Revert "fix bug : gpload does not stop after informatica sends exit call (#3089)"

We believe the pipeline is red due to this commit:
https://github.com/greenplum-db/gpdb/commits/fdc9e0a2812dbb01f0883c570f90d82397e2c573

The PR pipeline is red when it was pushed:
https://github.com/greenplum-db/gpdb/pull/3089

src/bin/gpfdist/gpfdist.c

@@ -98,15 +98,6 @@ static void flush_ssl_buffer(int fd, short event, void* arg);
 /* SSL end */
 #endif
 
-/* signal handler global flag for asyc function*/
-volatile static int sig_flag = 0;
-void asyc_signal_handler(void);
-#define CHECK_SIGNAL() do { \
-	if (sig_flag == SIGINT || sig_flag == SIGTERM) \
-	{ \
-		asyc_signal_handler(); \
-	} \
-} while(0)
 /**************
 
  NOTE on GP_PROTO
@@ -2177,7 +2168,6 @@ static void do_accept(int fd, short event, void* arg)
 	return;
 
 failure:
-	CHECK_SIGNAL();
 	gwarning(NULL, "accept failed");
 	return;
 }
@@ -2538,28 +2528,23 @@ http_setup(void)
 	}
 }
 
-void 
-asyc_signal_handler(void )
-{
-	gwarning(NULL, "signal %d received. gpfdist exits", sig_flag);
-	log_gpfdist_status();
-	fflush(stdout);
-
-	int i;
-	for (i = 0; i < gcb.listen_sock_count; i++)
-	{
-		if (gcb.listen_socks[i] > 0)
-		{
-			closesocket(gcb.listen_socks[i]);
-		}
-	}
-	exit(1);
-}
-
 void
 process_signal(int sig)
 {
-	sig_flag = sig;
+	if (sig == SIGINT || sig == SIGTERM)
+	{
+		gwarning(NULL, "signal %d received. gpfdist exits", sig);
+		log_gpfdist_status();
+		fflush(stdout);
+
+		int i;
+		for (i = 0; i < gcb.listen_sock_count; i++)
+			if (gcb.listen_socks[i] > 0)
+			{
+				closesocket(gcb.listen_socks[i]);
+			}
+		exit(1);
+	}
 }
 
 
@@ -3576,16 +3561,7 @@ int gpfdist_init(int argc, const char* const argv[])
 
 int gpfdist_run()
 {
-	struct timeval t;
-	t.tv_sec = 1;
-	t.tv_usec = 0;
-	for(;;)
-	{
-		event_loopexit(&t);
-		event_dispatch();
-		CHECK_SIGNAL();
-	}
-	return 0;
+	return event_dispatch();
 }
 
 #ifndef WIN32
@@ -3985,9 +3961,7 @@ static SSL_CTX *initialize_ctx(void)
  */
 static int gpfdist_socket_send(const request_t *r, const void *buf, const size_t buflen)
 {
-	int ret = send(r->sock, buf, buflen, 0);
-	CHECK_SIGNAL();
-	return ret;
+	return send(r->sock, buf, buflen, 0);
 }
 
 #ifdef USE_SSL
@@ -4001,7 +3975,6 @@ static int gpfdist_SSL_send(const request_t *r, const void *buf, const size_t bu
 
 	/* Write the data to socket */
 	int n = BIO_write(r->io, buf, buflen);
-	CHECK_SIGNAL();
 	/* Try to flush */
 	(void)BIO_flush(r->io);
 
@@ -4047,9 +4020,7 @@ static int gpfdist_SSL_send(const request_t *r, const void *buf, const size_t bu
  */
 static int gpfdist_socket_receive(const request_t *r, void *buf, const size_t buflen)
 {
-	int ret = recv(r->sock, buf, buflen, 0);
-	CHECK_SIGNAL();
-	return ret;
+	return ( recv(r->sock, buf, buflen, 0) );
 }
 
 
@@ -4061,9 +4032,8 @@ static int gpfdist_socket_receive(const request_t *r, void *buf, const size_t bu
  */
 static int gpfdist_SSL_receive(const request_t *r, void *buf, const size_t buflen)
 {
-	int ret = BIO_read(r->io, buf, buflen);
-	CHECK_SIGNAL();
-	return ret;
+	return ( BIO_read(r->io, buf, buflen) );
+	/* todo: add error checks here */
 }