Debugger startup

[Robert Lunnon]

To implement a Solaris debugger I have traced the wineservers startup and 
there is something I don't understand. I get the following stack trace:

send_thread_signal+0x4a(80aab90, 10)
stop_thread+0x1f(80aab90)
suspend_process+0x4d(81c72a8)
debugger_attach+0xf1(81c72a8, 81d1b58)
req_debug_process+0x4c(81d1c38, 80477a0)
call_req_handler+0x74(81d1b58)
read_request+0x68(81d1b58)
thread_poll_event+0x62(81d22b0, 1)
fd_poll_event+0x14(81d22b0, 1)
main_loop+0x9e(804785c, 8056a51, 1, 8047868, 8047870, 804785c)
main+0xc6(1, 8047868, 8047870)
_start+0x5d(1, 804795c, 0, 8047979, 80479f6, 8047a0a)

bebugger_attach calls suspend_process then stop_thread

stop_thread sends a SIGUSR1 at the thread of interest. The result of this is 
that the thread is terminated and there is nothing to attach to....

Why is this SIGUSR1 sent ?


Bob