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#ifndef SCM_CONTINUATIONS_H
#define SCM_CONTINUATIONS_H
/* Copyright 1995-1996,2000-2001,2006,2008-2010,2012-2014,2018
Free Software Foundation, Inc.
This file is part of Guile.
Guile is free software: you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published
by the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Guile is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
License for more details.
You should have received a copy of the GNU Lesser General Public
License along with Guile. If not, see
<https://www.gnu.org/licenses/>. */
#include <setjmp.h>
#include "libguile/programs.h"
#include "libguile/throw.h"
#define SCM_CONTINUATIONP(x) \
(SCM_PROGRAM_P (x) && SCM_PROGRAM_IS_CONTINUATION (x))
/* a continuation SCM is a non-immediate pointing to a heap cell with:
word 0: bits 0-15: smob type tag: scm_tc16_continuation.
bits 16-31: unused.
word 1: malloc block containing an scm_t_contregs structure with a
tail array of SCM_STACKITEM. the size of the array is stored
in the num_stack_items field of the structure.
*/
typedef struct
{
jmp_buf jmpbuf;
#if SCM_HAVE_AUXILIARY_STACK
void *auxiliary_stack;
unsigned long auxiliary_stack_size;
#endif
size_t num_stack_items; /* size of the saved stack. */
SCM root; /* continuation root identifier. */
SCM vm_cont; /* vm's stack and regs */
/* The offset from the live stack location to this copy. This is
used to adjust pointers from within the copied stack to the stack
itself.
Thus, when you read a pointer from the copied stack that points
into the live stack, you need to add OFFSET so that it points
into the copy.
*/
ptrdiff_t offset;
SCM_STACKITEM stack[1]; /* copied stack of size num_stack_items. */
} scm_t_contregs;
SCM_INTERNAL SCM scm_i_make_continuation (scm_thread *thread, SCM vm_cont);
SCM_INTERNAL void scm_i_reinstate_continuation (SCM cont,
uint8_t *mra) SCM_NORETURN;
SCM_INTERNAL int scm_i_continuation_to_frame (SCM cont,
struct scm_frame *frame);
SCM_INTERNAL scm_t_contregs* scm_i_contregs (SCM contregs);
SCM_API void *scm_c_with_continuation_barrier (void *(*func)(void*), void *);
SCM_API SCM scm_with_continuation_barrier (SCM proc);
SCM_INTERNAL SCM
scm_i_with_continuation_barrier (scm_t_catch_body body,
void *body_data,
scm_t_catch_handler handler,
void *handler_data,
scm_t_catch_handler pre_unwind_handler,
void *pre_unwind_handler_data);
SCM_INTERNAL void scm_init_continuations (void);
#endif /* SCM_CONTINUATIONS_H */
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