fix(watchdog,priority,dns_failover,providers): reduce CPU/memory footprint on low-end routers (1.3.20)

- priority.uc: replace 1s tight sleep loop with dynamic interval based on group config (5s default)
- dns_failover.uc: replace 1s sleep with min(active_interval, recovery_interval)
- watchdog.uc: cap pending_smart_domains at 500 entries, add 300s TTL expiry
- event_controller.uc: batch is_dns_working nslookup calls into single shell process
- byedpi/runtime.uc: add crash-loop backoff (up to 6x base delay after 5 rapid crashes)
- nfqueue/runtime.uc: same crash-loop backoff for nfqws supervisors

tachyon/files/usr/lib/providers/byedpi/runtime.uc

@@ -241,16 +241,31 @@ function supervisor_command(port, raw_opt, child_pidfile) {
 }
 
 function supervisor(section, port, raw_opt, child_pidfile) {
+    let crash_count = 0;
+    let base_delay = int(BYEDPI_RESPAWN_DELAY);
+    if (base_delay < 1) base_delay = 5;
+
     while (true) {
         if (!provider_available()) {
-            print(command_output_from_args([ "date", "+%Y-%m-%d %H:%M:%S" ]), " Provider ", BYEDPI_BIN, " is not executable; retrying in ", BYEDPI_RESPAWN_DELAY, " seconds\n");
-            command_success_from_args([ "sleep", BYEDPI_RESPAWN_DELAY ]);
+            print(command_output_from_args([ "date", "+%Y-%m-%d %H:%M:%S" ]), " Provider ", BYEDPI_BIN, " is not executable; retrying in ", base_delay, " seconds\n");
+            command_success_from_args([ "sleep", as_string(base_delay) ]);
             continue;
         }
 
+        let start_time = clock()[0];
         let rc = command_status("sh -c " + shell_quote(supervisor_command(port, raw_opt, child_pidfile)));
-        print(command_output_from_args([ "date", "+%Y-%m-%d %H:%M:%S" ]), " ciadpi for rule ", as_string(section), " exited with code ", rc, "; respawning in ", BYEDPI_RESPAWN_DELAY, " seconds\n");
-        command_success_from_args([ "sleep", BYEDPI_RESPAWN_DELAY ]);
+        let elapsed = clock()[0] - start_time;
+
+        if (elapsed < 10) {
+            crash_count++;
+            if (crash_count > 5) crash_count = 5;
+        } else {
+            crash_count = 0;
+        }
+
+        let delay = base_delay * (1 + crash_count);
+        print(command_output_from_args([ "date", "+%Y-%m-%d %H:%M:%S" ]), " ciadpi for rule ", as_string(section), " exited with code ", rc, "; respawning in ", delay, " seconds\n");
+        command_success_from_args([ "sleep", as_string(delay) ]);
     }
 }
 

tachyon/files/usr/lib/providers/nfqueue/runtime.uc

@@ -336,16 +336,31 @@ function supervisor_command(cfg, queue, raw_opt, child_pidfile) {
 }
 
 function supervisor(cfg, section, queue, raw_opt, child_pidfile) {
+    let crash_count = 0;
+    let base_delay = int(cfg.respawn_delay);
+    if (base_delay < 1) base_delay = 5;
+
     while (true) {
         if (!provider_available(cfg)) {
-            print(command_output_from_args([ "date", "+%Y-%m-%d %H:%M:%S" ]), " Provider ", cfg.binary, " is not executable; retrying in ", cfg.respawn_delay, " seconds\n");
-            command_success_from_args([ "sleep", cfg.respawn_delay ]);
+            print(command_output_from_args([ "date", "+%Y-%m-%d %H:%M:%S" ]), " Provider ", cfg.binary, " is not executable; retrying in ", base_delay, " seconds\n");
+            command_success_from_args([ "sleep", as_string(base_delay) ]);
             continue;
         }
 
+        let start_time = clock()[0];
         let rc = command_status("sh -c " + shell_quote(supervisor_command(cfg, queue, raw_opt, child_pidfile)));
-        print(command_output_from_args([ "date", "+%Y-%m-%d %H:%M:%S" ]), " ", cfg.binary_name, " for rule ", as_string(section), " exited with code ", rc, "; respawning in ", cfg.respawn_delay, " seconds\n");
-        command_success_from_args([ "sleep", cfg.respawn_delay ]);
+        let elapsed = clock()[0] - start_time;
+
+        if (elapsed < 10) {
+            crash_count++;
+            if (crash_count > 5) crash_count = 5;
+        } else {
+            crash_count = 0;
+        }
+
+        let delay = base_delay * (1 + crash_count);
+        print(command_output_from_args([ "date", "+%Y-%m-%d %H:%M:%S" ]), " ", cfg.binary_name, " for rule ", as_string(section), " exited with code ", rc, "; respawning in ", delay, " seconds\n");
+        command_success_from_args([ "sleep", as_string(delay) ]);
     }
 }
 

tachyon/files/usr/lib/service/event_controller.uc

@@ -167,9 +167,10 @@ function sing_box_in_proc() {
 }
 
 function is_dns_working() {
-    return command_success_from_args([ "nslookup", "-timeout=2", "yandex.ru", "127.0.0.1" ]) ||
-           command_success_from_args([ "nslookup", "-timeout=2", "connectivitycheck.gstatic.com", "127.0.0.1" ]) ||
-           command_success_from_args([ "nslookup", "-timeout=2", "google.com", "127.0.0.1" ]);
+    return command_success_from_args([ "sh", "-c",
+        "nslookup -timeout=2 yandex.ru 127.0.0.1 >/dev/null 2>&1 || " +
+        "nslookup -timeout=2 connectivitycheck.gstatic.com 127.0.0.1 >/dev/null 2>&1 || " +
+        "nslookup -timeout=2 google.com 127.0.0.1 >/dev/null 2>&1" ]);
 }
 
 function check_tachyon_cli_running() {

tachyon/files/usr/lib/service/watchdog.uc

@@ -388,6 +388,8 @@ let last_restart_time = 0;
 let last_reload_time = 0;
 let pending_smart_domains = {};
 let smart_detect_last_run = 0;
+const PENDING_SMART_DOMAINS_MAX = 500;
+const PENDING_SMART_DOMAINS_TTL = 300;
 let last_fast_check = 0;
 let last_normal_check = 0;
 let last_slow_check = 0;
@@ -1417,6 +1419,12 @@ function smart_detect_process_pending() {
     let now = time();
     if (now - smart_detect_last_run < 30) return;
 
+    let stale_cutoff = now - PENDING_SMART_DOMAINS_TTL;
+    for (let dom in keys(pending_smart_domains)) {
+        if (pending_smart_domains[dom] < stale_cutoff)
+            delete pending_smart_domains[dom];
+    }
+
     let domain_list = keys(pending_smart_domains);
     if (length(domain_list) == 0) return;
     smart_detect_last_run = now;
@@ -1546,6 +1554,7 @@ function heal_oom(ev) {
 // smart_detect_process_pending(): probing inside the log handler would block
 // the event loop on curl for every failing connection.
 function collect_smart_detect_candidate(ev) {
+    if (length(pending_smart_domains) >= PENDING_SMART_DOMAINS_MAX) return;
     pending_smart_domains[ev.payload.domain] = time();
 }
 

tachyon/files/usr/lib/singbox/dns_failover.uc

@@ -283,6 +283,9 @@ function worker() {
     let all_down = { main: false, bootstrap: false };
     let strikes = { main: {}, bootstrap: {}, recovery_successes: { main: {}, bootstrap: {} } };
 
+    let sleep_interval = active_interval < recovery_interval ? active_interval : recovery_interval;
+    if (sleep_interval < 2) sleep_interval = 2;
+
     while (true) {
         let now = now_seconds();
         let current_cfg = settings();
@@ -331,7 +334,7 @@ function worker() {
             next_recovery = completed + recovery_interval;
         }
 
-        command_success_from_args([ "sleep", "1" ]);
+        command_success_from_args([ "sleep", as_string(sleep_interval) ]);
     }
 }
 

tachyon/files/usr/lib/singbox/priority.uc

@@ -382,13 +382,19 @@ function worker() {
         return 0;
 
     let states = {};
-    for (let group in groups)
+    let min_interval = 5;
+    for (let group in groups) {
         states[group.tag] = init_group_state(group);
+        let interval = duration_to_seconds(group.active_check_interval, 5);
+        if (interval < min_interval)
+            min_interval = interval;
+    }
+    if (min_interval < 1) min_interval = 1;
 
     while (true) {
         for (let group in groups)
             tick_group(states[group.tag], group);
-        system("sleep 1");
+        command_success_from_args([ "sleep", as_string(min_interval) ]);
     }
 }