DHAT hangs

[little-dude]

Hello,

I'm having a similar issue to #25 where my program, when running with the dhat allocator hangs.

This seems related to backtrace collection:

(lldb) thread b 2
  thread #2, name = 'test_bgp_origin'
    frame #0: 0x000055555585d6dc dhat_bgp_originate-f82b65681502d053`mintex::Mutex$LT$T$GT$::lock::h72ad4838d4d3a11d(self=0x0000555556bb0330) at lib.rs:65:19
    frame #1: 0x000055555583e02b dhat_bgp_originate-f82b65681502d053`_$LT$dhat..Alloc$u20$as$u20$core..alloc..global..GlobalAlloc$GT$::realloc::h09bd1dadf21796a0(self=0x000055555672a2ab, old_ptr="\U00000001", layout=Layout @ 0x00007ffff7cc81e8, new_size=3584) at lib.rs:1251:51
    frame #2: 0x0000555555819683 dhat_bgp_originate-f82b65681502d053`__rust_realloc(arg0="\U00000001", arg1=1792, arg2=8, arg3=3584) at dhat_bgp_originate.rs:40:15
    frame #3: 0x000055555666a29a dhat_bgp_originate-f82b65681502d053`alloc::alloc::Global::grow_impl::hd18a19f867acb51a [inlined] alloc::alloc::realloc::h964c149612511afa(ptr="\U00000001", layout=Layout @ 0x00007ffff7cc8518, new_size=3584) at alloc.rs:140:14
    frame #4: 0x000055555666a24c dhat_bgp_originate-f82b65681502d053`alloc::alloc::Global::grow_impl::hd18a19f867acb51a(self=0x00007ffff7cc9158, ptr=(pointer = "\U00000001"), old_layout=Layout @ 0x00007ffff7cc84e8, new_layout=Layout @ 0x00007ffff7cc84f8, zeroed=false) at alloc.rs:217:31
    frame #5: 0x000055555666a6b0 dhat_bgp_originate-f82b65681502d053`_$LT$alloc..alloc..Global$u20$as$u20$core..alloc..Allocator$GT$::grow::h6ca616e266c3d9bf(self=0x00007ffff7cc9158, ptr=(pointer = "\U00000001"), old_layout=Layout @ 0x00007ffff7cc8718, new_layout=Layout @ 0x00007ffff7cc8728) at alloc.rs:270:18
    frame #6: 0x0000555556669522 dhat_bgp_originate-f82b65681502d053`alloc::raw_vec::finish_grow::h91c9a9cb3a8d6648(new_layout=Result<core::alloc::layout::Layout, core::alloc::layout::LayoutError> @ 0x00007ffff7cc8858, current_memory=Option<(core::ptr::non_null::NonNull<u8>, core::alloc::layout::Layout)> @ 0x00007ffff7cc8a00, alloc=0x00007ffff7cc9158) at raw_vec.rs:472:13
    frame #7: 0x00005555565d2a29 dhat_bgp_originate-f82b65681502d053`alloc::raw_vec::RawVec$LT$T$C$A$GT$::grow_amortized::ha3a5dbf65c921676(self=0x00007ffff7cc9158, len=32, additional=1) at raw_vec.rs:404:19
    frame #8: 0x00005555565d3199 dhat_bgp_originate-f82b65681502d053`alloc::raw_vec::RawVec$LT$T$C$A$GT$::reserve_for_push::hb8093cccd384d669(self=0x00007ffff7cc9158, len=32) at raw_vec.rs:302:24
    frame #9: 0x00005555565d38ee dhat_bgp_originate-f82b65681502d053`alloc::vec::Vec$LT$T$C$A$GT$::push::h4ef4cacd71132877(self=0x00007ffff7cc9158, value=BacktraceFrame @ 0x00007ffff7cc8c60) at mod.rs:1828:13
    frame #10: 0x00005555565cc1da dhat_bgp_originate-f82b65681502d053`anyhow::backtrace::capture::Backtrace::create::_$u7b$$u7b$closure$u7d$$u7d$::h1d20a3049ba382a1(frame=0x00007ffff7cc8d40) at backtrace.rs:217:17
    frame #11: 0x00005555565f0943 dhat_bgp_originate-f82b65681502d053`core::ops::function::impls::_$LT$impl$u20$core..ops..function..FnMut$LT$A$GT$$u20$for$u20$$RF$mut$u20$F$GT$::call_mut::hd906021a43fd6b3a(self=0x00007ffff7cc9098, args=(&backtrace::backtrace::Frame) @ 0x00007ffff7cc8d08) at function.rs:294:13
    frame #12: 0x000055555660fb70 dhat_bgp_originate-f82b65681502d053`backtrace::backtrace::libunwind::trace::trace_fn::h2d05dcca6e0b2934(ctx=0x00007ffff7cc8dd0, arg=0x00007ffff7cc9098) at libunwind.rs:105:26
    frame #13: 0x00007ffff7fa6664 libgcc_s.so.1`_Unwind_Backtrace + 212
    frame #14: 0x00005555565ca50a dhat_bgp_originate-f82b65681502d053`backtrace::backtrace::trace_unsynchronized::hc4aaf54ef431d84c [inlined] backtrace::backtrace::libunwind::trace::h4252170f1a5aeec7(cb=&mut dyn core::ops::function::FnMut<(&backtrace::backtrace::Frame), Output=bool> @ 0x00007ffff7cc9098) at libunwind.rs:93:5
    frame #15: 0x00005555565ca4f5 dhat_bgp_originate-f82b65681502d053`backtrace::backtrace::trace_unsynchronized::hc4aaf54ef431d84c(cb=<unavailable>) at mod.rs:66:5
    frame #16: 0x00005555565ca5b2 dhat_bgp_originate-f82b65681502d053`backtrace::backtrace::trace::h83cd1b0fb300834b(cb={closure_env#0} @ 0x00007ffff7cc9180) at mod.rs:53:14
    frame #17: 0x00005555565cbf9e dhat_bgp_originate-f82b65681502d053`anyhow::backtrace::capture::Backtrace::create::h4febc7bf8250ab2a(ip=93825009499872) at backtrace.rs:216:13
    frame #18: 0x00005555565cbf24 dhat_bgp_originate-f82b65681502d053`anyhow::backtrace::capture::Backtrace::capture::heffd32e41bc285a0 at backtrace.rs:204:17
    frame #19: 0x000055555655e85f dhat_bgp_originate-f82b65681502d053`anyhow::private::new_adhoc::hb6e92295a89bc5aa(message=(data_ptr = "no event in sys channel", length = 23)) at lib.rs:632:36
[snip]

The other thread:

(lldb) thread b 3
  thread #3, name = 'flockd mock'
    frame #0: 0x00007ffff7dd0539 libc.so.6`syscall + 25
    frame #1: 0x0000555555706e84 dhat_bgp_originate-f82b65681502d053`std::sys::unix::locks::futex_mutex::Mutex::lock_contended::hbeb97827cd69d2db [inlined] std::sys::unix::futex::futex_wait::h3942933e6d137880 at futex.rs:62:21
    frame #2: 0x0000555555706e40 dhat_bgp_originate-f82b65681502d053`std::sys::unix::locks::futex_mutex::Mutex::lock_contended::hbeb97827cd69d2db at futex_mutex.rs:56:13
    frame #3: 0x000055555663759b dhat_bgp_originate-f82b65681502d053`std::sys::unix::locks::futex_mutex::Mutex::lock::h017642c2a4c9b3f7(self=0x00007ffff0000d30) at futex_mutex.rs:28:13
    frame #4: 0x00005555565e9365 dhat_bgp_originate-f82b65681502d053`std::sync::mutex::Mutex$LT$T$GT$::lock::haed0e33a58df9efe(self=0x00007ffff0000d30) at mutex.rs:273:13
    frame #5: 0x000055555663b1b8 dhat_bgp_originate-f82b65681502d053`backtrace::lock::lock::hfe5d8a30ad1f16b6 at lib.rs:185:28
    frame #6: 0x00005555558465dc dhat_bgp_originate-f82b65681502d053`backtrace::backtrace::trace::hb176e61194442b59(cb=<unavailable>) at mod.rs:52:18
    frame #7: 0x000055555583d776 dhat_bgp_originate-f82b65681502d053`dhat::new_backtrace_inner::h6d115f8baa267306(trim_backtraces=Option<usize> @ 0x00007ffff7ab6d70, frames_to_trim=0x0000555556bb0418) at lib.rs:1192:5
    frame #8: 0x000055555583de25 dhat_bgp_originate-f82b65681502d053`_$LT$dhat..Alloc$u20$as$u20$core..alloc..global..GlobalAlloc$GT$::alloc::h02222c84985aaf7e(self=0x000055555672a2ab, layout=Layout @ 0x00007ffff7ab6e98) at lib.rs:1235:26
    frame #9: 0x00005555558195b3 dhat_bgp_originate-f82b65681502d053`__rust_alloc(arg0=1120, arg1=8) at dhat_bgp_originate.rs:40:15
    frame #10: 0x000055555647c54e dhat_bgp_originate-f82b65681502d053`alloc::alloc::Global::alloc_impl::hc97dea3396771259 [inlined] alloc::alloc::alloc::hbf20be51a0187697(layout=Layout @ 0x00007ffff7ab70d0) at alloc.rs:102:9
    frame #11: 0x000055555647c4e1 dhat_bgp_originate-f82b65681502d053`alloc::alloc::Global::alloc_impl::hc97dea3396771259(self=0x00007ffff7ab79d8, layout=Layout @ 0x00007ffff7ab7080, zeroed=false) at alloc.rs:185:73
    frame #12: 0x000055555647ce49 dhat_bgp_originate-f82b65681502d053`_$LT$alloc..alloc..Global$u20$as$u20$core..alloc..Allocator$GT$::allocate::h1487027bb14d76e9(self=0x00007ffff7ab79d8, layout=Layout @ 0x00007ffff7ab7268) at alloc.rs:245:9
    frame #13: 0x0000555556482887 dhat_bgp_originate-f82b65681502d053`alloc::raw_vec::finish_grow::h261ffb947d013934(new_layout=Result<core::alloc::layout::Layout, core::alloc::layout::LayoutError> @ 0x00007ffff7ab7398, current_memory=Option<(core::ptr::non_null::NonNull<u8>, core::alloc::layout::Layout)> @ 0x00007ffff7ab7540, alloc=0x00007ffff7ab79d8) at raw_vec.rs:475:9
    frame #14: 0x0000555556012249 dhat_bgp_originate-f82b65681502d053`alloc::raw_vec::RawVec$LT$T$C$A$GT$::grow_amortized::h1b339c7e73182694(self=0x00007ffff7ab79d8, len=0, additional=1) at raw_vec.rs:404:19
    frame #15: 0x0000555556039c69 dhat_bgp_originate-f82b65681502d053`alloc::raw_vec::RawVec$LT$T$C$A$GT$::reserve_for_push::h884425a82cdf927b(self=0x00007ffff7ab79d8, len=0) at raw_vec.rs:302:24
    frame #16: 0x0000555556169f81 dhat_bgp_originate-f82b65681502d053`alloc::collections::vec_deque::VecDeque$LT$T$C$A$GT$::grow::h76670ef032cb9192(self=0x00007ffff7ab79d8) at mod.rs:2061:9
    frame #17: 0x000055555616e36a dhat_bgp_originate-f82b65681502d053`alloc::collections::vec_deque::VecDeque$LT$T$C$A$GT$::push_back::h901b552c9d675eeb(self=0x00007ffff7ab79d8, value=BgpConfEvent @ 0x00007ffff7ab7c28) at mod.rs:1659:13
[snip]

Running with RUST_BACKTRACE=0 fixes the problem.