ae13219ef8
* linux-low.c (check_removed_breakpoint): Add an early prototype. Improve debug output. (linux_attach): Doc update. (linux_detach_one_process, linux_detach): Clean up before releasing each process. (send_sigstop, wait_for_sigstop): Improve comments and debug output. * linux-low.h (struct process_info): Doc improvement. * mem-break.c (delete_all_breakpoints): New. * mem-break.h (delete_all_breakpoints): New prototype. * thread-db.c (find_first_thread): New. (thread_db_create_event): Call it instead of thread_db_find_new_threads. Clean up unused variables. (maybe_attach_thread): Remove first thread handling. (thread_db_find_new_threads): Use find_first_thread. (thread_db_get_tls_address): Likewise.
456 lines
12 KiB
C
456 lines
12 KiB
C
/* Thread management interface, for the remote server for GDB.
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Copyright (C) 2002, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
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Contributed by MontaVista Software.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor,
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Boston, MA 02110-1301, USA. */
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#include "server.h"
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#include "linux-low.h"
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extern int debug_threads;
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#ifdef HAVE_THREAD_DB_H
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#include <thread_db.h>
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#endif
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#include "gdb_proc_service.h"
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#include <stdint.h>
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/* Structure that identifies the child process for the
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<proc_service.h> interface. */
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static struct ps_prochandle proc_handle;
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/* Connection to the libthread_db library. */
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static td_thragent_t *thread_agent;
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static int find_first_thread (void);
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static int find_new_threads_callback (const td_thrhandle_t *th_p, void *data);
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static char *
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thread_db_err_str (td_err_e err)
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{
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static char buf[64];
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switch (err)
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{
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case TD_OK:
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return "generic 'call succeeded'";
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case TD_ERR:
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return "generic error";
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case TD_NOTHR:
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return "no thread to satisfy query";
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case TD_NOSV:
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return "no sync handle to satisfy query";
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case TD_NOLWP:
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return "no LWP to satisfy query";
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case TD_BADPH:
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return "invalid process handle";
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case TD_BADTH:
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return "invalid thread handle";
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case TD_BADSH:
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return "invalid synchronization handle";
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case TD_BADTA:
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return "invalid thread agent";
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case TD_BADKEY:
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return "invalid key";
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case TD_NOMSG:
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return "no event message for getmsg";
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case TD_NOFPREGS:
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return "FPU register set not available";
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case TD_NOLIBTHREAD:
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return "application not linked with libthread";
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case TD_NOEVENT:
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return "requested event is not supported";
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case TD_NOCAPAB:
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return "capability not available";
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case TD_DBERR:
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return "debugger service failed";
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case TD_NOAPLIC:
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return "operation not applicable to";
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case TD_NOTSD:
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return "no thread-specific data for this thread";
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case TD_MALLOC:
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return "malloc failed";
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case TD_PARTIALREG:
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return "only part of register set was written/read";
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case TD_NOXREGS:
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return "X register set not available for this thread";
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#ifdef HAVE_TD_VERSION
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case TD_VERSION:
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return "version mismatch between libthread_db and libpthread";
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#endif
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default:
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snprintf (buf, sizeof (buf), "unknown thread_db error '%d'", err);
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return buf;
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}
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}
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#if 0
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static char *
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thread_db_state_str (td_thr_state_e state)
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{
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static char buf[64];
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switch (state)
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{
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case TD_THR_STOPPED:
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return "stopped by debugger";
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case TD_THR_RUN:
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return "runnable";
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case TD_THR_ACTIVE:
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return "active";
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case TD_THR_ZOMBIE:
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return "zombie";
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case TD_THR_SLEEP:
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return "sleeping";
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case TD_THR_STOPPED_ASLEEP:
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return "stopped by debugger AND blocked";
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default:
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snprintf (buf, sizeof (buf), "unknown thread_db state %d", state);
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return buf;
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}
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}
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#endif
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static void
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thread_db_create_event (CORE_ADDR where)
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{
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td_event_msg_t msg;
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td_err_e err;
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struct process_info *process;
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if (debug_threads)
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fprintf (stderr, "Thread creation event.\n");
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/* FIXME: This assumes we don't get another event.
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In the LinuxThreads implementation, this is safe,
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because all events come from the manager thread
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(except for its own creation, of course). */
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err = td_ta_event_getmsg (thread_agent, &msg);
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if (err != TD_OK)
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fprintf (stderr, "thread getmsg err: %s\n",
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thread_db_err_str (err));
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/* If we do not know about the main thread yet, this would be a good time to
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find it. We need to do this to pick up the main thread before any newly
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created threads. */
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process = get_thread_process (current_inferior);
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if (process->thread_known == 0)
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find_first_thread ();
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/* msg.event == TD_EVENT_CREATE */
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find_new_threads_callback (msg.th_p, NULL);
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}
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#if 0
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static void
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thread_db_death_event (CORE_ADDR where)
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{
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if (debug_threads)
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fprintf (stderr, "Thread death event.\n");
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}
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#endif
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static int
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thread_db_enable_reporting ()
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{
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td_thr_events_t events;
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td_notify_t notify;
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td_err_e err;
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/* Set the process wide mask saying which events we're interested in. */
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td_event_emptyset (&events);
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td_event_addset (&events, TD_CREATE);
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#if 0
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/* This is reported to be broken in glibc 2.1.3. A different approach
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will be necessary to support that. */
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td_event_addset (&events, TD_DEATH);
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#endif
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err = td_ta_set_event (thread_agent, &events);
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if (err != TD_OK)
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{
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warning ("Unable to set global thread event mask: %s",
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thread_db_err_str (err));
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return 0;
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}
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/* Get address for thread creation breakpoint. */
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err = td_ta_event_addr (thread_agent, TD_CREATE, ¬ify);
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if (err != TD_OK)
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{
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warning ("Unable to get location for thread creation breakpoint: %s",
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thread_db_err_str (err));
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return 0;
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}
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set_breakpoint_at ((CORE_ADDR) (unsigned long) notify.u.bptaddr,
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thread_db_create_event);
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#if 0
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/* Don't concern ourselves with reported thread deaths, only
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with actual thread deaths (via wait). */
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/* Get address for thread death breakpoint. */
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err = td_ta_event_addr (thread_agent, TD_DEATH, ¬ify);
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if (err != TD_OK)
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{
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warning ("Unable to get location for thread death breakpoint: %s",
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thread_db_err_str (err));
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return;
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}
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set_breakpoint_at ((CORE_ADDR) (unsigned long) notify.u.bptaddr,
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thread_db_death_event);
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#endif
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return 1;
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}
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static int
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find_first_thread (void)
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{
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td_thrhandle_t th;
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td_thrinfo_t ti;
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td_err_e err;
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struct thread_info *inferior;
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struct process_info *process;
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inferior = (struct thread_info *) all_threads.head;
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process = get_thread_process (inferior);
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if (process->thread_known)
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return 1;
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/* Get information about the one thread we know we have. */
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err = td_ta_map_lwp2thr (thread_agent, process->lwpid, &th);
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if (err != TD_OK)
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error ("Cannot get first thread handle: %s", thread_db_err_str (err));
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err = td_thr_get_info (&th, &ti);
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if (err != TD_OK)
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error ("Cannot get first thread info: %s", thread_db_err_str (err));
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if (debug_threads)
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fprintf (stderr, "Found first thread %ld (LWP %d)\n",
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ti.ti_tid, ti.ti_lid);
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if (process->lwpid != ti.ti_lid)
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fatal ("PID mismatch! Expected %ld, got %ld",
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(long) process->lwpid, (long) ti.ti_lid);
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/* If the new thread ID is zero, a final thread ID will be available
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later. Do not enable thread debugging yet. */
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if (ti.ti_tid == 0)
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{
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err = td_thr_event_enable (&th, 1);
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if (err != TD_OK)
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error ("Cannot enable thread event reporting for %d: %s",
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ti.ti_lid, thread_db_err_str (err));
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return 0;
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}
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/* Switch to indexing the threads list by TID. */
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change_inferior_id (&all_threads, ti.ti_tid);
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new_thread_notify (ti.ti_tid);
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process->tid = ti.ti_tid;
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process->lwpid = ti.ti_lid;
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process->thread_known = 1;
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process->th = th;
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err = td_thr_event_enable (&th, 1);
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if (err != TD_OK)
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error ("Cannot enable thread event reporting for %d: %s",
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ti.ti_lid, thread_db_err_str (err));
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return 1;
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}
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static void
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maybe_attach_thread (const td_thrhandle_t *th_p, td_thrinfo_t *ti_p)
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{
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td_err_e err;
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struct thread_info *inferior;
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struct process_info *process;
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inferior = (struct thread_info *) find_inferior_id (&all_threads,
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ti_p->ti_tid);
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if (inferior != NULL)
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return;
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if (debug_threads)
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fprintf (stderr, "Attaching to thread %ld (LWP %d)\n",
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ti_p->ti_tid, ti_p->ti_lid);
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linux_attach_lwp (ti_p->ti_lid, ti_p->ti_tid);
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inferior = (struct thread_info *) find_inferior_id (&all_threads,
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ti_p->ti_tid);
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if (inferior == NULL)
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{
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warning ("Could not attach to thread %ld (LWP %d)\n",
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ti_p->ti_tid, ti_p->ti_lid);
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return;
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}
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process = inferior_target_data (inferior);
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new_thread_notify (ti_p->ti_tid);
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process->tid = ti_p->ti_tid;
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process->lwpid = ti_p->ti_lid;
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process->thread_known = 1;
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process->th = *th_p;
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err = td_thr_event_enable (th_p, 1);
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if (err != TD_OK)
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error ("Cannot enable thread event reporting for %d: %s",
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ti_p->ti_lid, thread_db_err_str (err));
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}
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static int
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find_new_threads_callback (const td_thrhandle_t *th_p, void *data)
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{
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td_thrinfo_t ti;
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td_err_e err;
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err = td_thr_get_info (th_p, &ti);
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if (err != TD_OK)
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error ("Cannot get thread info: %s", thread_db_err_str (err));
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/* Check for zombies. */
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if (ti.ti_state == TD_THR_UNKNOWN || ti.ti_state == TD_THR_ZOMBIE)
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return 0;
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maybe_attach_thread (th_p, &ti);
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return 0;
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}
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static void
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thread_db_find_new_threads (void)
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{
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td_err_e err;
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/* This function is only called when we first initialize thread_db.
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First locate the initial thread. If it is not ready for
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debugging yet, then stop. */
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if (find_first_thread () == 0)
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return;
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/* Iterate over all user-space threads to discover new threads. */
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err = td_ta_thr_iter (thread_agent, find_new_threads_callback, NULL,
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TD_THR_ANY_STATE, TD_THR_LOWEST_PRIORITY,
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TD_SIGNO_MASK, TD_THR_ANY_USER_FLAGS);
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if (err != TD_OK)
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error ("Cannot find new threads: %s", thread_db_err_str (err));
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}
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/* Cache all future symbols that thread_db might request. We can not
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request symbols at arbitrary states in the remote protocol, only
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when the client tells us that new symbols are available. So when
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we load the thread library, make sure to check the entire list. */
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static void
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thread_db_look_up_symbols (void)
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{
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const char **sym_list = td_symbol_list ();
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CORE_ADDR unused;
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for (sym_list = td_symbol_list (); *sym_list; sym_list++)
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look_up_one_symbol (*sym_list, &unused);
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}
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int
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thread_db_get_tls_address (struct thread_info *thread, CORE_ADDR offset,
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CORE_ADDR load_module, CORE_ADDR *address)
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{
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#if HAVE_TD_THR_TLS_GET_ADDR
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psaddr_t addr;
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td_err_e err;
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struct process_info *process;
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process = get_thread_process (thread);
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if (!process->thread_known)
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find_first_thread ();
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if (!process->thread_known)
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return TD_NOTHR;
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/* Note the cast through uintptr_t: this interface only works if
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a target address fits in a psaddr_t, which is a host pointer.
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So a 32-bit debugger can not access 64-bit TLS through this. */
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err = td_thr_tls_get_addr (&process->th, (psaddr_t) (uintptr_t) load_module,
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offset, &addr);
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if (err == TD_OK)
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{
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*address = (CORE_ADDR) (uintptr_t) addr;
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return 0;
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}
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else
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return err;
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#else
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return -1;
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#endif
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}
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int
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thread_db_init ()
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{
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int err;
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/* FIXME drow/2004-10-16: This is the "overall process ID", which
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GNU/Linux calls tgid, "thread group ID". When we support
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attaching to threads, the original thread may not be the correct
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thread. We would have to get the process ID from /proc for NPTL.
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For LinuxThreads we could do something similar: follow the chain
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of parent processes until we find the highest one we're attached
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to, and use its tgid.
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This isn't the only place in gdbserver that assumes that the first
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process in the list is the thread group leader. */
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proc_handle.pid = ((struct inferior_list_entry *)current_inferior)->id;
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/* Allow new symbol lookups. */
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all_symbols_looked_up = 0;
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err = td_ta_new (&proc_handle, &thread_agent);
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switch (err)
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{
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case TD_NOLIBTHREAD:
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/* No thread library was detected. */
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return 0;
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case TD_OK:
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/* The thread library was detected. */
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if (thread_db_enable_reporting () == 0)
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return 0;
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thread_db_find_new_threads ();
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thread_db_look_up_symbols ();
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all_symbols_looked_up = 1;
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return 1;
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default:
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warning ("error initializing thread_db library: %s",
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thread_db_err_str (err));
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}
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return 0;
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}
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