src/thread.h

   1 /* Thread definitions
   2    Copyright (C) 2012 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Emacs.
   5
   6 GNU Emacs 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 GNU Emacs 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 GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef THREAD_H
  20 #define THREAD_H
  21
  22 #include "regex.h"
  23
  24 struct thread_state
  25 {
  26   struct vectorlike_header header;
  27
  28   /* The buffer in which the last search was performed, or
  29      Qt if the last search was done in a string;
  30      Qnil if no searching has been done yet.  */
  31   Lisp_Object m_last_thing_searched;
  32 #define last_thing_searched (current_thread->m_last_thing_searched)
  33
  34   Lisp_Object m_saved_last_thing_searched;
  35 #define saved_last_thing_searched (current_thread->m_saved_last_thing_searched)
  36
  37   /* The thread's name.  */
  38   Lisp_Object name;
  39
  40   /* The thread's function.  */
  41   Lisp_Object function;
  42
  43   /* If non-nil, this thread has been signalled.  */
  44   Lisp_Object error_symbol;
  45   Lisp_Object error_data;
  46
  47   /* If we are waiting for some event, this holds the object we are
  48      waiting on.  */
  49   Lisp_Object event_object;
  50
  51   /* m_gcprolist must be the first non-lisp field.  */
  52   /* Recording what needs to be marked for gc.  */
  53   struct gcpro *m_gcprolist;
  54 #define gcprolist (current_thread->m_gcprolist)
  55
  56   /* A list of currently active byte-code execution value stacks.
  57      Fbyte_code adds an entry to the head of this list before it starts
  58      processing byte-code, and it removed the entry again when it is
  59      done.  Signalling an error truncates the list analoguous to
  60      gcprolist.  */
  61   struct byte_stack *m_byte_stack_list;
  62 #define byte_stack_list (current_thread->m_byte_stack_list)
  63
  64   /* An address near the bottom of the stack.
  65      Tells GC how to save a copy of the stack.  */
  66   char *m_stack_bottom;
  67 #define stack_bottom (current_thread->m_stack_bottom)
  68
  69   /* An address near the top of the stack.  */
  70   char *stack_top;
  71
  72   struct backtrace *m_backtrace_list;
  73 #define backtrace_list (current_thread->m_backtrace_list)
  74
  75   struct catchtag *m_catchlist;
  76 #define catchlist (current_thread->m_catchlist)
  77
  78   /* Chain of condition handlers currently in effect.
  79      The elements of this chain are contained in the stack frames
  80      of Fcondition_case and internal_condition_case.
  81      When an error is signaled (by calling Fsignal, below),
  82      this chain is searched for an element that applies.  */
  83   struct handler *m_handlerlist;
  84 #define handlerlist (current_thread->m_handlerlist)
  85
  86   /* Count levels of GCPRO to detect failure to UNGCPRO.  */
  87   int m_gcpro_level;
  88 #define gcpro_level (current_thread->m_gcpro_level)
  89
  90   /* Current number of specbindings allocated in specpdl.  */
  91   ptrdiff_t m_specpdl_size;
  92 #define specpdl_size (current_thread->m_specpdl_size)
  93
  94   /* Pointer to beginning of specpdl.  */
  95   struct specbinding *m_specpdl;
  96 #define specpdl (current_thread->m_specpdl)
  97
  98   /* Pointer to first unused element in specpdl.  */
  99   struct specbinding *m_specpdl_ptr;
 100 #define specpdl_ptr (current_thread->m_specpdl_ptr)
 101
 102   /* Pointer to the first "saved" element in specpdl.  When this
 103      thread is swapped out, the current values of all specpdl bindings
 104      are pushed onto the specpdl; then these are popped again when
 105      switching back to this thread.  */
 106   struct specbinding *m_saved_specpdl_ptr;
 107
 108   /* Depth in Lisp evaluations and function calls.  */
 109   EMACS_INT m_lisp_eval_depth;
 110 #define lisp_eval_depth (current_thread->m_lisp_eval_depth)
 111
 112   /* This points to the current buffer.  */
 113   struct buffer *m_current_buffer;
 114 #define current_buffer (current_thread->m_current_buffer)
 115
 116   /* Every call to re_match, etc., must pass &search_regs as the regs
 117      argument unless you can show it is unnecessary (i.e., if re_match
 118      is certainly going to be called again before region-around-match
 119      can be called).
 120
 121      Since the registers are now dynamically allocated, we need to make
 122      sure not to refer to the Nth register before checking that it has
 123      been allocated by checking search_regs.num_regs.
 124
 125      The regex code keeps track of whether it has allocated the search
 126      buffer using bits in the re_pattern_buffer.  This means that whenever
 127      you compile a new pattern, it completely forgets whether it has
 128      allocated any registers, and will allocate new registers the next
 129      time you call a searching or matching function.  Therefore, we need
 130      to call re_set_registers after compiling a new pattern or after
 131      setting the match registers, so that the regex functions will be
 132      able to free or re-allocate it properly.  */
 133   struct re_registers m_search_regs;
 134 #define search_regs (current_thread->m_search_regs)
 135
 136   /* If non-zero the match data have been saved in saved_search_regs
 137      during the execution of a sentinel or filter. */
 138   int m_search_regs_saved;
 139 #define search_regs_saved (current_thread->m_search_regs_saved)
 140
 141   struct re_registers m_saved_search_regs;
 142 #define saved_search_regs (current_thread->m_saved_search_regs)
 143
 144   /* This is the string or buffer in which we
 145      are matching.  It is used for looking up syntax properties.  */
 146   Lisp_Object m_re_match_object;
 147 #define re_match_object (current_thread->m_re_match_object)
 148
 149   /* Set by `re_set_syntax' to the current regexp syntax to recognize.  Can
 150      also be assigned to arbitrarily: each pattern buffer stores its own
 151      syntax, so it can be changed between regex compilations.  */
 152   reg_syntax_t m_re_syntax_options;
 153 #define re_syntax_options (current_thread->m_re_syntax_options)
 154
 155   /* Regexp to use to replace spaces, or NULL meaning don't.  */
 156   /*re_char*/ unsigned char *m_whitespace_regexp;
 157 #define whitespace_regexp (current_thread->m_whitespace_regexp)
 158
 159   /* The OS identifier for this thread.  */
 160   sys_thread_t thread_id;
 161
 162   /* The condition variable for this thread.  This is associated with
 163      the global lock.  This thread broadcasts to it when it exits.  */
 164   sys_cond_t thread_condvar;
 165
 166   /* This thread might be waiting for some condition.  If so, this
 167      points to the condition.  If the thread is interrupted, the
 168      interrupter should broadcast to this condition.  */
 169   sys_cond_t *wait_condvar;
 170
 171   /* Threads are kept on a linked list.  */
 172   struct thread_state *next_thread;
 173 };
 174
 175 struct Lisp_Mutex
 176 {
 177   struct vectorlike_header header;
 178
 179   Lisp_Object name;
 180
 181   lisp_mutex_t mutex;
 182 };
 183
 184 extern struct thread_state *current_thread;
 185
 186 extern sys_mutex_t global_lock;
 187 extern void post_acquire_global_lock (struct thread_state *);
 188
 189 extern void unmark_threads (void);
 190 extern void finalize_one_thread (struct thread_state *state);
 191 extern void finalize_one_mutex (struct Lisp_Mutex *);
 192
 193 extern void init_threads_once (void);
 194 extern void init_threads (void);
 195 extern void syms_of_threads (void);
 196
 197 #endif /* THREAD_H */