| 1 | |
|---|---|
| 2 | // Copyright Oliver Kowalke 2013. |
| 3 | // Distributed under the Boost Software License, Version 1.0. |
| 4 | // (See accompanying file LICENSE_1_0.txt or copy at |
| 5 | // http://www.boost.org/LICENSE_1_0.txt) |
| 6 | |
| 7 | #include "boost/fiber/recursive_mutex.hpp" |
| 8 | |
| 9 | #include <algorithm> |
| 10 | #include <functional> |
| 11 | |
| 12 | #include "boost/fiber/exceptions.hpp" |
| 13 | #include "boost/fiber/scheduler.hpp" |
| 14 | |
| 15 | #ifdef BOOST_HAS_ABI_HEADERS |
| 16 | # include BOOST_ABI_PREFIX |
| 17 | #endif |
| 18 | |
| 19 | namespace boost { |
| 20 | namespace fibers { |
| 21 | |
| 22 | void |
| 23 | recursive_mutex::lock() { |
| 24 | while ( true) { |
| 25 | context * active_ctx = context::active(); |
| 26 | // store this fiber in order to be notified later |
| 27 | detail::spinlock_lock lk{ wait_queue_splk_ }; |
| 28 | if ( active_ctx == owner_) { |
| 29 | ++count_; |
| 30 | return; |
| 31 | } |
| 32 | if ( nullptr == owner_) { |
| 33 | owner_ = active_ctx; |
| 34 | count_ = 1; |
| 35 | return; |
| 36 | } |
| 37 | |
| 38 | wait_queue_.suspend_and_wait( lk, active_ctx); |
| 39 | } |
| 40 | } |
| 41 | |
| 42 | bool |
| 43 | recursive_mutex::try_lock() noexcept { |
| 44 | context * active_ctx = context::active(); |
| 45 | detail::spinlock_lock lk{ wait_queue_splk_ }; |
| 46 | if ( nullptr == owner_) { |
| 47 | owner_ = active_ctx; |
| 48 | count_ = 1; |
| 49 | } else if ( active_ctx == owner_) { |
| 50 | ++count_; |
| 51 | } |
| 52 | lk.unlock(); |
| 53 | // let other fiber release the lock |
| 54 | context::active()->yield(); |
| 55 | return active_ctx == owner_; |
| 56 | } |
| 57 | |
| 58 | void |
| 59 | recursive_mutex::unlock() { |
| 60 | context * active_ctx = context::active(); |
| 61 | detail::spinlock_lock lk( wait_queue_splk_); |
| 62 | if ( BOOST_UNLIKELY( active_ctx != owner_) ) { |
| 63 | throw lock_error( |
| 64 | std::make_error_code( e: std::errc::operation_not_permitted), |
| 65 | "boost fiber: no privilege to perform the operation"); |
| 66 | } |
| 67 | if ( 0 == --count_) { |
| 68 | owner_ = nullptr; |
| 69 | wait_queue_.notify_one(); |
| 70 | } |
| 71 | } |
| 72 | |
| 73 | }} |
| 74 | |
| 75 | #ifdef BOOST_HAS_ABI_HEADERS |
| 76 | # include BOOST_ABI_SUFFIX |
| 77 | #endif |
| 78 |