <pthread.h> // for PTHREAD_PROCESS_SHARED, PTHREAD_PROCESS_PRIVATE |
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| 15 | |
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| 16 | namespace LIBC_NAMESPACE_DECL { |
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| 17 | |
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| 18 | static_assert(sizeof(pthread_spinlock_t::__lockword) == sizeof(SpinLock) && |
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| 19 | alignof(decltype(pthread_spinlock_t::__lockword)) == |
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| 20 | alignof(SpinLock), |
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| 21 | "pthread_spinlock_t::__lockword and SpinLock must be of the same " |
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| 22 | "size and alignment" ); |
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| 23 | |
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| 24 | LLVM_LIBC_FUNCTION(int, pthread_spin_init, |
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| 25 | (pthread_spinlock_t * lock, [[maybe_unused]] int pshared)) { |
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| 26 | if (!lock) |
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| 27 | return EINVAL; |
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| 28 | if (pshared != PTHREAD_PROCESS_SHARED && pshared != PTHREAD_PROCESS_PRIVATE) |
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| 29 | return EINVAL; |
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| 30 | // The spin lock here is a simple atomic flag, so we don't need to do any |
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| 31 | // special handling for pshared. |
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| 32 | ::new (&lock->__lockword) SpinLock(); |
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| 33 | lock->__owner = 0; |
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| 34 | return 0; |
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| 35 | } |
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| 36 | |
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| 37 | } // namespace LIBC_NAMESPACE_DECL |
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| 38 | |
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