| |
| <h1>multithreaded_client.cpp</h1> |
| <div class="highlight"><pre><span></span><span class="c1">//</span> |
| <span class="c1">// C++11 or greater</span> |
| <span class="c1">//</span> |
| <span class="c1">// A multi-threaded client that calls proton::container::run() in one thread, sends</span> |
| <span class="c1">// messages in another and receives messages in a third.</span> |
| <span class="c1">//</span> |
| <span class="c1">// Note this client does not deal with flow-control. If the sender is faster</span> |
| <span class="c1">// than the receiver, messages will build up in memory on the sending side.</span> |
| <span class="c1">// See @ref multithreaded_client_flow_control.cpp for a more complex example with</span> |
| <span class="c1">// flow control.</span> |
| <span class="c1">//</span> |
| <span class="c1">// NOTE: no proper error handling</span> |
| |
| <span class="cp">#include</span> <span class="cpf"><proton/connection.hpp></span><span class="cp"></span> |
| <span class="cp">#include</span> <span class="cpf"><proton/connection_options.hpp></span><span class="cp"></span> |
| <span class="cp">#include</span> <span class="cpf"><proton/container.hpp></span><span class="cp"></span> |
| <span class="cp">#include</span> <span class="cpf"><proton/message.hpp></span><span class="cp"></span> |
| <span class="cp">#include</span> <span class="cpf"><proton/messaging_handler.hpp></span><span class="cp"></span> |
| <span class="cp">#include</span> <span class="cpf"><proton/receiver.hpp></span><span class="cp"></span> |
| <span class="cp">#include</span> <span class="cpf"><proton/sender.hpp></span><span class="cp"></span> |
| <span class="cp">#include</span> <span class="cpf"><proton/work_queue.hpp></span><span class="cp"></span> |
| |
| <span class="cp">#include</span> <span class="cpf"><condition_variable></span><span class="cp"></span> |
| <span class="cp">#include</span> <span class="cpf"><iostream></span><span class="cp"></span> |
| <span class="cp">#include</span> <span class="cpf"><mutex></span><span class="cp"></span> |
| <span class="cp">#include</span> <span class="cpf"><queue></span><span class="cp"></span> |
| <span class="cp">#include</span> <span class="cpf"><sstream></span><span class="cp"></span> |
| <span class="cp">#include</span> <span class="cpf"><string></span><span class="cp"></span> |
| <span class="cp">#include</span> <span class="cpf"><thread></span><span class="cp"></span> |
| |
| <span class="c1">// Lock output from threads to avoid scrambling</span> |
| <span class="n">std</span><span class="o">::</span><span class="n">mutex</span> <span class="n">out_lock</span><span class="p">;</span> |
| <span class="cp">#define OUT(x) do { std::lock_guard<std::mutex> l(out_lock); x; } while (false)</span> |
| |
| <span class="c1">// Handler for a single thread-safe sending and receiving connection.</span> |
| <span class="k">class</span> <span class="nc">client</span> <span class="o">:</span> <span class="k">public</span> <span class="n">proton</span><span class="o">::</span><span class="n">messaging_handler</span> <span class="p">{</span> |
| <span class="c1">// Invariant</span> |
| <span class="k">const</span> <span class="n">std</span><span class="o">::</span><span class="n">string</span> <span class="n">url_</span><span class="p">;</span> |
| <span class="k">const</span> <span class="n">std</span><span class="o">::</span><span class="n">string</span> <span class="n">address_</span><span class="p">;</span> |
| |
| <span class="c1">// Only used in proton handler thread</span> |
| <span class="n">proton</span><span class="o">::</span><span class="n">sender</span> <span class="n">sender_</span><span class="p">;</span> |
| |
| <span class="c1">// Shared by proton and user threads, protected by lock_</span> |
| <span class="n">std</span><span class="o">::</span><span class="n">mutex</span> <span class="n">lock_</span><span class="p">;</span> |
| <span class="n">proton</span><span class="o">::</span><span class="n">work_queue</span> <span class="o">*</span><span class="n">work_queue_</span><span class="p">;</span> |
| <span class="n">std</span><span class="o">::</span><span class="n">condition_variable</span> <span class="n">sender_ready_</span><span class="p">;</span> |
| <span class="n">std</span><span class="o">::</span><span class="n">queue</span><span class="o"><</span><span class="n">proton</span><span class="o">::</span><span class="n">message</span><span class="o">></span> <span class="n">messages_</span><span class="p">;</span> |
| <span class="n">std</span><span class="o">::</span><span class="n">condition_variable</span> <span class="n">messages_ready_</span><span class="p">;</span> |
| |
| <span class="k">public</span><span class="o">:</span> |
| <span class="n">client</span><span class="p">(</span><span class="k">const</span> <span class="n">std</span><span class="o">::</span><span class="n">string</span><span class="o">&</span> <span class="n">url</span><span class="p">,</span> <span class="k">const</span> <span class="n">std</span><span class="o">::</span><span class="n">string</span><span class="o">&</span> <span class="n">address</span><span class="p">)</span> <span class="o">:</span> <span class="n">url_</span><span class="p">(</span><span class="n">url</span><span class="p">),</span> <span class="n">address_</span><span class="p">(</span><span class="n">address</span><span class="p">),</span> <span class="n">work_queue_</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span> <span class="p">{}</span> |
| |
| <span class="c1">// Thread safe</span> |
| <span class="kt">void</span> <span class="n">send</span><span class="p">(</span><span class="k">const</span> <span class="n">proton</span><span class="o">::</span><span class="n">message</span><span class="o">&</span> <span class="n">msg</span><span class="p">)</span> <span class="p">{</span> |
| <span class="c1">// Use [=] to copy the message, we cannot pass it by reference since it</span> |
| <span class="c1">// will be used in another thread.</span> |
| <span class="n">work_queue</span><span class="p">()</span><span class="o">-></span><span class="n">add</span><span class="p">([</span><span class="o">=</span><span class="p">]()</span> <span class="p">{</span> <span class="n">sender_</span><span class="p">.</span><span class="n">send</span><span class="p">(</span><span class="n">msg</span><span class="p">);</span> <span class="p">});</span> |
| <span class="p">}</span> |
| |
| <span class="c1">// Thread safe</span> |
| <span class="n">proton</span><span class="o">::</span><span class="n">message</span> <span class="n">receive</span><span class="p">()</span> <span class="p">{</span> |
| <span class="n">std</span><span class="o">::</span><span class="n">unique_lock</span><span class="o"><</span><span class="n">std</span><span class="o">::</span><span class="n">mutex</span><span class="o">></span> <span class="n">l</span><span class="p">(</span><span class="n">lock_</span><span class="p">);</span> |
| <span class="k">while</span> <span class="p">(</span><span class="n">messages_</span><span class="p">.</span><span class="n">empty</span><span class="p">())</span> <span class="n">messages_ready_</span><span class="p">.</span><span class="n">wait</span><span class="p">(</span><span class="n">l</span><span class="p">);</span> |
| <span class="k">auto</span> <span class="n">msg</span> <span class="o">=</span> <span class="n">std</span><span class="o">::</span><span class="n">move</span><span class="p">(</span><span class="n">messages_</span><span class="p">.</span><span class="n">front</span><span class="p">());</span> |
| <span class="n">messages_</span><span class="p">.</span><span class="n">pop</span><span class="p">();</span> |
| <span class="k">return</span> <span class="n">msg</span><span class="p">;</span> |
| <span class="p">}</span> |
| |
| <span class="c1">// Thread safe</span> |
| <span class="kt">void</span> <span class="n">close</span><span class="p">()</span> <span class="p">{</span> |
| <span class="n">work_queue</span><span class="p">()</span><span class="o">-></span><span class="n">add</span><span class="p">([</span><span class="o">=</span><span class="p">]()</span> <span class="p">{</span> <span class="n">sender_</span><span class="p">.</span><span class="n">connection</span><span class="p">().</span><span class="n">close</span><span class="p">();</span> <span class="p">});</span> |
| <span class="p">}</span> |
| |
| <span class="k">private</span><span class="o">:</span> |
| |
| <span class="n">proton</span><span class="o">::</span><span class="n">work_queue</span><span class="o">*</span> <span class="n">work_queue</span><span class="p">()</span> <span class="p">{</span> |
| <span class="c1">// Wait till work_queue_ and sender_ are initialized.</span> |
| <span class="n">std</span><span class="o">::</span><span class="n">unique_lock</span><span class="o"><</span><span class="n">std</span><span class="o">::</span><span class="n">mutex</span><span class="o">></span> <span class="n">l</span><span class="p">(</span><span class="n">lock_</span><span class="p">);</span> |
| <span class="k">while</span> <span class="p">(</span><span class="o">!</span><span class="n">work_queue_</span><span class="p">)</span> <span class="n">sender_ready_</span><span class="p">.</span><span class="n">wait</span><span class="p">(</span><span class="n">l</span><span class="p">);</span> |
| <span class="k">return</span> <span class="n">work_queue_</span><span class="p">;</span> |
| <span class="p">}</span> |
| |
| <span class="c1">// == messaging_handler overrides, only called in proton handler thread</span> |
| |
| <span class="c1">// Note: this example creates a connection when the container starts.</span> |
| <span class="c1">// To create connections after the container has started, use</span> |
| <span class="c1">// container::connect().</span> |
| <span class="c1">// See @ref multithreaded_client_flow_control.cpp for an example.</span> |
| <span class="kt">void</span> <span class="n">on_container_start</span><span class="p">(</span><span class="n">proton</span><span class="o">::</span><span class="n">container</span><span class="o">&</span> <span class="n">cont</span><span class="p">)</span> <span class="k">override</span> <span class="p">{</span> |
| <span class="n">cont</span><span class="p">.</span><span class="n">connect</span><span class="p">(</span><span class="n">url_</span><span class="p">);</span> |
| <span class="p">}</span> |
| |
| <span class="kt">void</span> <span class="n">on_connection_open</span><span class="p">(</span><span class="n">proton</span><span class="o">::</span><span class="n">connection</span><span class="o">&</span> <span class="n">conn</span><span class="p">)</span> <span class="k">override</span> <span class="p">{</span> |
| <span class="n">conn</span><span class="p">.</span><span class="n">open_sender</span><span class="p">(</span><span class="n">address_</span><span class="p">);</span> |
| <span class="n">conn</span><span class="p">.</span><span class="n">open_receiver</span><span class="p">(</span><span class="n">address_</span><span class="p">);</span> |
| <span class="p">}</span> |
| |
| <span class="kt">void</span> <span class="n">on_sender_open</span><span class="p">(</span><span class="n">proton</span><span class="o">::</span><span class="n">sender</span><span class="o">&</span> <span class="n">s</span><span class="p">)</span> <span class="k">override</span> <span class="p">{</span> |
| <span class="c1">// sender_ and work_queue_ must be set atomically</span> |
| <span class="n">std</span><span class="o">::</span><span class="n">lock_guard</span><span class="o"><</span><span class="n">std</span><span class="o">::</span><span class="n">mutex</span><span class="o">></span> <span class="n">l</span><span class="p">(</span><span class="n">lock_</span><span class="p">);</span> |
| <span class="n">sender_</span> <span class="o">=</span> <span class="n">s</span><span class="p">;</span> |
| <span class="n">work_queue_</span> <span class="o">=</span> <span class="o">&</span><span class="n">s</span><span class="p">.</span><span class="n">work_queue</span><span class="p">();</span> |
| <span class="n">sender_ready_</span><span class="p">.</span><span class="n">notify_all</span><span class="p">();</span> |
| <span class="p">}</span> |
| |
| <span class="kt">void</span> <span class="n">on_message</span><span class="p">(</span><span class="n">proton</span><span class="o">::</span><span class="n">delivery</span><span class="o">&</span> <span class="n">dlv</span><span class="p">,</span> <span class="n">proton</span><span class="o">::</span><span class="n">message</span><span class="o">&</span> <span class="n">msg</span><span class="p">)</span> <span class="k">override</span> <span class="p">{</span> |
| <span class="n">std</span><span class="o">::</span><span class="n">lock_guard</span><span class="o"><</span><span class="n">std</span><span class="o">::</span><span class="n">mutex</span><span class="o">></span> <span class="n">l</span><span class="p">(</span><span class="n">lock_</span><span class="p">);</span> |
| <span class="n">messages_</span><span class="p">.</span><span class="n">push</span><span class="p">(</span><span class="n">msg</span><span class="p">);</span> |
| <span class="n">messages_ready_</span><span class="p">.</span><span class="n">notify_all</span><span class="p">();</span> |
| <span class="p">}</span> |
| |
| <span class="kt">void</span> <span class="n">on_error</span><span class="p">(</span><span class="k">const</span> <span class="n">proton</span><span class="o">::</span><span class="n">error_condition</span><span class="o">&</span> <span class="n">e</span><span class="p">)</span> <span class="k">override</span> <span class="p">{</span> |
| <span class="n">OUT</span><span class="p">(</span><span class="n">std</span><span class="o">::</span><span class="n">cerr</span> <span class="o"><<</span> <span class="s">"unexpected error: "</span> <span class="o"><<</span> <span class="n">e</span> <span class="o"><<</span> <span class="n">std</span><span class="o">::</span><span class="n">endl</span><span class="p">);</span> |
| <span class="n">exit</span><span class="p">(</span><span class="mi">1</span><span class="p">);</span> |
| <span class="p">}</span> |
| <span class="p">};</span> |
| |
| <span class="kt">int</span> <span class="nf">main</span><span class="p">(</span><span class="kt">int</span> <span class="n">argc</span><span class="p">,</span> <span class="k">const</span> <span class="kt">char</span><span class="o">**</span> <span class="n">argv</span><span class="p">)</span> <span class="p">{</span> |
| <span class="k">try</span> <span class="p">{</span> |
| <span class="k">if</span> <span class="p">(</span><span class="n">argc</span> <span class="o">!=</span> <span class="mi">4</span><span class="p">)</span> <span class="p">{</span> |
| <span class="n">std</span> <span class="o">::</span><span class="n">cerr</span> <span class="o"><<</span> |
| <span class="s">"Usage: "</span> <span class="o"><<</span> <span class="n">argv</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="o"><<</span> <span class="s">" CONNECTION-URL AMQP-ADDRESS MESSAGE-COUNT</span><span class="se">\n</span><span class="s">"</span> |
| <span class="s">"CONNECTION-URL: connection address, e.g.'amqp://127.0.0.1'</span><span class="se">\n</span><span class="s">"</span> |
| <span class="s">"AMQP-ADDRESS: AMQP node address, e.g. 'examples'</span><span class="se">\n</span><span class="s">"</span> |
| <span class="s">"MESSAGE-COUNT: number of messages to send</span><span class="se">\n</span><span class="s">"</span><span class="p">;</span> |
| <span class="k">return</span> <span class="mi">1</span><span class="p">;</span> |
| <span class="p">}</span> |
| <span class="k">const</span> <span class="kt">char</span> <span class="o">*</span><span class="n">url</span> <span class="o">=</span> <span class="n">argv</span><span class="p">[</span><span class="mi">1</span><span class="p">];</span> |
| <span class="k">const</span> <span class="kt">char</span> <span class="o">*</span><span class="n">address</span> <span class="o">=</span> <span class="n">argv</span><span class="p">[</span><span class="mi">2</span><span class="p">];</span> |
| <span class="kt">int</span> <span class="n">n_messages</span> <span class="o">=</span> <span class="n">atoi</span><span class="p">(</span><span class="n">argv</span><span class="p">[</span><span class="mi">3</span><span class="p">]);</span> |
| |
| <span class="n">client</span> <span class="n">cl</span><span class="p">(</span><span class="n">url</span><span class="p">,</span> <span class="n">address</span><span class="p">);</span> |
| <span class="n">proton</span><span class="o">::</span><span class="n">container</span> <span class="n">container</span><span class="p">(</span><span class="n">cl</span><span class="p">);</span> |
| <span class="n">std</span><span class="o">::</span><span class="kr">thread</span> <span class="n">container_thread</span><span class="p">([</span><span class="o">&</span><span class="p">]()</span> <span class="p">{</span> <span class="n">container</span><span class="p">.</span><span class="n">run</span><span class="p">();</span> <span class="p">});</span> |
| |
| <span class="n">std</span><span class="o">::</span><span class="kr">thread</span> <span class="n">sender</span><span class="p">([</span><span class="o">&</span><span class="p">]()</span> <span class="p">{</span> |
| <span class="k">for</span> <span class="p">(</span><span class="kt">int</span> <span class="n">i</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span> <span class="n">i</span> <span class="o"><</span> <span class="n">n_messages</span><span class="p">;</span> <span class="o">++</span><span class="n">i</span><span class="p">)</span> <span class="p">{</span> |
| <span class="n">proton</span><span class="o">::</span><span class="n">message</span> <span class="n">msg</span><span class="p">(</span><span class="n">std</span><span class="o">::</span><span class="n">to_string</span><span class="p">(</span><span class="n">i</span> <span class="o">+</span> <span class="mi">1</span><span class="p">));</span> |
| <span class="n">cl</span><span class="p">.</span><span class="n">send</span><span class="p">(</span><span class="n">msg</span><span class="p">);</span> |
| <span class="n">OUT</span><span class="p">(</span><span class="n">std</span><span class="o">::</span><span class="n">cout</span> <span class="o"><<</span> <span class="s">"sent </span><span class="se">\"</span><span class="s">"</span> <span class="o"><<</span> <span class="n">msg</span><span class="p">.</span><span class="n">body</span><span class="p">()</span> <span class="o"><<</span> <span class="sc">'"'</span> <span class="o"><<</span> <span class="n">std</span><span class="o">::</span><span class="n">endl</span><span class="p">);</span> |
| <span class="p">}</span> |
| <span class="p">});</span> |
| |
| <span class="kt">int</span> <span class="n">received</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span> |
| <span class="n">std</span><span class="o">::</span><span class="kr">thread</span> <span class="n">receiver</span><span class="p">([</span><span class="o">&</span><span class="p">]()</span> <span class="p">{</span> |
| <span class="k">for</span> <span class="p">(</span><span class="kt">int</span> <span class="n">i</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span> <span class="n">i</span> <span class="o"><</span> <span class="n">n_messages</span><span class="p">;</span> <span class="o">++</span><span class="n">i</span><span class="p">)</span> <span class="p">{</span> |
| <span class="k">auto</span> <span class="n">msg</span> <span class="o">=</span> <span class="n">cl</span><span class="p">.</span><span class="n">receive</span><span class="p">();</span> |
| <span class="n">OUT</span><span class="p">(</span><span class="n">std</span><span class="o">::</span><span class="n">cout</span> <span class="o"><<</span> <span class="s">"received </span><span class="se">\"</span><span class="s">"</span> <span class="o"><<</span> <span class="n">msg</span><span class="p">.</span><span class="n">body</span><span class="p">()</span> <span class="o"><<</span> <span class="sc">'"'</span> <span class="o"><<</span> <span class="n">std</span><span class="o">::</span><span class="n">endl</span><span class="p">);</span> |
| <span class="o">++</span><span class="n">received</span><span class="p">;</span> |
| <span class="p">}</span> |
| <span class="p">});</span> |
| |
| <span class="n">sender</span><span class="p">.</span><span class="n">join</span><span class="p">();</span> |
| <span class="n">receiver</span><span class="p">.</span><span class="n">join</span><span class="p">();</span> |
| <span class="n">cl</span><span class="p">.</span><span class="n">close</span><span class="p">();</span> |
| <span class="n">container_thread</span><span class="p">.</span><span class="n">join</span><span class="p">();</span> |
| <span class="n">std</span><span class="o">::</span><span class="n">cout</span> <span class="o"><<</span> <span class="n">received</span> <span class="o"><<</span> <span class="s">" messages sent and received"</span> <span class="o"><<</span> <span class="n">std</span><span class="o">::</span><span class="n">endl</span><span class="p">;</span> |
| |
| <span class="k">return</span> <span class="mi">0</span><span class="p">;</span> |
| <span class="p">}</span> <span class="k">catch</span> <span class="p">(</span><span class="k">const</span> <span class="n">std</span><span class="o">::</span><span class="n">exception</span><span class="o">&</span> <span class="n">e</span><span class="p">)</span> <span class="p">{</span> |
| <span class="n">std</span><span class="o">::</span><span class="n">cerr</span> <span class="o"><<</span> <span class="n">e</span><span class="p">.</span><span class="n">what</span><span class="p">()</span> <span class="o"><<</span> <span class="n">std</span><span class="o">::</span><span class="n">endl</span><span class="p">;</span> |
| <span class="p">}</span> |
| |
| <span class="k">return</span> <span class="mi">1</span><span class="p">;</span> |
| <span class="p">}</span> |
| </pre></div> |
| |
| <p><a href="multithreaded_client.cpp">Download this file</a></p> |
