Compared Signal handling between LinuxThread and NPTL

Versions:
$ getconf GNU_LIBPTHREAD_VERSION
linuxthreads-0.10
$getconf GNU_LIBPTHREAD_VERSION
NPTL 2.5

The main program will starts up 5 threads, and we use the USR1 Signal:
Signal                   Linux Thread                               NPTL
 ------------------------------------------------------------------------------------------------------------
non-block             6 threads captured, exit            only main thread
                                                                             get 1, not exit
 ------------------------------------------------------------------------------------------------------------
block main           no                                                no
 ------------------------------------------------------------------------------------------------------------
block main+         one kill, everyone gets/exit        round-robin until
unblock threads                                                       last one get then exit
------------------------------------------------------------------------------------------------------------
block child+         main, multiple kill, no exit           main, multiple kill
unblock main                                                            , no exit
------------------------------------------------------------------------------------------------------------
pthread_kill          as expected                                 as expected
to each other