src/runtime/interrupt.h

   1 /*
   2  * This software is part of the SBCL system. See the README file for
   3  * more information.
   4  *
   5  * This software is derived from the CMU CL system, which was
   6  * written at Carnegie Mellon University and released into the
   7  * public domain. The software is in the public domain and is
   8  * provided with absolutely no warranty. See the COPYING and CREDITS
   9  * files for more information.
  10  */
  11
  12 #if !defined(_INCLUDE_INTERRUPT_H_)
  13 #define _INCLUDE_INTERRUPT_H_
  14
  15 #include <signal.h>
  16
  17 /* maximum signal nesting depth
  18  *
  19  * Note: In CMU CL, this was 4096, but there was no explanation given,
  20  * and it's hard to see why we'd need that many nested interrupts, so
  21  * I've scaled it back (to 256) to see what happens. -- WHN 20000730
  22
  23  * Nothing happened, so let's creep it back a bit further -- dan 20030411 */
  24 #define MAX_INTERRUPTS 32
  25
  26 union interrupt_handler {
  27     lispobj lisp;
  28     void (*c)(int, siginfo_t*, void*);
  29 };
  30
  31 struct interrupt_data {
  32     void (*interrupt_low_level_handlers[NSIG]) (int, siginfo_t*, void*) ;
  33     union interrupt_handler interrupt_handlers[NSIG];
  34
  35     /* signal number, siginfo_t, and old mask information for pending
  36      * signal.  pending_signal=0 when there is no pending signal. */
  37     int pending_signal ;
  38     siginfo_t pending_info;
  39     sigset_t pending_mask;
  40 };
  41
  42
  43 extern void interrupt_init();
  44 extern void fake_foreign_function_call(os_context_t* context);
  45 extern void undo_fake_foreign_function_call(os_context_t* context);
  46 extern void interrupt_handle_now(int, siginfo_t*, void*);
  47 extern void interrupt_handle_pending(os_context_t*);
  48 extern void interrupt_internal_error(int, siginfo_t*, os_context_t*,
  49                                      boolean continuable);
  50 extern boolean handle_control_stack_guard_triggered(os_context_t *,void *);
  51 extern boolean interrupt_maybe_gc(int, siginfo_t*, void*);
  52 extern void undoably_install_low_level_interrupt_handler (int signal,
  53                                                           void
  54                                                           handler(int,
  55                                                                   siginfo_t*,
  56                                                                   void*));
  57 extern unsigned long install_handler(int signal,
  58                                      void handler(int, siginfo_t*, void*));
  59
  60 extern union interrupt_handler interrupt_handlers[NSIG];
  61
  62 /* Set all blockable signals into *s. */
  63 void sigaddset_blockable(sigset_t *s);
  64
  65 /* The void* casting here avoids having to mess with the various types
  66  * of function argument lists possible for signal handlers:
  67  * SA_SIGACTION handlers have one signature, and the default old-style
  68  * signal(..) handlers have another, and attempting to represent them
  69  * "cleanly" with union types is in fact a mess. */
  70 #define ARE_SAME_HANDLER(x, y) ((void*)(x) == (void*)(y))
  71 #endif