From e01b6bd43578838dea2aae4f87b27caf19190940 Mon Sep 17 00:00:00 2001
From: Andrew Johnson <anj@aps.anl.gov>
Date: Tue, 14 Apr 2009 20:04:05 +0000
Subject: [PATCH] Calculate monitor events properly.

---
 src/rec/longinRecord.c  | 50 +++++++++++++++++++----------------------
 src/rec/longoutRecord.c | 50 ++++++++++++++++++++---------------------
 2 files changed, 47 insertions(+), 53 deletions(-)

diff --git a/src/rec/longinRecord.c b/src/rec/longinRecord.c
index dee03263e..9f211a0a0 100644
--- a/src/rec/longinRecord.c
+++ b/src/rec/longinRecord.c
@@ -262,38 +262,34 @@ static void checkAlarms(longinRecord *prec)
     return;
 }
 
+/* DELTA calculates the absolute difference between its arguments
+ * expressed as an unsigned 32-bit integer */
+#define DELTA(last, val) \
+    ((epicsUInt32) ((last) > (val) ? (last) - (val) : (val) - (last)))
+
 static void monitor(longinRecord *prec)
 {
-	unsigned short	monitor_mask;
-	epicsInt32	delta;
+    unsigned short monitor_mask = recGblResetAlarms(prec);
 
-	/* get previous stat and sevr  and new stat and sevr*/
-        monitor_mask = recGblResetAlarms(prec);
-	/* check for value change */
-	delta = prec->mlst - prec->val;
-	if(delta<0) delta = -delta;
-        if (delta > prec->mdel || delta==0x80000000) {
-		/* post events for value change */
-		monitor_mask |= DBE_VALUE;
-		/* update last value monitored */
-		prec->mlst = prec->val;
-	}
+    if (prec->mdel < 0 ||
+        DELTA(prec->mlst, prec->val) > (epicsUInt32) prec->mdel) {
+        /* post events for value change */
+        monitor_mask |= DBE_VALUE;
+        /* update last value monitored */
+        prec->mlst = prec->val;
+    }
 
-	/* check for archive change */
-	delta = prec->alst - prec->val;
-	if(delta<0) delta = -delta;
-	if (delta > prec->adel || delta==0x80000000) {
-		/* post events on value field for archive change */
-		monitor_mask |= DBE_LOG;
-		/* update last archive value monitored */
-		prec->alst = prec->val;
-	}
+    if (prec->adel < 0 ||
+        DELTA(prec->alst, prec->val) > (epicsUInt32) prec->adel) {
+        /* post events for archive value change */
+        monitor_mask |= DBE_LOG;
+        /* update last archive value monitored */
+        prec->alst = prec->val;
+    }
 
-	/* send out monitors connected to the value field */
-	if (monitor_mask){
-		db_post_events(prec,&prec->val,monitor_mask);
-	}
-	return;
+    /* send out monitors connected to the value field */
+    if (monitor_mask)
+        db_post_events(prec, &prec->val, monitor_mask);
 }
 
 static long readValue(longinRecord *prec)
diff --git a/src/rec/longoutRecord.c b/src/rec/longoutRecord.c
index 6309a5d32..d143be23b 100644
--- a/src/rec/longoutRecord.c
+++ b/src/rec/longoutRecord.c
@@ -302,36 +302,34 @@ static void checkAlarms(longoutRecord *prec)
     return;
 }
 
+/* DELTA calculates the absolute difference between its arguments
+ * expressed as an unsigned 32-bit integer */
+#define DELTA(last, val) \
+    ((epicsUInt32) ((last) > (val) ? (last) - (val) : (val) - (last)))
+
 static void monitor(longoutRecord *prec)
 {
-	unsigned short	monitor_mask;
-	epicsInt32	delta;
+    unsigned short monitor_mask = recGblResetAlarms(prec);
 
-        monitor_mask = recGblResetAlarms(prec);
-        /* check for value change */
-        delta = prec->mlst - prec->val;
-        if(delta<0) delta = -delta;
-        if (delta > prec->mdel || delta==0x80000000) {
-                /* post events for value change */
-                monitor_mask |= DBE_VALUE;
-                /* update last value monitored */
-                prec->mlst = prec->val;
-        }
-        /* check for archive change */
-        delta = prec->alst - prec->val;
-        if(delta<0) delta = -delta;
-        if (delta > prec->adel || delta==0x80000000) {
-                /* post events on value field for archive change */
-                monitor_mask |= DBE_LOG;
-                /* update last archive value monitored */
-                prec->alst = prec->val;
-        }
+    if (prec->mdel < 0 ||
+        DELTA(prec->mlst, prec->val) > (epicsUInt32) prec->mdel) {
+        /* post events for value change */
+        monitor_mask |= DBE_VALUE;
+        /* update last value monitored */
+        prec->mlst = prec->val;
+    }
 
-        /* send out monitors connected to the value field */
-        if (monitor_mask){
-                db_post_events(prec,&prec->val,monitor_mask);
-	}
-	return;
+    if (prec->adel < 0 ||
+        DELTA(prec->alst, prec->val) > (epicsUInt32) prec->adel) {
+        /* post events for archive value change */
+        monitor_mask |= DBE_LOG;
+        /* update last archive value monitored */
+        prec->alst = prec->val;
+    }
+
+    /* send out monitors connected to the value field */
+    if (monitor_mask)
+        db_post_events(prec, &prec->val, monitor_mask);
 }
 
 static long writeValue(longoutRecord *prec)