Fire up validation when SIGUSR1 is received while sleeping

Tentatively fixes #42, except it applies on SIGUSR1, not SIGHUP.
I don't understand the logic of using SIGHUP for this.

diff --git a/src/log.c b/src/log.c
index ecff284eb3a192ac63711c4f48b5c5e789bf3168..0b12ce19af7f5402d096203756de03af1398e358 100644 (file)
--- a/src/log.c
+++ b/src/log.c
@@ -144,6 +144,18 @@ sigsegv_handler(int signum)
 
 #endif
 
+static void
+sigusr1_handler(int signum)
+{
+       /*
+        * Nothing.
+        * We want to wake up the main thread's sleep(), but according to its
+        * documentation, that happens automatically.
+        * All we had to do was set up SIGUSR1 so it's neither ignored nor
+        * results in program termination.
+        */
+}
+
 /*
  * Register better handlers for some signals.
  *
@@ -152,8 +164,9 @@ sigsegv_handler(int signum)
 static void
 register_signal_handlers(void)
 {
-#ifdef BACKTRACE_ENABLED
        struct sigaction action;
+
+#ifdef BACKTRACE_ENABLED
        void* dummy;
 
        /*
@@ -167,7 +180,6 @@ register_signal_handlers(void)
        memset(&action, 0, sizeof(action));
        action.sa_handler = sigsegv_handler;
        sigemptyset(&action.sa_mask);
-       action.sa_flags = 0;
        if (sigaction(SIGSEGV, &action, NULL) == -1) {
                /*
                 * Not fatal; it just means we will not print stack traces on
@@ -178,6 +190,14 @@ register_signal_handlers(void)
        }
 #endif
 
+       /* SIGUSR1 handler */
+       memset(&action, 0, sizeof(action));
+       action.sa_handler = sigusr1_handler;
+       sigemptyset(&action.sa_mask);
+       if (sigaction(SIGUSR1, &action, NULL) == -1)
+               pr_op_err("SIGUSR1 handler registration failure: %s",
+                   strerror(errno));
+
        /*
         * SIGPIPE can be triggered by any I/O function. libcurl is particularly
         * tricky:
@@ -196,7 +216,10 @@ register_signal_handlers(void)
         *
         * https://github.com/NICMx/FORT-validator/issues/49
         */
-       if (signal(SIGPIPE, SIG_IGN) == SIG_ERR) {
+       memset(&action, 0, sizeof(action));
+       action.sa_handler = SIG_IGN;
+       sigemptyset(&action.sa_mask);
+       if (sigaction(SIGPIPE, &action, NULL) == -1)
                /*
                 * Not fatal. It just means that, if a broken pipe happens, we
                 * will die silently.
@@ -204,7 +227,6 @@ register_signal_handlers(void)
                 */
                pr_op_err("SIGPIPE handler registration failure: %s",
                    strerror(errno));
-       }
 }
 
 int