fix(modules): Warmup in runner thread to avoid block

include/modules/meta/base.inl

@@ -94,14 +94,18 @@ namespace modules {
 
   template <typename Impl>
   void module<Impl>::idle() {
+    if (running()) {
       CAST_MOD(Impl)->sleep(25ms);
     }
+  }
 
   template <typename Impl>
   void module<Impl>::sleep(chrono::duration<double> sleep_duration) {
+    if (running()) {
       std::unique_lock<std::mutex> lck(m_sleeplock);
       m_sleephandler.wait_for(lck, sleep_duration);
     }
+  }
 
   template <typename Impl>
   void module<Impl>::wakeup() {

include/modules/meta/event_module.hpp

@@ -11,33 +11,29 @@ namespace modules {
     using module<Impl>::module;
 
     void start() {
-      CAST_MOD(Impl)->update();
-      CAST_MOD(Impl)->broadcast();
-
       this->m_mainthread = thread(&event_module::runner, this);
     }
 
    protected:
     void runner() {
+      this->m_log.trace("%s: Thread id = %i", this->name(), concurrency_util::thread_id(this_thread::get_id()));
       try {
-        while (this->running()) {
-          CAST_MOD(Impl)->idle();
-
-          if (!this->running()) {
-            break;
-          }
-
-          std::lock_guard<std::mutex> guard(this->m_updatelock);
-
-          if (!CAST_MOD(Impl)->has_event()) {
-            continue;
-          } else if (!this->running()) {
-            break;
-          } else if (!CAST_MOD(Impl)->update()) {
-            continue;
-          }
-
+        // warm up module output before entering the loop
+        std::unique_lock<std::mutex> guard(this->m_updatelock);
+        CAST_MOD(Impl)->update();
         CAST_MOD(Impl)->broadcast();
+        guard.unlock();
+
+        const auto check = [&]() -> bool {
+          std::lock_guard<std::mutex> guard(this->m_updatelock);
+          return CAST_MOD(Impl)->has_event() && CAST_MOD(Impl)->update();
+        };
+
+        while (this->running()) {
+          if (check()) {
+            CAST_MOD(Impl)->broadcast();
+          }
+          CAST_MOD(Impl)->idle();
         }
       } catch (const exception& err) {
         CAST_MOD(Impl)->halt(err.what());

include/modules/meta/inotify_module.hpp

@@ -17,10 +17,13 @@ namespace modules {
 
    protected:
     void runner() {
+      this->m_log.trace("%s: Thread id = %i", this->name(), concurrency_util::thread_id(this_thread::get_id()));
       try {
         // Warm up module output before entering the loop
+        std::unique_lock<std::mutex> guard(this->m_updatelock);
         CAST_MOD(Impl)->on_event(nullptr);
         CAST_MOD(Impl)->broadcast();
+        guard.unlock();
 
         while (this->running()) {
           std::lock_guard<std::mutex> guard(this->m_updatelock);

include/modules/meta/static_module.hpp

@@ -11,8 +11,12 @@ namespace modules {
     using module<Impl>::module;
 
     void start() {
+      this->m_mainthread = thread([&] {
+        this->m_log.trace("%s: Thread id = %i", this->name(), concurrency_util::thread_id(this_thread::get_id()));
+        std::unique_lock<std::mutex> guard(this->m_updatelock);
         CAST_MOD(Impl)->update();
         CAST_MOD(Impl)->broadcast();
+      });
     }
 
     bool build(builder*, string) const {

include/modules/meta/timer_module.hpp

@@ -13,28 +13,31 @@ namespace modules {
     using module<Impl>::module;
 
     void start() {
-      CAST_MOD(Impl)->update();
       this->m_mainthread = thread(&timer_module::runner, this);
     }
 
    protected:
     void runner() {
+      this->m_log.trace("%s: Thread id = %i", this->name(), concurrency_util::thread_id(this_thread::get_id()));
+
+      const auto check = [&]() -> bool {
+        std::unique_lock<std::mutex> guard(this->m_updatelock);
+        return CAST_MOD(Impl)->update();
+      };
+
+      // warm up module output before entering the loop
+      check();
+      CAST_MOD(Impl)->broadcast();
+
       try {
         while (this->running()) {
-          this->sleep(m_interval);
-
-          if (!this->running()) {
-            break;
-          }
-
-          std::unique_lock<std::mutex> guard(this->m_updatelock);
-
-          if (CAST_MOD(Impl)->update()) {
-            this->broadcast();
+          if (check()) {
+            CAST_MOD(Impl)->broadcast();
           }
+          CAST_MOD(Impl)->sleep(m_interval);
         }
       } catch (const exception& err) {
-        this->halt(err.what());
+        CAST_MOD(Impl)->halt(err.what());
       }
     }
 

src/components/controller.cpp

@@ -157,6 +157,8 @@ controller::~controller() {
  */
 bool controller::run(bool writeback, string snapshot_dst) {
   m_log.info("Starting application");
+  m_log.trace("controller: Main thread id = %i", concurrency_util::thread_id(this_thread::get_id()));
+
   assert(!m_connection.connection_has_error());
 
   m_writeback = writeback;

src/modules/github.cpp

@@ -2,6 +2,7 @@
 
 #include "drawtypes/label.hpp"
 #include "modules/github.hpp"
+#include "utils/concurrency.hpp"
 
 #include "modules/meta/base.inl"
 
@@ -25,8 +26,6 @@ namespace modules {
       m_label = load_optional_label(m_conf, name(), TAG_LABEL, "Notifications: %notifications%");
       m_label->replace_token("%notifications%", m_empty_notifications ? "0" : "");
     }
-
-    assert(static_cast<bool>(m_label));
   }
 
   /**

src/modules/xbacklight.cpp

@@ -96,13 +96,6 @@ namespace modules {
    * Query the RandR extension for the new values
    */
   void xbacklight_module::update() {
-    if (!m_updatelock.try_lock()) {
-      return;
-    }
-
-    std::lock_guard<mutex> guard(m_updatelock, std::adopt_lock);
-
-    // Query for the new backlight value
     auto& bl = m_output->backlight;
     randr_util::get_backlight_value(m_connection, m_output, bl);
     m_percentage = math_util::nearest_5(math_util::percentage<double>(bl.val, bl.min, bl.max));