async dset example

testApp/test1.db

@@ -22,3 +22,9 @@ record(waveform, "$(P)wf") {
   field(NELM, "10")
   field(SCAN, "2 second")
 }
+
+record(longin, "$(P)async:cnt") {
+  field(DTYP, "Python Device")
+  field(INP , "@test4")
+  field(SCAN, "1 second")
+}

testApp/test3.py

@@ -28,7 +28,9 @@ class WfSup(object):
         val=self.arr[:N]
         x=self.x[:N]
 
-        val[:] = pha*x
+        # calculate inplace: uniform(0.5,2.0)*sin(pha*x)+2
+        val[:] = x
+        val[:] *= pha
         np.sin(val, out=val)
         val[:]*=uniform(0.5,2.0)
         val[:]+=2

testApp/test4.py

@@ -0,0 +1,26 @@
+
+import threading
+
+AsyncComplete = object()
+
+class Counter(object):
+    def __init__(self, rec, args):
+        self.val = rec.field('VAL')
+        self.nextval = None
+        self.timer = None
+    def detach(self, rec):
+        if self.timer:
+            self.timer.cancel()
+
+    def process(self, rec, reason):
+        if reason is AsyncComplete:
+            self.val.putval(self.nextval)
+            
+        else:
+            self.nextval = self.val.getval()+1
+            self.timer = threading.Timer(0.2, rec.asyncFinish, kwargs={'reason':AsyncComplete})
+            rec.asyncStart()
+            self.timer.start()
+
+
+build = Counter