Merge pull request #148 from IBM/142-treat-any-thread-with-a-truncated-stack-as-interesting

#142 treat any thread with a truncated stack as interesting

Author: kkazmierczyk

src/javacore_analyser/java_thread.py

@@ -4,6 +4,7 @@
 #
 from javacore_analyser.abstract_snapshot_collection import AbstractSnapshotCollection
 from javacore_analyser.properties import Properties
+from javacore_analyser.stack_trace import StackTrace
 
 
 class Thread(AbstractSnapshotCollection):
@@ -21,6 +22,7 @@ def is_interesting(self):
         if self.get_avg_mem() // (1024 * 1024) > 0: return True     # memory in megabytes
         if len(self.get_blocker_threads()) > 0: return True
         if len(self.get_blocking_threads()) > 0: return True
+        if self.has_tall_stacks(): return True
         return False
 
     def get_hash(self):
@@ -144,3 +146,9 @@ def get_blocker_threads(self):
 
     def get_id(self):
         return self.get_hash()
+
+    def has_tall_stacks(self):
+        for snapshot in self.thread_snapshots:
+            if snapshot.stack_trace and snapshot.stack_trace.get_java_stack_depth() > StackTrace.TRUNCATION_DEPTH:
+                return True
+        return False

src/javacore_analyser/stack_trace.py

@@ -1,5 +1,5 @@
 #
-# Copyright IBM Corp. 2024 - 2024
+# Copyright IBM Corp. 2024 - 2025
 # SPDX-License-Identifier: Apache-2.0
 #
 
@@ -10,6 +10,7 @@
 class StackTrace:
     java_stack_depth: int
     EMPTY_STACK = "No stack"
+    TRUNCATION_DEPTH = 50  # as per https://github.ibm.com/IOT-ELM-Poznan/Wait2/issues/430
 
     """
     how many first lines of the stack need to be equal

test/test_java_thread.py

@@ -8,6 +8,8 @@
 
 from javacore_analyser.java_thread import Thread
 from javacore_analyser.javacore import Javacore
+from javacore_analyser.stack_trace import StackTrace
+from javacore_analyser.stack_trace_element import StackTraceElement
 from javacore_analyser.thread_snapshot import ThreadSnapshot
 
 
@@ -129,3 +131,28 @@ def test_is_interesting(self):
         thread_snapshot1.blocker = thread_snapshot2
         self.assertTrue(thread.is_interesting(), "This thread is blocked, so should be interesting")
 
+        thread = Thread()
+        thread_snapshot = ThreadSnapshot()
+        stack_trace = StackTrace()
+        for i in range(51):
+            stack_trace_element = StackTraceElement()
+            stack_trace.stack_trace_elements.append(stack_trace_element)
+        thread.thread_snapshots.append(thread_snapshot)
+        thread_snapshot.stack_trace = stack_trace
+        self.assertTrue(thread.is_interesting(), "This thread has a tall stack, so should be interesting")
+
+    def test_has_tall_stacks(self):
+        thread = Thread()
+        thread_snapshot = ThreadSnapshot()
+        stack_trace = StackTrace()
+        assert(not thread.has_tall_stacks())
+        for i in range(50):
+            stack_trace_element = StackTraceElement()
+            stack_trace.stack_trace_elements.append(stack_trace_element)
+        thread.thread_snapshots.append(thread_snapshot)
+        thread_snapshot.stack_trace = stack_trace
+        assert (not thread.has_tall_stacks())
+        stack_trace.stack_trace_elements.append(StackTraceElement())
+        assert (thread.has_tall_stacks())
+
+