signals.h

/**************************************************************************/
/*                                                                        */
/*                                 OCaml                                  */
/*                                                                        */
/*          Xavier Leroy and Damien Doligez, INRIA Rocquencourt           */
/*                                                                        */
/*   Copyright 1996 Institut National de Recherche en Informatique et     */
/*     en Automatique.                                                    */
/*                                                                        */
/*   All rights reserved.  This file is distributed under the terms of    */
/*   the GNU Lesser General Public License version 2.1, with the          */
/*   special exception on linking described in the file LICENSE.          */
/*                                                                        */
/**************************************************************************/

#ifndef CAML_SIGNALS_H
#define CAML_SIGNALS_H

#if defined(CAML_INTERNALS)
#include <signal.h>
#endif

#include "misc.h"
#include "mlvalues.h"

#ifdef __cplusplus
extern "C" {
#endif

CAMLextern void caml_enter_blocking_section (void);
CAMLextern void caml_enter_blocking_section_no_pending (void);
CAMLextern void caml_leave_blocking_section (void);

CAMLextern void caml_process_pending_actions (void);
/* Checks for pending actions and executes them. This includes pending
   minor and major collections, thread switching, signal handlers,
   finalisers, and Memprof callbacks. Assumes that the runtime lock is
   held. Can raise exceptions asynchronously into OCaml code. */

/* Same as [caml_process_pending_actions], but returns the reified
   result instead of raising exceptions directly (if any). */
CAMLextern caml_result caml_process_pending_actions_res (void);

/* Returns [Val_unit] or an encoded exception.
   Superseded by the safer [_res] variant above,
   kept around for compatibility. */
CAMLextern value caml_process_pending_actions_exn (void);

CAMLextern int caml_check_pending_actions (void);
/* Returns 1 if there are pending actions, 0 otherwise. */

#ifdef __cplusplus
}
#endif

#ifdef CAML_INTERNALS

value caml_process_pending_actions_with_root (value extra_root); // raises
/* This is identical to [caml_process_pending_actions], except that it
   registers its argument as a root and eventually returns it. This is
   useful to safely process pending actions before returning from
   functions that manipulate a 'value' without proper rooting.

   This would be incorrect:
     {
       value ret;
       ...
       caml_process_pending_actions(); // this may call a GC
       return ret; // 'ret' was not rooted and may have been moved
     }

   This is correct:
     {
       value ret;
       ...
       ret = caml_process_pending_actions_with_root(ret);
       return ret;
     }
*/

caml_result caml_process_pending_actions_with_root_res (value extra_root);

#ifndef NSIG
#define NSIG 65
#endif

#define BITS_PER_WORD (sizeof(uintnat) * 8)
#define NSIG_WORDS ((NSIG - 1 + BITS_PER_WORD - 1) / BITS_PER_WORD)

CAMLextern atomic_uintnat caml_pending_signals[NSIG_WORDS];

/* Global variables moved to Caml_state in 4.10 */
#define caml_requested_major_slice (Caml_state_field(requested_major_slice))
#define caml_requested_minor_gc (Caml_state_field(requested_minor_gc))

CAMLextern int caml_check_pending_signals(void);
void caml_request_major_slice (int global);
void caml_request_minor_gc (void);
CAMLextern int caml_convert_signal_number (int);
CAMLextern int caml_rev_convert_signal_number (int);
caml_result caml_execute_signal_res(int signal_number);
CAMLextern void caml_record_signal(int signal_number);
CAMLextern caml_result caml_process_pending_signals_res(void);
CAMLextern void caml_set_action_pending(caml_domain_state *);
caml_result caml_do_pending_actions_res(void);

void caml_init_signal_handling(void);
void caml_init_signals(void);
void caml_terminate_signals(void);
CAMLextern void * caml_init_signal_stack(void);
CAMLextern void caml_free_signal_stack(void *);

/* These hooks are not modified after other threads are spawned. */
CAMLextern void (*caml_enter_blocking_section_hook)(void);
CAMLextern void (*caml_leave_blocking_section_hook)(void);

#endif /* CAML_INTERNALS */

#endif /* CAML_SIGNALS_H */