Blame view

3rdparty/boost_1_81_0/libs/fiber/src/mutex.cpp 2.08 KB
977ed18d   Hu Chunming   提交三方库
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
  
  //          Copyright Oliver Kowalke 2013.
  // Distributed under the Boost Software License, Version 1.0.
  //    (See accompanying file LICENSE_1_0.txt or copy at
  //          http://www.boost.org/LICENSE_1_0.txt)
  
  #include "boost/fiber/mutex.hpp"
  
  #include <algorithm>
  #include <functional>
  #include <system_error>
  
  #include "boost/fiber/exceptions.hpp"
  #include "boost/fiber/scheduler.hpp"
  #include "boost/fiber/waker.hpp"
  
  #ifdef BOOST_HAS_ABI_HEADERS
  #  include BOOST_ABI_PREFIX
  #endif
  
  namespace boost {
  namespace fibers {
  
  void
  mutex::lock() {
      while ( true) {
          context * active_ctx = context::active();
          // store this fiber in order to be notified later
          detail::spinlock_lock lk{ wait_queue_splk_ };
          if ( BOOST_UNLIKELY( active_ctx == owner_) ) {
              throw lock_error{
                      std::make_error_code( std::errc::resource_deadlock_would_occur),
                      "boost fiber: a deadlock is detected" };
          }
          if ( nullptr == owner_) {
              owner_ = active_ctx;
              return;
          }
  
          wait_queue_.suspend_and_wait( lk, active_ctx);
      }
  }
  
  bool
  mutex::try_lock() {
      context * active_ctx = context::active();
      detail::spinlock_lock lk{ wait_queue_splk_ };
      if ( BOOST_UNLIKELY( active_ctx == owner_) ) {
          throw lock_error{
                  std::make_error_code( std::errc::resource_deadlock_would_occur),
                  "boost fiber: a deadlock is detected" };
      }
      if ( nullptr == owner_) {
          owner_ = active_ctx;
      }
      lk.unlock();
      // let other fiber release the lock
      active_ctx->yield();
      return active_ctx == owner_;
  }
  
  void
  mutex::unlock() {
      context * active_ctx = context::active();
      detail::spinlock_lock lk{ wait_queue_splk_ };
      if ( BOOST_UNLIKELY( active_ctx != owner_) ) {
          throw lock_error{
                  std::make_error_code( std::errc::operation_not_permitted),
                  "boost fiber: no  privilege to perform the operation" };
      }
      owner_ = nullptr;
  
      wait_queue_.notify_one();
  }
  
  }}
  
  #ifdef BOOST_HAS_ABI_HEADERS
  #  include BOOST_ABI_SUFFIX
  #endif