| 1 | /***************************************************************************
|
|---|
| 2 | * _ _ ____ _
|
|---|
| 3 | * Project ___| | | | _ \| |
|
|---|
| 4 | * / __| | | | |_) | |
|
|---|
| 5 | * | (__| |_| | _ <| |___
|
|---|
| 6 | * \___|\___/|_| \_\_____|
|
|---|
| 7 | *
|
|---|
| 8 | * Copyright (C) 1998 - 2022, Daniel Stenberg, <daniel@haxx.se>, et al.
|
|---|
| 9 | *
|
|---|
| 10 | * This software is licensed as described in the file COPYING, which
|
|---|
| 11 | * you should have received as part of this distribution. The terms
|
|---|
| 12 | * are also available at https://curl.se/docs/copyright.html.
|
|---|
| 13 | *
|
|---|
| 14 | * You may opt to use, copy, modify, merge, publish, distribute and/or sell
|
|---|
| 15 | * copies of the Software, and permit persons to whom the Software is
|
|---|
| 16 | * furnished to do so, under the terms of the COPYING file.
|
|---|
| 17 | *
|
|---|
| 18 | * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
|
|---|
| 19 | * KIND, either express or implied.
|
|---|
| 20 | *
|
|---|
| 21 | * SPDX-License-Identifier: curl
|
|---|
| 22 | *
|
|---|
| 23 | ***************************************************************************/
|
|---|
| 24 |
|
|---|
| 25 | #include "curl_setup.h"
|
|---|
| 26 |
|
|---|
| 27 | #define GLOBAL_INIT_IS_THREADSAFE
|
|---|
| 28 |
|
|---|
| 29 | #if defined(_WIN32_WINNT) && _WIN32_WINNT >= 0x600
|
|---|
| 30 |
|
|---|
| 31 | #ifdef __MINGW32__
|
|---|
| 32 | #ifndef __MINGW64_VERSION_MAJOR
|
|---|
| 33 | #if (__MINGW32_MAJOR_VERSION < 5) || \
|
|---|
| 34 | (__MINGW32_MAJOR_VERSION == 5 && __MINGW32_MINOR_VERSION == 0)
|
|---|
| 35 | /* mingw >= 5.0.1 defines SRWLOCK, and slightly different from MS define */
|
|---|
| 36 | typedef PVOID SRWLOCK, *PSRWLOCK;
|
|---|
| 37 | #endif
|
|---|
| 38 | #endif
|
|---|
| 39 | #ifndef SRWLOCK_INIT
|
|---|
| 40 | #define SRWLOCK_INIT NULL
|
|---|
| 41 | #endif
|
|---|
| 42 | #endif /* __MINGW32__ */
|
|---|
| 43 |
|
|---|
| 44 | #define curl_simple_lock SRWLOCK
|
|---|
| 45 | #define CURL_SIMPLE_LOCK_INIT SRWLOCK_INIT
|
|---|
| 46 |
|
|---|
| 47 | #define curl_simple_lock_lock(m) AcquireSRWLockExclusive(m)
|
|---|
| 48 | #define curl_simple_lock_unlock(m) ReleaseSRWLockExclusive(m)
|
|---|
| 49 |
|
|---|
| 50 | #elif defined(HAVE_ATOMIC) && defined(HAVE_STDATOMIC_H)
|
|---|
| 51 | #include <stdatomic.h>
|
|---|
| 52 | #if defined(HAVE_SCHED_YIELD)
|
|---|
| 53 | #include <sched.h>
|
|---|
| 54 | #endif
|
|---|
| 55 |
|
|---|
| 56 | #define curl_simple_lock atomic_int
|
|---|
| 57 | #define CURL_SIMPLE_LOCK_INIT 0
|
|---|
| 58 |
|
|---|
| 59 | /* a clang-thing */
|
|---|
| 60 | #ifndef __has_builtin
|
|---|
| 61 | #define __has_builtin(x) 0
|
|---|
| 62 | #endif
|
|---|
| 63 |
|
|---|
| 64 | #ifndef __INTEL_COMPILER
|
|---|
| 65 | /* The Intel compiler tries to look like GCC *and* clang *and* lies in its
|
|---|
| 66 | __has_builtin() function, so override it. */
|
|---|
| 67 |
|
|---|
| 68 | /* if GCC on i386/x86_64 or if the built-in is present */
|
|---|
| 69 | #if ( (defined(__GNUC__) && !defined(__clang__)) && \
|
|---|
| 70 | (defined(__i386__) || defined(__x86_64__))) || \
|
|---|
| 71 | __has_builtin(__builtin_ia32_pause)
|
|---|
| 72 | #define HAVE_BUILTIN_IA32_PAUSE
|
|---|
| 73 | #endif
|
|---|
| 74 |
|
|---|
| 75 | #endif
|
|---|
| 76 |
|
|---|
| 77 | static inline void curl_simple_lock_lock(curl_simple_lock *lock)
|
|---|
| 78 | {
|
|---|
| 79 | for(;;) {
|
|---|
| 80 | if(!atomic_exchange_explicit(lock, true, memory_order_acquire))
|
|---|
| 81 | break;
|
|---|
| 82 | /* Reduce cache coherency traffic */
|
|---|
| 83 | while(atomic_load_explicit(lock, memory_order_relaxed)) {
|
|---|
| 84 | /* Reduce load (not mandatory) */
|
|---|
| 85 | #ifdef HAVE_BUILTIN_IA32_PAUSE
|
|---|
| 86 | __builtin_ia32_pause();
|
|---|
| 87 | #elif defined(__aarch64__)
|
|---|
| 88 | __asm__ volatile("yield" ::: "memory");
|
|---|
| 89 | #elif defined(HAVE_SCHED_YIELD)
|
|---|
| 90 | sched_yield();
|
|---|
| 91 | #endif
|
|---|
| 92 | }
|
|---|
| 93 | }
|
|---|
| 94 | }
|
|---|
| 95 |
|
|---|
| 96 | static inline void curl_simple_lock_unlock(curl_simple_lock *lock)
|
|---|
| 97 | {
|
|---|
| 98 | atomic_store_explicit(lock, false, memory_order_release);
|
|---|
| 99 | }
|
|---|
| 100 |
|
|---|
| 101 | #else
|
|---|
| 102 |
|
|---|
| 103 | #undef GLOBAL_INIT_IS_THREADSAFE
|
|---|
| 104 |
|
|---|
| 105 | #endif
|
|---|