On 5/19/21 3:37 PM, Bernd Edlinger wrote: > On 5/19/21 3:27 PM, Jonathan Wakely wrote: >> On 18/05/21 13:58 +0200, Bernd Edlinger wrote: >>> On 5/18/21 1:55 PM, Bernd Edlinger wrote: >>>> On 5/17/21 7:13 PM, Jonathan Wakely via Gcc-patches wrote: >>>>> libstdc++-v3/ChangeLog: >>>>> >>>>> * include/std/thread (jthread::_S_create): Fix static assert >>>>> message. >>>>> * testsuite/30_threads/jthread/95989.cc: Re-enable test. >>>>> * testsuite/30_threads/jthread/jthread.cc: Do not require >>>>> pthread effective target. >>>>> * testsuite/30_threads/jthread/2.cc: Moved to... >>>>> * testsuite/30_threads/jthread/version.cc: ...here. >>>>> >>>>> Tested powerpc64le-linux. Committed to trunk. >>>>> >>>>> Let's see if this test is actually fixed, or if it still causes >>>>> failures on some targets. >>>>> >>>>> >>>> >>>> Yes, indeed it is failing on x86_64-pc-linux-gnu. >>>> >>> >>> that means only this one: >>> >>> FAIL: 30_threads/jthread/95989.cc execution test >> >> What's your glibc version? >> >> > > that is ubuntu 20.04 with latest patches: > > $ ldd --version > ldd (Ubuntu GLIBC 2.31-0ubuntu9.3) 2.31 > Copyright (C) 2020 Free Software Foundation, Inc. > This is free software; see the source for copying conditions. There is NO > warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. > Written by Roland McGrath and Ulrich Drepper. >
The glibc version is probably not the reason, I've got the same effect with Ubuntu EGLIBC 2.19-0ubuntu6.15 as well. But I use binutils-2.36.1. I think the problem is here: libstdc++-v3/src/c++11/thread.cc: __e = __gthread_join(_M_id._M_thread, 0); which calls libgcc/gthr-posix.h: return __gthrw_(pthread_join) (__threadid, __value_ptr); but this is only a weak reference to pthread_join: 669 return __gthrw_(pthread_join) (__threadid, __value_ptr); (gdb) disass Dump of assembler code for function std::thread::join(): 0x0000000000405e20 <+0>: endbr64 0x0000000000405e24 <+4>: push %rbx 0x0000000000405e25 <+5>: mov %rdi,%rbx 0x0000000000405e28 <+8>: mov (%rdi),%rdi 0x0000000000405e2b <+11>: test %rdi,%rdi 0x0000000000405e2e <+14>: je 0x405e44 <std::thread::join()+36> => 0x0000000000405e30 <+16>: xor %esi,%esi 0x0000000000405e32 <+18>: callq 0x0 0x0000000000405e37 <+23>: test %eax,%eax 0x0000000000405e39 <+25>: jne 0x405e49 <std::thread::join()+41> 0x0000000000405e3b <+27>: movq $0x0,(%rbx) 0x0000000000405e42 <+34>: pop %rbx 0x0000000000405e43 <+35>: retq 0x0000000000405e44 <+36>: mov $0x16,%eax 0x0000000000405e49 <+41>: mov %eax,%edi 0x0000000000405e4b <+43>: callq 0x4012a9 <std::__throw_system_error(int)> End of assembler dump. but the pthread_join symbol is not checked for potentially being null. The test case passes if I change this: diff --git a/libstdc++-v3/testsuite/30_threads/jthread/95989.cc b/libstdc++-v3/testsuite/30_threads/jthread/95989.cc index fb3f43bc722..61a3ff76aa1 100644 --- a/libstdc++-v3/testsuite/30_threads/jthread/95989.cc +++ b/libstdc++-v3/testsuite/30_threads/jthread/95989.cc @@ -52,4 +52,5 @@ main() test01(); test02(); test03(); + pthread_join(NULL, NULL); } Thanks Bernd.
