1 /* Copyright (C) 1996, 1997, 2000 Free Software Foundation, Inc.
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation; either version 2, or (at your option)
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License
14 * along with this software; see the file COPYING. If not, write to
15 * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
16 * Boston, MA 02111-1307 USA
18 * As a special exception, the Free Software Foundation gives permission
19 * for additional uses of the text contained in its release of GUILE.
21 * The exception is that, if you link the GUILE library with other files
22 * to produce an executable, this does not by itself cause the
23 * resulting executable to be covered by the GNU General Public License.
24 * Your use of that executable is in no way restricted on account of
25 * linking the GUILE library code into it.
27 * This exception does not however invalidate any other reasons why
28 * the executable file might be covered by the GNU General Public License.
30 * This exception applies only to the code released by the
31 * Free Software Foundation under the name GUILE. If you copy
32 * code from other Free Software Foundation releases into a copy of
33 * GUILE, as the General Public License permits, the exception does
34 * not apply to the code that you add in this way. To avoid misleading
35 * anyone as to the status of such modified files, you must delete
36 * this exception notice from them.
38 * If you write modifications of your own for GUILE, it is your choice
39 * whether to permit this exception to apply to your modifications.
40 * If you do not wish that, delete this exception notice. */
42 /* Software engineering face-lift by Greg J. Badros, 11-Dec-1999,
43 gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */
46 #include "libguile/_scm.h"
47 #include "libguile/print.h"
48 #include "libguile/smob.h"
49 #include "libguile/dynwind.h"
50 #include "libguile/fluids.h"
51 #include "libguile/alist.h"
52 #include "libguile/eval.h"
53 #include "libguile/ports.h"
55 #define INITIAL_FLUIDS 10
56 #include "libguile/validate.h"
58 static volatile int n_fluids
;
62 scm_make_initial_fluids ()
64 return scm_make_vector (SCM_MAKINUM (INITIAL_FLUIDS
),
69 grow_fluids (scm_root_state
*root_state
, int new_length
)
71 SCM old_fluids
, new_fluids
;
74 old_fluids
= root_state
->fluids
;
75 old_length
= SCM_LENGTH (old_fluids
);
76 new_fluids
= scm_make_vector (SCM_MAKINUM (new_length
), SCM_BOOL_F
);
78 while (i
< old_length
)
80 SCM_VELTS(new_fluids
)[i
] = SCM_VELTS(old_fluids
)[i
];
83 while (i
< new_length
)
85 SCM_VELTS(new_fluids
)[i
] = SCM_BOOL_F
;
89 root_state
->fluids
= new_fluids
;
93 scm_copy_fluids (scm_root_state
*root_state
)
95 grow_fluids (root_state
, SCM_LENGTH(root_state
->fluids
));
99 print_fluid (SCM exp
, SCM port
, scm_print_state
*pstate
)
101 scm_puts ("#<fluid ", port
);
102 scm_intprint ((int) SCM_FLUID_NUM (exp
), 10, port
);
103 scm_putc ('>', port
);
112 SCM_THREAD_CRITICAL_SECTION_START
;
116 SCM_THREAD_CRITICAL_SECTION_END
;
121 SCM_DEFINE (scm_make_fluid
, "make-fluid", 0, 0, 0,
123 "Return a newly created fluid.\n"
124 "Fluids are objects of a certain type (a smob) that can hold one SCM\n"
125 "value per dynamic root. That is, modifications to this value are\n"
126 "only visible to code that executes within the same dynamic root as\n"
127 "the modifying code. When a new dynamic root is constructed, it\n"
128 "inherits the values from its parent. Because each thread executes\n"
129 "in its own dynamic root, you can use fluids for thread local storage.")
130 #define FUNC_NAME s_scm_make_fluid
135 n
= next_fluid_num ();
136 SCM_RETURN_NEWSMOB (scm_tc16_fluid
, n
);
140 SCM_DEFINE (scm_fluid_p
, "fluid?", 1, 0, 0,
142 "Return #t iff @var{obj} is a fluid; otherwise, return #f.")
143 #define FUNC_NAME s_scm_fluid_p
145 return SCM_BOOL(SCM_FLUIDP (obj
));
149 SCM_DEFINE (scm_fluid_ref
, "fluid-ref", 1, 0, 0,
151 "Return the value associated with @var{fluid} in the current dynamic root.\n"
152 "If @var{fluid} has not been set, then this returns #f.")
153 #define FUNC_NAME s_scm_fluid_ref
157 SCM_VALIDATE_FLUID (1, fluid
);
159 n
= SCM_FLUID_NUM (fluid
);
161 if (SCM_LENGTH (scm_root
->fluids
) <= n
)
162 grow_fluids (scm_root
, n
+1);
163 return SCM_VELTS(scm_root
->fluids
)[n
];
167 SCM_DEFINE (scm_fluid_set_x
, "fluid-set!", 2, 0, 0,
168 (SCM fluid
, SCM value
),
169 "Set the value associated with @var{fluid} in the current dynamic root.")
170 #define FUNC_NAME s_scm_fluid_set_x
174 SCM_VALIDATE_FLUID (1, fluid
);
175 n
= SCM_FLUID_NUM (fluid
);
177 if (SCM_LENGTH (scm_root
->fluids
) <= n
)
178 grow_fluids (scm_root
, n
+1);
179 SCM_VELTS(scm_root
->fluids
)[n
] = value
;
185 scm_swap_fluids (SCM fluids
, SCM vals
)
187 while (SCM_NIMP (fluids
))
189 SCM fl
= SCM_CAR (fluids
);
190 SCM old_val
= scm_fluid_ref (fl
);
191 scm_fluid_set_x (fl
, SCM_CAR (vals
));
192 SCM_SETCAR (vals
, old_val
);
193 fluids
= SCM_CDR (fluids
);
194 vals
= SCM_CDR (vals
);
198 /* Swap the fluid values in reverse order. This is important when the
199 same fluid appears multiple times in the fluids list. */
202 scm_swap_fluids_reverse (SCM fluids
, SCM vals
)
204 if (SCM_NIMP (fluids
))
208 scm_swap_fluids_reverse (SCM_CDR (fluids
), SCM_CDR (vals
));
209 fl
= SCM_CAR (fluids
);
210 old_val
= scm_fluid_ref (fl
);
211 scm_fluid_set_x (fl
, SCM_CAR (vals
));
212 SCM_SETCAR (vals
, old_val
);
218 apply_thunk (void *thunk
)
220 return scm_apply (SCM_PACK (thunk
), SCM_EOL
, SCM_EOL
);
223 SCM_DEFINE (scm_with_fluids
, "with-fluids*", 3, 0, 0,
224 (SCM fluids
, SCM values
, SCM thunk
),
225 "Set @var{fluids} to @var{values} temporary, and call @var{thunk}.\n"
226 "@var{fluids} must be a list of fluids and @var{values} must be the same\n"
227 "number of their values to be applied. Each substitution is done\n"
228 "one after another. @var{thunk} must be a procedure with no argument.")
229 #define FUNC_NAME s_scm_with_fluids
231 return scm_internal_with_fluids (fluids
, values
, apply_thunk
, (void *) SCM_UNPACK (thunk
));
236 scm_internal_with_fluids (SCM fluids
, SCM values
, SCM (*cproc
) (), void *cdata
)
237 #define FUNC_NAME "scm_internal_with_fluids"
242 SCM_VALIDATE_LIST_COPYLEN (1, fluids
, flen
);
243 SCM_VALIDATE_LIST_COPYLEN (2, values
, vlen
);
245 scm_out_of_range (s_scm_with_fluids
, values
);
247 scm_swap_fluids (fluids
, values
);
248 scm_dynwinds
= scm_acons (fluids
, values
, scm_dynwinds
);
250 scm_dynwinds
= SCM_CDR (scm_dynwinds
);
251 scm_swap_fluids_reverse (fluids
, values
);
261 scm_tc16_fluid
= scm_make_smob_type_mfpe ("fluid", 0,
262 NULL
, NULL
, print_fluid
, NULL
);
263 #include "libguile/fluids.x"