From mboxrd@z Thu Jan 1 00:00:00 1970 From: jtc@redback.com (J.T. Conklin) To: Fernando Nasser Cc: Andrew Cagney , GDB Discussion Subject: Re: gdb/remote - I/O Date: Fri, 06 Apr 2001 12:56:00 -0000 Message-id: <5md7apvm4c.fsf@jtc.redback.com> References: <3ABBDDE4.7C22709D@cygnus.com> <3ACE0AD6.913C9A94@cygnus.com> <3ACE0E6B.CF3C9A2B@redhat.com> X-SW-Source: 2001-04/msg00057.html >>>>> "Fernando" == Fernando Nasser writes: Fernando> We do have two different kinds of output coming from the Fernando> target: output produced by the os/monitor/stub or whatever Fernando> we are talking to and the output from the application Fernando> (little bit of semi-hosting). Fernando> Fernando> Fortunately for us, they happen at different times. When Fernando> the program is running (after run or step) the output can be Fernando> assumed to be from the program and should go to gdb_stdtarg. Fernando> When the program is not running the output can only be from Fernando> the controlling software, and we can send it to gdb_stdout. I've been thinking about the proposed changes to the remote protocol since they were first brought up. I've been trying to come to terms with an issue myself before I put it up for discussion in a coherent manner, but since I'm not making much progress on my own I thought I'd better better share what I've got. Question: Does the remote protocol support systems where other threads continue to execute when one being debugged is halted. This is a hard question to answer, since the existing implementation of both GDB and the debug agents (stubs, gdbserver, and I suppose libremote (although I've never seen it)) assume the target completely stops. But does the protocol itself allow this? From what I can tell, it can. If it does not, it almost does --- especially when you consider how loosely some of the commands are defined. The proposals wrt. I/O seem to require the target to halt for I/O, which precludes enhancing GDB and the debug agents to take full advantage of the remote protocol. I ask whether or not this is desirable? --jtc -- J.T. Conklin RedBack Networks