Experimental Physics and
Industrial Control System

Andrew Johnson <[email protected]> · Thu, 27 Sep 2007 12:21:50 -0500

I received the attached patch from Eric Berryman, which I'm posting here

for additional comments. The change should not break existing

asTrapWrite plug-ins since it merely adds fields to the message

structure that contains all of the information about the write being

performed — the fields it adds contain the new data and metadata from

the put. However it does increase the size of the asTrapWriteMessage

structure from 4 to 7 pointers.



I can see that it simplifies the use of the asTrapWrite API, but I am

not convinced that it is strictly necessary. The existing API does not

provide the put data & metadata directly, but this information can be

obtained from the record field by the 'after' call to the registered

plug-in. This would not be true if the put causes record processing

which modifies the value of the field before the 'after' call, but by

forcing users to fetch the 'after' data they also find out what the real

effect was of that put, not just what the client tried to do (if you

rely only on what was in the put buffer as provided by this patch you

can't be 100% sure what value actually ended up in the field).


Comments, positive or negative?

- Andrew
--
When a distinguished but elderly scientist states that something is
possible, he is almost certainly right.  When he states that something
is impossible, he is very probably wrong.  -- Arthur C. Clarke

--- /opt/epicsB/base_old/src/as/asLib.h	2007-09-24 13:11:43.000000000 -0400
+++ /opt/epicsB/base/src/as/asLib.h	2007-09-24 13:28:44.969781176 -0400
@@ -42,9 +42,9 @@
 	(asActive \
 	? ((asClientPvt)->access>=asWRITE ? TRUE : FALSE)\
 	: TRUE)
-#define asTrapWriteBefore(asClientPvt,user,host,addr) \
+#define asTrapWriteBefore(asClientPvt,user,host,addr,dtype,dptr,dcnt) \
     (((asActive) && (asClientPvt)->trapMask) \
-    ? asTrapWriteBeforeWrite((user),(host),(addr)) \
+    ? asTrapWriteBeforeWrite((user),(host),(addr),(dtype),(dptr),(dcnt)) \
     : 0)
 
 #define asTrapWriteAfter(pvt) if((pvt)) asTrapWriteAfterWrite((pvt))
@@ -101,7 +101,7 @@
 epicsShareFunc int epicsShareAPI asDumpHashFP(FILE *fp);
 
 epicsShareFunc void * epicsShareAPI asTrapWriteBeforeWrite(
-    const char *userid,const char *hostid,void *addr);
+    const char *userid,const char *hostid,void *addr,unsigned short dataType,void *dataptr,unsigned long count);
 
 epicsShareFunc void epicsShareAPI asTrapWriteAfterWrite(void *pvt);
 
--- /opt/epicsB/base_old/src/as/asTrapWrite.h	2007-09-24 13:11:43.000000000 -0400
+++ /opt/epicsB/base/src/as/asTrapWrite.h	2007-09-24 13:24:48.000000000 -0400
@@ -24,6 +24,9 @@
     const char *hostid;
     void *serverSpecific;
     void *userPvt;
+    unsigned short *dataType;
+    void *dataptr;
+    unsigned long *count;
 } asTrapWriteMessage;
 
 
--- /opt/epicsB/base_old/src/as/asTrapWrite.c	2007-09-24 13:57:45.117261852 -0400
+++ /opt/epicsB/base/src/as/asTrapWrite.c	2007-09-24 13:21:17.000000000 -0400
@@ -112,7 +112,7 @@
 }
 
 void * epicsShareAPI asTrapWriteBeforeWrite(
-    const char *userid,const char *hostid,void *addr)
+    const char *userid,const char *hostid,void *addr,unsigned short dataType,void *dataptr,unsigned long count)
 {
     writeMessage *pwriteMessage;
     listener *plistener;
@@ -125,6 +125,9 @@
     pwriteMessage->message.userid = userid;
     pwriteMessage->message.hostid = hostid;
     pwriteMessage->message.serverSpecific = addr;
+    pwriteMessage->message.dataType = dataType;
+    pwriteMessage->message.dataptr = dataptr;
+    pwriteMessage->message.count = count;
     ellInit(&pwriteMessage->listenerPvtList);
     epicsMutexMustLock(pasTrapWritePvt->lock);
     ellAdd(&pasTrapWritePvt->writeMessageList,&pwriteMessage->node);
--- /opt/epicsB/base_old/src/rsrv/camessage.c	2007-09-24 13:59:25.992793308 -0400
+++ /opt/epicsB/base/src/rsrv/camessage.c	2007-09-24 13:45:17.414564490 -0400
@@ -791,7 +791,10 @@
     asWritePvt = asTrapWriteBefore ( pciu->asClientPVT,
         pciu->client->pUserName ? pciu->client->pUserName : "",
         pciu->client->pHostName ? pciu->client->pHostName : "",
-        (void *) &pciu->addr );
+        (void *) &pciu->addr,
+		mp->m_dataType,
+		pPayload,
+		mp->m_count);
 
     dbStatus = db_put_field(
                   &pciu->addr,
@@ -1774,7 +1777,10 @@
         pciu->asClientPVT,
         pciu->client->pUserName ? pciu->client->pUserName : "",
         pciu->client->pHostName ? pciu->client->pHostName : "",
-        (void *) &pciu->addr );
+        (void *) &pciu->addr,
+		mp->m_dataType,
+		pPayload,
+		mp->m_count);
 
     dbPutNotify(&pciu->pPutNotify->dbPutNotify);
 


Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System