1 //===-- Types related to the callonce function ----------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef LLVM_LIBC_SRC___SUPPORT_THREADS_CALLONCE_H 10 #define LLVM_LIBC_SRC___SUPPORT_THREADS_CALLONCE_H 11 12 #include "src/__support/macros/config.h" 13 #include "src/__support/macros/optimization.h" // LIBC_LIKELY 14 15 // Plaform specific routines, provides: 16 // - OnceFlag definition 17 // - callonce_impl::callonce_fastpath for fast path check 18 // - callonce_impl::callonce_slowpath for slow path execution 19 #ifdef __linux__ 20 #include "src/__support/threads/linux/callonce.h" 21 #else 22 #error "callonce is not supported on this platform" 23 #endif 24 25 namespace LIBC_NAMESPACE_DECL { 26 27 // Common definitions 28 using CallOnceCallback = void(void); 29 namespace callonce_impl { 30 int callonce_slowpath(CallOnceFlag *flag, CallOnceCallback *callback); 31 } // namespace callonce_impl 32 callonce(CallOnceFlag * flag,CallOnceCallback * callback)33LIBC_INLINE int callonce(CallOnceFlag *flag, CallOnceCallback *callback) { 34 if (LIBC_LIKELY(callonce_impl::callonce_fastpath(flag))) 35 return 0; 36 37 return callonce_impl::callonce_slowpath(flag, callback); 38 } 39 } // namespace LIBC_NAMESPACE_DECL 40 41 #endif // LLVM_LIBC_SRC___SUPPORT_THREADS_CALLONCE_H 42