add a signal handler to tell VSL to flush pending transactions

src/child.c

@@ -99,7 +99,7 @@ static unsigned long seen = 0, submitted = 0, len_overflows = 0, no_data = 0,
 
 static volatile sig_atomic_t flush = 0, term = 0;
 
-static struct sigaction terminate_action, dump_action;
+static struct sigaction terminate_action, dump_action, flush_action;
 
 /* Local freelist */
 static struct freehead_s reader_freelist = 
@@ -140,6 +140,14 @@ term_s(int sig)
     flush = 1;
 }
 
+static void
+sigflush(int sig)
+{
+    flush = 1;
+    LOG_Log(LOG_NOTICE, "Received signal %d (%s), "
+            "flushing pending transactions", sig, strsignal(sig));
+}
+
 /*--------------------------------------------------------------------*/
 
 /* efficiently retrieve a single data entry */
@@ -487,6 +495,10 @@ CHILD_Main(int readconfig)
     AZ(sigemptyset(&terminate_action.sa_mask));
     terminate_action.sa_flags &= ~SA_RESTART;
 
+    flush_action.sa_handler = sigflush;
+    AZ(sigemptyset(&flush_action.sa_mask));
+    flush_action.sa_flags |= SA_RESTART;
+
 #define CHILD(SIG,disp) SIGDISP(SIG,disp)
 #define PARENT(SIG,disp) ((void) 0)
 #include "signals.h"

src/signals.h

@@ -44,7 +44,7 @@ CHILD(SIGTERM, terminate_action);
 CHILD(SIGINT, terminate_action);
 CHILD(SIGUSR1, dump_action);
 CHILD(SIGUSR2, ignore_action);
-CHILD(SIGHUP, ignore_action);
+CHILD(SIGHUP, flush_action);
 #ifndef DISABLE_STACKTRACE
 CHILD(SIGABRT, stacktrace_action);
 CHILD(SIGSEGV, stacktrace_action);