From 32990adaadc1b119700cd0dfd2dd8849114e0135 Mon Sep 17 00:00:00 2001 From: Pedro Alves Date: Thu, 2 Oct 2014 09:55:38 +0100 Subject: Reduce Hg packet (select remote general thread) bouncing A patch I wrote made GDB pull the thread list sooner when debugging with target remote, and I noticed an intended consequence. GDB started bouncing around the currently selected remote/general thread more frequently. E.g.: Sending packet: $qTMinFTPILen#3b...Packet received: 5 +Sending packet: $Hgp726d.726d#53...Packet received: OK Sending packet: $m400680,40#2f...Packet received: 85c0741455bff00d60004889e5ffd05de97bffffff0f1f00e973ffffff0f1f00554889e5c745fc00000000c745fc01000000e900000000c745fc02000000b800 +Sending packet: $Hgp726d.7278#28...Packet received: OK Sending packet: $m4006b2,1#28...Packet received: e9 Fast tracepoint 2 at 0x4006b2: file gdb/testsuite/gdb.trace/range-stepping.c, line 53. Sending packet: $qTStatus#49...Packet received: T0;tnotrun:0;tframes:0;tcreated:0;tfree:500000;tsize:500000;circular:0;disconn:0;starttime:0;stoptime:0;username:;notes:: This ended up breaking "tstart" when one has fast tracepoints set, because gdbserver isn't expecting an Hg packet in response to qRelocInsn: (gdb) ftrace *set_point Fast tracepoint 3 at 0x4006b2: file gdb/testsuite/gdb.trace/range-stepping.c, line 53. (gdb) PASS: gdb.trace/range-stepping.exp: ftrace: ftrace *set_point tstart gdbserver: Malformed response to qRelocInsn, ignoring: Hgp2783.2783 Target does not support this command. (gdb) FAIL: gdb.trace/range-stepping.exp: ftrace: tstart remote_trace_start should probably start by making sure the remote current thread matches inferior_ptid (calling set_general_thread), but still, reducing unnecessary bouncing is a good idea. It happens because the memory/symbol/breakpoint routines use switch_to_program_space_and_thread to do something in the right context and then revert back to the previously current thread. The fix is to simply make any_thread_of_process, find_inferior_for_program_space, etc. give preference to the current thread/inferior it if matches. gdb/ 2014-10-02 Pedro Alves * gdbthread.h (any_thread_of_process, any_live_thread_of_process): Adjust comments. * inferior.c (find_inferior_for_program_space): Give preference to the current inferior. * inferior.h (find_inferior_for_program_space): Update comment. * progspace.c (switch_to_program_space_and_thread): Prefer the current inferior if it's bound to the program space requested. If the inferior found doesn't have a PID yet, don't bother looking up a thread. * progspace.h (switch_to_program_space_and_thread): Adjust comment. * thread.c (any_thread_of_process, any_live_thread_of_process): Give preference to the current thread. --- gdb/progspace.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'gdb/progspace.c') diff --git a/gdb/progspace.c b/gdb/progspace.c index b111a50..48cb34a 100644 --- a/gdb/progspace.c +++ b/gdb/progspace.c @@ -459,8 +459,7 @@ save_current_space_and_thread (void) return old_chain; } -/* Switches full context to program space PSPACE. Switches to the - first thread found bound to PSPACE. */ +/* See progspace.h */ void switch_to_program_space_and_thread (struct program_space *pspace) @@ -468,7 +467,7 @@ switch_to_program_space_and_thread (struct program_space *pspace) struct inferior *inf; inf = find_inferior_for_program_space (pspace); - if (inf != NULL) + if (inf != NULL && inf->pid != 0) { struct thread_info *tp; -- cgit v1.1