Experimental Physics and
Industrial Control System

Dirk Zimoch <[email protected]> · Thu, 8 Feb 2018 14:23:55 +0100

Attached is a patch file for dbScan.c which should fix the problem and

restore backward compatibility.



I have created (and quickly tested) it with EPICS 7 but I guess it

should work with 3.16 as well.



The hack is to treat "x.000000" and "x" as the same event name if x is

an integer between 0 and 255. ("0" and "0.000000" are no event at all

now just like "").



I will create a merge request for the EPICS base repo once I have proper

tests and documentation.


Dirk

On 08.02.2018 10:08, Dirk Zimoch wrote:

This is interesting. When I wrote the "named Events" feature some years

ago, I tested with something like 2 which became "2" and all was fine.

However I never thought about generating the value from a calc. This

should be fixed, or at least "2.000000" and "2" should be treated as equal.


I will start working on it...

Dirk


On 30.01.2018 17:20, Simon Reiter wrote:

Thanks so far.

postEvent 2
works fine.


Up to now, my event record has an INP field, which links to a calc

record.

This calc record only provides the correct value under some conditions.
How can I do this without using a state machine?

record(calc,"$(BOARDNAME):ErrorFlags:calc")
{
   field(INPA, "$(BOARDNAME):InitDone:S CPP")
   field(CALC, "A ? 2 : 0")
}

record(event, "$(BOARDNAME):ErrorFlags:trg")
{
   field(INP,  "$(BOARDNAME):ErrorFlags:calc CPP")
}


This is my current code. The value of event is now 2.000000 in the

correct case.

diff --git a/src/ioc/db/dbScan.c b/src/ioc/db/dbScan.c
index 9f7df4c..ccaa831 100644
--- a/src/ioc/db/dbScan.c
+++ b/src/ioc/db/dbScan.c
@@ -112,6 +112,10 @@ typedef struct event_list {
     struct event_list *next;
     char                event_name[MAX_STRING_SIZE];
 } event_list;
+
+/* For backward compatibility with numeric events keep 255 slots.
+   Named events are in slot 0.
+*/
 static event_list * volatile pevent_list[256];
 static epicsMutexId event_lock;
 
@@ -478,10 +482,24 @@ event_list *eventNameToHandle(const char *eventname)
     int prio;
     event_list *pel;
     static epicsThreadOnceId onceId = EPICS_THREAD_ONCE_INIT;
+    char* p;
+    long eventnumber;
 
     if (!eventname || eventname[0] == 0)
         return NULL;
 
+    /* Backward compatibility with numeric events:
+       Treat "x.000000" with 0<=x<=255 like "x"
+       because it is most probably a conversion from double
+       like from a calc record.
+    */
+    eventnumber = strtol(eventname, &p, 0);
+    if (eventnumber >= 0 && eventnumber <= 255
+        && (*p == 0 || strcmp(p, ".000000") == 0))
+        *p = 0; /* truncate ".000000" */
+    else 
+        eventnumber = 0; /* not a numeric event */
+
     epicsThreadOnce(&onceId, eventOnce, NULL);
     epicsMutexMustLock(event_lock);
     for (pel = pevent_list[0]; pel; pel=pel->next) {
@@ -501,12 +519,9 @@ event_list *eventNameToHandle(const char *eventname)
         }
         pel->next=pevent_list[0];
         pevent_list[0]=pel;
-        { /* backward compatibility */
-            char* p;
-            long e = strtol(eventname, &p, 0);
-            if (*p == 0 && e > 0 && e <= 255)
-                pevent_list[e] = pel;
-        }
+        /* backward compatibility */
+        if (eventnumber > 0)
+            pevent_list[eventnumber] = pel;
     }
 done:
     epicsMutexUnlock(event_lock);


Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System