gdb/thread-fsm.h

   1 /* Thread command's finish-state machine, for GDB, the GNU debugger.
   2    Copyright (C) 2015-2018 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef THREAD_FSM_H
  20 #define THREAD_FSM_H
  21
  22 #include "mi/mi-common.h" /* For enum async_reply_reason.  */
  23
  24 struct return_value_info;
  25 struct thread_fsm_ops;
  26
  27 /* A thread finite-state machine structure contains the necessary info
  28    and callbacks to manage the state machine protocol of a thread's
  29    execution command.  */
  30
  31 struct thread_fsm
  32 {
  33   /* Pointer of the virtual table of methods.  */
  34   struct thread_fsm_ops *ops;
  35
  36   /* Whether the FSM is done successfully.  */
  37   int finished;
  38
  39   /* The interpreter that issued the execution command that caused
  40      this thread to resume.  If the top level interpreter is MI/async,
  41      and the execution command was a CLI command (next/step/etc.),
  42      we'll want to print stop event output to the MI console channel
  43      (the stepped-to line, etc.), as if the user entered the execution
  44      command on a real GDB console.  */
  45   struct interp *command_interp;
  46 };
  47
  48 /* The virtual table of a thread_fsm.  */
  49
  50 struct thread_fsm_ops
  51 {
  52   /* The destructor.  This should simply free heap allocated data
  53      structures.  Cleaning up target resources (like, e.g.,
  54      breakpoints) should be done in the clean_up method.  */
  55   void (*dtor) (struct thread_fsm *self);
  56
  57   /* Called to clean up target resources after the FSM.  E.g., if the
  58      FSM created internal breakpoints, this is where they should be
  59      deleted.  */
  60   void (*clean_up) (struct thread_fsm *self, struct thread_info *thread);
  61
  62   /* Called after handle_inferior_event decides the target is done
  63      (that is, after stop_waiting).  The FSM is given a chance to
  64      decide whether the command is done and thus the target should
  65      stop, or whether there's still more to do and thus the thread
  66      should be re-resumed.  This is a good place to cache target data
  67      too.  For example, the "finish" command saves the just-finished
  68      function's return value here.  */
  69   int (*should_stop) (struct thread_fsm *self, struct thread_info *thread);
  70
  71   /* If this FSM saved a function's return value, you can use this
  72      method to retrieve it.  Otherwise, this returns NULL.  */
  73   struct return_value_info *(*return_value) (struct thread_fsm *self);
  74
  75   /* The async_reply_reason that is broadcast to MI clients if this
  76      FSM finishes successfully.  */
  77   enum async_reply_reason (*async_reply_reason) (struct thread_fsm *self);
  78
  79   /* Whether the stop should be notified to the user/frontend.  */
  80   int (*should_notify_stop) (struct thread_fsm *self);
  81 };
  82 /* Initialize FSM.  */
  83 extern void thread_fsm_ctor (struct thread_fsm *self,
  84                              struct thread_fsm_ops *ops,
  85                              struct interp *cmd_interp);
  86
  87 /* Calls the FSM's dtor method, and then frees FSM.  */
  88 extern void thread_fsm_delete (struct thread_fsm *fsm);
  89
  90 /* Calls the FSM's clean_up method.  */
  91 extern void thread_fsm_clean_up (struct thread_fsm *fsm,
  92                                  struct thread_info *thread);
  93
  94 /* Calls the FSM's should_stop method.  */
  95 extern int thread_fsm_should_stop (struct thread_fsm *fsm,
  96                                    struct thread_info *thread);
  97
  98 /* Calls the FSM's return_value method.  */
  99 extern struct return_value_info *
 100   thread_fsm_return_value (struct thread_fsm *fsm);
 101
 102 /* Marks the FSM as completed successfully.  */
 103 extern void thread_fsm_set_finished (struct thread_fsm *fsm);
 104
 105 /* Returns true if the FSM completed successfully.  */
 106 extern int thread_fsm_finished_p (struct thread_fsm *fsm);
 107
 108 /* Calls the FSM's reply_reason method.  */
 109 extern enum async_reply_reason
 110   thread_fsm_async_reply_reason (struct thread_fsm *fsm);
 111
 112 /* Calls the FSM's should_notify_stop method.  */
 113 extern int thread_fsm_should_notify_stop (struct thread_fsm *self);
 114
 115 #endif /* THREAD_FSM_H */