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Diffstat (limited to 'Utilities/cmcurl/lib/easy_lock.h')
| -rw-r--r-- | Utilities/cmcurl/lib/easy_lock.h | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/Utilities/cmcurl/lib/easy_lock.h b/Utilities/cmcurl/lib/easy_lock.h new file mode 100644 index 0000000000..5fa9477d06 --- /dev/null +++ b/Utilities/cmcurl/lib/easy_lock.h @@ -0,0 +1,105 @@ +/*************************************************************************** + * _ _ ____ _ + * Project ___| | | | _ \| | + * / __| | | | |_) | | + * | (__| |_| | _ <| |___ + * \___|\___/|_| \_\_____| + * + * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. + * + * This software is licensed as described in the file COPYING, which + * you should have received as part of this distribution. The terms + * are also available at https://curl.se/docs/copyright.html. + * + * You may opt to use, copy, modify, merge, publish, distribute and/or sell + * copies of the Software, and permit persons to whom the Software is + * furnished to do so, under the terms of the COPYING file. + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY + * KIND, either express or implied. + * + * SPDX-License-Identifier: curl + * + ***************************************************************************/ + +#include "curl_setup.h" + +#define GLOBAL_INIT_IS_THREADSAFE + +#if defined(_WIN32_WINNT) && _WIN32_WINNT >= 0x600 + +#ifdef __MINGW32__ +#ifndef __MINGW64_VERSION_MAJOR +#if (__MINGW32_MAJOR_VERSION < 5) || \ + (__MINGW32_MAJOR_VERSION == 5 && __MINGW32_MINOR_VERSION == 0) +/* mingw >= 5.0.1 defines SRWLOCK, and slightly different from MS define */ +typedef PVOID SRWLOCK, *PSRWLOCK; +#endif +#endif +#ifndef SRWLOCK_INIT +#define SRWLOCK_INIT NULL +#endif +#endif /* __MINGW32__ */ + +#define curl_simple_lock SRWLOCK +#define CURL_SIMPLE_LOCK_INIT SRWLOCK_INIT + +#define curl_simple_lock_lock(m) AcquireSRWLockExclusive(m) +#define curl_simple_lock_unlock(m) ReleaseSRWLockExclusive(m) + +#elif defined(HAVE_ATOMIC) && defined(HAVE_STDATOMIC_H) +#include <stdatomic.h> +#if defined(HAVE_SCHED_YIELD) +#include <sched.h> +#endif + +#define curl_simple_lock atomic_int +#define CURL_SIMPLE_LOCK_INIT 0 + +/* a clang-thing */ +#ifndef __has_builtin +#define __has_builtin(x) 0 +#endif + +#ifndef __INTEL_COMPILER +/* The Intel compiler tries to look like GCC *and* clang *and* lies in its + __has_builtin() function, so override it. */ + +/* if GCC on i386/x86_64 or if the built-in is present */ +#if ( (defined(__GNUC__) && !defined(__clang__)) && \ + (defined(__i386__) || defined(__x86_64__))) || \ + __has_builtin(__builtin_ia32_pause) +#define HAVE_BUILTIN_IA32_PAUSE +#endif + +#endif + +static inline void curl_simple_lock_lock(curl_simple_lock *lock) +{ + for(;;) { + if(!atomic_exchange_explicit(lock, true, memory_order_acquire)) + break; + /* Reduce cache coherency traffic */ + while(atomic_load_explicit(lock, memory_order_relaxed)) { + /* Reduce load (not mandatory) */ +#ifdef HAVE_BUILTIN_IA32_PAUSE + __builtin_ia32_pause(); +#elif defined(__aarch64__) + __asm__ volatile("yield" ::: "memory"); +#elif defined(HAVE_SCHED_YIELD) + sched_yield(); +#endif + } + } +} + +static inline void curl_simple_lock_unlock(curl_simple_lock *lock) +{ + atomic_store_explicit(lock, false, memory_order_release); +} + +#else + +#undef GLOBAL_INIT_IS_THREADSAFE + +#endif |