c++ - Threads disappeared on DLL ExitInstance -

i have windows dll functions initinstance , exitinstance. dll creates threads, worker threads _beginthreadex , threads message queue, derived cwinthread (mfc).

the dll should useable application.

i wrote small host application dll test , worked fine, except when close host application without calling freelibrary before. in case, exitinstance called well, threads disappeard, quite unusual , leads deadlock routines waiting thread finished not exist longer - finished or killed. need go way (skip call freelibrary) in order simulate hapen when other applications use dll.

exitinstance called, threads still running disappeared - because dll handled somehow differently when unloaded host process if not call freelibrary before.

they disappear silently, instance, if thread implements loop waitforsingleobject within loop, thread not finish normally.

thread() {     while(running == true)     {         waitforsingleobject(...);     }     threadfinished=true; /// 1 } 

if calling freelibrary before closing application, code section 1 called. when closing application without calling freelibrary before, code section 1 never called loop not running longer thread removed.

how should handle situation ? thank you

the documentation cwinthread::exitinstance clear: "do not call member function anywhere within run member function." (i.e. cwinthread::run, thread itself).

obviously, means windows not going call exitinstance you. nor host application, since has no idea threads.

what is called dllmain, once , argument dll_process_detach. won't dll_thread_detach because happens after threads exit cleanly (i.e. exitinstance or returning cwinthread::run).

by way, consider code threads running after dll has been unloaded. can't functions or mfc, since functions no longer exists. thread crash access violation because instruction pointer points unallocated memory.