fixed: clang address sanitizer reports that there is an use after free bug at the end when winix shuts down:

==3859==ERROR: AddressSanitizer: heap-use-after-free on address 0x61b0000053e0 at pc 0x000800697160 bp 0x7fffffffcfb0 sp 0x7fffffffcfa8
READ of size 8 at 0x61b0000053e0 thread T0
    #0 0x80069715f in PT::MemBuffer<wchar_t, 256ul, 4096ul>::empty() const /usr/home/tomek/roboczy/prog/web.ttmath.org/../pikotools/membuffer/membuffer.h:675:9
    #1 0x80069700d in PT::TextStreamBase<wchar_t, 256ul, 4096ul>::empty() const /usr/home/tomek/roboczy/prog/web.ttmath.org/../pikotools/textstream/textstream.h:161:16
    #2 0x8009af0e3 in PT::FileLog::save_log(PT::TextStreamBase<wchar_t, 256ul, 4096ul>*) /usr/home/tomek/roboczy/prog/pikotools/log/filelog.cpp:105:14
    #3 0x8009b3f8a in PT::Log::save_log() /usr/home/tomek/roboczy/prog/pikotools/log/log.cpp:461:13
    #4 0x8009b3d72 in PT::Log::save_log_and_clear() /usr/home/tomek/roboczy/prog/pikotools/log/log.cpp:448:2
    #5 0x8009b0627 in PT::Log::~Log() /usr/home/tomek/roboczy/prog/pikotools/log/log.cpp:62:2
    #6 0x8007288e7 in Winix::Log::~Log() /usr/home/tomek/roboczy/prog/winix/winixd/core/log.cpp:56:1
    #7 0x8007eac96 in Winix::WinixBase::~WinixBase() /usr/home/tomek/roboczy/prog/winix/winixd/core/winixbase.cpp:51:1
    #8 0x8007eb097 in Winix::WinixModel::~WinixModel() /usr/home/tomek/roboczy/prog/winix/winixd/core/winixmodel.cpp:52:1
    #9 0x80069e552 in Winix::BaseThread::~BaseThread() /usr/home/tomek/roboczy/prog/winix/winixd/core/basethread.cpp:54:1
    #10 0x2f8132 in Winix::Job::~Job() /usr/home/tomek/roboczy/prog/web.ttmath.org/../winix/winixd/core/job.h:54:7
    #11 0x2e0c8a in Winix::System::~System() /usr/home/tomek/roboczy/prog/web.ttmath.org/../winix/winixd/core/system.h:67:7
    #12 0x2df017 in Winix::App::~App() /usr/home/tomek/roboczy/prog/web.ttmath.org/../winix/winixd/core/app.h:70:7
    #13 0x800cc9f50 in __cxa_finalize /hddraidzfs/usr/src/lib/libc/stdlib/atexit.c:238:5
    #14 0x800c5ef10 in exit /hddraidzfs/usr/src/lib/libc/stdlib/exit.c:74:2
    #15 0x25c935 in _start /hddraidzfs/usr/src/lib/csu/amd64/crt1.c:76:2

0x61b0000053e0 is located 1632 bytes inside of 1656-byte region [0x61b000004d80,0x61b0000053f8)
freed by thread T0 here:
    #0 0x2dc07d in operator delete(void*) /hddraidzfs/usr/src/contrib/llvm-project/compiler-rt/lib/asan/asan_new_delete.cpp:160:3
    #1 0x8007c3b2c in Winix::ThreadManager::StopAll() /usr/home/tomek/roboczy/prog/winix/winixd/core/threadmanager.cpp:189:3
    #2 0x800647474 in Winix::App::WaitForThreads() /usr/home/tomek/roboczy/prog/winix/winixd/core/app.cpp:2122:24
    #3 0x800647311 in Winix::App::Close() /usr/home/tomek/roboczy/prog/winix/winixd/core/app.cpp:340:2
    #4 0x2dec7c in main /usr/home/tomek/roboczy/prog/winix/winixd/main/main.cpp:224:6
    #5 0x25c92e in _start /hddraidzfs/usr/src/lib/csu/amd64/crt1.c:76:7
    #6 0x80033efff  (<unknown module>)

previously allocated by thread T0 here:
    #0 0x2db81d in operator new(unsigned long) /hddraidzfs/usr/src/contrib/llvm-project/compiler-rt/lib/asan/asan_new_delete.cpp:99:3
    #1 0x8007c17c3 in Winix::ThreadManager::Add(Winix::BaseThread*, wchar_t const*) /usr/home/tomek/roboczy/prog/winix/winixd/core/threadmanager.cpp:77:26
    #2 0x8007b0b81 in Winix::System::Init() /usr/home/tomek/roboczy/prog/winix/winixd/core/system.cpp:170:17
    #3 0x8006468d4 in Winix::App::Init() /usr/home/tomek/roboczy/prog/winix/winixd/core/app.cpp:295:9
    #4 0x2deb7e in main /usr/home/tomek/roboczy/prog/winix/winixd/main/main.cpp:206:11
    #5 0x25c92e in _start /hddraidzfs/usr/src/lib/csu/amd64/crt1.c:76:7
    #6 0x80033efff  (<unknown module>)

in ThreadManager::StopAll() there is item.thread_item_data pointer which was freed (the pointer was pointing to an object with a log_buffer)
but internal Log buffer from item.object was pointing to that object and when thread_tab.clear() was called then the d-ctor was called
and then save_log_and_clear() method was called and tried to use the freed object.

winixd/core/basethread.cpp

@@ -254,6 +254,7 @@ void * BaseThread::StartRoutine(void * this_object)
 		}
 	}
 
+	base->save_log();
 	pthread_exit(0);
 	return 0;
 }

winixd/core/threadmanager.cpp

@@ -186,6 +186,10 @@ void ThreadManager::StopAll()
 		item.object->WaitForThread();
 		log << log4 << "TM: thread " << id << " terminated" << logend;
 
+		// the thread is stopped and we can set the thread log buffer pointing to
+		// the main log buffer (from the main thread)
+		item.object->set_log_buffer(log.GetLogBuffer());
+
 		delete item.thread_item_data;
 		id += 1;
 	}

winixd/core/winixbase.cpp

@@ -5,7 +5,7 @@
  */
 
 /*
- * Copyright (c) 2018, Tomasz Sowa
+ * Copyright (c) 2018-2021, Tomasz Sowa
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -90,6 +90,13 @@ void WinixBase::set_dependency(WinixBase * winix_base)
 
 
 
+void WinixBase::save_log()
+{
+	log << logsave;
+}
+
+
+
 }
 
 

winixd/core/winixbase.h

@@ -5,7 +5,7 @@
  */
 
 /*
- * Copyright (c) 2018, Tomasz Sowa
+ * Copyright (c) 2018-2021, Tomasz Sowa
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -65,6 +65,8 @@ public:
 
 	void set_dependency(WinixBase * winix_base);
 
+	void save_log();
+
 
 protected: