From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 22849 invoked by alias); 8 Aug 2008 01:33:53 -0000 Received: (qmail 22840 invoked by uid 22791); 8 Aug 2008 01:33:52 -0000 X-Spam-Check-By: sourceware.org Received: from mail.codesourcery.com (HELO mail.codesourcery.com) (65.74.133.4) by sourceware.org (qpsmtpd/0.31) with ESMTP; Fri, 08 Aug 2008 01:33:10 +0000 Received: (qmail 32313 invoked from network); 8 Aug 2008 01:33:08 -0000 Received: from unknown (HELO orlando.local) (pedro@127.0.0.2) by mail.codesourcery.com with ESMTPA; 8 Aug 2008 01:33:08 -0000 From: Pedro Alves To: gdb-patches@sourceware.org Subject: [1/7] Register the main thread/task in fork-child.c Date: Fri, 08 Aug 2008 01:33:00 -0000 User-Agent: KMail/1.9.9 MIME-Version: 1.0 Content-Type: Multipart/Mixed; boundary="Boundary-00=_8J6mIsN4f9Cjy54" Message-Id: <200808080233.48834.pedro@codesourcery.com> X-IsSubscribed: yes Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2008-08/txt/msg00170.txt.bz2 --Boundary-00=_8J6mIsN4f9Cjy54 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Content-length: 2977 Hi, This patch makes it so that right after a fork-child, we add the main task of the inferior to GDB's thread tables. We don't have lwp or thread info at this point, which means that targets should decorate more of inferior_ptid as soon as they have the chance. Some targets will do it as soon as we get to the first target_wait, others, will only have info available when a thread library is loaded. The issue of changing inferior_ptid to accomodate a new ptid that represents the same task, in GDB's perspective is not new. See below for examples are all over the place. Since we're now making sure inferior_ptid is always in the thread list, when we update it to include more lwp or tid info, we also need to make sure that entry in the thread list is updated. In addition, if there are other GDB's sub-components that were holding info on this thread, we should be able to inform them of the ptid change. Hence, I'm adding a new thread_change_ptid function, which takes care of updating the thread table, and a new observer that is called by this function, so other modules can react: @deftypefun void thread_ptid_changed (ptid_t @var{old_ptid}, ptid_t @var{new_ptid}) The thread's ptid has changed. The @var{old_ptid} parameter specifies the old value, and @var{new_ptid} specifies the new value. @end deftypefun I'm including the linux-nat.c change in this patch, for an example usable. The following patches in the series will introduce more uses. The whole series was tested on x86_64-unknown-linux-gnu, i386-pc-solaris2.11 (OpenSolaris 10), i386-unknown-openbsd4.3, i386-unknown-freebsd6.0, i386-unknown-freebsd7.0 and i686-unknown-gnu0.3 (Debian GNU/Hurd). OK, when the rest of the series is OK? -------- infrun.c: /* The call to in_thread_list is necessary because PTIDs sometimes change when we go from single-threaded to multi-threaded. If the singlestep_ptid is still in the list, assume that it is really different from ecs->ptid. */ if (!ptid_equal (singlestep_ptid, ecs->ptid) && in_thread_list (singlestep_ptid)) { bsd-uthread.c: /* HACK: Twiddle INFERIOR_PTID such that the initial thread of a process isn't recognized as a new thread. */ if (ptid_get_tid (ptid) != 0 && !in_thread_list (ptid) && ptid_get_tid (inferior_ptid) == 0) { add_thread_silent (ptid); inferior_ptid = ptid; } linux-nat.c: /* The first time we get here after starting a new inferior, we may not have added it to the LWP list yet - this is the earliest moment at which we know its PID. */ if (num_lwps == 0) { gdb_assert (!is_lwp (inferior_ptid)); inferior_ptid = BUILD_LWP (GET_PID (inferior_ptid), GET_PID (inferior_ptid)); inf-trace.c: /* HACK: Twiddle INFERIOR_PTID such that the initial thread of a process isn't recognized as a new thread. */ if (ptid_get_lwp (inferior_ptid) == 0) inferior_ptid = ptid; -- Pedro Alves --Boundary-00=_8J6mIsN4f9Cjy54 Content-Type: text/x-diff; charset="utf-8"; name="001-always_a_thread_fork.diff" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="001-always_a_thread_fork.diff" Content-length: 6955 2008-08-08 Pedro Alves gdb/doc/ * observer.texi (thread_ptid_changed): New. gdb/ * gdbthread.h (thread_change_ptid): Declare. * infrun.c (infrun_thread_ptid_changed): New. (_initialize_infrun): Attach infrun_thread_ptid_changed to the thread_ptid_changed observer. * linux-nat.c (linux_nat_wait): Update inferior_ptid's ptid with thread_change_ptid. Don't add or mark the main thread as running and executing here. * regcache.c (regcache_thread_ptid_changed): New. (_initialize_regcache): Attach regcache_thread_ptid_changed to the thread_ptid_changed observer. * thread.c (thread_change_ptid): New. * fork-child.c (fork_inferior): Add the main thread here, and set it running and executing. --- gdb/doc/observer.texi | 4 ++++ gdb/fork-child.c | 6 ++++++ gdb/gdbthread.h | 3 +++ gdb/infrun.c | 26 ++++++++++++++++++++++++++ gdb/linux-nat.c | 11 +++++------ gdb/regcache.c | 11 +++++++++++ gdb/thread.c | 9 +++++++++ 7 files changed, 64 insertions(+), 6 deletions(-) Index: src/gdb/doc/observer.texi =================================================================== --- src.orig/gdb/doc/observer.texi 2008-08-07 17:20:10.000000000 +0100 +++ src/gdb/doc/observer.texi 2008-08-07 19:34:53.000000000 +0100 @@ -175,3 +175,7 @@ The current architecture has changed. T a pointer to the new architecture. @end deftypefun +@deftypefun void thread_ptid_changed (ptid_t @var{old_ptid}, ptid_t @var{new_ptid}) +The thread's ptid has changed. The @var{old_ptid} parameter specifies +the old value, and @var{new_ptid} specifies the new value. +@end deftypefun Index: src/gdb/gdbthread.h =================================================================== --- src.orig/gdb/gdbthread.h 2008-08-07 17:23:21.000000000 +0100 +++ src/gdb/gdbthread.h 2008-08-07 17:23:29.000000000 +0100 @@ -151,6 +151,9 @@ extern struct thread_info *find_thread_p /* Find thread by GDB user-visible thread number. */ struct thread_info *find_thread_id (int num); +/* Change the ptid of thread OLD_PTID to NEW_PTID. */ +void thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid); + /* Iterator function to call a user-provided callback function once for each known thread. */ typedef int (*thread_callback_func) (struct thread_info *, void *); Index: src/gdb/infrun.c =================================================================== --- src.orig/gdb/infrun.c 2008-08-07 17:20:10.000000000 +0100 +++ src/gdb/infrun.c 2008-08-07 17:23:29.000000000 +0100 @@ -865,6 +865,30 @@ displaced_step_fixup (ptid_t event_ptid, } } +/* Update global variables old ptids to hold NEW_PTID if they were + holding OLD_PTID. */ +static void +infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid) +{ + struct displaced_step_request *it; + + if (ptid_equal (inferior_ptid, old_ptid)) + inferior_ptid = new_ptid; + + if (ptid_equal (singlestep_ptid, old_ptid)) + singlestep_ptid = new_ptid; + + if (ptid_equal (displaced_step_ptid, old_ptid)) + displaced_step_ptid = new_ptid; + + if (ptid_equal (deferred_step_ptid, old_ptid)) + deferred_step_ptid = new_ptid; + + for (it = displaced_step_request_queue; it; it = it->next) + if (ptid_equal (it->ptid, old_ptid)) + it->ptid = new_ptid; +} + /* Resuming. */ @@ -4853,4 +4877,6 @@ breakpoints, even if such is supported b inferior_ptid = null_ptid; target_last_wait_ptid = minus_one_ptid; displaced_step_ptid = null_ptid; + + observer_attach_thread_ptid_changed (infrun_thread_ptid_changed); } Index: src/gdb/linux-nat.c =================================================================== --- src.orig/gdb/linux-nat.c 2008-08-07 17:20:10.000000000 +0100 +++ src/gdb/linux-nat.c 2008-08-07 19:30:21.000000000 +0100 @@ -2722,14 +2722,13 @@ linux_nat_wait (ptid_t ptid, struct targ { gdb_assert (!is_lwp (inferior_ptid)); - inferior_ptid = BUILD_LWP (GET_PID (inferior_ptid), - GET_PID (inferior_ptid)); + /* Upgrade the main thread's ptid. */ + thread_change_ptid (inferior_ptid, + BUILD_LWP (GET_PID (inferior_ptid), + GET_PID (inferior_ptid))); + lp = add_lwp (inferior_ptid); lp->resumed = 1; - /* Add the main thread to GDB's thread list. */ - add_thread_silent (lp->ptid); - set_running (lp->ptid, 1); - set_executing (lp->ptid, 1); } /* Block events while we're here. */ Index: src/gdb/regcache.c =================================================================== --- src.orig/gdb/regcache.c 2008-08-07 17:20:10.000000000 +0100 +++ src/gdb/regcache.c 2008-08-07 17:23:29.000000000 +0100 @@ -453,6 +453,16 @@ regcache_observer_target_changed (struct registers_changed (); } +/* Update global variables old ptids to hold NEW_PTID if they were + holding OLD_PTID. */ +static void +regcache_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid) +{ + if (current_regcache != NULL + && ptid_equal (current_regcache->ptid, old_ptid)) + current_regcache->ptid = new_ptid; +} + /* Low level examining and depositing of registers. The caller is responsible for making sure that the inferior is @@ -1134,6 +1144,7 @@ _initialize_regcache (void) regcache_descr_handle = gdbarch_data_register_post_init (init_regcache_descr); observer_attach_target_changed (regcache_observer_target_changed); + observer_attach_thread_ptid_changed (regcache_thread_ptid_changed); add_com ("flushregs", class_maintenance, reg_flush_command, _("Force gdb to flush its register cache (maintainer command)")); Index: src/gdb/thread.c =================================================================== --- src.orig/gdb/thread.c 2008-08-07 17:20:10.000000000 +0100 +++ src/gdb/thread.c 2008-08-07 17:23:29.000000000 +0100 @@ -589,6 +589,15 @@ prune_threads (void) } void +thread_change_ptid (ptid_t old_ptid, ptid_t new_ptid) +{ + struct thread_info * tp = find_thread_pid (old_ptid); + tp->ptid = new_ptid; + + observer_notify_thread_ptid_changed (old_ptid, new_ptid); +} + +void set_running (ptid_t ptid, int running) { struct thread_info *tp; Index: src/gdb/fork-child.c =================================================================== --- src.orig/gdb/fork-child.c 2008-08-07 17:20:10.000000000 +0100 +++ src/gdb/fork-child.c 2008-08-07 17:23:29.000000000 +0100 @@ -397,6 +397,12 @@ fork_inferior (char *exec_file_arg, char /* Needed for wait_for_inferior stuff below. */ inferior_ptid = pid_to_ptid (pid); + /* We have something that executes now. We'll be running through + the shell at this point, but the pid shouldn't change. Targets + supporting MT should fill this task's ptid with more data as soon + as they can. */ + add_thread_silent (inferior_ptid); + /* Now that we have a child process, make it our target, and initialize anything target-vector-specific that needs initializing. */ --Boundary-00=_8J6mIsN4f9Cjy54--