fix the config updates

src/config/config.cpp

@@ -3,10 +3,12 @@
 
 #include <linux/limits.h>
 #include <sys/inotify.h>
+#include <sys/poll.h>
 #include <toml11/find.hpp>
 #include <toml11/parser.hpp>
 #include <toml.hpp>
 #include <unistd.h>
+#include <poll.h>
 
 #include <unordered_map>
 #include <string_view>
@@ -35,22 +37,17 @@ namespace {
 
 Configuration Config::activeConf{};
 
-bool Config::loadAndWatchConfig(const std::string& file) {
+namespace {
-    globalConf.valid = std::make_shared<std::atomic_bool>(true);
+    [[noreturn]] void thread(
-
+            const std::string& file,
-    auto res = updateConfig(file);
+            const std::shared_ptr<std::atomic_bool>& valid) {
-    if (!res)
-        return false;
-
-    // prepare config watcher
-    std::thread([file = file, valid = globalConf.valid]() {
-        try {
         const int fd = inotify_init();
         if (fd < 0)
             throw std::runtime_error("Failed to initialize inotify:\n"
                 "- " + std::string(strerror(errno)));
 
-            const int wd = inotify_add_watch(fd, file.c_str(), IN_MODIFY | IN_CLOSE_WRITE);
+        const int wd = inotify_add_watch(fd, file.c_str(),
+            IN_MODIFY | IN_CLOSE_WRITE | IN_MOVE_SELF);
         if (wd < 0) {
             close(fd);
 
@@ -63,12 +60,26 @@ bool Config::loadAndWatchConfig(const std::string& file) {
 
         std::array<char, (sizeof(inotify_event) + NAME_MAX + 1) * 20> buffer{};
         while (true) {
-                const ssize_t len = read(fd, buffer.data(), buffer.size());
+            // poll fd
-                if (len <= 0 && errno != EINTR) {
+            struct pollfd pfd{};
+            pfd.fd = fd;
+            pfd.events = POLLIN;
+            const int pollRes = poll(&pfd, 1, 100);
+            if (pollRes < 0 && errno != EINTR) {
                 inotify_rm_watch(fd, wd);
                 close(fd);
 
-                    throw std::runtime_error("Error reading inotify event:\n"
+                throw std::runtime_error("Error polling inotify events:\n"
+                    "- " + std::string(strerror(errno)));
+            }
+
+            // read fd if there are events
+            const ssize_t len = pollRes == 0 ? 0 : read(fd, buffer.data(), buffer.size());
+            if (len <= 0 && errno != EINTR && pollRes > 0) {
+                inotify_rm_watch(fd, wd);
+                close(fd);
+
+                throw std::runtime_error("Error reading inotify events:\n"
                     "- " + std::string(strerror(errno)));
             }
 
@@ -76,10 +87,9 @@ bool Config::loadAndWatchConfig(const std::string& file) {
             while (std::cmp_less(i, len)) {
                 auto* event = reinterpret_cast<inotify_event*>(&buffer.at(i));
                 i += sizeof(inotify_event) + event->len;
-                    if (event->len <= 0)
-                        continue;
 
                 // stall a bit, then mark as invalid
+                if (!discard_until.has_value())
                     std::cerr << "lsfg-vk: Configuration file changed, invalidating config...\n";
                 discard_until.emplace(std::chrono::steady_clock::now()
                     + std::chrono::milliseconds(500));
@@ -97,6 +107,20 @@ bool Config::loadAndWatchConfig(const std::string& file) {
                     std::this_thread::sleep_for(std::chrono::milliseconds(50));
             }
         }
+    }
+}
+
+bool Config::loadAndWatchConfig(const std::string& file) {
+    globalConf.valid = std::make_shared<std::atomic_bool>(true);
+
+    auto res = updateConfig(file);
+    if (!res)
+        return false;
+
+    // prepare config watcher
+    std::thread([file = file, valid = globalConf.valid]() {
+        try {
+            thread(file, valid);
         } catch (const std::exception& e) {
             std::cerr << "lsfg-vk: Error in config watcher thread:\n";
             std::cerr << "- " << e.what() << '\n';