From 087def8ca3493b69fe1353f20abeecaa0b3205e0 Mon Sep 17 00:00:00 2001
From: Richard Fuchs <rfuchs@sipwise.com>
Date: Tue, 18 Feb 2025 13:25:58 -0400
Subject: [PATCH] MT#62181 use std::thread instead of pthread

Change-Id: I9276d41f596c7216a2b0023302deeedb029626a5
---
 core/AmThread.cpp | 66 +++++++++++++++++++++--------------------------
 core/AmThread.h   |  7 ++---
 2 files changed, 33 insertions(+), 40 deletions(-)

diff --git a/core/AmThread.cpp b/core/AmThread.cpp
index 648660bb..9e2ed3a9 100644
--- a/core/AmThread.cpp
+++ b/core/AmThread.cpp
@@ -33,31 +33,27 @@
 #include <string>
 using std::string;
 
+#include <system_error>
+#include <exception>
+
 AmThread::AmThread()
   : _stopped(true)
 {
 }
 
-void * AmThread::_start(void * _t)
+void AmThread::_start()
 {
-  AmThread* _this = (AmThread*)_t;
-  _this->_pid = (unsigned long) _this->_td;
-  DBG("Thread %lu is starting.\n", (unsigned long) _this->_pid);
-  _this->run();
+  _pid = static_cast<unsigned long>(_td.native_handle());
+  DBG("Thread %lu is starting.\n", _pid);
+  run();
 
-  DBG("Thread %lu is ending.\n", (unsigned long) _this->_pid);
-  _this->_stopped = true;
+  DBG("Thread %lu is ending.\n", _pid);
+  _stopped = true;
     
-  return NULL;
 }
 
 void AmThread::start()
 {
-  pthread_attr_t attr;
-  pthread_attr_init(&attr);
-  pthread_attr_setstacksize(&attr,1024*1024);// 1 MB
-
-  int res;
   _pid = 0;
 
   // unless placed here, a call seq like run(); join(); will not wait to join
@@ -68,12 +64,7 @@ void AmThread::start()
     return;
   }
 
-  res = pthread_create(&_td,&attr,_start,this);
-  pthread_attr_destroy(&attr);
-  if (res != 0) {
-    ERROR("pthread create failed with code %i\n", res);
-    throw string("thread could not be started");
-  }	
+  _td = std::thread(&AmThread::_start, this);
   //DBG("Thread %lu is just created.\n", (unsigned long int) _pid);
 }
 
@@ -86,23 +77,24 @@ void AmThread::stop()
   }
 
   // gives the thread a chance to clean up
-  DBG("Thread %lu (%lu) calling on_stop, give it a chance to clean up.\n", 
-      (unsigned long int) _pid, (unsigned long int) _td);
+  DBG("Thread %lu calling on_stop, give it a chance to clean up.\n", _pid);
 
   try { on_stop(); } catch(...) {}
 
-  int res;
-  if ((res = pthread_detach(_td)) != 0) {
-    if (res == EINVAL) {
-      WARN("pthread_detach failed with code EINVAL: thread already in detached state.\n");
-    } else if (res == ESRCH) {
-      WARN("pthread_detach failed with code ESRCH: thread could not be found.\n");
-    } else {
-      WARN("pthread_detach failed with code %i\n", res);
-    }
+  try {
+    _td.detach();
+  }
+  catch (std::system_error &e) {
+    WARN("Failed to detach thread: code %d (%s)\n", e.code().value(), e.what());
+  }
+  catch (std::exception &e) {
+    WARN("Failed to detach thread: %s\n", e.what());
+  }
+  catch (...) {
+    WARN("Failed to detach thread: unknown error\n");
   }
 
-  DBG("Thread %lu (%lu) finished detach.\n", (unsigned long int) _pid, (unsigned long int) _td);
+  DBG("Thread %lu finished detach.\n", _pid);
 
   //pthread_cancel(_td);
 }
@@ -110,7 +102,7 @@ void AmThread::stop()
 void AmThread::join()
 {
   if(!is_stopped())
-    pthread_join(_td,NULL);
+    _td.join();
 }
 
 
@@ -136,12 +128,12 @@ AmThreadWatcher* AmThreadWatcher::instance()
 
 void AmThreadWatcher::add(AmThread* t)
 {
-  DBG("trying to add thread %lu to thread watcher.\n", (unsigned long int) t->_pid);
+  DBG("trying to add thread %lu to thread watcher.\n", t->_pid);
   q_mut.lock();
   thread_queue.push(t);
   _run_cond.set(true);
   q_mut.unlock();
-  DBG("added thread %lu to thread watcher.\n", (unsigned long int) t->_pid);
+  DBG("added thread %lu to thread watcher.\n", t->_pid);
 }
 
 void AmThreadWatcher::on_stop()
@@ -169,13 +161,13 @@ void AmThreadWatcher::run()
 	thread_queue.pop();
 
 	q_mut.unlock();
-	DBG("thread %lu is to be processed in thread watcher.\n", (unsigned long int) cur_thread->_pid);
+	DBG("thread %lu is to be processed in thread watcher.\n", cur_thread->_pid);
 	if(cur_thread->is_stopped()){
-	  DBG("thread %lu has been destroyed.\n", (unsigned long int) cur_thread->_pid);
+	  DBG("thread %lu has been destroyed.\n", cur_thread->_pid);
 	  delete cur_thread;
 	}
 	else {
-	  DBG("thread %lu still running.\n", (unsigned long int) cur_thread->_pid);
+	  DBG("thread %lu still running.\n", cur_thread->_pid);
 	  n_thread_queue.push(cur_thread);
 	}
 
diff --git a/core/AmThread.h b/core/AmThread.h
index 6dc23e51..d8e24bca 100644
--- a/core/AmThread.h
+++ b/core/AmThread.h
@@ -37,6 +37,7 @@
 #include <mutex>
 #include <atomic>
 #include <condition_variable>
+#include <thread>
 
 using std::lock_guard;
 using std::atomic_bool;
@@ -107,16 +108,16 @@ public:
 };
 
 /**
- * \brief C++ Wrapper class for pthread
+ * \brief Wrapper class for std::thread
  */
 class AmThread
 {
-  pthread_t _td;
+  std::thread _td;
   AmMutex   _m_td;
 
   atomic_bool _stopped;
 
-  static void* _start(void*);
+  void _start();
 
 protected:
   virtual void run()=0;