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</pre><pre class="rust ">
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">prelude</span>::<span class="ident">v1</span>::<span class="kw-2">*</span>;
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">cell</span>::<span class="ident">Cell</span>;
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">fmt</span>;
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">marker</span>::<span class="ident">PhantomData</span>;
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">mem</span>;
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">ptr</span>;
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">sync</span>::{<span class="ident">Arc</span>, <span class="ident">Mutex</span>, <span class="ident">Condvar</span>, <span class="ident">Once</span>, <span class="ident">ONCE_INIT</span>};
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">sync</span>::<span class="ident">atomic</span>::{<span class="ident">AtomicUsize</span>, <span class="ident">Ordering</span>};
<span class="kw">use</span> {<span class="ident">Future</span>, <span class="ident">Stream</span>, <span class="ident">Sink</span>, <span class="ident">Poll</span>, <span class="ident">Async</span>, <span class="ident">StartSend</span>, <span class="ident">AsyncSink</span>};
<span class="kw">use</span> <span class="kw">super</span>::<span class="ident">core</span>;
<span class="kw">use</span> <span class="kw">super</span>::{<span class="ident">BorrowedTask</span>, <span class="ident">NotifyHandle</span>, <span class="ident">Spawn</span>, <span class="ident">spawn</span>, <span class="ident">Notify</span>, <span class="ident">UnsafeNotify</span>};
<span class="kw">mod</span> <span class="ident">unpark_mutex</span>;
<span class="kw">pub</span> <span class="kw">use</span> <span class="self">self</span>::<span class="ident">unpark_mutex</span>::<span class="ident">UnparkMutex</span>;
<span class="kw">mod</span> <span class="ident">data</span>;
<span class="kw">pub</span> <span class="kw">use</span> <span class="self">self</span>::<span class="ident">data</span>::<span class="kw-2">*</span>;
<span class="kw">mod</span> <span class="ident">task_rc</span>;
<span class="attribute">#[<span class="ident">allow</span>(<span class="ident">deprecated</span>)]</span>
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"with-deprecated"</span>)]</span>
<span class="kw">pub</span> <span class="kw">use</span> <span class="self">self</span>::<span class="ident">task_rc</span>::<span class="ident">TaskRc</span>;
<span class="kw">pub</span> <span class="kw">use</span> <span class="ident">task_impl</span>::<span class="ident">core</span>::<span class="ident">init</span>;
<span class="macro">thread_local</span><span class="macro">!</span>(<span class="kw">static</span> <span class="ident">CURRENT_TASK</span>: <span class="ident">Cell</span><span class="op"><</span><span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">u8</span><span class="op">></span> <span class="op">=</span> <span class="ident">Cell</span>::<span class="ident">new</span>(<span class="ident">ptr</span>::<span class="ident">null_mut</span>()));
<span class="kw">static</span> <span class="ident">INIT</span>: <span class="ident">Once</span> <span class="op">=</span> <span class="ident">ONCE_INIT</span>;
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">get_ptr</span>() <span class="op">-></span> <span class="prelude-ty">Option</span><span class="op"><</span><span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">u8</span><span class="op">></span> {
<span class="comment">// Since this condition will always return true when TLS task storage is</span>
<span class="comment">// used (the default), the branch predictor will be able to optimize the</span>
<span class="comment">// branching and a dynamic dispatch will be avoided, which makes the</span>
<span class="comment">// compiler happier.</span>
<span class="kw">if</span> <span class="ident">core</span>::<span class="ident">is_get_ptr</span>(<span class="number">0x1</span>) {
<span class="prelude-val">Some</span>(<span class="ident">CURRENT_TASK</span>.<span class="ident">with</span>(<span class="op">|</span><span class="ident">c</span><span class="op">|</span> <span class="ident">c</span>.<span class="ident">get</span>()))
} <span class="kw">else</span> {
<span class="ident">core</span>::<span class="ident">get_ptr</span>()
}
}
<span class="kw">fn</span> <span class="ident">tls_slot</span>() <span class="op">-></span> <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">Cell</span><span class="op"><</span><span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">u8</span><span class="op">></span> {
<span class="ident">CURRENT_TASK</span>.<span class="ident">with</span>(<span class="op">|</span><span class="ident">c</span><span class="op">|</span> <span class="ident">c</span> <span class="kw">as</span> <span class="kw-2">*</span><span class="kw">const</span> _)
}
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">set</span><span class="op"><</span><span class="lifetime">'a</span>, <span class="ident">F</span>, <span class="ident">R</span><span class="op">></span>(<span class="ident">task</span>: <span class="kw-2">&</span><span class="ident">BorrowedTask</span><span class="op"><</span><span class="lifetime">'a</span><span class="op">></span>, <span class="ident">f</span>: <span class="ident">F</span>) <span class="op">-></span> <span class="ident">R</span>
<span class="kw">where</span> <span class="ident">F</span>: <span class="ident">FnOnce</span>() <span class="op">-></span> <span class="ident">R</span>
{
<span class="comment">// Lazily initialize the get / set ptrs</span>
<span class="comment">//</span>
<span class="comment">// Note that we won't actually use these functions ever, we'll instead be</span>
<span class="comment">// testing the pointer's value elsewhere and calling our own functions.</span>
<span class="ident">INIT</span>.<span class="ident">call_once</span>(<span class="op">||</span> <span class="kw">unsafe</span> {
<span class="kw">let</span> <span class="ident">get</span> <span class="op">=</span> <span class="ident">mem</span>::<span class="ident">transmute</span>::<span class="op"><</span><span class="ident">usize</span>, _<span class="op">></span>(<span class="number">0x1</span>);
<span class="kw">let</span> <span class="ident">set</span> <span class="op">=</span> <span class="ident">mem</span>::<span class="ident">transmute</span>::<span class="op"><</span><span class="ident">usize</span>, _<span class="op">></span>(<span class="number">0x2</span>);
<span class="ident">init</span>(<span class="ident">get</span>, <span class="ident">set</span>);
});
<span class="comment">// Same as above.</span>
<span class="kw">if</span> <span class="ident">core</span>::<span class="ident">is_get_ptr</span>(<span class="number">0x1</span>) {
<span class="kw">struct</span> <span class="ident">Reset</span>(<span class="kw-2">*</span><span class="kw">const</span> <span class="ident">Cell</span><span class="op"><</span><span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">u8</span><span class="op">></span>, <span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">u8</span>);
<span class="kw">impl</span> <span class="ident">Drop</span> <span class="kw">for</span> <span class="ident">Reset</span> {
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">fn</span> <span class="ident">drop</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>) {
<span class="kw">unsafe</span> {
(<span class="kw-2">*</span><span class="self">self</span>.<span class="number">0</span>).<span class="ident">set</span>(<span class="self">self</span>.<span class="number">1</span>);
}
}
}
<span class="kw">unsafe</span> {
<span class="kw">let</span> <span class="ident">slot</span> <span class="op">=</span> <span class="ident">tls_slot</span>();
<span class="kw">let</span> <span class="ident">_reset</span> <span class="op">=</span> <span class="ident">Reset</span>(<span class="ident">slot</span>, (<span class="kw-2">*</span><span class="ident">slot</span>).<span class="ident">get</span>());
(<span class="kw-2">*</span><span class="ident">slot</span>).<span class="ident">set</span>(<span class="ident">task</span> <span class="kw">as</span> <span class="kw-2">*</span><span class="kw">const</span> _ <span class="kw">as</span> <span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">u8</span>);
<span class="ident">f</span>()
}
} <span class="kw">else</span> {
<span class="ident">core</span>::<span class="ident">set</span>(<span class="ident">task</span>, <span class="ident">f</span>)
}
}
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Copy</span>, <span class="ident">Clone</span>)]</span>
<span class="attribute">#[<span class="ident">allow</span>(<span class="ident">deprecated</span>)]</span>
<span class="kw">pub</span> <span class="kw">enum</span> <span class="ident">BorrowedUnpark</span><span class="op"><</span><span class="lifetime">'a</span><span class="op">></span> {
<span class="ident">Old</span>(<span class="kw-2">&</span><span class="lifetime">'a</span> <span class="ident">Arc</span><span class="op"><</span><span class="ident">Unpark</span><span class="op">></span>),
<span class="ident">New</span>(<span class="ident">core</span>::<span class="ident">BorrowedUnpark</span><span class="op"><</span><span class="lifetime">'a</span><span class="op">></span>),
}
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Copy</span>, <span class="ident">Clone</span>)]</span>
<span class="attribute">#[<span class="ident">allow</span>(<span class="ident">deprecated</span>)]</span>
<span class="kw">pub</span> <span class="kw">enum</span> <span class="ident">BorrowedEvents</span><span class="op"><</span><span class="lifetime">'a</span><span class="op">></span> {
<span class="prelude-val">None</span>,
<span class="ident">One</span>(<span class="kw-2">&</span><span class="lifetime">'a</span> <span class="ident">UnparkEvent</span>, <span class="kw-2">&</span><span class="lifetime">'a</span> <span class="ident">BorrowedEvents</span><span class="op"><</span><span class="lifetime">'a</span><span class="op">></span>),
}
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Clone</span>)]</span>
<span class="kw">pub</span> <span class="kw">enum</span> <span class="ident">TaskUnpark</span> {
<span class="attribute">#[<span class="ident">allow</span>(<span class="ident">deprecated</span>)]</span>
<span class="ident">Old</span>(<span class="ident">Arc</span><span class="op"><</span><span class="ident">Unpark</span><span class="op">></span>),
<span class="ident">New</span>(<span class="ident">core</span>::<span class="ident">TaskUnpark</span>),
}
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Clone</span>)]</span>
<span class="attribute">#[<span class="ident">allow</span>(<span class="ident">deprecated</span>)]</span>
<span class="kw">pub</span> <span class="kw">enum</span> <span class="ident">UnparkEvents</span> {
<span class="prelude-val">None</span>,
<span class="ident">One</span>(<span class="ident">UnparkEvent</span>),
<span class="ident">Many</span>(<span class="ident">Box</span><span class="op"><</span>[<span class="ident">UnparkEvent</span>]<span class="op">></span>),
}
<span class="kw">impl</span><span class="op"><</span><span class="lifetime">'a</span><span class="op">></span> <span class="ident">BorrowedUnpark</span><span class="op"><</span><span class="lifetime">'a</span><span class="op">></span> {
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">new</span>(<span class="ident">f</span>: <span class="kw-2">&</span><span class="lifetime">'a</span> <span class="ident">Fn</span>() <span class="op">-></span> <span class="ident">NotifyHandle</span>, <span class="ident">id</span>: <span class="ident">usize</span>) <span class="op">-></span> <span class="ident">BorrowedUnpark</span><span class="op"><</span><span class="lifetime">'a</span><span class="op">></span> {
<span class="ident">BorrowedUnpark</span>::<span class="ident">New</span>(<span class="ident">core</span>::<span class="ident">BorrowedUnpark</span>::<span class="ident">new</span>(<span class="ident">f</span>, <span class="ident">id</span>))
}
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">to_owned</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="ident">TaskUnpark</span> {
<span class="kw">match</span> <span class="kw-2">*</span><span class="self">self</span> {
<span class="ident">BorrowedUnpark</span>::<span class="ident">Old</span>(<span class="ident">old</span>) <span class="op">=></span> <span class="ident">TaskUnpark</span>::<span class="ident">Old</span>(<span class="ident">old</span>.<span class="ident">clone</span>()),
<span class="ident">BorrowedUnpark</span>::<span class="ident">New</span>(<span class="ident">new</span>) <span class="op">=></span> <span class="ident">TaskUnpark</span>::<span class="ident">New</span>(<span class="ident">new</span>.<span class="ident">to_owned</span>()),
}
}
}
<span class="kw">impl</span><span class="op"><</span><span class="lifetime">'a</span><span class="op">></span> <span class="ident">BorrowedEvents</span><span class="op"><</span><span class="lifetime">'a</span><span class="op">></span> {
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">new</span>() <span class="op">-></span> <span class="ident">BorrowedEvents</span><span class="op"><</span><span class="lifetime">'a</span><span class="op">></span> {
<span class="ident">BorrowedEvents</span>::<span class="prelude-val">None</span>
}
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">to_owned</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="ident">UnparkEvents</span> {
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">one_event</span> <span class="op">=</span> <span class="prelude-val">None</span>;
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">list</span> <span class="op">=</span> <span class="ident">Vec</span>::<span class="ident">new</span>();
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">cur</span> <span class="op">=</span> <span class="self">self</span>;
<span class="kw">while</span> <span class="kw">let</span> <span class="ident">BorrowedEvents</span>::<span class="ident">One</span>(<span class="ident">event</span>, <span class="ident">next</span>) <span class="op">=</span> <span class="kw-2">*</span><span class="ident">cur</span> {
<span class="kw">let</span> <span class="ident">event</span> <span class="op">=</span> <span class="ident">event</span>.<span class="ident">clone</span>();
<span class="kw">match</span> <span class="ident">one_event</span>.<span class="ident">take</span>() {
<span class="prelude-val">None</span> <span class="kw">if</span> <span class="ident">list</span>.<span class="ident">len</span>() <span class="op">==</span> <span class="number">0</span> <span class="op">=></span> <span class="ident">one_event</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="ident">event</span>),
<span class="prelude-val">None</span> <span class="op">=></span> <span class="ident">list</span>.<span class="ident">push</span>(<span class="ident">event</span>),
<span class="prelude-val">Some</span>(<span class="ident">event2</span>) <span class="op">=></span> {
<span class="ident">list</span>.<span class="ident">push</span>(<span class="ident">event2</span>);
<span class="ident">list</span>.<span class="ident">push</span>(<span class="ident">event</span>);
}
}
<span class="ident">cur</span> <span class="op">=</span> <span class="ident">next</span>;
}
<span class="kw">match</span> <span class="ident">one_event</span> {
<span class="prelude-val">None</span> <span class="kw">if</span> <span class="ident">list</span>.<span class="ident">len</span>() <span class="op">==</span> <span class="number">0</span> <span class="op">=></span> <span class="ident">UnparkEvents</span>::<span class="prelude-val">None</span>,
<span class="prelude-val">None</span> <span class="op">=></span> <span class="ident">UnparkEvents</span>::<span class="ident">Many</span>(<span class="ident">list</span>.<span class="ident">into_boxed_slice</span>()),
<span class="prelude-val">Some</span>(<span class="ident">e</span>) <span class="op">=></span> <span class="ident">UnparkEvents</span>::<span class="ident">One</span>(<span class="ident">e</span>),
}
}
}
<span class="kw">impl</span> <span class="ident">UnparkEvents</span> {
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">notify</span>(<span class="kw-2">&</span><span class="self">self</span>) {
<span class="kw">match</span> <span class="kw-2">*</span><span class="self">self</span> {
<span class="ident">UnparkEvents</span>::<span class="prelude-val">None</span> <span class="op">=></span> {}
<span class="ident">UnparkEvents</span>::<span class="ident">One</span>(<span class="kw-2">ref</span> <span class="ident">e</span>) <span class="op">=></span> <span class="ident">e</span>.<span class="ident">unpark</span>(),
<span class="ident">UnparkEvents</span>::<span class="ident">Many</span>(<span class="kw-2">ref</span> <span class="ident">list</span>) <span class="op">=></span> {
<span class="kw">for</span> <span class="ident">event</span> <span class="kw">in</span> <span class="ident">list</span>.<span class="ident">iter</span>() {
<span class="ident">event</span>.<span class="ident">unpark</span>();
}
}
}
}
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">will_notify</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">events</span>: <span class="kw-2">&</span><span class="ident">BorrowedEvents</span>) <span class="op">-></span> <span class="ident">bool</span> {
<span class="comment">// Pessimistically assume that any unpark events mean that we're not</span>
<span class="comment">// equivalent to the current task.</span>
<span class="kw">match</span> <span class="kw-2">*</span><span class="self">self</span> {
<span class="ident">UnparkEvents</span>::<span class="prelude-val">None</span> <span class="op">=></span> {}
_ <span class="op">=></span> <span class="kw">return</span> <span class="bool-val">false</span>,
}
<span class="kw">match</span> <span class="kw-2">*</span><span class="ident">events</span> {
<span class="ident">BorrowedEvents</span>::<span class="prelude-val">None</span> <span class="op">=></span> <span class="kw">return</span> <span class="bool-val">true</span>,
_ <span class="op">=></span> {},
}
<span class="kw">return</span> <span class="bool-val">false</span>
}
}
<span class="attribute">#[<span class="ident">allow</span>(<span class="ident">deprecated</span>)]</span>
<span class="kw">impl</span> <span class="ident">TaskUnpark</span> {
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">notify</span>(<span class="kw-2">&</span><span class="self">self</span>) {
<span class="kw">match</span> <span class="kw-2">*</span><span class="self">self</span> {
<span class="ident">TaskUnpark</span>::<span class="ident">Old</span>(<span class="kw-2">ref</span> <span class="ident">old</span>) <span class="op">=></span> <span class="ident">old</span>.<span class="ident">unpark</span>(),
<span class="ident">TaskUnpark</span>::<span class="ident">New</span>(<span class="kw-2">ref</span> <span class="ident">new</span>) <span class="op">=></span> <span class="ident">new</span>.<span class="ident">notify</span>(),
}
}
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">will_notify</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">unpark</span>: <span class="kw-2">&</span><span class="ident">BorrowedUnpark</span>) <span class="op">-></span> <span class="ident">bool</span> {
<span class="kw">match</span> (<span class="ident">unpark</span>, <span class="self">self</span>) {
(<span class="kw-2">&</span><span class="ident">BorrowedUnpark</span>::<span class="ident">Old</span>(<span class="ident">old1</span>), <span class="kw-2">&</span><span class="ident">TaskUnpark</span>::<span class="ident">Old</span>(<span class="kw-2">ref</span> <span class="ident">old2</span>)) <span class="op">=></span> {
<span class="kw-2">&</span><span class="kw-2">*</span><span class="kw-2">*</span><span class="ident">old1</span> <span class="kw">as</span> <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">Unpark</span> <span class="op">==</span> <span class="kw-2">&</span><span class="kw-2">*</span><span class="kw-2">*</span><span class="ident">old2</span> <span class="kw">as</span> <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">Unpark</span>
}
(<span class="kw-2">&</span><span class="ident">BorrowedUnpark</span>::<span class="ident">New</span>(<span class="kw-2">ref</span> <span class="ident">new1</span>), <span class="kw-2">&</span><span class="ident">TaskUnpark</span>::<span class="ident">New</span>(<span class="kw-2">ref</span> <span class="ident">new2</span>)) <span class="op">=></span> {
<span class="ident">new2</span>.<span class="ident">will_notify</span>(<span class="ident">new1</span>)
}
_ <span class="op">=></span> <span class="bool-val">false</span>,
}
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">F</span>: <span class="ident">Future</span><span class="op">></span> <span class="ident">Spawn</span><span class="op"><</span><span class="ident">F</span><span class="op">></span> {
<span class="doccomment">/// Polls the internal future, scheduling notifications to be sent to the</span>
<span class="doccomment">/// `unpark` argument.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This method will poll the internal future, testing if it's completed</span>
<span class="doccomment">/// yet. The `unpark` argument is used as a sink for notifications sent to</span>
<span class="doccomment">/// this future. That is, while the future is being polled, any call to</span>
<span class="doccomment">/// `task::park()` will return a handle that contains the `unpark`</span>
<span class="doccomment">/// specified.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// If this function returns `NotReady`, then the `unpark` should have been</span>
<span class="doccomment">/// scheduled to receive a notification when poll can be called again.</span>
<span class="doccomment">/// Otherwise if `Ready` or `Err` is returned, the `Spawn` task can be</span>
<span class="doccomment">/// safely destroyed.</span>
<span class="attribute">#[<span class="ident">deprecated</span>(<span class="ident">note</span> <span class="op">=</span> <span class="string">"recommended to use `poll_future_notify` instead"</span>)]</span>
<span class="attribute">#[<span class="ident">allow</span>(<span class="ident">deprecated</span>)]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">poll_future</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>, <span class="ident">unpark</span>: <span class="ident">Arc</span><span class="op"><</span><span class="ident">Unpark</span><span class="op">></span>) <span class="op">-></span> <span class="ident">Poll</span><span class="op"><</span><span class="ident">F</span>::<span class="ident">Item</span>, <span class="ident">F</span>::<span class="ident">Error</span><span class="op">></span> {
<span class="self">self</span>.<span class="ident">enter</span>(<span class="ident">BorrowedUnpark</span>::<span class="ident">Old</span>(<span class="kw-2">&</span><span class="ident">unpark</span>), <span class="op">|</span><span class="ident">f</span><span class="op">|</span> <span class="ident">f</span>.<span class="ident">poll</span>())
}
<span class="doccomment">/// Waits for the internal future to complete, blocking this thread's</span>
<span class="doccomment">/// execution until it does.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This function will call `poll_future` in a loop, waiting for the future</span>
<span class="doccomment">/// to complete. When a future cannot make progress it will use</span>
<span class="doccomment">/// `thread::park` to block the current thread.</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">wait_future</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>) <span class="op">-></span> <span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">F</span>::<span class="ident">Item</span>, <span class="ident">F</span>::<span class="ident">Error</span><span class="op">></span> {
<span class="ident">ThreadNotify</span>::<span class="ident">with_current</span>(<span class="op">|</span><span class="ident">notify</span><span class="op">|</span> {
<span class="kw">loop</span> {
<span class="kw">match</span> <span class="self">self</span>.<span class="ident">poll_future_notify</span>(<span class="ident">notify</span>, <span class="number">0</span>)<span class="question-mark">?</span> {
<span class="ident">Async</span>::<span class="ident">NotReady</span> <span class="op">=></span> <span class="ident">notify</span>.<span class="ident">park</span>(),
<span class="ident">Async</span>::<span class="ident">Ready</span>(<span class="ident">e</span>) <span class="op">=></span> <span class="kw">return</span> <span class="prelude-val">Ok</span>(<span class="ident">e</span>),
}
}
})
}
<span class="doccomment">/// A specialized function to request running a future to completion on the</span>
<span class="doccomment">/// specified executor.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This function only works for futures whose item and error types are `()`</span>
<span class="doccomment">/// and also implement the `Send` and `'static` bounds. This will submit</span>
<span class="doccomment">/// units of work (instances of `Run`) to the `exec` argument provided</span>
<span class="doccomment">/// necessary to drive the future to completion.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// When the future would block, it's arranged that when the future is again</span>
<span class="doccomment">/// ready it will submit another unit of work to the `exec` provided. This</span>
<span class="doccomment">/// will happen in a loop until the future has completed.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This method is not appropriate for all futures, and other kinds of</span>
<span class="doccomment">/// executors typically provide a similar function with perhaps relaxed</span>
<span class="doccomment">/// bounds as well.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Note that this method is likely to be deprecated in favor of the</span>
<span class="doccomment">/// `futures::Executor` trait and `execute` method, but if this'd cause</span>
<span class="doccomment">/// difficulty for you please let us know!</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">execute</span>(<span class="self">self</span>, <span class="ident">exec</span>: <span class="ident">Arc</span><span class="op"><</span><span class="ident">Executor</span><span class="op">></span>)
<span class="kw">where</span> <span class="ident">F</span>: <span class="ident">Future</span><span class="op"><</span><span class="ident">Item</span><span class="op">=</span>(), <span class="ident">Error</span><span class="op">=</span>()<span class="op">></span> <span class="op">+</span> <span class="ident">Send</span> <span class="op">+</span> <span class="lifetime">'static</span>,
{
<span class="ident">exec</span>.<span class="ident">clone</span>().<span class="ident">execute</span>(<span class="ident">Run</span> {
<span class="comment">// Ideally this method would be defined directly on</span>
<span class="comment">// `Spawn<BoxFuture<(), ()>>` so we wouldn't have to box here and</span>
<span class="comment">// it'd be more explicit, but unfortunately that currently has a</span>
<span class="comment">// link error on nightly: rust-lang/rust#36155</span>
<span class="ident">spawn</span>: <span class="ident">spawn</span>(<span class="ident">Box</span>::<span class="ident">new</span>(<span class="self">self</span>.<span class="ident">into_inner</span>())),
<span class="ident">inner</span>: <span class="ident">Arc</span>::<span class="ident">new</span>(<span class="ident">RunInner</span> {
<span class="ident">exec</span>: <span class="ident">exec</span>,
<span class="ident">mutex</span>: <span class="ident">UnparkMutex</span>::<span class="ident">new</span>()
}),
})
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">S</span>: <span class="ident">Stream</span><span class="op">></span> <span class="ident">Spawn</span><span class="op"><</span><span class="ident">S</span><span class="op">></span> {
<span class="doccomment">/// Like `poll_future`, except polls the underlying stream.</span>
<span class="attribute">#[<span class="ident">deprecated</span>(<span class="ident">note</span> <span class="op">=</span> <span class="string">"recommended to use `poll_stream_notify` instead"</span>)]</span>
<span class="attribute">#[<span class="ident">allow</span>(<span class="ident">deprecated</span>)]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">poll_stream</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>, <span class="ident">unpark</span>: <span class="ident">Arc</span><span class="op"><</span><span class="ident">Unpark</span><span class="op">></span>)
<span class="op">-></span> <span class="ident">Poll</span><span class="op"><</span><span class="prelude-ty">Option</span><span class="op"><</span><span class="ident">S</span>::<span class="ident">Item</span><span class="op">></span>, <span class="ident">S</span>::<span class="ident">Error</span><span class="op">></span> {
<span class="self">self</span>.<span class="ident">enter</span>(<span class="ident">BorrowedUnpark</span>::<span class="ident">Old</span>(<span class="kw-2">&</span><span class="ident">unpark</span>), <span class="op">|</span><span class="ident">s</span><span class="op">|</span> <span class="ident">s</span>.<span class="ident">poll</span>())
}
<span class="doccomment">/// Like `wait_future`, except only waits for the next element to arrive on</span>
<span class="doccomment">/// the underlying stream.</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">wait_stream</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>) <span class="op">-></span> <span class="prelude-ty">Option</span><span class="op"><</span><span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">S</span>::<span class="ident">Item</span>, <span class="ident">S</span>::<span class="ident">Error</span><span class="op">>></span> {
<span class="ident">ThreadNotify</span>::<span class="ident">with_current</span>(<span class="op">|</span><span class="ident">notify</span><span class="op">|</span> {
<span class="kw">loop</span> {
<span class="kw">match</span> <span class="self">self</span>.<span class="ident">poll_stream_notify</span>(<span class="ident">notify</span>, <span class="number">0</span>) {
<span class="prelude-val">Ok</span>(<span class="ident">Async</span>::<span class="ident">NotReady</span>) <span class="op">=></span> <span class="ident">notify</span>.<span class="ident">park</span>(),
<span class="prelude-val">Ok</span>(<span class="ident">Async</span>::<span class="ident">Ready</span>(<span class="prelude-val">Some</span>(<span class="ident">e</span>))) <span class="op">=></span> <span class="kw">return</span> <span class="prelude-val">Some</span>(<span class="prelude-val">Ok</span>(<span class="ident">e</span>)),
<span class="prelude-val">Ok</span>(<span class="ident">Async</span>::<span class="ident">Ready</span>(<span class="prelude-val">None</span>)) <span class="op">=></span> <span class="kw">return</span> <span class="prelude-val">None</span>,
<span class="prelude-val">Err</span>(<span class="ident">e</span>) <span class="op">=></span> <span class="kw">return</span> <span class="prelude-val">Some</span>(<span class="prelude-val">Err</span>(<span class="ident">e</span>)),
}
}
})
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">S</span>: <span class="ident">Sink</span><span class="op">></span> <span class="ident">Spawn</span><span class="op"><</span><span class="ident">S</span><span class="op">></span> {
<span class="doccomment">/// Invokes the underlying `start_send` method with this task in place.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// If the underlying operation returns `NotReady` then the `unpark` value</span>
<span class="doccomment">/// passed in will receive a notification when the operation is ready to be</span>
<span class="doccomment">/// attempted again.</span>
<span class="attribute">#[<span class="ident">deprecated</span>(<span class="ident">note</span> <span class="op">=</span> <span class="string">"recommended to use `start_send_notify` instead"</span>)]</span>
<span class="attribute">#[<span class="ident">allow</span>(<span class="ident">deprecated</span>)]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">start_send</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>, <span class="ident">value</span>: <span class="ident">S</span>::<span class="ident">SinkItem</span>, <span class="ident">unpark</span>: <span class="kw-2">&</span><span class="ident">Arc</span><span class="op"><</span><span class="ident">Unpark</span><span class="op">></span>)
<span class="op">-></span> <span class="ident">StartSend</span><span class="op"><</span><span class="ident">S</span>::<span class="ident">SinkItem</span>, <span class="ident">S</span>::<span class="ident">SinkError</span><span class="op">></span> {
<span class="self">self</span>.<span class="ident">enter</span>(<span class="ident">BorrowedUnpark</span>::<span class="ident">Old</span>(<span class="ident">unpark</span>), <span class="op">|</span><span class="ident">s</span><span class="op">|</span> <span class="ident">s</span>.<span class="ident">start_send</span>(<span class="ident">value</span>))
}
<span class="doccomment">/// Invokes the underlying `poll_complete` method with this task in place.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// If the underlying operation returns `NotReady` then the `unpark` value</span>
<span class="doccomment">/// passed in will receive a notification when the operation is ready to be</span>
<span class="doccomment">/// attempted again.</span>
<span class="attribute">#[<span class="ident">deprecated</span>(<span class="ident">note</span> <span class="op">=</span> <span class="string">"recommended to use `poll_flush_notify` instead"</span>)]</span>
<span class="attribute">#[<span class="ident">allow</span>(<span class="ident">deprecated</span>)]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">poll_flush</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>, <span class="ident">unpark</span>: <span class="kw-2">&</span><span class="ident">Arc</span><span class="op"><</span><span class="ident">Unpark</span><span class="op">></span>)
<span class="op">-></span> <span class="ident">Poll</span><span class="op"><</span>(), <span class="ident">S</span>::<span class="ident">SinkError</span><span class="op">></span> {
<span class="self">self</span>.<span class="ident">enter</span>(<span class="ident">BorrowedUnpark</span>::<span class="ident">Old</span>(<span class="ident">unpark</span>), <span class="op">|</span><span class="ident">s</span><span class="op">|</span> <span class="ident">s</span>.<span class="ident">poll_complete</span>())
}
<span class="doccomment">/// Blocks the current thread until it's able to send `value` on this sink.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This function will send the `value` on the sink that this task wraps. If</span>
<span class="doccomment">/// the sink is not ready to send the value yet then the current thread will</span>
<span class="doccomment">/// be blocked until it's able to send the value.</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">wait_send</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>, <span class="kw-2">mut</span> <span class="ident">value</span>: <span class="ident">S</span>::<span class="ident">SinkItem</span>)
<span class="op">-></span> <span class="prelude-ty">Result</span><span class="op"><</span>(), <span class="ident">S</span>::<span class="ident">SinkError</span><span class="op">></span> {
<span class="ident">ThreadNotify</span>::<span class="ident">with_current</span>(<span class="op">|</span><span class="ident">notify</span><span class="op">|</span> {
<span class="kw">loop</span> {
<span class="ident">value</span> <span class="op">=</span> <span class="kw">match</span> <span class="self">self</span>.<span class="ident">start_send_notify</span>(<span class="ident">value</span>, <span class="ident">notify</span>, <span class="number">0</span>)<span class="question-mark">?</span> {
<span class="ident">AsyncSink</span>::<span class="ident">NotReady</span>(<span class="ident">v</span>) <span class="op">=></span> <span class="ident">v</span>,
<span class="ident">AsyncSink</span>::<span class="ident">Ready</span> <span class="op">=></span> <span class="kw">return</span> <span class="prelude-val">Ok</span>(()),
};
<span class="ident">notify</span>.<span class="ident">park</span>();
}
})
}
<span class="doccomment">/// Blocks the current thread until it's able to flush this sink.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This function will call the underlying sink's `poll_complete` method</span>
<span class="doccomment">/// until it returns that it's ready, proxying out errors upwards to the</span>
<span class="doccomment">/// caller if one occurs.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// The thread will be blocked until `poll_complete` returns that it's</span>
<span class="doccomment">/// ready.</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">wait_flush</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>) <span class="op">-></span> <span class="prelude-ty">Result</span><span class="op"><</span>(), <span class="ident">S</span>::<span class="ident">SinkError</span><span class="op">></span> {
<span class="ident">ThreadNotify</span>::<span class="ident">with_current</span>(<span class="op">|</span><span class="ident">notify</span><span class="op">|</span> {
<span class="kw">loop</span> {
<span class="kw">if</span> <span class="self">self</span>.<span class="ident">poll_flush_notify</span>(<span class="ident">notify</span>, <span class="number">0</span>)<span class="question-mark">?</span>.<span class="ident">is_ready</span>() {
<span class="kw">return</span> <span class="prelude-val">Ok</span>(())
}
<span class="ident">notify</span>.<span class="ident">park</span>();
}
})
}
<span class="doccomment">/// Blocks the current thread until it's able to close this sink.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This function will close the sink that this task wraps. If the sink</span>
<span class="doccomment">/// is not ready to be close yet, then the current thread will be blocked</span>
<span class="doccomment">/// until it's closed.</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">wait_close</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>) <span class="op">-></span> <span class="prelude-ty">Result</span><span class="op"><</span>(), <span class="ident">S</span>::<span class="ident">SinkError</span><span class="op">></span> {
<span class="ident">ThreadNotify</span>::<span class="ident">with_current</span>(<span class="op">|</span><span class="ident">notify</span><span class="op">|</span> {
<span class="kw">loop</span> {
<span class="kw">if</span> <span class="self">self</span>.<span class="ident">close_notify</span>(<span class="ident">notify</span>, <span class="number">0</span>)<span class="question-mark">?</span>.<span class="ident">is_ready</span>() {
<span class="kw">return</span> <span class="prelude-val">Ok</span>(())
}
<span class="ident">notify</span>.<span class="ident">park</span>();
}
})
}
}
<span class="doccomment">/// A trait which represents a sink of notifications that a future is ready to</span>
<span class="doccomment">/// make progress.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This trait is provided as an argument to the `Spawn::poll_future` and</span>
<span class="doccomment">/// `Spawn::poll_stream` functions. It's transitively used as part of the</span>
<span class="doccomment">/// `Task::unpark` method to internally deliver notifications of readiness of a</span>
<span class="doccomment">/// future to move forward.</span>
<span class="attribute">#[<span class="ident">deprecated</span>(<span class="ident">note</span> <span class="op">=</span> <span class="string">"recommended to use `Notify` instead"</span>)]</span>
<span class="kw">pub</span> <span class="kw">trait</span> <span class="ident">Unpark</span>: <span class="ident">Send</span> <span class="op">+</span> <span class="ident">Sync</span> {
<span class="doccomment">/// Indicates that an associated future and/or task are ready to make</span>
<span class="doccomment">/// progress.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Typically this means that the receiver of the notification should</span>
<span class="doccomment">/// arrange for the future to get poll'd in a prompt fashion.</span>
<span class="kw">fn</span> <span class="ident">unpark</span>(<span class="kw-2">&</span><span class="self">self</span>);
}
<span class="doccomment">/// A trait representing requests to poll futures.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This trait is an argument to the `Spawn::execute` which is used to run a</span>
<span class="doccomment">/// future to completion. An executor will receive requests to run a future and</span>
<span class="doccomment">/// an executor is responsible for ensuring that happens in a timely fashion.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Note that this trait is likely to be deprecated and/or renamed to avoid</span>
<span class="doccomment">/// clashing with the `future::Executor` trait. If you've got a use case for</span>
<span class="doccomment">/// this or would like to comment on the name please let us know!</span>
<span class="kw">pub</span> <span class="kw">trait</span> <span class="ident">Executor</span>: <span class="ident">Send</span> <span class="op">+</span> <span class="ident">Sync</span> <span class="op">+</span> <span class="lifetime">'static</span> {
<span class="doccomment">/// Requests that `Run` is executed soon on the given executor.</span>
<span class="kw">fn</span> <span class="ident">execute</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">r</span>: <span class="ident">Run</span>);
}
<span class="doccomment">/// Units of work submitted to an `Executor`, currently only created</span>
<span class="doccomment">/// internally.</span>
<span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">Run</span> {
<span class="ident">spawn</span>: <span class="ident">Spawn</span><span class="op"><</span><span class="ident">Box</span><span class="op"><</span><span class="ident">Future</span><span class="op"><</span><span class="ident">Item</span> <span class="op">=</span> (), <span class="ident">Error</span> <span class="op">=</span> ()<span class="op">></span> <span class="op">+</span> <span class="ident">Send</span><span class="op">>></span>,
<span class="ident">inner</span>: <span class="ident">Arc</span><span class="op"><</span><span class="ident">RunInner</span><span class="op">></span>,
}
<span class="kw">struct</span> <span class="ident">RunInner</span> {
<span class="ident">mutex</span>: <span class="ident">UnparkMutex</span><span class="op"><</span><span class="ident">Run</span><span class="op">></span>,
<span class="ident">exec</span>: <span class="ident">Arc</span><span class="op"><</span><span class="ident">Executor</span><span class="op">></span>,
}
<span class="kw">impl</span> <span class="ident">Run</span> {
<span class="doccomment">/// Actually run the task (invoking `poll` on its future) on the current</span>
<span class="doccomment">/// thread.</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">run</span>(<span class="self">self</span>) {
<span class="kw">let</span> <span class="ident">Run</span> { <span class="kw-2">mut</span> <span class="ident">spawn</span>, <span class="ident">inner</span> } <span class="op">=</span> <span class="self">self</span>;
<span class="comment">// SAFETY: the ownership of this `Run` object is evidence that</span>
<span class="comment">// we are in the `POLLING`/`REPOLL` state for the mutex.</span>
<span class="kw">unsafe</span> {
<span class="ident">inner</span>.<span class="ident">mutex</span>.<span class="ident">start_poll</span>();
<span class="kw">loop</span> {
<span class="kw">match</span> <span class="ident">spawn</span>.<span class="ident">poll_future_notify</span>(<span class="kw-2">&</span><span class="ident">inner</span>, <span class="number">0</span>) {
<span class="prelude-val">Ok</span>(<span class="ident">Async</span>::<span class="ident">NotReady</span>) <span class="op">=></span> {}
<span class="prelude-val">Ok</span>(<span class="ident">Async</span>::<span class="ident">Ready</span>(())) <span class="op">|</span>
<span class="prelude-val">Err</span>(()) <span class="op">=></span> <span class="kw">return</span> <span class="ident">inner</span>.<span class="ident">mutex</span>.<span class="ident">complete</span>(),
}
<span class="kw">let</span> <span class="ident">run</span> <span class="op">=</span> <span class="ident">Run</span> { <span class="ident">spawn</span>: <span class="ident">spawn</span>, <span class="ident">inner</span>: <span class="ident">inner</span>.<span class="ident">clone</span>() };
<span class="kw">match</span> <span class="ident">inner</span>.<span class="ident">mutex</span>.<span class="ident">wait</span>(<span class="ident">run</span>) {
<span class="prelude-val">Ok</span>(()) <span class="op">=></span> <span class="kw">return</span>, <span class="comment">// we've waited</span>
<span class="prelude-val">Err</span>(<span class="ident">r</span>) <span class="op">=></span> <span class="ident">spawn</span> <span class="op">=</span> <span class="ident">r</span>.<span class="ident">spawn</span>, <span class="comment">// someone's notified us</span>
}
}
}
}
}
<span class="kw">impl</span> <span class="ident">fmt</span>::<span class="ident">Debug</span> <span class="kw">for</span> <span class="ident">Run</span> {
<span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">f</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">fmt</span>::<span class="ident">Formatter</span>) <span class="op">-></span> <span class="ident">fmt</span>::<span class="prelude-ty">Result</span> {
<span class="ident">f</span>.<span class="ident">debug_struct</span>(<span class="string">"Run"</span>)
.<span class="ident">field</span>(<span class="string">"contents"</span>, <span class="kw-2">&</span><span class="string">"..."</span>)
.<span class="ident">finish</span>()
}
}
<span class="kw">impl</span> <span class="ident">Notify</span> <span class="kw">for</span> <span class="ident">RunInner</span> {
<span class="kw">fn</span> <span class="ident">notify</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">_id</span>: <span class="ident">usize</span>) {
<span class="kw">match</span> <span class="self">self</span>.<span class="ident">mutex</span>.<span class="ident">notify</span>() {
<span class="prelude-val">Ok</span>(<span class="ident">run</span>) <span class="op">=></span> <span class="self">self</span>.<span class="ident">exec</span>.<span class="ident">execute</span>(<span class="ident">run</span>),
<span class="prelude-val">Err</span>(()) <span class="op">=></span> {}
}
}
}
<span class="comment">// ===== ThreadNotify =====</span>
<span class="kw">struct</span> <span class="ident">ThreadNotify</span> {
<span class="ident">state</span>: <span class="ident">AtomicUsize</span>,
<span class="ident">mutex</span>: <span class="ident">Mutex</span><span class="op"><</span>()<span class="op">></span>,
<span class="ident">condvar</span>: <span class="ident">Condvar</span>,
}
<span class="kw">const</span> <span class="ident">IDLE</span>: <span class="ident">usize</span> <span class="op">=</span> <span class="number">0</span>;
<span class="kw">const</span> <span class="ident">NOTIFY</span>: <span class="ident">usize</span> <span class="op">=</span> <span class="number">1</span>;
<span class="kw">const</span> <span class="ident">SLEEP</span>: <span class="ident">usize</span> <span class="op">=</span> <span class="number">2</span>;
<span class="macro">thread_local</span><span class="macro">!</span> {
<span class="kw">static</span> <span class="ident">CURRENT_THREAD_NOTIFY</span>: <span class="ident">Arc</span><span class="op"><</span><span class="ident">ThreadNotify</span><span class="op">></span> <span class="op">=</span> <span class="ident">Arc</span>::<span class="ident">new</span>(<span class="ident">ThreadNotify</span> {
<span class="ident">state</span>: <span class="ident">AtomicUsize</span>::<span class="ident">new</span>(<span class="ident">IDLE</span>),
<span class="ident">mutex</span>: <span class="ident">Mutex</span>::<span class="ident">new</span>(()),
<span class="ident">condvar</span>: <span class="ident">Condvar</span>::<span class="ident">new</span>(),
});
}
<span class="kw">impl</span> <span class="ident">ThreadNotify</span> {
<span class="kw">fn</span> <span class="ident">with_current</span><span class="op"><</span><span class="ident">F</span>, <span class="ident">R</span><span class="op">></span>(<span class="ident">f</span>: <span class="ident">F</span>) <span class="op">-></span> <span class="ident">R</span>
<span class="kw">where</span> <span class="ident">F</span>: <span class="ident">FnOnce</span>(<span class="kw-2">&</span><span class="ident">Arc</span><span class="op"><</span><span class="ident">ThreadNotify</span><span class="op">></span>) <span class="op">-></span> <span class="ident">R</span>,
{
<span class="ident">CURRENT_THREAD_NOTIFY</span>.<span class="ident">with</span>(<span class="op">|</span><span class="ident">notify</span><span class="op">|</span> <span class="ident">f</span>(<span class="ident">notify</span>))
}
<span class="kw">fn</span> <span class="ident">park</span>(<span class="kw-2">&</span><span class="self">self</span>) {
<span class="comment">// If currently notified, then we skip sleeping. This is checked outside</span>
<span class="comment">// of the lock to avoid acquiring a mutex if not necessary.</span>
<span class="kw">match</span> <span class="self">self</span>.<span class="ident">state</span>.<span class="ident">compare_and_swap</span>(<span class="ident">NOTIFY</span>, <span class="ident">IDLE</span>, <span class="ident">Ordering</span>::<span class="ident">SeqCst</span>) {
<span class="ident">NOTIFY</span> <span class="op">=></span> <span class="kw">return</span>,
<span class="ident">IDLE</span> <span class="op">=></span> {},
_ <span class="op">=></span> <span class="macro">unreachable</span><span class="macro">!</span>(),
}
<span class="comment">// The state is currently idle, so obtain the lock and then try to</span>
<span class="comment">// transition to a sleeping state.</span>
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">m</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">mutex</span>.<span class="ident">lock</span>().<span class="ident">unwrap</span>();
<span class="comment">// Transition to sleeping</span>
<span class="kw">match</span> <span class="self">self</span>.<span class="ident">state</span>.<span class="ident">compare_and_swap</span>(<span class="ident">IDLE</span>, <span class="ident">SLEEP</span>, <span class="ident">Ordering</span>::<span class="ident">SeqCst</span>) {
<span class="ident">NOTIFY</span> <span class="op">=></span> {
<span class="comment">// Notified before we could sleep, consume the notification and</span>
<span class="comment">// exit</span>
<span class="self">self</span>.<span class="ident">state</span>.<span class="ident">store</span>(<span class="ident">IDLE</span>, <span class="ident">Ordering</span>::<span class="ident">SeqCst</span>);
<span class="kw">return</span>;
}
<span class="ident">IDLE</span> <span class="op">=></span> {},
_ <span class="op">=></span> <span class="macro">unreachable</span><span class="macro">!</span>(),
}
<span class="comment">// Loop until we've been notified</span>
<span class="kw">loop</span> {
<span class="ident">m</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">condvar</span>.<span class="ident">wait</span>(<span class="ident">m</span>).<span class="ident">unwrap</span>();
<span class="comment">// Transition back to idle, loop otherwise</span>
<span class="kw">if</span> <span class="ident">NOTIFY</span> <span class="op">==</span> <span class="self">self</span>.<span class="ident">state</span>.<span class="ident">compare_and_swap</span>(<span class="ident">NOTIFY</span>, <span class="ident">IDLE</span>, <span class="ident">Ordering</span>::<span class="ident">SeqCst</span>) {
<span class="kw">return</span>;
}
}
}
}
<span class="kw">impl</span> <span class="ident">Notify</span> <span class="kw">for</span> <span class="ident">ThreadNotify</span> {
<span class="kw">fn</span> <span class="ident">notify</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">_unpark_id</span>: <span class="ident">usize</span>) {
<span class="comment">// First, try transitioning from IDLE -> NOTIFY, this does not require a</span>
<span class="comment">// lock.</span>
<span class="kw">match</span> <span class="self">self</span>.<span class="ident">state</span>.<span class="ident">compare_and_swap</span>(<span class="ident">IDLE</span>, <span class="ident">NOTIFY</span>, <span class="ident">Ordering</span>::<span class="ident">SeqCst</span>) {
<span class="ident">IDLE</span> <span class="op">|</span> <span class="ident">NOTIFY</span> <span class="op">=></span> <span class="kw">return</span>,
<span class="ident">SLEEP</span> <span class="op">=></span> {}
_ <span class="op">=></span> <span class="macro">unreachable</span><span class="macro">!</span>(),
}
<span class="comment">// The other half is sleeping, this requires a lock</span>
<span class="kw">let</span> <span class="ident">_m</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">mutex</span>.<span class="ident">lock</span>().<span class="ident">unwrap</span>();
<span class="comment">// Transition from SLEEP -> NOTIFY</span>
<span class="kw">match</span> <span class="self">self</span>.<span class="ident">state</span>.<span class="ident">compare_and_swap</span>(<span class="ident">SLEEP</span>, <span class="ident">NOTIFY</span>, <span class="ident">Ordering</span>::<span class="ident">SeqCst</span>) {
<span class="ident">SLEEP</span> <span class="op">=></span> {}
_ <span class="op">=></span> <span class="kw">return</span>,
}
<span class="comment">// Wakeup the sleeper</span>
<span class="self">self</span>.<span class="ident">condvar</span>.<span class="ident">notify_one</span>();
}
}
<span class="comment">// ===== UnparkEvent =====</span>
<span class="doccomment">/// For the duration of the given callback, add an "unpark event" to be</span>
<span class="doccomment">/// triggered when the task handle is used to unpark the task.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Unpark events are used to pass information about what event caused a task to</span>
<span class="doccomment">/// be unparked. In some cases, tasks are waiting on a large number of possible</span>
<span class="doccomment">/// events, and need precise information about the wakeup to avoid extraneous</span>
<span class="doccomment">/// polling.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Every `Task` handle comes with a set of unpark events which will fire when</span>
<span class="doccomment">/// `unpark` is called. When fired, these events insert an identifier into a</span>
<span class="doccomment">/// concurrent set, which the task can read from to determine what events</span>
<span class="doccomment">/// occurred.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This function immediately invokes the closure, `f`, but arranges things so</span>
<span class="doccomment">/// that `task::park` will produce a `Task` handle that includes the given</span>
<span class="doccomment">/// unpark event.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Panics</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This function will panic if a task is not currently being executed. That</span>
<span class="doccomment">/// is, this method can be dangerous to call outside of an implementation of</span>
<span class="doccomment">/// `poll`.</span>
<span class="attribute">#[<span class="ident">deprecated</span>(<span class="ident">note</span> <span class="op">=</span> <span class="string">"recommended to use `FuturesUnordered` instead"</span>)]</span>
<span class="attribute">#[<span class="ident">allow</span>(<span class="ident">deprecated</span>)]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">with_unpark_event</span><span class="op"><</span><span class="ident">F</span>, <span class="ident">R</span><span class="op">></span>(<span class="ident">event</span>: <span class="ident">UnparkEvent</span>, <span class="ident">f</span>: <span class="ident">F</span>) <span class="op">-></span> <span class="ident">R</span>
<span class="kw">where</span> <span class="ident">F</span>: <span class="ident">FnOnce</span>() <span class="op">-></span> <span class="ident">R</span>
{
<span class="kw">super</span>::<span class="ident">with</span>(<span class="op">|</span><span class="ident">task</span><span class="op">|</span> {
<span class="kw">let</span> <span class="ident">new_task</span> <span class="op">=</span> <span class="ident">BorrowedTask</span> {
<span class="ident">id</span>: <span class="ident">task</span>.<span class="ident">id</span>,
<span class="ident">unpark</span>: <span class="ident">task</span>.<span class="ident">unpark</span>,
<span class="ident">events</span>: <span class="ident">BorrowedEvents</span>::<span class="ident">One</span>(<span class="kw-2">&</span><span class="ident">event</span>, <span class="kw-2">&</span><span class="ident">task</span>.<span class="ident">events</span>),
<span class="ident">map</span>: <span class="ident">task</span>.<span class="ident">map</span>,
};
<span class="kw">super</span>::<span class="ident">set</span>(<span class="kw-2">&</span><span class="ident">new_task</span>, <span class="ident">f</span>)
})
}
<span class="doccomment">/// A set insertion to trigger upon `unpark`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Unpark events are used to communicate information about *why* an unpark</span>
<span class="doccomment">/// occurred, in particular populating sets with event identifiers so that the</span>
<span class="doccomment">/// unparked task can avoid extraneous polling. See `with_unpark_event` for</span>
<span class="doccomment">/// more.</span>
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Clone</span>)]</span>
<span class="attribute">#[<span class="ident">deprecated</span>(<span class="ident">note</span> <span class="op">=</span> <span class="string">"recommended to use `FuturesUnordered` instead"</span>)]</span>
<span class="attribute">#[<span class="ident">allow</span>(<span class="ident">deprecated</span>)]</span>
<span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">UnparkEvent</span> {
<span class="ident">set</span>: <span class="ident">Arc</span><span class="op"><</span><span class="ident">EventSet</span><span class="op">></span>,
<span class="ident">item</span>: <span class="ident">usize</span>,
}
<span class="attribute">#[<span class="ident">allow</span>(<span class="ident">deprecated</span>)]</span>
<span class="kw">impl</span> <span class="ident">UnparkEvent</span> {
<span class="doccomment">/// Construct an unpark event that will insert `id` into `set` when</span>
<span class="doccomment">/// triggered.</span>
<span class="attribute">#[<span class="ident">deprecated</span>(<span class="ident">note</span> <span class="op">=</span> <span class="string">"recommended to use `FuturesUnordered` instead"</span>)]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">new</span>(<span class="ident">set</span>: <span class="ident">Arc</span><span class="op"><</span><span class="ident">EventSet</span><span class="op">></span>, <span class="ident">id</span>: <span class="ident">usize</span>) <span class="op">-></span> <span class="ident">UnparkEvent</span> {
<span class="ident">UnparkEvent</span> {
<span class="ident">set</span>: <span class="ident">set</span>,
<span class="ident">item</span>: <span class="ident">id</span>,
}
}
<span class="kw">fn</span> <span class="ident">unpark</span>(<span class="kw-2">&</span><span class="self">self</span>) {
<span class="self">self</span>.<span class="ident">set</span>.<span class="ident">insert</span>(<span class="self">self</span>.<span class="ident">item</span>);
}
}
<span class="attribute">#[<span class="ident">allow</span>(<span class="ident">deprecated</span>)]</span>
<span class="kw">impl</span> <span class="ident">fmt</span>::<span class="ident">Debug</span> <span class="kw">for</span> <span class="ident">UnparkEvent</span> {
<span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">f</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">fmt</span>::<span class="ident">Formatter</span>) <span class="op">-></span> <span class="ident">fmt</span>::<span class="prelude-ty">Result</span> {
<span class="ident">f</span>.<span class="ident">debug_struct</span>(<span class="string">"UnparkEvent"</span>)
.<span class="ident">field</span>(<span class="string">"set"</span>, <span class="kw-2">&</span><span class="string">"..."</span>)
.<span class="ident">field</span>(<span class="string">"item"</span>, <span class="kw-2">&</span><span class="self">self</span>.<span class="ident">item</span>)
.<span class="ident">finish</span>()
}
}
<span class="doccomment">/// A concurrent set which allows for the insertion of `usize` values.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// `EventSet`s are used to communicate precise information about the event(s)</span>
<span class="doccomment">/// that triggered a task notification. See `task::with_unpark_event` for details.</span>
<span class="attribute">#[<span class="ident">deprecated</span>(<span class="ident">since</span><span class="op">=</span><span class="string">"0.1.18"</span>, <span class="ident">note</span> <span class="op">=</span> <span class="string">"recommended to use `FuturesUnordered` instead"</span>)]</span>
<span class="kw">pub</span> <span class="kw">trait</span> <span class="ident">EventSet</span>: <span class="ident">Send</span> <span class="op">+</span> <span class="ident">Sync</span> <span class="op">+</span> <span class="lifetime">'static</span> {
<span class="doccomment">/// Insert the given ID into the set</span>
<span class="kw">fn</span> <span class="ident">insert</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">id</span>: <span class="ident">usize</span>);
}
<span class="comment">// Safe implementation of `UnsafeNotify` for `Arc` in the standard library.</span>
<span class="comment">//</span>
<span class="comment">// Note that this is a very unsafe implementation! The crucial pieces is that</span>
<span class="comment">// these two values are considered equivalent:</span>
<span class="comment">//</span>
<span class="comment">// * Arc<T></span>
<span class="comment">// * *const ArcWrapped<T></span>
<span class="comment">//</span>
<span class="comment">// We don't actually know the layout of `ArcWrapped<T>` as it's an</span>
<span class="comment">// implementation detail in the standard library. We can work, though, by</span>
<span class="comment">// casting it through and back an `Arc<T>`.</span>
<span class="comment">//</span>
<span class="comment">// This also means that you won't actually fine `UnsafeNotify for Arc<T>`</span>
<span class="comment">// because it's the wrong level of indirection. These methods are sort of</span>
<span class="comment">// receiving Arc<T>, but not an owned version. It's... complicated. We may be</span>
<span class="comment">// one of the first users of unsafe trait objects!</span>
<span class="kw">struct</span> <span class="ident">ArcWrapped</span><span class="op"><</span><span class="ident">T</span><span class="op">></span>(<span class="ident">PhantomData</span><span class="op"><</span><span class="ident">T</span><span class="op">></span>);
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span>: <span class="ident">Notify</span> <span class="op">+</span> <span class="lifetime">'static</span><span class="op">></span> <span class="ident">Notify</span> <span class="kw">for</span> <span class="ident">ArcWrapped</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="kw">fn</span> <span class="ident">notify</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">id</span>: <span class="ident">usize</span>) {
<span class="kw">unsafe</span> {
<span class="kw">let</span> <span class="ident">me</span>: <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">ArcWrapped</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="op">=</span> <span class="self">self</span>;
<span class="ident">T</span>::<span class="ident">notify</span>(<span class="kw-2">&</span><span class="kw-2">*</span>(<span class="kw-2">&</span><span class="ident">me</span> <span class="kw">as</span> <span class="kw-2">*</span><span class="kw">const</span> <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">ArcWrapped</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="kw">as</span> <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">Arc</span><span class="op"><</span><span class="ident">T</span><span class="op">></span>),
<span class="ident">id</span>)
}
}
<span class="kw">fn</span> <span class="ident">clone_id</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">id</span>: <span class="ident">usize</span>) <span class="op">-></span> <span class="ident">usize</span> {
<span class="kw">unsafe</span> {
<span class="kw">let</span> <span class="ident">me</span>: <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">ArcWrapped</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="op">=</span> <span class="self">self</span>;
<span class="ident">T</span>::<span class="ident">clone_id</span>(<span class="kw-2">&</span><span class="kw-2">*</span>(<span class="kw-2">&</span><span class="ident">me</span> <span class="kw">as</span> <span class="kw-2">*</span><span class="kw">const</span> <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">ArcWrapped</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="kw">as</span> <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">Arc</span><span class="op"><</span><span class="ident">T</span><span class="op">></span>),
<span class="ident">id</span>)
}
}
<span class="kw">fn</span> <span class="ident">drop_id</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">id</span>: <span class="ident">usize</span>) {
<span class="kw">unsafe</span> {
<span class="kw">let</span> <span class="ident">me</span>: <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">ArcWrapped</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="op">=</span> <span class="self">self</span>;
<span class="ident">T</span>::<span class="ident">drop_id</span>(<span class="kw-2">&</span><span class="kw-2">*</span>(<span class="kw-2">&</span><span class="ident">me</span> <span class="kw">as</span> <span class="kw-2">*</span><span class="kw">const</span> <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">ArcWrapped</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="kw">as</span> <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">Arc</span><span class="op"><</span><span class="ident">T</span><span class="op">></span>),
<span class="ident">id</span>)
}
}
}
<span class="kw">unsafe</span> <span class="kw">impl</span><span class="op"><</span><span class="ident">T</span>: <span class="ident">Notify</span> <span class="op">+</span> <span class="lifetime">'static</span><span class="op">></span> <span class="ident">UnsafeNotify</span> <span class="kw">for</span> <span class="ident">ArcWrapped</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="kw">unsafe</span> <span class="kw">fn</span> <span class="ident">clone_raw</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="ident">NotifyHandle</span> {
<span class="kw">let</span> <span class="ident">me</span>: <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">ArcWrapped</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="op">=</span> <span class="self">self</span>;
<span class="kw">let</span> <span class="ident">arc</span> <span class="op">=</span> (<span class="kw-2">*</span>(<span class="kw-2">&</span><span class="ident">me</span> <span class="kw">as</span> <span class="kw-2">*</span><span class="kw">const</span> <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">ArcWrapped</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="kw">as</span> <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">Arc</span><span class="op"><</span><span class="ident">T</span><span class="op">></span>)).<span class="ident">clone</span>();
<span class="ident">NotifyHandle</span>::<span class="ident">from</span>(<span class="ident">arc</span>)
}
<span class="kw">unsafe</span> <span class="kw">fn</span> <span class="ident">drop_raw</span>(<span class="kw-2">&</span><span class="self">self</span>) {
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">me</span>: <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">ArcWrapped</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="op">=</span> <span class="self">self</span>;
<span class="kw">let</span> <span class="ident">me</span> <span class="op">=</span> <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">me</span> <span class="kw">as</span> <span class="kw-2">*</span><span class="kw-2">mut</span> <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">ArcWrapped</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="kw">as</span> <span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">Arc</span><span class="op"><</span><span class="ident">T</span><span class="op">></span>;
<span class="ident">ptr</span>::<span class="ident">drop_in_place</span>(<span class="ident">me</span>);
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="ident">From</span><span class="op"><</span><span class="ident">Arc</span><span class="op"><</span><span class="ident">T</span><span class="op">>></span> <span class="kw">for</span> <span class="ident">NotifyHandle</span>
<span class="kw">where</span> <span class="ident">T</span>: <span class="ident">Notify</span> <span class="op">+</span> <span class="lifetime">'static</span>,
{
<span class="kw">fn</span> <span class="ident">from</span>(<span class="ident">rc</span>: <span class="ident">Arc</span><span class="op"><</span><span class="ident">T</span><span class="op">></span>) <span class="op">-></span> <span class="ident">NotifyHandle</span> {
<span class="kw">unsafe</span> {
<span class="kw">let</span> <span class="ident">ptr</span> <span class="op">=</span> <span class="ident">mem</span>::<span class="ident">transmute</span>::<span class="op"><</span><span class="ident">Arc</span><span class="op"><</span><span class="ident">T</span><span class="op">></span>, <span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">ArcWrapped</span><span class="op"><</span><span class="ident">T</span><span class="op">>></span>(<span class="ident">rc</span>);
<span class="ident">NotifyHandle</span>::<span class="ident">new</span>(<span class="ident">ptr</span>)
}
}
}
</pre>
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