/* Continuations for GDB, the GNU debugger. Copyright (C) 1986, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 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 3 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, see . */ #include "defs.h" #include "gdbthread.h" #include "inferior.h" #include "continuations.h" struct continuation { struct continuation *next; continuation_ftype *function; continuation_free_arg_ftype *free_arg; void *arg; }; /* Add a new continuation to the continuation chain. Args are FUNCTION to run the continuation up with, and ARG to pass to it. */ static void make_continuation (struct continuation **pmy_chain, continuation_ftype *function, void *arg, void (*free_arg) (void *)) { struct continuation *new = XNEW (struct continuation); new->next = *pmy_chain; new->function = function; new->free_arg = free_arg; new->arg = arg; *pmy_chain = new; } static void do_my_continuations_1 (struct continuation **pmy_chain) { struct continuation *ptr; while ((ptr = *pmy_chain) != NULL) { *pmy_chain = ptr->next; /* Do this first in case of recursion. */ (*ptr->function) (ptr->arg); if (ptr->free_arg) (*ptr->free_arg) (ptr->arg); xfree (ptr); } } static void do_my_continuations (struct continuation **list) { struct continuation *continuations; if (*list == NULL) return; /* Copy the list header into another pointer, and set the global list header to null, so that the global list can change as a side effect of invoking the continuations and the processing of the preexisting continuations will not be affected. */ continuations = *list; *list = NULL; /* Work now on the list we have set aside. */ do_my_continuations_1 (&continuations); } static void discard_my_continuations_1 (struct continuation **pmy_chain) { struct continuation *ptr; while ((ptr = *pmy_chain) != NULL) { *pmy_chain = ptr->next; if (ptr->free_arg) (*ptr->free_arg) (ptr->arg); xfree (ptr); } } static void discard_my_continuations (struct continuation **list) { struct continuation *continuation_ptr = *list; discard_my_continuations_1 (list); *list = NULL; } /* Add a continuation to the continuation list of INFERIOR. The new continuation will be added at the front. */ void add_inferior_continuation (continuation_ftype *hook, void *args, continuation_free_arg_ftype *free_arg) { struct inferior *inf = current_inferior (); make_continuation (&inf->continuations, hook, args, free_arg); } /* Do all continuations of the current inferior. */ void do_all_inferior_continuations (void) { struct inferior *inf = current_inferior (); do_my_continuations (&inf->continuations); } /* Get rid of all the inferior-wide continuations of INF. */ void discard_all_inferior_continuations (struct inferior *inf) { discard_my_continuations (&inf->continuations); } /* Add a continuation to the continuation list of THREAD. The new continuation will be added at the front. */ void add_continuation (struct thread_info *thread, continuation_ftype *hook, void *args, continuation_free_arg_ftype *free_arg) { make_continuation (&thread->continuations, hook, args, free_arg); } static void restore_thread_cleanup (void *arg) { ptid_t *ptid_p = arg; switch_to_thread (*ptid_p); } /* Walk down the continuation list of PTID, and execute all the continuations. There is a problem though. In some cases new continuations may be added while we are in the middle of this loop. If this happens they will be added in the front, and done before we have a chance of exhausting those that were already there. We need to then save the beginning of the list in a pointer and do the continuations from there on, instead of using the global beginning of list as our iteration pointer. */ static void do_all_continuations_ptid (ptid_t ptid, struct continuation **continuations_p) { struct cleanup *old_chain; ptid_t current_thread; if (*continuations_p == NULL) return; current_thread = inferior_ptid; /* Restore selected thread on exit. Don't try to restore the frame as well, because: - When running continuations, the selected frame is always #0. - The continuations may trigger symbol file loads, which may change the frame layout (frame ids change), which would trigger a warning if we used make_cleanup_restore_current_thread. */ old_chain = make_cleanup (restore_thread_cleanup, ¤t_thread); /* Let the continuation see this thread as selected. */ switch_to_thread (ptid); do_my_continuations (continuations_p); do_cleanups (old_chain); } /* Callback for iterate over threads. */ static int do_all_continuations_thread_callback (struct thread_info *thread, void *data) { do_all_continuations_ptid (thread->ptid, &thread->continuations); return 0; } /* Do all continuations of thread THREAD. */ void do_all_continuations_thread (struct thread_info *thread) { do_all_continuations_thread_callback (thread, NULL); } /* Do all continuations of all threads. */ void do_all_continuations (void) { iterate_over_threads (do_all_continuations_thread_callback, NULL); } /* Callback for iterate over threads. */ static int discard_all_continuations_thread_callback (struct thread_info *thread, void *data) { discard_my_continuations (&thread->continuations); return 0; } /* Get rid of all the continuations of THREAD. */ void discard_all_continuations_thread (struct thread_info *thread) { discard_all_continuations_thread_callback (thread, NULL); } /* Get rid of all the continuations of all threads. */ void discard_all_continuations (void) { iterate_over_threads (discard_all_continuations_thread_callback, NULL); } /* Add a continuation to the intermediate continuation list of THREAD. The new continuation will be added at the front. */ void add_intermediate_continuation (struct thread_info *thread, continuation_ftype *hook, void *args, continuation_free_arg_ftype *free_arg) { make_continuation (&thread->intermediate_continuations, hook, args, free_arg); } /* Walk down the cmd_continuation list, and execute all the continuations. There is a problem though. In some cases new continuations may be added while we are in the middle of this loop. If this happens they will be added in the front, and done before we have a chance of exhausting those that were already there. We need to then save the beginning of the list in a pointer and do the continuations from there on, instead of using the global beginning of list as our iteration pointer. */ static int do_all_intermediate_continuations_thread_callback (struct thread_info *thread, void *data) { do_all_continuations_ptid (thread->ptid, &thread->intermediate_continuations); return 0; } /* Do all intermediate continuations of thread THREAD. */ void do_all_intermediate_continuations_thread (struct thread_info *thread) { do_all_intermediate_continuations_thread_callback (thread, NULL); } /* Do all intermediate continuations of all threads. */ void do_all_intermediate_continuations (void) { iterate_over_threads (do_all_intermediate_continuations_thread_callback, NULL); } /* Callback for iterate over threads. */ static int discard_all_intermediate_continuations_thread_callback (struct thread_info *thread, void *data) { discard_my_continuations (&thread->intermediate_continuations); return 0; } /* Get rid of all the intermediate continuations of THREAD. */ void discard_all_intermediate_continuations_thread (struct thread_info *thread) { discard_all_intermediate_continuations_thread_callback (thread, NULL); } /* Get rid of all the intermediate continuations of all threads. */ void discard_all_intermediate_continuations (void) { iterate_over_threads (discard_all_intermediate_continuations_thread_callback, NULL); }