add protection to PLL access

Pcie40Applications/main_pcie40_statlink.cpp

@@ -5,9 +5,10 @@
   Qi-Dong Zhou, KEK 
 
   2020.04.28  0.01 first version based on staths.c
-
+  2020.12.19  0.01 rename statlink to pcie40_statlink
+  2020.12.23  0.02 add protection for pll status access
 \*--------------------------------------------------------------------------------*/
-#define VERSION 01
+#define VERSION 02
 #define MOD_DATE 20200428
 
 #include "pcie40_b2slc.h"
@@ -20,7 +21,7 @@
 #include <iostream>
 #include <vector>
 #include <bitset>
-
+#include <sys/file.h>
 
 #define MAX_NUM_CH   48
 #define MAX_SLOT     3
@@ -101,6 +102,7 @@ void argument(int argc, char **argv){
 int
 statpice40(pcie40reg_t pcie40reg)
 {
+  FILE *fp = fopen("/tmp/pcie40_pll_lockfile_statlink.lck","w");
   pcie40reg_t *pcie = &pcie40reg;
   memset(pcie, 0, sizeof(*pcie));
   int pcie40_sta = pcie40_status(dev_slot);
@@ -112,6 +114,7 @@ statpice40(pcie40reg_t pcie40reg)
 	 pcie40_run_number(dev_slot),
 	 D(pcie40_sta, 28, 17),
 	 pcie40_trg_type(dev_slot));	 
+  flock( fileno(fp), LOCK_EX );
   printf("PLLs:%s | rxlink: %s | txlink: %s | txlink: %s | rxdisp: %s | rxdata: %s\n", 	  
 	 (pcie40_pllLockStatus(dev_slot, 1)&&pcie40_pllLockStatus(dev_slot, 2)&&pcie40_pllLockStatus(dev_slot, 3))?"LOCKED":"NOT LOCKED",
 	 B(pcie40_sta, 0)?"READY":"NOT READY",
@@ -146,7 +149,9 @@ statpice40(pcie40reg_t pcie40reg)
 	   pcie40_pllInputCounter(dev_slot, 3)?"OK ":"LOS",
 	   pcie40_pllFrequencyCounter(dev_slot, 3)?"OK ":"OOF");
     printf("__________________________________\n");
-  }  
+  }
+  flock( fileno(fp), LOCK_UN );
+  fclose(fp);
   return 0;
 }