Reapply r184270 by Jim Ingham to avoid abort on FreeBSD
Reapply r184270 by Jim Ingham to avoid abort on FreeBSD

  Don't actually Halt in the Interrupt handler for the Process, just
  send an AsyncInterrupt.  That's actually not async-signal-clean, but
  it is a lot safer than Halt...

The underlying problem is actually a nested pthread_cond_wait from the
signal handler.  Note frames 4, 13, 18 in the backtrace of the aborting
path below.

    frame #1: 0x000000080715fff9 libc.so.7`abort + 73 at abort.c:65
    frame #2: 0x0000000805d20fda libthr.so.3`_thread_exit(fname=<unavailable>, lineno=<unavailable>, msg=<unavailable>) + 58 at thr_exit.c:182
    frame #3: 0x0000000805d1fdc8 libthr.so.3`cond_wait_common [inlined] cond_wait_user(mp=<unavailable>, abstime=<unavailable>, cancel=<unavailable>) + 936 at thr_cond.c:223
    frame #4: 0x0000000805d1fd5b libthr.so.3`cond_wait_common(cond=<unavailable>, mutex=<unavailable>, abstime=<unavailable>, cancel=<unavailable>) + 827 at thr_cond.c:311
    frame #5: 0x00000008013450b5 liblldb.so.3.5`lldb_private::Condition::Wait(lldb_private::Mutex&, lldb_private::TimeValue const*, bool*) + 117
    frame #6: 0x00000008013411e8 liblldb.so.3.5`lldb_private::Predicate<bool>::WaitForValueEqualTo(bool, lldb_private::TimeValue const*, bool*) + 200
    frame #7: 0x00000008013eb34c liblldb.so.3.5`lldb_private::Listener::WaitForEventsInternal(lldb_private::TimeValue const*, lldb_private::Broadcaster*, lldb_private::ConstString const*, unsigned int, unsigned int, std::__1::shared_ptr<lldb_private::Event>&) + 876
    frame #8: 0x00000008013eb751 liblldb.so.3.5`lldb_private::Listener::WaitForEvent(lldb_private::TimeValue const*, std::__1::shared_ptr<lldb_private::Event>&) + 81
    frame #9: 0x00000008017c5bcf liblldb.so.3.5`lldb_private::Process::Halt(bool) + 783
    frame #10: 0x00000008017def3a liblldb.so.3.5`IOHandlerProcessSTDIO::Interrupt() + 74
    frame #11: 0x00000008013823d3 liblldb.so.3.5`lldb_private::Debugger::DispatchInputInterrupt() + 115
    frame #12: 0x00000008011d69c5 liblldb.so.3.5`lldb::SBDebugger::DispatchInputInterrupt() + 69
    frame #13: 0x000000000040b254 lldb`sigint_handler(int) + 68
    frame #14: 0x0000000805d1b3da libthr.so.3`handle_signal(actp=<unavailable>, sig=<unavailable>, info=<unavailable>, ucp=<unavailable>) + 234 at thr_sig.c:240
    frame #15: 0x0000000805d1afc2 libthr.so.3`thr_sighandler(sig=<unavailable>, info=<unavailable>, _ucp=<unavailable>) + 306 at thr_sig.c:183
    frame #16: 0x00007ffffffff003
    frame #17: 0x0000000805d1fc7e libthr.so.3`cond_wait_common [inlined] cond_wait_user(mp=<unavailable>, abstime=<unavailable>, cancel=1) + 239 at thr_cond.c:255
    frame #18: 0x0000000805d1fb8f libthr.so.3`cond_wait_common(cond=<unavailable>, mutex=<unavailable>, abstime=0x0000000000000000, cancel=1) + 367 at thr_cond.c:311
    frame #19: 0x00000008013450d2 liblldb.so.3.5`lldb_private::Condition::Wait(lldb_private::Mutex&, lldb_private::TimeValue const*, bool*) + 146


git-svn-id: 4c4cc70b1ef44ba2b7963015e681894188cea27e@202154 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-lldb,llvm-mirror/lldb,llvm-mirror/lldb,apple/swift-lldb,llvm-mirror/lldb,apple/swift-lldb,llvm-mirror/lldb,apple/swift-lldb,apple/swift-lldb,apple/swift-lldb,llvm-mirror/lldb