add signal decouple support

examples/buttons/buttons_main.c

@@ -219,9 +219,11 @@ static int button_daemon(int argc, char *argv[])
       goto errout_with_fd;
     }
 
+#ifndef CONFIG_DISABLE_SIGNALS
   /* Ignore the default signal action */
 
   signal(CONFIG_EXAMPLES_BUTTONS_SIGNO, SIG_IGN);
+#endif
 #endif
 
   /* Now loop forever, waiting BUTTONs events */

examples/chrono/chrono_main.c

@@ -165,9 +165,11 @@ static int chrono_daemon(int argc, char *argv[])
       goto errout_with_fd;
     }
 
+#ifndef CONFIG_DISABLE_SIGNALS
   /* Ignore the default signal action */
 
   signal(BUTTON_SIGNO, SIG_IGN);
+#endif
 
   /* Now loop forever, waiting BUTTONs events */
 

examples/timer/Kconfig

@@ -6,7 +6,7 @@
 config EXAMPLES_TIMER
 	tristate "Timer example"
 	default n
-	depends on TIMER
+	depends on TIMER && !DISABLE_SIGNALS
 	---help---
 		Enable the timer example
 

netutils/dhcpc/dhcpc.c

@@ -533,8 +533,16 @@ static void *dhcpc_run(void *args)
   struct dhcpc_state result;
   int ret;
 
+#ifdef CONFIG_DISABLE_SIGNALS
+  pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
+  pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, NULL);
+#endif
+
   while (1)
     {
+#ifdef CONFIG_DISABLE_SIGNALS
+      pthread_testcancel();
+#endif
       ret = dhcpc_request(pdhcpc, &result);
       if (ret == OK)
         {
@@ -701,7 +709,9 @@ void dhcpc_close(FAR void *handle)
 void dhcpc_cancel(FAR void *handle)
 {
   struct dhcpc_state_s *pdhcpc = (struct dhcpc_state_s *)handle;
+#ifndef CONFIG_DISABLE_SIGNALS
   sighandler_t old;
+#endif
   int ret;
 
   if (pdhcpc)
@@ -710,6 +720,9 @@ void dhcpc_cancel(FAR void *handle)
 
       if (pdhcpc->thread)
         {
+#ifdef CONFIG_DISABLE_SIGNALS
+          pthread_cancel(pdhcpc->thread);
+#else
           old = signal(SIGQUIT, SIG_IGN);
 
           /* Signal the dhcpc_run */
@@ -719,6 +732,7 @@ void dhcpc_cancel(FAR void *handle)
             {
               nerr("ERROR: pthread_kill DHCPC thread\n");
             }
+#endif
 
           /* Wait for the end of dhcpc_run */
 
@@ -729,7 +743,9 @@ void dhcpc_cancel(FAR void *handle)
             }
 
           pdhcpc->thread = 0;
+#ifndef CONFIG_DISABLE_SIGNALS
           signal(SIGQUIT, old);
+#endif
         }
     }
 }

netutils/ping/icmp_ping.c

@@ -91,6 +91,7 @@ static volatile bool g_exiting;
  * Private Functions
  ****************************************************************************/
 
+#ifndef CONFIG_DISABLE_SIGNALS
 /****************************************************************************
  * Name: sigexit
  ****************************************************************************/
@@ -99,6 +100,7 @@ static void sigexit(int signo)
 {
   g_exiting = true;
 }
+#endif
 
 /****************************************************************************
  * Name: ping_newid
@@ -199,7 +201,9 @@ void icmp_ping(FAR const struct ping_info_s *info)
   int i;
 
   g_exiting = false;
+#ifndef CONFIG_DISABLE_SIGNALS
   signal(SIGINT, sigexit);
+#endif
 
   /* Initialize result structure */
 

netutils/telnetd/telnetd_daemon.c

@@ -74,7 +74,7 @@ int telnetd_daemon(FAR const struct telnetd_config_s *config)
 #endif
   } addr;
 
-#ifdef CONFIG_SCHED_HAVE_PARENT
+#if defined(CONFIG_SCHED_HAVE_PARENT) && !defined(CONFIG_DISABLE_SIGNALS)
   struct sigaction sa;
   sigset_t blockset;
 #endif
@@ -85,7 +85,7 @@ int telnetd_daemon(FAR const struct telnetd_config_s *config)
   int optval;
 #endif
 
-#ifdef CONFIG_SCHED_HAVE_PARENT
+#if defined(CONFIG_SCHED_HAVE_PARENT) && !defined(CONFIG_DISABLE_SIGNALS)
   /* Call sigaction with the SA_NOCLDWAIT flag so that we do not transform
    * children into "zombies" when they terminate:  Child exit status will
    * not be retained.
@@ -113,7 +113,7 @@ int telnetd_daemon(FAR const struct telnetd_config_s *config)
       nerr("ERROR: sigprocmask failed: %d\n", errno);
       goto errout;
     }
-#endif /* CONFIG_SCHED_HAVE_PARENT */
+#endif /* CONFIG_SCHED_HAVE_PARENT && !CONFIG_DISABLE_SIGNALS */
 
   /* Create a new TCP socket to use to listen for connections */
 

nshlib/nsh_builtin.c

@@ -74,10 +74,14 @@ int nsh_builtin(FAR struct nsh_vtbl_s *vtbl, FAR const char *cmd,
                 FAR char **argv,
                 FAR const struct nsh_param_s *param)
 {
-#if !defined(CONFIG_NSH_DISABLEBG) && defined(CONFIG_SCHED_CHILD_STATUS)
+#if !defined(CONFIG_NSH_DISABLEBG) && defined(CONFIG_SCHED_CHILD_STATUS) && \
+    !defined(CONFIG_DISABLE_SIGNALS)
   struct sigaction act;
   struct sigaction old;
-#endif
+#endif /* !CONFIG_NSH_DISABLEBG && CONFIG_SCHED_CHILD_STATUS &&
+        * !CONFIG_DISABLE_SIGNALS
+        */
+
   int ret = OK;
 
   /* Lock the scheduler in an attempt to prevent the application from
@@ -86,7 +90,8 @@ int nsh_builtin(FAR struct nsh_vtbl_s *vtbl, FAR const char *cmd,
 
   sched_lock();
 
-#if !defined(CONFIG_NSH_DISABLEBG) && defined(CONFIG_SCHED_CHILD_STATUS)
+#if !defined(CONFIG_NSH_DISABLEBG) && \
+    defined(CONFIG_SCHED_CHILD_STATUS) && !defined(CONFIG_DISABLE_SIGNALS)
   /* Ignore the child status if run the application on background. */
 
   if (vtbl->np.np_bg == true)
@@ -98,7 +103,9 @@ int nsh_builtin(FAR struct nsh_vtbl_s *vtbl, FAR const char *cmd,
       sigaction(SIGCHLD, &act, &old);
     }
 
-#endif /* CONFIG_NSH_DISABLEBG */
+#endif /* !CONFIG_NSH_DISABLEBG && !CONFIG_SCHED_CHILD_STATUS &&
+        * !CONFIG_DISABLE_SIGNALS
+        */
 
   /* Try to find and execute the command within the list of builtin
    * applications.
@@ -230,7 +237,8 @@ int nsh_builtin(FAR struct nsh_vtbl_s *vtbl, FAR const char *cmd,
 
 #if !defined(CONFIG_SCHED_WAITPID) || !defined(CONFIG_NSH_DISABLEBG)
         {
-#if !defined(CONFIG_NSH_DISABLEBG) && defined(CONFIG_SCHED_CHILD_STATUS)
+#if !defined(CONFIG_NSH_DISABLEBG) && defined(CONFIG_SCHED_CHILD_STATUS) && \
+    !defined(CONFIG_DISABLE_SIGNALS)
 
           /* Restore the old actions */
 
@@ -241,7 +249,10 @@ int nsh_builtin(FAR struct nsh_vtbl_s *vtbl, FAR const char *cmd,
               sigaction(SIGCHLD, &old, NULL);
             }
 
-#  endif
+#  endif /* !CONFIG_NSH_DISABLEBG && CONFIG_SCHED_CHILD_STATUS && \
+          * !CONFIG_DISABLE_SIGNALS
+          */
+
           struct sched_param sched;
           sched_getparam(ret, &sched);
           nsh_output(vtbl, "%s [%d:%d]\n", cmd, ret, sched.sched_priority);

nshlib/nsh_proccmds.c

@@ -873,6 +873,7 @@ static int top_cmpcpuload(FAR const void *item1, FAR const void *item2)
     }
 }
 
+#ifndef CONFIG_DISABLE_SIGNALS
 /****************************************************************************
  * Name: top_exit
  ****************************************************************************/
@@ -882,7 +883,9 @@ static void top_exit(int signo, FAR siginfo_t *siginfo, FAR void *context)
   *(FAR bool *)siginfo->si_user = true;
 }
 
-#endif
+#endif /* !CONFIG_DISABLE_SIGNALS */
+
+#endif /* !CONFIG_NSH_DISABLE_TOP && NSH_HAVE_CPULOAD */
 
 /****************************************************************************
  * Public Functions
@@ -1357,7 +1360,9 @@ int cmd_top(FAR struct nsh_vtbl_s *vtbl, int argc, FAR char **argv)
   FAR char *pidlist = NULL;
   size_t num = SIZE_MAX;
   size_t i;
+#ifndef CONFIG_DISABLE_SIGNALS
   struct sigaction act;
+#endif
   bool quit = false;
   int delay = 3;
   int ret = 0;
@@ -1393,6 +1398,7 @@ int cmd_top(FAR struct nsh_vtbl_s *vtbl, int argc, FAR char **argv)
         }
     }
 
+#ifndef CONFIG_DISABLE_SIGNALS
   act.sa_user = &quit;
   act.sa_sigaction = top_exit;
   sigemptyset(&act.sa_mask);
@@ -1402,6 +1408,7 @@ int cmd_top(FAR struct nsh_vtbl_s *vtbl, int argc, FAR char **argv)
       nsh_error(vtbl, g_fmtcmdfailed, "top", "sigaction", NSH_ERRNO);
       return ERROR;
     }
+#endif
 
   if (vtbl->isctty)
     {