3 #ifndef SCM_CONTINUATIONS_H
4 #define SCM_CONTINUATIONS_H
6 /* Copyright (C) 1995,1996,2000,2001, 2006 Free Software Foundation, Inc.
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this library; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 #include "libguile/__scm.h"
33 /* a continuation SCM is a non-immediate pointing to a heap cell with:
34 word 0: bits 0-15: smob type tag: scm_tc16_continuation.
36 word 1: malloc block containing an scm_t_contregs structure with a
37 tail array of SCM_STACKITEM. the size of the array is stored
38 in the num_stack_items field of the structure.
41 SCM_API scm_t_bits scm_tc16_continuation;
50 unsigned long backing_store_size;
52 size_t num_stack_items; /* size of the saved stack. */
53 SCM root; /* continuation root identifier. */
55 /* The offset from the live stack location to this copy. This is
56 used to adjust pointers from within the copied stack to the stack
59 Thus, when you read a pointer from the copied stack that points
60 into the live stack, you need to add OFFSET so that it points
65 /* The most recently created debug frame on the live stack, before
66 it was saved. This needs to be adjusted with OFFSET, above.
68 struct scm_t_debug_frame *dframe;
70 SCM_STACKITEM stack[1]; /* copied stack of size num_stack_items. */
73 #define SCM_CONTINUATIONP(x) SCM_TYP16_PREDICATE (scm_tc16_continuation, x)
75 #define SCM_CONTREGS(x) ((scm_t_contregs *) SCM_CELL_WORD_1 (x))
77 #define SCM_CONTINUATION_LENGTH(x) (SCM_CONTREGS (x)->num_stack_items)
78 #define SCM_SET_CONTINUATION_LENGTH(x, n)\
79 (SCM_CONTREGS (x)->num_stack_items = (n))
80 #define SCM_JMPBUF(x) ((SCM_CONTREGS (x))->jmpbuf)
81 #define SCM_DYNENV(x) ((SCM_CONTREGS (x))->dynenv)
82 #define SCM_THROW_VALUE(x) ((SCM_CONTREGS (x))->throw_value)
83 #define SCM_CONTINUATION_ROOT(x) ((SCM_CONTREGS (x))->root)
84 #define SCM_DFRAME(x) ((SCM_CONTREGS (x))->dframe)
88 SCM_API SCM scm_make_continuation (int *first);
90 SCM_API void *scm_c_with_continuation_barrier (void *(*func)(void*), void *);
91 SCM_API SCM scm_with_continuation_barrier (SCM proc);
93 SCM_API SCM scm_i_with_continuation_barrier (scm_t_catch_body body,
95 scm_t_catch_handler handler,
97 scm_t_catch_handler pre_unwind_handler,
98 void *pre_unwind_handler_data);
100 SCM_API void scm_init_continuations (void);
102 #endif /* SCM_CONTINUATIONS_H */