From d9fd7361dd75830851c80180e0100b825787e9ce Mon Sep 17 00:00:00 2001
From: Gabriel-Andrew Pollo-Guilbert <gabrielpolloguilbert@gmail.com>
Date: Fri, 8 May 2020 12:01:11 -0400
Subject: [PATCH] WIP: Add marker example python

This simple example computes the region of 5 ms containing the most
`sched_switch` events and highlights it using a marker.

Signed-off-by: Gabriel-Andrew Pollo-Guilbert <gabrielpolloguilbert@gmail.com>
---
 examples/python/marker.py | 105 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 105 insertions(+)
 create mode 100644 examples/python/marker.py

diff --git a/examples/python/marker.py b/examples/python/marker.py
new file mode 100644
index 0000000..a0551a5
--- /dev/null
+++ b/examples/python/marker.py
@@ -0,0 +1,105 @@
+################################################################################
+# Copyright (c) 2020 Gabriel-Andrew Pollo-Guilbert
+# All rights reserved. This program and the accompanying materials
+# are made available under the terms of the Eclipse Public License v1.0
+# which accompanies this distribution, and is available at
+# http://www.eclipse.org/legal/epl-v10.html
+#
+# markers.py
+################################################################################
+
+from py4j.java_gateway import JavaClass
+from py4j.protocol import Py4JError
+
+loadModule('/TraceCompass/Analysis')
+loadModule('/TraceCompass/DataProvider')
+loadModule('/TraceCompass/View')
+loadModule('/TraceCompass/Trace')
+loadModule('/TraceCompass/TraceMarker')
+
+trace = getActiveTrace()
+if trace is None:
+    print("Trace is null")
+    exit()
+
+analysis = getAnalysis("events.py")
+if analysis is None:
+    print("Trace is null")
+    exit()
+
+def strToVarargs(str):
+    object_class = java.lang.String
+    object_array = gateway.new_array(object_class, 1)
+    object_array[0] = str
+    return object_array
+
+# basic state system analysis based on sched_switch events
+stateSystem = analysis.getStateSystem(False)
+def updateStateSystem(event):
+    cpu = getFieldValue(event, "CPU")
+    tid = getFieldValue(event, "next_tid")
+    
+    if cpu is not None and tid is not None:
+        quark = stateSystem.getQuarkAbsoluteAndAdd(strToVarargs(str(cpu)))
+        stateSystem.modifyAttribute(event.getTimestamp().toNanos(), str(tid), quark)
+
+# marker region containing the most sched_switch events
+most_events = []
+most_start = None
+most_end = None
+most_count = None
+def updateMostEventful(event, duration):
+    global most_events
+    global most_start
+    global most_end
+    global most_count
+
+    most_events.append(event)
+    
+    while len(most_events) > 0:
+        start = most_events[0].getTimestamp().toNanos()
+        end = event.getTimestamp().toNanos()
+        
+        if end - start > duration:
+            most_events = most_events[1:]
+        else:
+            break
+    
+    if most_count is None or most_count < len(most_events):
+        most_count = len(most_events)
+        most_start = most_events[0].getTimestamp().toNanos()
+        most_end = most_events[len(most_events) - 1].getTimestamp().toNanos()
+
+# iterate through all events for analysis
+def runAnalysis(duration):
+    iterator = analysis.getEventIterator()
+    event = None
+    while iterator.hasNext():
+        if event is not None:
+            gateway.detach(event)
+        event = iterator.next()
+        
+        if event.getName() == "sched_switch":
+            updateStateSystem(event)
+            
+            # TODO: Py4J throws exceptions sometimes, we ignore them for the time being
+            #       event though it causes the Python version to give different results
+            #       from the Javascript version
+            try:
+                updateMostEventful(event, duration)
+            except Py4JError:
+                pass
+
+    if event is not None:
+        stateSystem.closeHistory(event.getTimestamp().toNanos())
+
+# run analysis and show results
+if not stateSystem.waitUntilBuilt(0):
+    runAnalysis(5e6)
+    addTraceMarker(trace, most_start, most_end, "{} events".format(most_count), "most sched_switch in 5ms")
+    
+provider = createTimeGraphProvider(analysis, {ENTRY_PATH : '*'})
+if not(provider is None):
+    openTimeGraphView(provider)
+
+