From fa98b52ae1333fe4a1e565daedb1966c25dffa6f Mon Sep 17 00:00:00 2001
From: Zhengyu Gu <zhengyu.gu@datadoghq.com>
Date: Thu, 15 Jan 2026 13:24:17 -0500
Subject: [PATCH] v0

---
 ddprof-lib/src/main/cpp/profiler.cpp | 33 ++++++++--------------------
 1 file changed, 9 insertions(+), 24 deletions(-)

diff --git a/ddprof-lib/src/main/cpp/profiler.cpp b/ddprof-lib/src/main/cpp/profiler.cpp
index 5f83a14d..4885c085 100644
--- a/ddprof-lib/src/main/cpp/profiler.cpp
+++ b/ddprof-lib/src/main/cpp/profiler.cpp
@@ -29,6 +29,7 @@
 #include "vmStructs_dd.h"
 #include "wallClock.h"
 #include <algorithm>
+#include <cassert>
 #include <dlfcn.h>
 #include <fstream>
 #include <memory>
@@ -106,8 +107,9 @@ void Profiler::addRuntimeStub(const void *address, int length,
 }
 
 void Profiler::onThreadStart(jvmtiEnv *jvmti, JNIEnv *jni, jthread thread) {
-  ProfiledThread::initCurrentThread();
   ProfiledThread *current = ProfiledThread::current();
+  assert(current != nullptr);
+
   int tid = current->tid();
   if (_thread_filter.enabled()) {
     int slot_id = _thread_filter.registerThread();
@@ -115,39 +117,22 @@ void Profiler::onThreadStart(jvmtiEnv *jvmti, JNIEnv *jni, jthread thread) {
     _thread_filter.remove(slot_id);  // Remove from filtering initially
   }
   updateThreadName(jvmti, jni, thread, true);
-
-  _cpu_engine->registerThread(tid);
-  _wall_engine->registerThread(tid);
 }
 
 void Profiler::onThreadEnd(jvmtiEnv *jvmti, JNIEnv *jni, jthread thread) {
   ProfiledThread *current = ProfiledThread::current();
-  int tid = -1;
-  
-  if (current != nullptr) {
-    // ProfiledThread is alive - do full cleanup and use efficient tid access
-    int slot_id = current->filterSlotId();
-    tid = current->tid();
+  assert(current != nullptr);
+  // ProfiledThread is alive - do full cleanup and use efficient tid access
+  int slot_id = current->filterSlotId();
+  int tid = current->tid();
     
-    if (_thread_filter.enabled()) {
+  if (_thread_filter.enabled()) {
       _thread_filter.unregisterThread(slot_id);
       current->setFilterSlotId(-1);
-    }
-    
-    ProfiledThread::release();
-  } else {
-    // ProfiledThread already cleaned up - try to get tid from JVMTI as fallback
-    tid = VMThread::nativeThreadId(jni, thread);
-    if (tid < 0) {
-      // No ProfiledThread AND can't get tid from JVMTI - nothing we can do
-      return;
-    }
   }
-  
+
   // These can run if we have a valid tid
   updateThreadName(jvmti, jni, thread, false);  // false = not self
-  _cpu_engine->unregisterThread(tid);
-  _wall_engine->unregisterThread(tid);
 }
 
 int Profiler::registerThread(int tid) {