userspace/snmpd: allow snmpd to start without RTUd

Make possible to start snmpd without successful open of RTUd's shmem (in other words having RTUd running). SNMPd shall start even on faulty system since it is a way to report if and what is wrong. Signed-off-by: Adam Wujek <adam.wujek@cern.ch>

userspace/snmpd: allow snmpd to start without RTUd
Make possible to start snmpd without successful open of RTUd's shmem (in other words having RTUd running). SNMPd shall start even on faulty system since it is a way to report if and what is wrong. Signed-off-by: Adam Wujek <adam.wujek@cern.ch>
cb42b967 · Adam Wujek · c380ffc0 · cb42b967 · cb42b967 · cb42b967
Commit cb42b967 authored Aug 19, 2015 by Adam Wujek 💬
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Showing with 47 additions and 21 deletions

snmp_shmem.c userspace/snmpd/snmp_shmem.c +41 -19

snmp_shmem.h userspace/snmpd/snmp_shmem.h +1 -1

wrsStartCntGroup.c userspace/snmpd/wrsStartCntGroup.c +5 -1

No files found.
--- a/userspace/snmpd/snmp_shmem.c
+++ b/userspace/snmpd/snmp_shmem.c
@@ -17,6 +17,8 @@ int *ppsi_ppi_nlinks;
 /* RTUd */
 struct wrs_shm_head *rtud_head;

+int shmem_open_rtud;
+
 static void init_shm_hal(void)
 {
 	int ret;
@@ -110,26 +112,25 @@ static void init_shm_ppsi(void)
 	ppsi_ppi_nlinks = &(ppg->nlinks);
 }

-static void init_shm_rtud(void)
+static int init_shm_rtud(void)
 {
 	int ret;
-	int n_wait = 0;
-
-	while ((ret = wrs_shm_get_and_check(wrs_shm_rtu, &rtud_head)) != 0) {
-		n_wait++;
-		if (n_wait > 10) {
-			/* timeout! */
-			if (ret == 1) {
-				snmp_log(LOG_ERR, "Unable to open shm for "
-					 "RTUd!\n");
-			}
-			if (ret == 2) {
-				snmp_log(LOG_ERR, "Unable to read RTUd's "
-					 "version!\n");
-			}
-			exit(-1);
+	static int n_wait = 0;
+
+	ret = wrs_shm_get_and_check(wrs_shm_rtu, &rtud_head);
+	n_wait++;
+	/* start printing error after 5 messages */
+	if (n_wait > 5) {
+		if (ret == 1) {
+			snmp_log(LOG_ERR, "Unable to open shm for RTUd!\n");
 		}
-		sleep(1);
+		if (ret == 2) {
+			snmp_log(LOG_ERR, "Unable to read RTUd's version!\n");
+		}
+	}
+	if (ret) {
+		/* return if error while opening shmem */
+		return ret;
 	}

 	/* check rtud's shm version */
@@ -137,12 +138,33 @@ static void init_shm_rtud(void)
 		snmp_log(LOG_ERR, "unknown RTUd's shm version %i "
 			 "(known is %i)\n", rtud_head->version,
 			 RTU_SHMEM_VERSION);
-		exit(-1);
+		return 3;
+	}
+
+	/* everything is ok */
+	return 0;
+}
+
+int shmem_ready_rtud(void)
+{
+	if (shmem_open_rtud) {
+		return 1;
 	}
+	shmem_open_rtud = !init_shm_rtud();
+	return shmem_open_rtud;
 }

 void init_shm(void){
+	int i;
+
 	init_shm_hal();
 	init_shm_ppsi();
-	init_shm_rtud();
+	for (i = 0; i < 10; i++) {
+		if (shmem_ready_rtud()) {
+			/* shmem opened successfully */
+			break;
+		}
+		/* wait 1 second before another try */
+		sleep(1);
+	}
 }
--- a/userspace/snmpd/snmp_shmem.h
+++ b/userspace/snmpd/snmp_shmem.h
@@ -23,5 +23,5 @@ extern int *ppsi_ppi_nlinks;
 struct wrs_shm_head *rtud_head;

 void init_shm();
-
+int shmem_ready_rtud(void);
 #endif /* WRS_SNMP_SHMEM_H */
--- a/userspace/snmpd/wrsStartCntGroup.c
+++ b/userspace/snmpd/wrsStartCntGroup.c
@@ -55,7 +55,11 @@ time_t wrsStartCnt_data_fill(void){
 	/* get start counters from shmem's */
 	wrsStartCnt_s.wrsStartCntHAL = hal_head->pidsequence;
 	wrsStartCnt_s.wrsStartCntPTP = ppsi_head->pidsequence;
-	wrsStartCnt_s.wrsStartCntRTUd = rtud_head->pidsequence;
+	if (shmem_ready_rtud()) {
+		wrsStartCnt_s.wrsStartCntRTUd = rtud_head->pidsequence;
+	} else {
+		snmp_log(LOG_ERR, "Unable to read rtu's shmem\n");
+	}

 	read_start_count(START_CNT_SSHD, &wrsStartCnt_s.wrsStartCntSshd);
 	read_start_count(START_CNT_HTTPD, &wrsStartCnt_s.wrsStartCntHttpd);