6 /* Copyright (C) 1996,2000,2001, 2006, 2008, 2009, 2010, 2011, 2012, 2013 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"
27 #include "libguile/root.h"
28 #include "libguile/vectors.h"
33 Fluids are objects of a certain type that can hold one SCM value per
34 dynamic state. That is, modifications to this value are only visible
35 to code that executes with the same dynamic state as the modifying
36 code. When a new dynamic state is constructed, it inherits the
37 values from its parent. Because each thread executes with its own
38 dynamic state, you can use fluids for thread local storage.
40 Each fluid is identified by a small integer. This integer is used to
41 index a vector that holds the values of all fluids. A dynamic state
42 consists of this vector, wrapped in an object so that the vector can
46 #define SCM_FLUID_P(x) (SCM_HAS_TYP7 (x, scm_tc7_fluid))
47 #ifdef BUILDING_LIBGUILE
48 #define SCM_I_FLUID_NUM(x) ((size_t)(SCM_CELL_WORD_0 (x) >> 8))
49 #define SCM_I_FLUID_DEFAULT(x) (SCM_CELL_OBJECT_1 (x))
52 SCM_API SCM
scm_make_fluid (void);
53 SCM_API SCM
scm_make_fluid_with_default (SCM dflt
);
54 SCM_API SCM
scm_make_unbound_fluid (void);
55 SCM_API
int scm_is_fluid (SCM obj
);
56 SCM_API SCM
scm_fluid_p (SCM fl
);
57 SCM_API SCM
scm_fluid_ref (SCM fluid
);
58 SCM_API SCM
scm_fluid_set_x (SCM fluid
, SCM value
);
59 SCM_API SCM
scm_fluid_unset_x (SCM fluid
);
60 SCM_API SCM
scm_fluid_bound_p (SCM fluid
);
62 SCM_INTERNAL
void scm_swap_fluid (SCM fluid
, SCM value_box
, SCM dynamic_state
);
64 SCM_API SCM
scm_c_with_fluids (SCM fluids
, SCM vals
,
65 SCM (*cproc
)(void *), void *cdata
);
66 SCM_API SCM
scm_c_with_fluid (SCM fluid
, SCM val
,
67 SCM (*cproc
)(void *), void *cdata
);
68 SCM_API SCM
scm_with_fluids (SCM fluids
, SCM vals
, SCM thunk
);
69 SCM_API SCM
scm_with_fluid (SCM fluid
, SCM val
, SCM thunk
);
71 SCM_API
void scm_dynwind_fluid (SCM fluid
, SCM value
);
73 #ifdef BUILDING_LIBGUILE
74 #define SCM_I_DYNAMIC_STATE_P(x) (SCM_HAS_TYP7 (x, scm_tc7_dynamic_state))
75 #define SCM_I_DYNAMIC_STATE_FLUIDS(x) SCM_PACK (SCM_CELL_WORD_1 (x))
78 SCM_API SCM
scm_make_dynamic_state (SCM parent
);
79 SCM_API SCM
scm_dynamic_state_p (SCM obj
);
80 SCM_API
int scm_is_dynamic_state (SCM obj
);
81 SCM_API SCM
scm_current_dynamic_state (void);
82 SCM_API SCM
scm_set_current_dynamic_state (SCM state
);
83 SCM_API
void scm_dynwind_current_dynamic_state (SCM state
);
84 SCM_API
void *scm_c_with_dynamic_state (SCM state
,
85 void *(*func
)(void *), void *data
);
86 SCM_API SCM
scm_with_dynamic_state (SCM state
, SCM proc
);
88 SCM_INTERNAL SCM
scm_i_make_initial_dynamic_state (void);
90 SCM_INTERNAL
void scm_i_fluid_print (SCM exp
, SCM port
, scm_print_state
*pstate
);
91 SCM_INTERNAL
void scm_i_dynamic_state_print (SCM exp
, SCM port
, scm_print_state
*pstate
);
92 SCM_INTERNAL
void scm_init_fluids (void);
94 #endif /* SCM_FLUIDS_H */