How about calling select() before accept() with a 5 second timeout. If we get a timeout, clean up and return an error. If we don't get a timeout, there's activity on the socket, so the normal path would handle any issues.
-- Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project -----Original Message----- From: Greg Clayton [mailto:gclay...@apple.com] Sent: Wednesday, June 17, 2015 3:28 PM To: Ted Woodward Cc: lldb-dev@cs.uiuc.edu Subject: Re: [lldb-dev] lldb hangs during reverse-connect if lldb-server dies We should implement a timeout of say 5 seconds (since this is a locally spawned lldb-server) and also watch for the spawned lldb-server process to be reaped. If the lldb-server gets reaped we need to cancel. Don't do any fancy thread canceling (no pthread_cancel or anything like that) if you do fix this, just have something locally connect to the socket and allow the accept thread to exit normally. > On Jun 17, 2015, at 11:32 AM, Ted Woodward <ted.woodw...@codeaurora.org> wrote: > > > With reverse-connect, lldb gets a port from the OS, spawns a listen thread using the port, and launches lldb-server/debugserver, telling it to connect back to lldb. lldb with then join with the listen thread. The listen thread calls accept() to wait for the server to connect back to it. > > On Linux (and possibly other OSes), if lldb-server dies or quits before connecting, lldb will hang. It sits waiting for accept() to return, but it never will. > > If the child dies, the listen thread should be killed, and an error returned to the user. > > > This is easily seen on Linux. Simply point to an alternate debugserver. Set LLDB_DEBUGSERVER_PATH to something else, say /bin/ls. This will finish and never connect back to lldb. > > -> setenv LLDB_DEBUGSERVER_PATH /bin/ls bin/lldb /bin/ls > (lldb) target create "/bin/ls" > Current executable set to '/bin/ls' (x86_64). > (lldb) r > > <hang> > > -- > Qualcomm Innovation Center, Inc. > The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, > a Linux Foundation Collaborative Project > > _______________________________________________ > lldb-dev mailing list > lldb-dev@cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev _______________________________________________ lldb-dev mailing list lldb-dev@cs.uiuc.edu http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev
