quickjs-tart

quickjs-based runtime for wallet-core logic
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easy_lock.h (3283B)

      1 #ifndef HEADER_CURL_EASY_LOCK_H
      2 #define HEADER_CURL_EASY_LOCK_H
      3 /***************************************************************************
      4  *                                  _   _ ____  _
      5  *  Project                     ___| | | |  _ \| |
      6  *                             / __| | | | |_) | |
      7  *                            | (__| |_| |  _ <| |___
      8  *                             \___|\___/|_| \_\_____|
      9  *
     10  * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
     11  *
     12  * This software is licensed as described in the file COPYING, which
     13  * you should have received as part of this distribution. The terms
     14  * are also available at https://curl.se/docs/copyright.html.
     15  *
     16  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
     17  * copies of the Software, and permit persons to whom the Software is
     18  * furnished to do so, under the terms of the COPYING file.
     19  *
     20  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
     21  * KIND, either express or implied.
     22  *
     23  * SPDX-License-Identifier: curl
     24  *
     25  ***************************************************************************/
     26 
     27 #include "curl_setup.h"
     28 
     29 #define GLOBAL_INIT_IS_THREADSAFE
     30 
     31 #if defined(_WIN32_WINNT) && _WIN32_WINNT >= 0x600
     32 
     33 #ifdef __MINGW32__
     34 #ifndef SRWLOCK_INIT
     35 #define SRWLOCK_INIT NULL
     36 #endif
     37 #endif /* __MINGW32__ */
     38 
     39 #define curl_simple_lock SRWLOCK
     40 #define CURL_SIMPLE_LOCK_INIT SRWLOCK_INIT
     41 
     42 #define curl_simple_lock_lock(m) AcquireSRWLockExclusive(m)
     43 #define curl_simple_lock_unlock(m) ReleaseSRWLockExclusive(m)
     44 
     45 #elif defined(HAVE_ATOMIC) && defined(HAVE_STDATOMIC_H)
     46 #include <stdatomic.h>
     47 #if defined(HAVE_SCHED_YIELD)
     48 #include <sched.h>
     49 #endif
     50 
     51 #define curl_simple_lock atomic_int
     52 #define CURL_SIMPLE_LOCK_INIT 0
     53 
     54 /* a clang-thing */
     55 #ifndef __has_builtin
     56 #define __has_builtin(x) 0
     57 #endif
     58 
     59 #ifndef __INTEL_COMPILER
     60 /* The Intel compiler tries to look like GCC *and* clang *and* lies in its
     61    __has_builtin() function, so override it. */
     62 
     63 /* if GCC on i386/x86_64 or if the built-in is present */
     64 #if ( (defined(__GNUC__) && !defined(__clang__)) &&     \
     65       (defined(__i386__) || defined(__x86_64__))) ||    \
     66   __has_builtin(__builtin_ia32_pause)
     67 #define HAVE_BUILTIN_IA32_PAUSE
     68 #endif
     69 
     70 #endif
     71 
     72 static CURL_INLINE void curl_simple_lock_lock(curl_simple_lock *lock)
     73 {
     74   for(;;) {
     75     if(!atomic_exchange_explicit(lock, true, memory_order_acquire))
     76       break;
     77     /* Reduce cache coherency traffic */
     78     while(atomic_load_explicit(lock, memory_order_relaxed)) {
     79       /* Reduce load (not mandatory) */
     80 #ifdef HAVE_BUILTIN_IA32_PAUSE
     81       __builtin_ia32_pause();
     82 #elif defined(__aarch64__)
     83       __asm__ volatile("yield" ::: "memory");
     84 #elif defined(_WIN32)
     85       Sleep(1);
     86 #elif defined(HAVE_SCHED_YIELD)
     87       sched_yield();
     88 #endif
     89     }
     90   }
     91 }
     92 
     93 static CURL_INLINE void curl_simple_lock_unlock(curl_simple_lock *lock)
     94 {
     95   atomic_store_explicit(lock, false, memory_order_release);
     96 }
     97 
     98 #elif defined(USE_THREADS_POSIX) && defined(HAVE_PTHREAD_H)
     99 
    100 #include <pthread.h>
    101 
    102 #define curl_simple_lock pthread_mutex_t
    103 #define CURL_SIMPLE_LOCK_INIT PTHREAD_MUTEX_INITIALIZER
    104 #define curl_simple_lock_lock(m) pthread_mutex_lock(m)
    105 #define curl_simple_lock_unlock(m) pthread_mutex_unlock(m)
    106 
    107 #else
    108 
    109 #undef  GLOBAL_INIT_IS_THREADSAFE
    110 
    111 #endif
    112 
    113 #endif /* HEADER_CURL_EASY_LOCK_H */