gdb/continuations.c

   1 /* Continuations for GDB, the GNU debugger.
   2
   3    Copyright (C) 1986-2019 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21
  22 /* Local non-gdb includes.  */
  23 #include "continuations.h"
  24 #include "gdbthread.h"
  25 #include "inferior.h"
  26
  27 struct continuation
  28 {
  29   struct continuation *next;
  30   continuation_ftype *function;
  31   continuation_free_arg_ftype *free_arg;
  32   void *arg;
  33 };
  34
  35 /* Add a new continuation to the continuation chain.  Args are
  36    FUNCTION to run the continuation up with, and ARG to pass to
  37    it.  */
  38
  39 static void
  40 make_continuation (struct continuation **pmy_chain,
  41                    continuation_ftype *function,
  42                    void *arg,  void (*free_arg) (void *))
  43 {
  44   struct continuation *newobj = XNEW (struct continuation);
  45
  46   newobj->next = *pmy_chain;
  47   newobj->function = function;
  48   newobj->free_arg = free_arg;
  49   newobj->arg = arg;
  50   *pmy_chain = newobj;
  51 }
  52
  53 static void
  54 do_my_continuations_1 (struct continuation **pmy_chain, int err)
  55 {
  56   struct continuation *ptr;
  57
  58   while ((ptr = *pmy_chain) != NULL)
  59     {
  60       *pmy_chain = ptr->next;   /* Do this first in case of recursion.  */
  61       (*ptr->function) (ptr->arg, err);
  62       if (ptr->free_arg)
  63         (*ptr->free_arg) (ptr->arg);
  64       xfree (ptr);
  65     }
  66 }
  67
  68 static void
  69 do_my_continuations (struct continuation **list, int err)
  70 {
  71   struct continuation *continuations;
  72
  73   if (*list == NULL)
  74     return;
  75
  76   /* Copy the list header into another pointer, and set the global
  77      list header to null, so that the global list can change as a side
  78      effect of invoking the continuations and the processing of the
  79      preexisting continuations will not be affected.  */
  80
  81   continuations = *list;
  82   *list = NULL;
  83
  84   /* Work now on the list we have set aside.  */
  85   do_my_continuations_1 (&continuations, err);
  86 }
  87
  88 static void
  89 discard_my_continuations_1 (struct continuation **pmy_chain)
  90 {
  91   struct continuation *ptr;
  92
  93   while ((ptr = *pmy_chain) != NULL)
  94     {
  95       *pmy_chain = ptr->next;
  96       if (ptr->free_arg)
  97         (*ptr->free_arg) (ptr->arg);
  98       xfree (ptr);
  99     }
 100 }
 101
 102 static void
 103 discard_my_continuations (struct continuation **list)
 104 {
 105   discard_my_continuations_1 (list);
 106   *list = NULL;
 107 }
 108
 109 /* Add a continuation to the continuation list of INFERIOR.  The new
 110    continuation will be added at the front.  */
 111
 112 void
 113 add_inferior_continuation (continuation_ftype *hook, void *args,
 114                            continuation_free_arg_ftype *free_arg)
 115 {
 116   struct inferior *inf = current_inferior ();
 117
 118   make_continuation (&inf->continuations, hook, args, free_arg);
 119 }
 120
 121 /* Do all continuations of the current inferior.  */
 122
 123 void
 124 do_all_inferior_continuations (int err)
 125 {
 126   struct inferior *inf = current_inferior ();
 127   do_my_continuations (&inf->continuations, err);
 128 }
 129
 130 /* Get rid of all the inferior-wide continuations of INF.  */
 131
 132 void
 133 discard_all_inferior_continuations (struct inferior *inf)
 134 {
 135   discard_my_continuations (&inf->continuations);
 136 }