refactor: Drop modules on failure

If a module error occur, just stop the failing
module and let the application keep running.

include/components/controller.hpp

@@ -67,6 +67,7 @@ class controller {
     for (auto&& block : m_modules) {
       for (auto&& module : block.second) {
         module->on_update.disconnect(this, &controller::on_module_update);
+        module->on_stop.disconnect(this, &controller::on_module_stop);
         module->stop();
       }
     }
@@ -95,6 +96,7 @@ class controller {
     for (auto&& block : m_modules) {
       for (auto&& module : block.second) {
         module->on_update.disconnect(this, &controller::on_module_update);
+        module->on_stop.disconnect(this, &controller::on_module_stop);
         module->stop();
       }
     }
@@ -203,7 +205,13 @@ class controller {
       for (auto&& block : m_modules) {
         for (auto&& module : block.second) {
           module->on_update.connect(this, &controller::on_module_update);
-          module->start();
+          module->on_stop.connect(this, &controller::on_module_stop);
+
+          try {
+            module->start();
+          } catch (const application_error& err) {
+            m_log.err("Failed to start '%s' (reason: %s)", module->name(), err.what());
+          }
         }
       }
 
@@ -463,6 +471,18 @@ class controller {
       m_bar->parse(contents);
   }
 
+  void on_module_stop(string module_name) {
+    for (auto&& block : m_modules) {
+      for (auto&& module : block.second) {
+        if (module->running())
+          return;
+      }
+    }
+
+    m_log.warn("No running modules, raising SIGTERM");
+    kill(getpid(), SIGTERM);
+  }
+
   void on_module_click(string input) {
     if (!m_mutex.try_lock())
       return;

include/modules/meta.hpp

@@ -148,6 +148,7 @@ namespace modules {
     virtual ~module_interface() {}
 
     virtual string name() const = 0;
+    virtual bool running() const = 0;
 
     virtual void setup() = 0;
     virtual void start() = 0;
@@ -159,6 +160,7 @@ namespace modules {
     virtual bool receive_events() const = 0;
 
     delegate::Signal1<string> on_update;
+    delegate::Signal1<string> on_stop;
   };
 
   // }}}
@@ -195,17 +197,23 @@ namespace modules {
       return m_name;
     }
 
+    bool running() const {
+      return enabled();
+    }
+
     void setup() {
       m_log.trace("%s: Setup", name());
       CAST_MODULE(Impl)->setup();
     }
 
     void stop() {
-      // std::lock_guard<concurrency::SpinLock> lck(this->broadcast_lock);
-      // std::lock_guard<threading_util::spin_lock> lck(this->update_lock);
+      if (!enabled())
+        return;
       m_log.trace("%s: Stop", name());
       enable(false);
       wakeup();
+      if (!on_stop.empty())
+        on_stop.emit(name());
     }
 
     void refresh() {
@@ -265,8 +273,6 @@ namespace modules {
     }
 
     string get_output() {
-      // std::lock_guard<concurrency::SpinLock> lck(this->output_lock);
-
       if (!enabled()) {
         m_log.trace("%s: Module is disabled", name());
         return "";
@@ -332,7 +338,7 @@ namespace modules {
     void start() {
       CAST_MODULE(Impl)->setup();
       CAST_MODULE(Impl)->enable(true);
-      CAST_MODULE(Impl)->m_threads.emplace_back(thread(&static_module::broadcast, this));
+      CAST_MODULE(Impl)->broadcast();
     }
 
     bool build(builder*, string) {
@@ -359,15 +365,21 @@ namespace modules {
     interval_t m_interval = 1s;
 
     void runner() {
-      CAST_MODULE(Impl)->setup();
+      try {
+        CAST_MODULE(Impl)->setup();
 
-      while (CONST_CAST_MODULE(Impl).enabled()) {
-        {
-          std::lock_guard<threading_util::spin_lock> lck(this->update_lock);
-          if (CAST_MODULE(Impl)->update())
-            CAST_MODULE(Impl)->broadcast();
+        while (CONST_CAST_MODULE(Impl).enabled()) {
+          {
+            std::lock_guard<threading_util::spin_lock> lck(this->update_lock);
+            if (CAST_MODULE(Impl)->update())
+              CAST_MODULE(Impl)->broadcast();
+          }
+          CAST_MODULE(Impl)->sleep(m_interval);
         }
-        CAST_MODULE(Impl)->sleep(m_interval);
+      } catch (const application_error& err) {
+        this->m_log.err("%s: %s", this->name(), err.what());
+        this->m_log.warn("Stopping '%s'...", this->name());
+        CAST_MODULE(Impl)->stop();
       }
     }
   };
@@ -387,25 +399,31 @@ namespace modules {
 
    protected:
     void runner() {
-      CAST_MODULE(Impl)->setup();
-
-      // warmup
-      CAST_MODULE(Impl)->update();
-      CAST_MODULE(Impl)->broadcast();
-
-      while (CONST_CAST_MODULE(Impl).enabled()) {
-        std::unique_lock<threading_util::spin_lock> lck(this->update_lock);
-
-        if (!CAST_MODULE(Impl)->has_event())
-          continue;
-
-        if (!CAST_MODULE(Impl)->update())
-          continue;
+      try {
+        CAST_MODULE(Impl)->setup();
 
+        // warmup
+        CAST_MODULE(Impl)->update();
         CAST_MODULE(Impl)->broadcast();
 
-        lck.unlock();
-        CAST_MODULE(Impl)->idle();
+        while (CONST_CAST_MODULE(Impl).enabled()) {
+          std::unique_lock<threading_util::spin_lock> lck(this->update_lock);
+
+          if (!CAST_MODULE(Impl)->has_event())
+            continue;
+
+          if (!CAST_MODULE(Impl)->update())
+            continue;
+
+          CAST_MODULE(Impl)->broadcast();
+
+          lck.unlock();
+          CAST_MODULE(Impl)->idle();
+        }
+      } catch (const application_error& err) {
+        this->m_log.err("%s: %s", this->name(), err.what());
+        this->m_log.warn("Stopping '%s'...", this->name());
+        CAST_MODULE(Impl)->stop();
       }
     }
   };
@@ -425,18 +443,19 @@ namespace modules {
 
    protected:
     void runner() {
-      CAST_MODULE(Impl)->setup();
-      CAST_MODULE(Impl)->on_event(nullptr);  // warmup
-      CAST_MODULE(Impl)->broadcast();
+      try {
+        CAST_MODULE(Impl)->setup();
+        CAST_MODULE(Impl)->on_event(nullptr);  // warmup
+        CAST_MODULE(Impl)->broadcast();
 
-      while (CAST_MODULE(Impl)->enabled()) {
-        std::lock_guard<threading_util::spin_lock> lck(this->update_lock);
-        try {
+        while (CAST_MODULE(Impl)->enabled()) {
+          std::lock_guard<threading_util::spin_lock> lck(this->update_lock);
           CAST_MODULE(Impl)->poll_events();
-        } catch (const system_error& e) {
-          this->m_log.err("%s: Error while polling for events (what: %s)", this->name(), e.what());
-          return;
         }
+      } catch (const application_error& err) {
+        this->m_log.err("%s: %s", this->name(), err.what());
+        this->m_log.warn("Stopping '%s'...", this->name());
+        CAST_MODULE(Impl)->stop();
       }
     }
 

include/modules/text.hpp

@@ -10,13 +10,17 @@ namespace modules {
     using static_module::static_module;
 
     void setup() {
-      m_formatter->add(FORMAT, "", {});
-      if (m_formatter->get(FORMAT)->value.empty())
-        throw undefined_format(FORMAT);
+      m_formatter->add("content", "", {});
+
+      if (m_formatter->get("content")->value.empty())
+        throw module_error(name() + ".content is empty or undefined");
+
+      m_formatter->get("content")->value =
+          string_util::replace_all(m_formatter->get("content")->value, " ", BUILDER_SPACE_TOKEN);
     }
 
     string get_format() {
-      return FORMAT;
+      return "content";
     }
 
     string get_output() {
@@ -41,9 +45,6 @@ namespace modules {
 
       return m_builder->flush();
     }
-
-   private:
-    static constexpr auto FORMAT = "content";
   };
 }