Small memory leak

[Thomas-Sparber]

First of all: thank you so much for this great piece of software!

I found a small memory leak in the stl version of your library, it is in line 233:

this->threads[i].reset(new std::thread(f));

As you can see, a new thread is created with new but it is never deleted. Valgrind gives me the following message:

==5111== 1,216 bytes in 4 blocks are possibly lost in loss record 1,514 of 1,551
==5111== at 0x4C31B25: calloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==5111== by 0x40134A6: allocate_dtv (dl-tls.c:286)
==5111== by 0x40134A6: _dl_allocate_tls (dl-tls.c:530)
==5111== by 0x5293227: allocate_stack (allocatestack.c:627)
==5111== by 0x5293227: pthread_create@@GLIBC_2.2.5 (pthread_create.c:644)
==5111== by 0x5AD4A18: std::thread::_M_start_thread(std::unique_ptr<std::thread::_State, std::default_deletestd::thread::_State >, void (*)()) (in /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.25)
==5111== by 0x255CB8: std::thread::threadctpl::thread_pool::set_thread(int)::{lambda()#1}&(ctpl::thread_pool::set_thread(int)::{lambda()#1}&) (thread:126)
==5111== by 0x253E17: ctpl::thread_pool::set_thread(int) (ctpl_stl.h:233)
==5111== by 0x2536C5: ctpl::thread_pool::resize(int) (ctpl_stl.h:102)
==5111== by 0x25349A: ctpl::thread_pool::thread_pool(int) (ctpl_stl.h:76)

I don't think that this error is very important and should be fixed ASAP, but I just wanted to let you know :-)

[s7726]

Looking further into this. The reset function of unique_ptr is passed the new object, according to the documentation it then takes over and handles the delete when appropriate.
Can you please post more info on the example you ran through valgrind?

[sigmasoldi3r]

@Thomas-Sparber Shouldn't the unique_ptr destroy the object? 🤔 Although valgrind is complaining... hmmm
https://en.cppreference.com/w/cpp/memory/unique_ptr/reset

If the old pointer was non-empty, deletes the previously managed object if(old_ptr) get_deleter()(old_ptr).

They say that 😮