3 #ifndef SCM_CONTINUATIONS_H
4 #define SCM_CONTINUATIONS_H
6 /* Copyright (C) 1995,1996,2000,2001, 2006, 2008 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 License
10 * as published by the Free Software Foundation; either version 3 of
11 * the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful, but
14 * 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
26 #include "libguile/__scm.h"
34 /* a continuation SCM is a non-immediate pointing to a heap cell with:
35 word 0: bits 0-15: smob type tag: scm_tc16_continuation.
37 word 1: malloc block containing an scm_t_contregs structure with a
38 tail array of SCM_STACKITEM. the size of the array is stored
39 in the num_stack_items field of the structure.
42 SCM_API scm_t_bits scm_tc16_continuation
;
51 unsigned long backing_store_size
;
53 size_t num_stack_items
; /* size of the saved stack. */
54 SCM root
; /* continuation root identifier. */
55 SCM vm_conts
; /* vm continuations (they use separate stacks) */
57 /* The offset from the live stack location to this copy. This is
58 used to adjust pointers from within the copied stack to the stack
61 Thus, when you read a pointer from the copied stack that points
62 into the live stack, you need to add OFFSET so that it points
67 /* The most recently created debug frame on the live stack, before
68 it was saved. This needs to be adjusted with OFFSET, above.
70 struct scm_t_debug_frame
*dframe
;
72 SCM_STACKITEM stack
[1]; /* copied stack of size num_stack_items. */
75 #define SCM_CONTINUATIONP(x) SCM_TYP16_PREDICATE (scm_tc16_continuation, x)
77 #define SCM_CONTREGS(x) ((scm_t_contregs *) SCM_CELL_WORD_1 (x))
79 #define SCM_CONTINUATION_LENGTH(x) (SCM_CONTREGS (x)->num_stack_items)
80 #define SCM_SET_CONTINUATION_LENGTH(x, n)\
81 (SCM_CONTREGS (x)->num_stack_items = (n))
82 #define SCM_JMPBUF(x) ((SCM_CONTREGS (x))->jmpbuf)
83 #define SCM_DYNENV(x) ((SCM_CONTREGS (x))->dynenv)
84 #define SCM_THROW_VALUE(x) ((SCM_CONTREGS (x))->throw_value)
85 #define SCM_CONTINUATION_ROOT(x) ((SCM_CONTREGS (x))->root)
86 #define SCM_DFRAME(x) ((SCM_CONTREGS (x))->dframe)
90 SCM_API SCM
scm_make_continuation (int *first
);
92 SCM_API
void *scm_c_with_continuation_barrier (void *(*func
)(void*), void *);
93 SCM_API SCM
scm_with_continuation_barrier (SCM proc
);
96 scm_i_with_continuation_barrier (scm_t_catch_body body
,
98 scm_t_catch_handler handler
,
100 scm_t_catch_handler pre_unwind_handler
,
101 void *pre_unwind_handler_data
);
103 SCM_INTERNAL
void scm_init_continuations (void);
105 #endif /* SCM_CONTINUATIONS_H */