eventloop: Throw exception for libuv errors

include/components/eventloop.hpp

@@ -2,10 +2,22 @@
 
 #include <uv.h>
 
+#include <stdexcept>
+
 #include "common.hpp"
 
 POLYBAR_NS
 
+/**
+ * Runs any libuv function with an integer error code return value and throws an
+ * exception on error.
+ */
+#define UV(fun, ...)                                                              \
+  int res = fun(__VA_ARGS__);                                                     \
+  if (res < 0) {                                                                  \
+    throw std::runtime_error("libuv error for '" #fun "': "s + uv_strerror(res)); \
+  }
+
 template <class H, class... Args>
 struct cb_helper {
   std::function<void(Args...)> func;
@@ -19,8 +31,7 @@ struct cb_helper {
 struct SignalHandle {
   SignalHandle(uv_loop_t* loop, std::function<void(int)> fun) {
     handle = std::make_unique<uv_signal_t>();
-    // TODO handle return value
-    uv_signal_init(loop, handle.get());
+    UV(uv_signal_init, loop, handle.get());
     cb = cb_helper<uv_signal_t, int>{fun};
 
     handle->data = &cb;
@@ -48,7 +59,7 @@ class eventloop {
 
   void signal_handler(int signum, std::function<void(int)> fun) {
     auto handle = std::make_unique<SignalHandle>(get(), fun);
-    uv_signal_start(handle->handle.get(), &handle->cb.callback, signum);
+    UV(uv_signal_start, handle->handle.get(), &handle->cb.callback, signum);
     m_sig_handles.push_back(std::move(handle));
   }
 

src/components/controller.cpp

@@ -204,6 +204,7 @@ static void conn_cb_wrapper(uv_poll_t* handle, int status, int events) {
 }
 
 void controller::signal_handler(int signum) {
+  m_log.notice("Received signal SIG%s", sigabbrev_np(signum));
   g_terminate = 1;
   g_reload = (signum == SIGUSR1);
   eloop->stop();
@@ -248,10 +249,14 @@ static void ipc_read_cb_wrapper(uv_stream_t* stream, ssize_t nread, const uv_buf
 void controller::read_events() {
   m_log.info("Entering event loop (thread-id=%lu)", this_thread::get_id());
 
+  auto conn_handle = std::make_unique<uv_poll_t>();
+  auto conf_handle = std::unique_ptr<uv_fs_event_t>(nullptr);
+  auto ipc_handle = std::unique_ptr<uv_pipe_t>(nullptr);
+
+  try {
     eloop = std::make_unique<eventloop>();
     auto loop = eloop->get();
 
-  auto conn_handle = std::make_unique<uv_poll_t>();
     uv_poll_init(loop, conn_handle.get(), m_connection.get_file_descriptor());
     conn_handle->data = this;
 
@@ -261,8 +266,6 @@ void controller::read_events() {
       eloop->signal_handler(s, [this](int signum) { signal_handler(signum); });
     }
 
-  auto conf_handle = std::unique_ptr<uv_fs_event_t>(nullptr);
-
     if (m_confwatch) {
       conf_handle = std::make_unique<uv_fs_event_t>();
       uv_fs_event_init(loop, conf_handle.get());
@@ -271,8 +274,6 @@ void controller::read_events() {
       uv_fs_event_start(conf_handle.get(), confwatch_cb_wrapper, m_confwatch->path().c_str(), 0);
     }
 
-  auto ipc_handle = std::unique_ptr<uv_pipe_t>(nullptr);
-
     if (m_ipc) {
       ipc_handle = std::make_unique<uv_pipe_t>();
       uv_pipe_init(loop, ipc_handle.get(), false);
@@ -282,6 +283,12 @@ void controller::read_events() {
     }
 
     eloop->run();
+  } catch (const exception& err) {
+    m_log.err("Fatal Error in eventloop: %s", err.what());
+    g_terminate = 1;
+    eloop->stop();
+  }
+
   eloop.reset();
 }
 

src/components/eventloop.cpp

@@ -4,9 +4,7 @@ POLYBAR_NS
 
 eventloop::eventloop() {
   m_loop = std::make_unique<uv_loop_t>();
-  uv_loop_init(m_loop.get());
-  // TODO handle return value
-
+  UV(uv_loop_init, m_loop.get());
   m_loop->data = this;
 }
 
@@ -23,28 +21,28 @@ static void close_walk_cb(uv_handle_t* handle, void*) {
  */
 static void close_loop(uv_loop_t* loop) {
   uv_walk(loop, close_walk_cb, nullptr);
-  uv_run(loop, UV_RUN_DEFAULT);
-  // TODO handle return value
+  UV(uv_run, loop, UV_RUN_DEFAULT);
 }
 
 eventloop::~eventloop() {
   if (m_loop) {
+    try {
       close_loop(m_loop.get());
-    uv_loop_close(m_loop.get());
-    // TODO handle return value
+      UV(uv_loop_close, m_loop.get());
+    } catch (const std::exception& e) {
+      // TODO log error
+    }
 
     m_loop.reset();
   }
 }
 
 void eventloop::run() {
-  uv_run(m_loop.get(), UV_RUN_DEFAULT);
-  // TODO handle return value
+  UV(uv_run, m_loop.get(), UV_RUN_DEFAULT);
 }
 
 void eventloop::stop() {
   uv_stop(m_loop.get());
-  // TODO handle return value
 }
 
 POLYBAR_NS_END