//===--- timeout linux implementation ---------------------------*- C++ -*-===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// #ifndef LLVM_LIBC_SRC___SUPPORT_TIME_LINUX_MONOTONICITY_H #define LLVM_LIBC_SRC___SUPPORT_TIME_LINUX_MONOTONICITY_H #include "hdr/time_macros.h" #include "src/__support/libc_assert.h" #include "src/__support/macros/config.h" #include "src/__support/time/linux/abs_timeout.h" #include "src/__support/time/linux/clock_conversion.h" namespace LIBC_NAMESPACE_DECL { namespace internal { // This function is separated from abs_timeout. // This function pulls in the dependency to clock_conversion.h, // which may transitively depend on vDSO hence futex. However, this structure // would be passed to futex, so we need to avoid cyclic dependencies. // This function is going to be used in timed locks. Pthread generally uses // realtime clocks for timeouts. However, due to non-monotoncity, realtime // clocks reportedly lead to undesired behaviors. Therefore, we also provide a // method to convert the timespec to a monotonic clock relative to the time of // function call. LIBC_INLINE void ensure_monotonicity(AbsTimeout &timeout) { … } } // namespace internal } // namespace LIBC_NAMESPACE_DECL #endif // LLVM_LIBC_SRC___SUPPORT_TIME_LINUX_MONOTONICITY_H