sndio: Add reconnection support.

include/modules/sndio.hpp

@@ -18,6 +18,7 @@ class Sndio : public ALabel {
   bool handleToggle(GdkEventButton* const&);
 
  private:
+  auto connect_to_sndio() -> void;
   util::SleeperThread thread_;
   struct sioctl_hdl *hdl_;
   std::vector<struct pollfd> pfds_;

src/modules/sndio.cpp

@@ -3,6 +3,7 @@
 #include <cstdlib>
 #include <poll.h>
 #include <fmt/format.h>
+#include <spdlog/spdlog.h>
 
 namespace waybar::modules {
 
@@ -20,15 +21,7 @@ void onval(void *arg, unsigned int addr, unsigned int val) {
   self->put_val(addr, val);
 }
 
-Sndio::Sndio(const std::string &id, const Json::Value &config)
-    : ALabel(config, "sndio", id, "{volume}%"),
-      hdl_(nullptr),
-      pfds_(0),
-      addr_(0),
-      volume_(0),
-      old_volume_(0),
-      maxval_(0),
-      muted_(false) {
+auto Sndio::connect_to_sndio() -> void {
   hdl_ = sioctl_open(SIO_DEVANY, SIOCTL_READ | SIOCTL_WRITE, 0);
   if (hdl_ == nullptr) {
     throw std::runtime_error("sioctl_open() failed.");
@@ -38,9 +31,23 @@ Sndio::Sndio(const std::string &id, const Json::Value &config)
     throw std::runtime_error("sioctl_ondesc() failed.");
   }
 
-  sioctl_onval(hdl_, onval, this);
+  if (sioctl_onval(hdl_, onval, this) == 0) {
+    throw std::runtime_error("sioctl_onval() failed.");
+  }
 
   pfds_.reserve(sioctl_nfds(hdl_));
+}
+
+Sndio::Sndio(const std::string &id, const Json::Value &config)
+    : ALabel(config, "sndio", id, "{volume}%", 1),
+      hdl_(nullptr),
+      pfds_(0),
+      addr_(0),
+      volume_(0),
+      old_volume_(0),
+      maxval_(0),
+      muted_(false) {
+  connect_to_sndio();
 
   event_box_.show();
 
@@ -65,7 +72,28 @@ Sndio::Sndio(const std::string &id, const Json::Value &config)
 
     int revents = sioctl_revents(hdl_, pfds_.data());
     if (revents & POLLHUP) {
-      throw std::runtime_error("disconnected!");
+      spdlog::warn("sndio disconnected!");
+      sioctl_close(hdl_);
+      hdl_ = nullptr;
+
+      // reconnection loop
+      while (thread_.isRunning()) {
+        try {
+          connect_to_sndio();
+        } catch(std::runtime_error const& e) {
+          // avoid leaking hdl_
+          if (hdl_) {
+            sioctl_close(hdl_);
+            hdl_ = nullptr;
+          }
+          // rate limiting for the retries
+          thread_.sleep_for(interval_);
+          continue;
+        }
+
+        spdlog::warn("sndio reconnected!");
+        break;
+      }
     }
   };
 }
@@ -116,6 +144,9 @@ bool Sndio::handleScroll(GdkEventScroll *e) {
     return AModule::handleScroll(e);
   }
 
+  // only try to talk to sndio if connected
+  if (hdl_ == nullptr) return true;
+
   auto dir = AModule::getScrollDir(e);
   if (dir == SCROLL_DIR::NONE) {
     return true;
@@ -152,6 +183,9 @@ bool Sndio::handleToggle(GdkEventButton* const& e) {
     return AModule::handleToggle(e);
   }
 
+  // only try to talk to sndio if connected
+  if (hdl_ == nullptr) return true;
+
   muted_ = !muted_;
   if (muted_) {
     // store old volume to be able to restore it later