From e24a49d86df6a5cdd58f36c65e25911aa30e52d8 Mon Sep 17 00:00:00 2001 From: Pedro Alves Date: Wed, 8 Oct 2008 19:16:31 +0000 Subject: [PATCH] * remote.c (struct remote_state) : New field. (remote_open_1): Clear waiting_for_stop_reply. (remote_resume): Set waiting_for_stop_reply. (remote_wait): Clear or set waiting_for_stop_reply accordingly. (putpkt_binary): If we're in async mode and waiting for a stop reply, bail out with an error. (extended_remote_mourn_1): Clear waiting_for_stop_reply. --- gdb/ChangeLog | 11 +++++++++++ gdb/remote.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 56 insertions(+) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index e5cac415ce5..270a4010724 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,14 @@ +2008-10-08 Pedro Alves + + * remote.c (struct remote_state) : New + field. + (remote_open_1): Clear waiting_for_stop_reply. + (remote_resume): Set waiting_for_stop_reply. + (remote_wait): Clear or set waiting_for_stop_reply accordingly. + (putpkt_binary): If we're in async mode and waiting for a stop + reply, bail out with an error. + (extended_remote_mourn_1): Clear waiting_for_stop_reply. + 2008-10-08 Pedro Alves * remote.c (remote_get_thread_info): If the remote doesn't support diff --git a/gdb/remote.c b/gdb/remote.c index 36dd981b3df..f648c36e075 100644 --- a/gdb/remote.c +++ b/gdb/remote.c @@ -263,6 +263,14 @@ struct remote_state /* True if the stub reported support for multi-process extensions. */ int multi_process_aware; + + /* True if we resumed the target and we're waiting for the target to + stop. In the mean time, we can't start another command/query. + The remote server wouldn't be ready to process it, so we'd + timeout waiting for a reply that would never come and eventually + we'd close the connection. This can happen in asynchronous mode + because we allow GDB commands while the target is running. */ + int waiting_for_stop_reply; }; /* Returns true if the multi-process extensions are in effect. */ @@ -2866,6 +2874,7 @@ remote_open_1 (char *name, int from_tty, struct target_ops *target, int extended rs->noack_mode = 0; rs->multi_process_aware = 0; rs->extended = extended_p; + rs->waiting_for_stop_reply = 0; general_thread = not_sent_ptid; continue_thread = not_sent_ptid; @@ -3411,6 +3420,12 @@ remote_resume (ptid_t ptid, int step, enum target_signal siggnal) NOT asynchronously. */ if (target_can_async_p ()) target_async (inferior_event_handler, 0); + + /* We've just told the target to resume. The remote server will + wait for the inferior to stop, and then send a stop reply. In + the mean time, we can't start another command/query ourselves + because the stub wouldn't be ready to process it. */ + rs->waiting_for_stop_reply = 1; } @@ -3649,6 +3664,9 @@ remote_wait (ptid_t ptid, struct target_waitstatus *status) remote_stopped_by_watchpoint_p = 0; + /* We got something. */ + rs->waiting_for_stop_reply = 0; + switch (buf[0]) { case 'E': /* Error of some sort. */ @@ -3660,6 +3678,10 @@ remote_wait (ptid_t ptid, struct target_waitstatus *status) goto got_status; case 'F': /* File-I/O request. */ remote_fileio_request (buf); + + /* This stop reply is special. We reply back to the stub, + and keep waiting for the target to stop. */ + rs->waiting_for_stop_reply = 1; continue; case 'T': /* Status with PC, SP, FP, ... */ { @@ -3828,6 +3850,10 @@ Packet: '%s'\n"), } case 'O': /* Console output. */ remote_console_output (buf + 1); + + /* The target didn't really stop; keep waiting. */ + rs->waiting_for_stop_reply = 1; + if (target_can_async_p ()) { /* Return immediately to the event loop. The event loop @@ -3851,11 +3877,17 @@ Packet: '%s'\n"), strcpy ((char *) buf, last_sent_step ? "s" : "c"); putpkt ((char *) buf); + + /* We just told the target to resume, so a stop reply is + in order. */ + rs->waiting_for_stop_reply = 1; continue; } /* else fallthrough */ default: warning (_("Invalid remote reply: %s"), buf); + /* Keep waiting. */ + rs->waiting_for_stop_reply = 1; continue; } } @@ -4968,6 +5000,15 @@ putpkt_binary (char *buf, int cnt) int tcount = 0; char *p; + /* Catch cases like trying to read memory or listing threads while + we're waiting for a stop reply. The remote server wouldn't be + ready to handle this request, so we'd hang and timeout. We don't + have to worry about this in synchronous mode, because in that + case it's not possible to issue a command while the target is + running. */ + if (target_can_async_p () && rs->waiting_for_stop_reply) + error (_("Cannot execute this command while the target is running.")); + /* We're sending out a new packet. Make sure we don't look at a stale cached response. */ rs->cached_wait_status = 0; @@ -5480,6 +5521,10 @@ extended_remote_mourn_1 (struct target_ops *target) { struct remote_state *rs = get_remote_state (); + /* In case we got here due to an error, but we're going to stay + connected. */ + rs->waiting_for_stop_reply = 0; + /* Unlike "target remote", we do not want to unpush the target; then the next time the user says "run", we won't be connected. */ -- 2.30.2