gdb/thread.c

/* Multi-process/thread control for GDB, the GNU debugger.
   Copyright 1986, 1987, 1988, 1993, 1998

   Contributed by Lynx Real-Time Systems, Inc.  Los Gatos, CA.
   Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include "defs.h"
#include "symtab.h"
#include "frame.h"
#include "inferior.h"
#include "environ.h"
#include "value.h"
#include "target.h"
#include "gdbthread.h"
#include "command.h"
#include "gdbcmd.h"

#include <ctype.h>
#include <sys/types.h>
#include <signal.h>

/*#include "lynxos-core.h" */

struct thread_info
  {
    struct thread_info *next;
    int pid;			/* Actual process id */
    int num;			/* Convenient handle */
    CORE_ADDR prev_pc;		/* State from wait_for_inferior */
    CORE_ADDR prev_func_start;
    char *prev_func_name;
    struct breakpoint *step_resume_breakpoint;
    struct breakpoint *through_sigtramp_breakpoint;
    CORE_ADDR step_range_start;
    CORE_ADDR step_range_end;
    CORE_ADDR step_frame_address;
    int trap_expected;
    int handling_longjmp;
    int another_trap;

    /* This is set TRUE when a catchpoint of a shared library event
       triggers.  Since we don't wish to leave the inferior in the
       solib hook when we report the event, we step the inferior
       back to user code before stopping and reporting the event.
     */
    int stepping_through_solib_after_catch;

    /* When stepping_through_solib_after_catch is TRUE, this is a
       list of the catchpoints that should be reported as triggering
       when we finally do stop stepping.
     */
    bpstat stepping_through_solib_catchpoints;

    /* This is set to TRUE when this thread is in a signal handler
       trampoline and we're single-stepping through it */
    int stepping_through_sigtramp;

  };

/* Prototypes for exported functions. */

void _initialize_thread PARAMS ((void));

/* Prototypes for local functions. */

static struct thread_info *thread_list = NULL;
static int highest_thread_num;

static struct thread_info *find_thread_id PARAMS ((int num));

static void thread_command PARAMS ((char *tidstr, int from_tty));
static void thread_apply_all_command PARAMS ((char *, int));
static int thread_alive PARAMS ((struct thread_info *));
static void info_threads_command PARAMS ((char *, int));
static void thread_apply_command PARAMS ((char *, int));
static void restore_current_thread PARAMS ((int));
static void switch_to_thread PARAMS ((int pid));
static void prune_threads PARAMS ((void));

void
init_thread_list ()
{
  struct thread_info *tp, *tpnext;

  if (!thread_list)
    return;

  for (tp = thread_list; tp; tp = tpnext)
    {
      tpnext = tp->next;
      free (tp);
    }

  thread_list = NULL;
  highest_thread_num = 0;
}

void
add_thread (pid)
     int pid;
{
  struct thread_info *tp;

  tp = (struct thread_info *) xmalloc (sizeof (struct thread_info));

  tp->pid = pid;
  tp->num = ++highest_thread_num;
  tp->prev_pc = 0;
  tp->prev_func_start = 0;
  tp->prev_func_name = NULL;
  tp->step_range_start = 0;
  tp->step_range_end = 0;
  tp->step_frame_address = 0;
  tp->step_resume_breakpoint = 0;
  tp->through_sigtramp_breakpoint = 0;
  tp->handling_longjmp = 0;
  tp->trap_expected = 0;
  tp->another_trap = 0;
  tp->stepping_through_solib_after_catch = 0;
  tp->stepping_through_solib_catchpoints = NULL;
  tp->stepping_through_sigtramp = 0;
  tp->next = thread_list;
  thread_list = tp;
}

void
delete_thread (pid)
     int pid;
{
  struct thread_info *tp, *tpprev;

  tpprev = NULL;

  for (tp = thread_list; tp; tpprev = tp, tp = tp->next)
    if (tp->pid == pid)
      break;

  if (!tp)
    return;

  if (tpprev)
    tpprev->next = tp->next;
  else
    thread_list = tp->next;

  /* NOTE: this will take care of any left-over step_resume breakpoints,
     but not any user-specified thread-specific breakpoints. */
  if (tp->step_resume_breakpoint)
    delete_breakpoint (tp->step_resume_breakpoint);

  free (tp);

  return;
}

static struct thread_info *
find_thread_id (num)
     int num;
{
  struct thread_info *tp;

  for (tp = thread_list; tp; tp = tp->next)
    if (tp->num == num)
      return tp;

  return NULL;
}

int
valid_thread_id (num)
     int num;
{
  struct thread_info *tp;

  for (tp = thread_list; tp; tp = tp->next)
    if (tp->num == num)
      return 1;

  return 0;
}

int
pid_to_thread_id (pid)
     int pid;
{
  struct thread_info *tp;

  for (tp = thread_list; tp; tp = tp->next)
    if (tp->pid == pid)
      return tp->num;

  return 0;
}

int
thread_id_to_pid (num)
     int num;
{
  struct thread_info *thread = find_thread_id (num);
  if (thread)
    return thread->pid;
  else
    return -1;
}

int
in_thread_list (pid)
     int pid;
{
  struct thread_info *tp;

  for (tp = thread_list; tp; tp = tp->next)
    if (tp->pid == pid)
      return 1;

  return 0;			/* Never heard of 'im */
}

/* Load infrun state for the thread PID.  */

void
load_infrun_state (pid, prev_pc, prev_func_start, prev_func_name,
		   trap_expected, step_resume_breakpoint,
		   through_sigtramp_breakpoint, step_range_start,
		   step_range_end, step_frame_address,
		   handling_longjmp, another_trap,
		   stepping_through_solib_after_catch,
		   stepping_through_solib_catchpoints,
		   stepping_through_sigtramp)
     int pid;
     CORE_ADDR *prev_pc;
     CORE_ADDR *prev_func_start;
     char **prev_func_name;
     int *trap_expected;
     struct breakpoint **step_resume_breakpoint;
     struct breakpoint **through_sigtramp_breakpoint;
     CORE_ADDR *step_range_start;
     CORE_ADDR *step_range_end;
     CORE_ADDR *step_frame_address;
     int *handling_longjmp;
     int *another_trap;
     int *stepping_through_solib_after_catch;
     bpstat *stepping_through_solib_catchpoints;
     int *stepping_through_sigtramp;
{
  struct thread_info *tp;

  /* If we can't find the thread, then we're debugging a single threaded
     process.  No need to do anything in that case.  */
  tp = find_thread_id (pid_to_thread_id (pid));
  if (tp == NULL)
    return;

  *prev_pc = tp->prev_pc;
  *prev_func_start = tp->prev_func_start;
  *prev_func_name = tp->prev_func_name;
  *step_resume_breakpoint = tp->step_resume_breakpoint;
  *step_range_start = tp->step_range_start;
  *step_range_end = tp->step_range_end;
  *step_frame_address = tp->step_frame_address;
  *through_sigtramp_breakpoint = tp->through_sigtramp_breakpoint;
  *handling_longjmp = tp->handling_longjmp;
  *trap_expected = tp->trap_expected;
  *another_trap = tp->another_trap;
  *stepping_through_solib_after_catch = tp->stepping_through_solib_after_catch;
  *stepping_through_solib_catchpoints = tp->stepping_through_solib_catchpoints;
  *stepping_through_sigtramp = tp->stepping_through_sigtramp;
}

/* Save infrun state for the thread PID.  */

void
save_infrun_state (pid, prev_pc, prev_func_start, prev_func_name,
		   trap_expected, step_resume_breakpoint,
		   through_sigtramp_breakpoint, step_range_start,
		   step_range_end, step_frame_address,
		   handling_longjmp, another_trap,
		   stepping_through_solib_after_catch,
		   stepping_through_solib_catchpoints,
		   stepping_through_sigtramp)
     int pid;
     CORE_ADDR prev_pc;
     CORE_ADDR prev_func_start;
     char *prev_func_name;
     int trap_expected;
     struct breakpoint *step_resume_breakpoint;
     struct breakpoint *through_sigtramp_breakpoint;
     CORE_ADDR step_range_start;
     CORE_ADDR step_range_end;
     CORE_ADDR step_frame_address;
     int handling_longjmp;
     int another_trap;
     int stepping_through_solib_after_catch;
     bpstat stepping_through_solib_catchpoints;
     int stepping_through_sigtramp;
{
  struct thread_info *tp;

  /* If we can't find the thread, then we're debugging a single-threaded
     process.  Nothing to do in that case.  */
  tp = find_thread_id (pid_to_thread_id (pid));
  if (tp == NULL)
    return;

  tp->prev_pc = prev_pc;
  tp->prev_func_start = prev_func_start;
  tp->prev_func_name = prev_func_name;
  tp->step_resume_breakpoint = step_resume_breakpoint;
  tp->step_range_start = step_range_start;
  tp->step_range_end = step_range_end;
  tp->step_frame_address = step_frame_address;
  tp->through_sigtramp_breakpoint = through_sigtramp_breakpoint;
  tp->handling_longjmp = handling_longjmp;
  tp->trap_expected = trap_expected;
  tp->another_trap = another_trap;
  tp->stepping_through_solib_after_catch = stepping_through_solib_after_catch;
  tp->stepping_through_solib_catchpoints = stepping_through_solib_catchpoints;
  tp->stepping_through_sigtramp = stepping_through_sigtramp;
}

/* Return true if TP is an active thread. */
static int
thread_alive (tp)
     struct thread_info *tp;
{
  if (tp->pid == -1)
    return 0;
  if (!target_thread_alive (tp->pid))
    {
      tp->pid = -1;		/* Mark it as dead */
      return 0;
    }
  return 1;
}

static void
prune_threads ()
{
  struct thread_info *tp, *next;

  for (tp = thread_list; tp; tp = next)
    {
      next = tp->next;
      if (!thread_alive (tp))
	delete_thread (tp->pid);
    }
}

/* Print information about currently known threads 

 * Note: this has the drawback that it _really_ switches
 *       threads, which frees the frame cache.  A no-side
 *       effects info-threads command would be nicer.
 */

static void
info_threads_command (arg, from_tty)
     char *arg;
     int from_tty;
{
  struct thread_info *tp;
  int current_pid;
  struct frame_info *cur_frame;
  int saved_frame_level = selected_frame_level;
  int counter;

  /* Avoid coredumps which would happen if we tried to access a NULL
     selected_frame.  */
  if (!target_has_stack)
    error ("No stack.");

  prune_threads ();
  target_find_new_threads ();
  current_pid = inferior_pid;
  for (tp = thread_list; tp; tp = tp->next)
    {
      if (tp->pid == current_pid)
	printf_filtered ("* ");
      else
	printf_filtered ("  ");

#ifdef HPUXHPPA
      printf_filtered ("%d %s  ", tp->num, target_tid_to_str (tp->pid));
#else
      printf_filtered ("%d %s  ", tp->num, target_pid_to_str (tp->pid));
#endif
      switch_to_thread (tp->pid);
      if (selected_frame)
	print_only_stack_frame (selected_frame, -1, 0);
      else
	printf_filtered ("[No stack.]\n");
    }

  switch_to_thread (current_pid);

  /* Code below copied from "up_silently_base" in "stack.c".
   * It restores the frame set by the user before the "info threads"
   * command.  We have finished the info-threads display by switching
   * back to the current thread.  That switch has put us at the top
   * of the stack (leaf frame).
   */
  counter = saved_frame_level;
  cur_frame = find_relative_frame (selected_frame, &counter);
  if (counter != 0)
    {
      /* Ooops, can't restore, tell user where we are. */
      warning ("Couldn't restore frame in current thread, at frame 0");
      print_stack_frame (selected_frame, -1, 0);
    }
  else
    {
      select_frame (cur_frame, saved_frame_level);
    }

  /* re-show current frame. */
  show_stack_frame (cur_frame);
}

/* Switch from one thread to another. */

static void
switch_to_thread (pid)
     int pid;
{
  if (pid == inferior_pid)
    return;

  inferior_pid = pid;
  flush_cached_frames ();
  registers_changed ();
  stop_pc = read_pc ();
  select_frame (get_current_frame (), 0);
}

static void
restore_current_thread (pid)
     int pid;
{
  if (pid != inferior_pid)
    {
      switch_to_thread (pid);
      print_stack_frame (get_current_frame (), 0, -1);
    }
}

/* Apply a GDB command to a list of threads.  List syntax is a whitespace
   seperated list of numbers, or ranges, or the keyword `all'.  Ranges consist
   of two numbers seperated by a hyphen.  Examples:

   thread apply 1 2 7 4 backtrace       Apply backtrace cmd to threads 1,2,7,4
   thread apply 2-7 9 p foo(1)  Apply p foo(1) cmd to threads 2->7 & 9
   thread apply all p x/i $pc   Apply x/i $pc cmd to all threads
 */

static void
thread_apply_all_command (cmd, from_tty)
     char *cmd;
     int from_tty;
{
  struct thread_info *tp;
  struct cleanup *old_chain;

  if (cmd == NULL || *cmd == '\000')
    error ("Please specify a command following the thread ID list");

  old_chain = make_cleanup ((make_cleanup_func) restore_current_thread,
			    (void *) inferior_pid);

  for (tp = thread_list; tp; tp = tp->next)
    if (thread_alive (tp))
      {
	switch_to_thread (tp->pid);
#ifdef HPUXHPPA
	printf_filtered ("\nThread %d (%s):\n",
			 tp->num,
			 target_tid_to_str (inferior_pid));
#else
	printf_filtered ("\nThread %d (%s):\n", tp->num,
			 target_pid_to_str (inferior_pid));
#endif
	execute_command (cmd, from_tty);
      }
}

static void
thread_apply_command (tidlist, from_tty)
     char *tidlist;
     int from_tty;
{
  char *cmd;
  char *p;
  struct cleanup *old_chain;

  if (tidlist == NULL || *tidlist == '\000')
    error ("Please specify a thread ID list");

  for (cmd = tidlist; *cmd != '\000' && !isalpha (*cmd); cmd++);

  if (*cmd == '\000')
    error ("Please specify a command following the thread ID list");

  old_chain = make_cleanup ((make_cleanup_func) restore_current_thread,
			    (void *) inferior_pid);

  while (tidlist < cmd)
    {
      struct thread_info *tp;
      int start, end;

      start = strtol (tidlist, &p, 10);
      if (p == tidlist)
	error ("Error parsing %s", tidlist);
      tidlist = p;

      while (*tidlist == ' ' || *tidlist == '\t')
	tidlist++;

      if (*tidlist == '-')	/* Got a range of IDs? */
	{
	  tidlist++;		/* Skip the - */
	  end = strtol (tidlist, &p, 10);
	  if (p == tidlist)
	    error ("Error parsing %s", tidlist);
	  tidlist = p;

	  while (*tidlist == ' ' || *tidlist == '\t')
	    tidlist++;
	}
      else
	end = start;

      for (; start <= end; start++)
	{
	  tp = find_thread_id (start);

	  if (!tp)
	    warning ("Unknown thread %d.", start);
	  else if (!thread_alive (tp))
	    warning ("Thread %d has terminated.", start);
	  else
	    {
	      switch_to_thread (tp->pid);
#ifdef HPUXHPPA
	      printf_filtered ("\nThread %d (%s):\n", tp->num,
			       target_tid_to_str (inferior_pid));
#else
	      printf_filtered ("\nThread %d (%s):\n", tp->num,
			       target_pid_to_str (inferior_pid));
#endif
	      execute_command (cmd, from_tty);
	    }
	}
    }
}

/* Switch to the specified thread.  Will dispatch off to thread_apply_command
   if prefix of arg is `apply'.  */

static void
thread_command (tidstr, from_tty)
     char *tidstr;
     int from_tty;
{
  int num;
  struct thread_info *tp;

  if (!tidstr)
    {
      /* Don't generate an error, just say which thread is current. */
      if (target_has_stack)
	printf_filtered ("[Current thread is %d (%s)]\n",
			 pid_to_thread_id (inferior_pid),
#if defined(HPUXHPPA)
			 target_tid_to_str (inferior_pid)
#else
			 target_pid_to_str (inferior_pid)
#endif
	  );
      else
	error ("No stack.");
      return;
    }
  num = atoi (tidstr);

  tp = find_thread_id (num);

  if (!tp)
    error ("Thread ID %d not known.  Use the \"info threads\" command to\n\
see the IDs of currently known threads.", num);

  if (!thread_alive (tp))
    error ("Thread ID %d has terminated.\n", num);

  switch_to_thread (tp->pid);

  if (context_hook)
    context_hook (num);

  printf_filtered ("[Switching to thread %d (%s)]\n",
		   pid_to_thread_id (inferior_pid),
#if defined(HPUXHPPA)
		   target_tid_to_str (inferior_pid)
#else
		   target_pid_to_str (inferior_pid)
#endif
    );
  print_stack_frame (selected_frame, selected_frame_level, 1);
}

/* Commands with a prefix of `thread'.  */
struct cmd_list_element *thread_cmd_list = NULL;

void
_initialize_thread ()
{
  static struct cmd_list_element *thread_apply_list = NULL;

  add_info ("threads", info_threads_command,
	    "IDs of currently known threads.");

  add_prefix_cmd ("thread", class_run, thread_command,
		  "Use this command to switch between threads.\n\
The new thread ID must be currently known.", &thread_cmd_list, "thread ", 1,
		  &cmdlist);

  add_prefix_cmd ("apply", class_run, thread_apply_command,
		  "Apply a command to a list of threads.",
		  &thread_apply_list, "apply ", 1, &thread_cmd_list);

  add_cmd ("all", class_run, thread_apply_all_command,
	   "Apply a command to all threads.",
	   &thread_apply_list);

  if (!xdb_commands)
    add_com_alias ("t", "thread", class_run, 1);
}