I think the thread naming is a reasonable way to go. > 1) Linux and MacOSX inferiors can use pthread_setname_np > 2) FreeBSD inferiors can use pthread_set_name_np
IIRC Linux and FreeBSD both are limited to a very short thread name, much shorter than OS X and, if I'm not mistaken, Windows as well. So we need to not go crazy on thread naming conventions. The code has it, but I think the limit on Linux and FreeBSD was something like 16 characters. On Wed, Sep 2, 2015 at 2:48 PM, Jim Ingham via lldb-dev < lldb-dev@lists.llvm.org> wrote: > > > On Sep 2, 2015, at 1:06 PM, Greg Clayton via lldb-dev < > lldb-dev@lists.llvm.org> wrote: > > > > One idea is add the ability to discover which of any of the current > threads are or are not user created. This might help us. > > > > On MacOSX, the main thread would always be considered user created, and > any other thread, it is quite easy to tell. User created threads could be > ones whose bottom stack frame is "thread_start" > > > > .... > > frame #8: 0x00007fff9b47c41d libsystem_pthread.dylib thread_start + 13 > > > > Where OS created threads have their last frames in "start_wqthread" or > "_dispatch_mgr_thread": > > > > ... > > frame #2: 0x00007fff9b47c40d libsystem_pthread.dylib start_wqthread + > 13 > > > > or: > > > > ... > > frame #2: 0x00007fff9c298a6a libdispatch.dylib _dispatch_mgr_thread + > 52 > > > > > > So it might be easy to add API to SBThread like: > > > > bool > > SBThread::IsUserCreated(); > > > > Then we could teach the tests to filter out any threads that are not > user created? > > I'm not sure on OS X this is a terribly useful distinction. There are > lots of threads that are created to run user code through the dispatch > library. They won't start with "thread_start" but I don't think most users > would think of them as "not user threads..." > > Jim > > > > > > Greg > > > > > >> On Sep 2, 2015, at 12:31 PM, Zachary Turner via lldb-dev < > lldb-dev@lists.llvm.org> wrote: > >> > >> Historically the pattern for tests that need to test situations > involving threads has been to write the tests using pthreads, and then a > common pattern on the python side of the test is to assert that the actual > number of threads equals the expected number of threads. > >> > >> To deal with the pthread portability issue, I ported most of these > tests over to std::threads, but there is still another issue with them. > >> > >> On Windows we can't assume anything about the number of threads in a > program. For example, a single-threaded hello world program actually has 3 > threads, 2 of which are reserved for use by the operating system. And the > fact that there's 2 is just arbitrary, that might not remain the same > between compiler versions, operating system versions, etc. And to make > matters worse it might not even remain constant through the life of the > program (the assumption just being that we cannot make any assumptions, > since we don't control the threads). > >> > >> So I need to find a way to write these tests portably. > >> > >> Do all platforms have a way to assign a thread a name? Looking in > Host/*/ThisThread.cpp, it seems: > >> > >> 1) Linux and MacOSX inferiors can use pthread_setname_np > >> 2) FreeBSD inferiors can use pthread_set_name_np > >> 3) Windows inferiors can raise a magic exception which the debugger is > expected to recognize > >> > >> Based on this, it seems that one possible way to write these tests > portably is to have the test inferiors assign names to the threads, and > have the tests index the threads by name instead of by ordinal. > >> > >> Does anyone have any thoughts on this or other possible approaches? > >> > >> I really would like to avoid having different inferiors or different > tests for all of this functionality, as it will be very easy to get out of > sync. > >> _______________________________________________ > >> lldb-dev mailing list > >> lldb-dev@lists.llvm.org > >> http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-dev > > > > _______________________________________________ > > lldb-dev mailing list > > lldb-dev@lists.llvm.org > > http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-dev > > _______________________________________________ > lldb-dev mailing list > lldb-dev@lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-dev > -- -Todd
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