unblock SIGUSR1 only around accept()

appsec/src/helper/runner.cpp

@@ -34,16 +34,19 @@ network::base_acceptor::ptr acceptor_from_config(const config::config &cfg)
     return std::make_unique<network::local::acceptor>(sock_path);
 }
 
-void unblock_sigusr1()
+void block_sigusr1()
 {
-    // the signal handler need not do anything (just interrupt accept())
-    struct sigaction alarmer = {};
-    alarmer.sa_handler = [](int) {};
-    if (sigaction(SIGUSR1, &alarmer, nullptr) < 0) {
+    sigset_t mask;
+    sigemptyset(&mask);
+    sigaddset(&mask, SIGUSR1);
+    if (pthread_sigmask(SIG_UNBLOCK, &mask, nullptr) != 0) {
         throw std::runtime_error{
-            "Failed to set SIGUSR1 handler: errno " + std::to_string(errno)};
+            "Failed to block SIGUSR1: errno " + std::to_string(errno)};
     }
+}
 
+void unblock_sigusr1()
+{
     sigset_t mask;
     sigemptyset(&mask);
     sigaddset(&mask, SIGUSR1);
@@ -53,6 +56,16 @@ void unblock_sigusr1()
     }
 }
 
+void handle_sigusr1()
+{
+    // the signal handler need not do anything (just interrupt accept())
+    struct sigaction alarmer = {};
+    alarmer.sa_handler = [](int) {};
+    if (sigaction(SIGUSR1, &alarmer, nullptr) < 0) {
+        throw std::runtime_error{
+            "Failed to set SIGUSR1 handler: errno " + std::to_string(errno)};
+    }
+}
 } // namespace
 
 runner::runner(const config::config &cfg, std::atomic<bool> &interrupted)
@@ -76,12 +89,16 @@ void runner::run()
 {
     try {
         SPDLOG_INFO("Runner running");
-        unblock_sigusr1();
+        handle_sigusr1();
+
         while (!interrupted()) {
             network::base_socket::ptr socket;
             try {
+                unblock_sigusr1();
                 socket = acceptor_->accept();
+                block_sigusr1();
             } catch (const timeout_error &e) {
+                block_sigusr1();
                 continue;
             }