value_type value_pop() {
for (;;) {
slot * s{ nullptr };
std::size_t idx{ 0 };
channel_op_status status{ try_value_pop_( s, idx) };
if ( channel_op_status::success == status) {
value_type value{ std::move( * reinterpret_cast< value_type * >( std::addressof( s->storage) ) ) };
s->cycle.store( idx + capacity_, std::memory_order_release);
not_full_cnd_.notify_one();
return std::move( value);
} else if ( channel_op_status::empty == status) {
std::unique_lock< std::mutex > lk{ mtx_ };
++waiting_consumer_;
if ( is_closed() ) {
throw std::runtime_error{ "boost fiber: channel is closed" };
}
if ( ! is_empty_() ) {
continue;
}
not_empty_cnd_.wait( lk, [this](){ return is_closed() || ! is_empty_(); });
--waiting_consumer_;
} else {
BOOST_ASSERT( channel_op_status::closed == status);
throw std::runtime_error{ "boost fiber: channel is closed" };
}
}
}
channel_op_status pop( value_type & va) {
std::unique_lock< mutex > lk( mtx_);
not_empty_cond_.wait( lk,
[this](){
return is_closed_() || ! is_empty_();
});
if ( is_closed_() && is_empty_() ) {
return channel_op_status::closed;
}
va = value_pop_( lk);
return channel_op_status::success;
}
value_type value_pop() {
std::unique_lock< mutex > lk( mtx_);
not_empty_cond_.wait( lk,
[this](){
return is_closed_() || ! is_empty_();
});
if ( is_closed_() && is_empty_() ) {
throw fiber_error(
std::make_error_code( std::errc::operation_not_permitted),
"boost fiber: queue is closed");
}
return value_pop_( lk);
}
channel_op_status pop_wait_until( value_type & va,
std::chrono::time_point< Clock, Duration > const& timeout_time) {
std::unique_lock< mutex > lk( mtx_);
if ( ! not_empty_cond_.wait_until( lk, timeout_time,
[this](){
return is_closed_() || ! is_empty_();
})) {
return channel_op_status::timeout;
}
if ( is_closed_() && is_empty_() ) {
return channel_op_status::closed;
}
va = value_pop_( lk);
return channel_op_status::success;
}
channel_op_status try_pop( value_type & va) {
std::unique_lock< mutex > lk( mtx_);
if ( is_closed_() && is_empty_() ) {
// let other fibers run
lk.unlock();
this_fiber::yield();
return channel_op_status::closed;
}
if ( is_empty_() ) {
// let other fibers run
lk.unlock();
this_fiber::yield();
return channel_op_status::empty;
}
va = value_pop_( lk);
return channel_op_status::success;
}
context * pop() {
spinlock_lock lk{ splk_ };
context * c = nullptr;
if ( ! is_empty_() ) {
c = slots_[cidx_];
cidx_ = (cidx_ + 1) % capacity_;
}
return c;
}
context * steal() {
spinlock_lock lk{ splk_ };
context * c = nullptr;
if ( ! is_empty_() ) {
c = slots_[cidx_];
if ( c->is_context( type::pinned_context) ) {
return nullptr;
}
cidx_ = (cidx_ + 1) % capacity_;
}
return c;
}
value_type value_pop_( std::unique_lock< mutex > & lk) {
BOOST_ASSERT( ! is_empty_() );
auto old_head = pop_head_();
return std::move( old_head->va);
}
bool empty() const noexcept {
spinlock_lock lk{ splk_ };
return is_empty_();
}