Reload on SIGHUP

refs #5230

diff --git a/lib/cli/daemoncommand.cpp b/lib/cli/daemoncommand.cpp
index 9f1133bf76da9699d62568b5942841795732345e..dbc68364988eaf237469558ef9eff87da967f096 100644 (file)
--- a/lib/cli/daemoncommand.cpp
+++ b/lib/cli/daemoncommand.cpp
@@ -178,6 +178,7 @@ std::vector<String> DaemonCommand::GetArgumentSuggestions(const String& argument
 
 #ifndef _WIN32
 pid_t l_UmbrellaPid = 0;
+static std::atomic<bool> l_AllowedToWork (false);
 #endif /* _WIN32 */
 
 static inline
@@ -194,6 +195,10 @@ int RunWorker(const std::vector<std::string>& configs)
 #ifndef _WIN32
                // Notify umbrella process about the config loading success.
                (void)kill(l_UmbrellaPid, SIGUSR2);
+
+               while (!l_AllowedToWork.load()) {
+                       Utility::Sleep(0.2);
+               }
 #endif /* _WIN32 */
 
                /* restore the previous program state */
@@ -248,6 +253,7 @@ static const sigset_t l_UnixWorkerSignals = ([]() -> sigset_t {
        (void)sigaddset(&s, SIGUSR2);
        (void)sigaddset(&s, SIGINT);
        (void)sigaddset(&s, SIGTERM);
+       (void)sigaddset(&s, SIGHUP);
 
        return s;
 })();
@@ -255,6 +261,7 @@ static const sigset_t l_UnixWorkerSignals = ([]() -> sigset_t {
 static std::atomic<pid_t> l_CurrentlyStartingUnixWorkerPid (-1);
 static std::atomic<UnixWorkerState> l_CurrentlyStartingUnixWorkerState (UnixWorkerState::Pending);
 static std::atomic<int> l_TermSignal (-1);
+static std::atomic<bool> l_RequestedReload (false);
 
 static void UmbrellaSignalHandler(int num, siginfo_t *info, void*)
 {
@@ -283,12 +290,20 @@ static void UmbrellaSignalHandler(int num, siginfo_t *info, void*)
                        }
 
                        l_TermSignal.store(num);
+                       break;
+               case SIGHUP:
+                       l_RequestedReload.store(true);
        }
 }
 
 static void WorkerSignalHandler(int num, siginfo_t *info, void*)
 {
        switch (num) {
+               case SIGUSR2:
+                       if (info->si_pid == l_UmbrellaPid) {
+                               l_AllowedToWork.store(true);
+                       }
+                       break;
                case SIGINT:
                case SIGTERM:
                        if (info->si_pid == l_UmbrellaPid) {
@@ -326,7 +341,7 @@ static pid_t StartUnixWorker(const std::vector<std::string>& configs)
                                        sa.sa_handler = SIG_DFL;
 
                                        (void)sigaction(SIGCHLD, &sa, nullptr);
-                                       (void)sigaction(SIGUSR2, &sa, nullptr);
+                                       (void)sigaction(SIGHUP, &sa, nullptr);
                                }
 
                                {
@@ -336,6 +351,7 @@ static pid_t StartUnixWorker(const std::vector<std::string>& configs)
                                        sa.sa_sigaction = &WorkerSignalHandler;
                                        sa.sa_flags = SA_RESTART | SA_SIGINFO;
 
+                                       (void)sigaction(SIGUSR2, &sa, nullptr);
                                        (void)sigaction(SIGINT, &sa, nullptr);
                                        (void)sigaction(SIGTERM, &sa, nullptr);
                                }
@@ -473,6 +489,7 @@ int DaemonCommand::Run(const po::variables_map& vm, const std::vector<std::strin
                (void)sigaction(SIGUSR2, &sa, nullptr);
                (void)sigaction(SIGINT, &sa, nullptr);
                (void)sigaction(SIGTERM, &sa, nullptr);
+               (void)sigaction(SIGHUP, &sa, nullptr);
        }
 
        pid_t currentWorker = StartUnixWorker(configs);
@@ -481,6 +498,8 @@ int DaemonCommand::Run(const po::variables_map& vm, const std::vector<std::strin
                return EXIT_FAILURE;
        }
 
+       (void)kill(currentWorker, SIGUSR2);
+
        bool requestedTermination = false;
 
        for (;;) {
@@ -492,6 +511,20 @@ int DaemonCommand::Run(const po::variables_map& vm, const std::vector<std::strin
                        }
                }
 
+               if (l_RequestedReload.exchange(false)) {
+                       pid_t nextWorker = StartUnixWorker(configs);
+
+                       if (nextWorker != -1) {
+                               (void)kill(currentWorker, SIGTERM);
+                               while (waitpid(currentWorker, nullptr, 0) == -1 && errno == EINTR) {
+                               }
+
+                               (void)kill(nextWorker, SIGUSR2);
+
+                               currentWorker = nextWorker;
+                       }
+               }
+
                {
                        int status;
                        if (waitpid(currentWorker, &status, WNOHANG) > 0) {