feat: use Type=notify-reload in daemon service (#7570)

* feat: use `Type=notify-reload` in daemon service

* build: keep systemd names consistent

---------

Co-authored-by: Charles Kerr <charles@charleskerr.com>

daemon/CMakeLists.txt

@@ -15,7 +15,7 @@ tr_allow_compile_if(
 
 target_compile_definitions(${TR_NAME}-daemon
     PRIVATE
-        $<$<BOOL:${WITH_SYSTEMD}>:USE_SYSTEMD>)
+        $<$<BOOL:${WITH_SYSTEMD}>:WITH_SYSTEMD>)
 
 tr_target_compile_definitions_for_headers(${TR_NAME}-daemon
     PRIVATE

daemon/daemon.cc

@@ -6,6 +6,7 @@
 #include <array>
 #include <cerrno>
 #include <chrono>
+#include <cstdint>
 #include <cstdio> /* printf */
 #include <iostream>
 #include <iterator> /* std::back_inserter */
@@ -48,7 +49,10 @@ struct tr_ctor;
 struct tr_session;
 struct tr_torrent;
 
-#ifdef USE_SYSTEMD
+#ifdef WITH_SYSTEMD
+
+#include <cinttypes>
+#include <ctime>
 
 #include <systemd/sd-daemon.h>
 
@@ -705,6 +709,25 @@ void tr_daemon::reconfigure()
     }
     else
     {
+#ifdef WITH_SYSTEMD
+        auto ts = timespec{};
+        if (clock_gettime(CLOCK_MONOTONIC, &ts) < 0)
+        {
+            auto error = tr_error{};
+            error.set_from_errno(errno);
+            tr_logAddError(fmt::format(
+                fmt::runtime(_("Failed to reload: Failed to get current monotonic time: {errmsg} ({errno})")),
+                fmt::arg("errmsg", error.message()),
+                fmt::arg("errno", error.code())));
+            return;
+        }
+
+        sd_notifyf(
+            0,
+            "STATUS=Reloading...\nRELOADING=1\nMONOTONIC_USEC=%" PRIu64 "\n",
+            static_cast<uint64_t>(ts.tv_sec) * 1000000U + static_cast<uint64_t>(ts.tv_nsec) / 1000U);
+#endif
+
         char const* configDir;
 
         /* reopen the logfile to allow for log rotation */
@@ -718,6 +741,8 @@ void tr_daemon::reconfigure()
 
         tr_sessionSet(my_session_, load_settings(configDir));
         tr_sessionReloadBlocklists(my_session_);
+
+        sd_notify(0, "STATUS=Reload complete.\nREADY=1\n");
     }
 }
 

daemon/transmission-daemon.service.in

@@ -6,9 +6,8 @@ Documentation=man:@TR_NAME@-daemon(1)
 
 [Service]
 User=transmission
-Type=notify
+Type=notify-reload
 ExecStart=@CMAKE_INSTALL_FULL_BINDIR@/@TR_NAME@-daemon -f --log-level=error
-ExecReload=/bin/kill -s HUP $MAINPID
 
 # Hardening
 CapabilityBoundingSet=