-/* Copyright (C) 1996,1997,2000,2001 Free Software Foundation, Inc.
+/* Copyright (C) 1996,1997,2000,2001, 2004, 2006, 2007, 2008, 2009, 2010,
+ * 2011, 2012, 2013 Free Software Foundation, Inc.
*
* This library 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 2.1 of the License, or (at your option) any later version.
+ * 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.
*
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * This library 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 this library; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301 USA
*/
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+#include <alloca.h>
+#include <stdio.h>
+#include <string.h>
#include "libguile/_scm.h"
#include "libguile/print.h"
-#include "libguile/smob.h"
#include "libguile/dynwind.h"
#include "libguile/fluids.h"
#include "libguile/alist.h"
#include "libguile/eval.h"
#include "libguile/ports.h"
#include "libguile/deprecation.h"
-#include "libguile/lang.h"
-
-#define INITIAL_FLUIDS 10
#include "libguile/validate.h"
+#include "libguile/bdw-gc.h"
-static volatile long n_fluids;
-scm_t_bits scm_tc16_fluid;
+/* Number of additional slots to allocate when ALLOCATED_FLUIDS is full. */
+#define FLUID_GROW 128
-SCM
-scm_make_initial_fluids ()
-{
- return scm_c_make_vector (INITIAL_FLUIDS, SCM_BOOL_F);
-}
+/* Vector of allocated fluids indexed by fluid numbers. Access is protected by
+ FLUID_ADMIN_MUTEX. */
+static void **allocated_fluids = NULL;
+static size_t allocated_fluids_len = 0;
+
+static scm_i_pthread_mutex_t fluid_admin_mutex = SCM_I_PTHREAD_MUTEX_INITIALIZER;
+
+#define IS_FLUID(x) SCM_FLUID_P (x)
+#define FLUID_NUM(x) SCM_I_FLUID_NUM (x)
+#define IS_DYNAMIC_STATE(x) SCM_I_DYNAMIC_STATE_P (x)
+#define DYNAMIC_STATE_FLUIDS(x) SCM_I_DYNAMIC_STATE_FLUIDS (x)
+#define SET_DYNAMIC_STATE_FLUIDS(x, y) SCM_SET_CELL_WORD_1 ((x), (SCM_UNPACK (y)))
+
+
+\f
+/* Grow STATE so that it can hold up to ALLOCATED_FLUIDS_LEN fluids. This may
+ be more than necessary since ALLOCATED_FLUIDS is sparse and the current
+ thread may not access all the fluids anyway. Memory usage could be improved
+ by using a 2-level array as is done in glibc for pthread keys (TODO). */
static void
-grow_fluids (scm_root_state *root_state, int new_length)
+grow_dynamic_state (SCM state)
{
- SCM old_fluids, new_fluids;
- long old_length, i;
+ SCM new_fluids;
+ SCM old_fluids = DYNAMIC_STATE_FLUIDS (state);
+ size_t i, len, old_len = SCM_SIMPLE_VECTOR_LENGTH (old_fluids);
- old_fluids = root_state->fluids;
- old_length = SCM_VECTOR_LENGTH (old_fluids);
- new_fluids = scm_c_make_vector (new_length, SCM_BOOL_F);
- i = 0;
- while (i < old_length)
- {
- SCM_VECTOR_SET (new_fluids, i, SCM_VELTS(old_fluids)[i]);
- i++;
- }
- while (i < new_length)
- {
- SCM_VECTOR_SET (new_fluids, i, SCM_BOOL_F);
- i++;
- }
+ /* Assume the assignment below is atomic. */
+ len = allocated_fluids_len;
+
+ new_fluids = scm_c_make_vector (len, SCM_UNDEFINED);
- root_state->fluids = new_fluids;
+ for (i = 0; i < old_len; i++)
+ SCM_SIMPLE_VECTOR_SET (new_fluids, i,
+ SCM_SIMPLE_VECTOR_REF (old_fluids, i));
+ SET_DYNAMIC_STATE_FLUIDS (state, new_fluids);
}
void
-scm_copy_fluids (scm_root_state *root_state)
+scm_i_fluid_print (SCM exp, SCM port, scm_print_state *pstate SCM_UNUSED)
{
- grow_fluids (root_state, SCM_VECTOR_LENGTH (root_state->fluids));
+ scm_puts ("#<fluid ", port);
+ scm_intprint ((int) FLUID_NUM (exp), 10, port);
+ scm_putc ('>', port);
}
-static int
-fluid_print (SCM exp, SCM port, scm_print_state *pstate SCM_UNUSED)
+void
+scm_i_dynamic_state_print (SCM exp, SCM port, scm_print_state *pstate SCM_UNUSED)
{
- scm_puts ("#<fluid ", port);
- scm_intprint ((int) SCM_FLUID_NUM (exp), 10, port);
+ scm_puts ("#<dynamic-state ", port);
+ scm_intprint (SCM_UNPACK (exp), 16, port);
scm_putc ('>', port);
- return 1;
}
-static long
-next_fluid_num ()
+void
+scm_i_with_fluids_print (SCM exp, SCM port, scm_print_state *pstate SCM_UNUSED)
{
- long n;
- SCM_CRITICAL_SECTION_START;
- n = n_fluids++;
- SCM_CRITICAL_SECTION_END;
- return n;
+ scm_puts ("#<with-fluids ", port);
+ scm_intprint (SCM_UNPACK (exp), 16, port);
+ scm_putc ('>', port);
}
-SCM_DEFINE (scm_make_fluid, "make-fluid", 0, 0, 0,
- (),
- "Return a newly created fluid.\n"
- "Fluids are objects of a certain type (a smob) that can hold one SCM\n"
- "value per dynamic root. That is, modifications to this value are\n"
- "only visible to code that executes within the same dynamic root as\n"
- "the modifying code. When a new dynamic root is constructed, it\n"
- "inherits the values from its parent. Because each thread executes\n"
- "in its own dynamic root, you can use fluids for thread local storage.")
-#define FUNC_NAME s_scm_make_fluid
+\f
+/* Return a new fluid. */
+static SCM
+new_fluid (SCM init)
{
- long n;
+ SCM fluid;
+ size_t trial, n;
- n = next_fluid_num ();
- SCM_RETURN_NEWSMOB (scm_tc16_fluid, n);
+ /* Fluids hold the type tag and the fluid number in the first word,
+ and the default value in the second word. */
+ fluid = scm_cell (scm_tc7_fluid, SCM_UNPACK (init));
+ SCM_SET_CELL_TYPE (fluid, scm_tc7_fluid);
+
+ scm_dynwind_begin (0);
+ scm_i_dynwind_pthread_mutex_lock (&fluid_admin_mutex);
+
+ for (trial = 0; trial < 2; trial++)
+ {
+ /* Look for a free fluid number. */
+ for (n = 0; n < allocated_fluids_len; n++)
+ /* TODO: Use `__sync_bool_compare_and_swap' where available. */
+ if (allocated_fluids[n] == NULL)
+ break;
+
+ if (trial == 0 && n >= allocated_fluids_len)
+ /* All fluid numbers are in use. Run a GC and retry. Explicitly
+ running the GC is costly and bad-style. We only do this because
+ dynamic state fluid vectors would grow unreasonably if fluid numbers
+ weren't reused. */
+ scm_i_gc ("fluids");
+ }
+
+ if (n >= allocated_fluids_len)
+ {
+ /* Grow the vector of allocated fluids. */
+ void **new_allocated_fluids =
+ scm_gc_malloc_pointerless ((allocated_fluids_len + FLUID_GROW)
+ * sizeof (*allocated_fluids),
+ "allocated fluids");
+
+ /* Copy over old values and initialize rest. GC can not run
+ during these two operations since there is no safe point in
+ them. */
+ memcpy (new_allocated_fluids, allocated_fluids,
+ allocated_fluids_len * sizeof (*allocated_fluids));
+ memset (new_allocated_fluids + allocated_fluids_len, 0,
+ FLUID_GROW * sizeof (*allocated_fluids));
+ n = allocated_fluids_len;
+
+ /* Update the vector of allocated fluids. Dynamic states will
+ eventually be lazily grown to accomodate the new value of
+ ALLOCATED_FLUIDS_LEN in `fluid-ref' and `fluid-set!'. */
+ allocated_fluids = new_allocated_fluids;
+ allocated_fluids_len += FLUID_GROW;
+ }
+
+ allocated_fluids[n] = SCM2PTR (fluid);
+ SCM_SET_CELL_WORD_0 (fluid, (scm_tc7_fluid | (n << 8)));
+
+ GC_GENERAL_REGISTER_DISAPPEARING_LINK (&allocated_fluids[n],
+ SCM2PTR (fluid));
+
+ scm_dynwind_end ();
+
+ /* Now null out values. We could (and probably should) do this when
+ the fluid is collected instead of now. */
+ scm_i_reset_fluid (n);
+
+ return fluid;
+}
+
+SCM
+scm_make_fluid (void)
+{
+ return new_fluid (SCM_BOOL_F);
+}
+
+SCM_DEFINE (scm_make_fluid_with_default, "make-fluid", 0, 1, 0,
+ (SCM dflt),
+ "Return a newly created fluid, whose initial value is @var{dflt},\n"
+ "or @code{#f} if @var{dflt} is not given.\n"
+ "Fluids are objects that can hold one\n"
+ "value per dynamic state. That is, modifications to this value are\n"
+ "only visible to code that executes with the same dynamic state as\n"
+ "the modifying code. When a new dynamic state is constructed, it\n"
+ "inherits the values from its parent. Because each thread normally executes\n"
+ "with its own dynamic state, you can use fluids for thread local storage.")
+#define FUNC_NAME s_scm_make_fluid_with_default
+{
+ return new_fluid (SCM_UNBNDP (dflt) ? SCM_BOOL_F : dflt);
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_make_unbound_fluid, "make-unbound-fluid", 0, 0, 0,
+ (),
+ "Make a fluid that is initially unbound.")
+#define FUNC_NAME s_scm_make_unbound_fluid
+{
+ return new_fluid (SCM_UNDEFINED);
}
#undef FUNC_NAME
"@code{#f}.")
#define FUNC_NAME s_scm_fluid_p
{
- return SCM_BOOL(SCM_FLUIDP (obj));
+ return scm_from_bool (IS_FLUID (obj));
}
#undef FUNC_NAME
+int
+scm_is_fluid (SCM obj)
+{
+ return IS_FLUID (obj);
+}
+
+/* Does not check type of `fluid'! */
+static SCM
+fluid_ref (SCM fluid)
+{
+ SCM ret;
+ SCM fluids = DYNAMIC_STATE_FLUIDS (SCM_I_CURRENT_THREAD->dynamic_state);
+
+ if (SCM_UNLIKELY (FLUID_NUM (fluid) >= SCM_SIMPLE_VECTOR_LENGTH (fluids)))
+ {
+ /* Lazily grow the current thread's dynamic state. */
+ grow_dynamic_state (SCM_I_CURRENT_THREAD->dynamic_state);
+
+ fluids = DYNAMIC_STATE_FLUIDS (SCM_I_CURRENT_THREAD->dynamic_state);
+ }
+
+ ret = SCM_SIMPLE_VECTOR_REF (fluids, FLUID_NUM (fluid));
+ if (SCM_UNBNDP (ret))
+ return SCM_I_FLUID_DEFAULT (fluid);
+ else
+ return ret;
+}
+
SCM_DEFINE (scm_fluid_ref, "fluid-ref", 1, 0, 0,
(SCM fluid),
"Return the value associated with @var{fluid} in the current\n"
"@code{#f}.")
#define FUNC_NAME s_scm_fluid_ref
{
- unsigned long int n;
-
+ SCM val;
SCM_VALIDATE_FLUID (1, fluid);
- n = SCM_FLUID_NUM (fluid);
-
- if (SCM_VECTOR_LENGTH (scm_root->fluids) <= n)
- grow_fluids (scm_root, n+1);
- return SCM_VELTS (scm_root->fluids)[n];
+ val = fluid_ref (fluid);
+ if (SCM_UNBNDP (val))
+ SCM_MISC_ERROR ("unbound fluid: ~S",
+ scm_list_1 (fluid));
+ return val;
}
#undef FUNC_NAME
"Set the value associated with @var{fluid} in the current dynamic root.")
#define FUNC_NAME s_scm_fluid_set_x
{
- unsigned long int n;
+ SCM fluids = DYNAMIC_STATE_FLUIDS (SCM_I_CURRENT_THREAD->dynamic_state);
SCM_VALIDATE_FLUID (1, fluid);
- n = SCM_FLUID_NUM (fluid);
- if (SCM_VECTOR_LENGTH (scm_root->fluids) <= n)
- grow_fluids (scm_root, n+1);
- SCM_VECTOR_SET (scm_root->fluids, n, value);
+ if (SCM_UNLIKELY (FLUID_NUM (fluid) >= SCM_SIMPLE_VECTOR_LENGTH (fluids)))
+ {
+ /* Lazily grow the current thread's dynamic state. */
+ grow_dynamic_state (SCM_I_CURRENT_THREAD->dynamic_state);
+
+ fluids = DYNAMIC_STATE_FLUIDS (SCM_I_CURRENT_THREAD->dynamic_state);
+ }
+
+ SCM_SIMPLE_VECTOR_SET (fluids, FLUID_NUM (fluid), value);
return SCM_UNSPECIFIED;
}
#undef FUNC_NAME
-void
-scm_swap_fluids (SCM fluids, SCM vals)
+SCM_DEFINE (scm_fluid_unset_x, "fluid-unset!", 1, 0, 0,
+ (SCM fluid),
+ "Unset the value associated with @var{fluid}.")
+#define FUNC_NAME s_scm_fluid_unset_x
{
- while (!SCM_NULL_OR_NIL_P (fluids))
- {
- SCM fl = SCM_CAR (fluids);
- SCM old_val = scm_fluid_ref (fl);
- scm_fluid_set_x (fl, SCM_CAR (vals));
- SCM_SETCAR (vals, old_val);
- fluids = SCM_CDR (fluids);
- vals = SCM_CDR (vals);
- }
+ /* FIXME: really unset the default value, too? The current test
+ suite demands it, but I would prefer not to. */
+ SCM_SET_CELL_OBJECT_1 (fluid, SCM_UNDEFINED);
+ return scm_fluid_set_x (fluid, SCM_UNDEFINED);
}
+#undef FUNC_NAME
-/* Swap the fluid values in reverse order. This is important when the
-same fluid appears multiple times in the fluids list. */
-
-void
-scm_swap_fluids_reverse (SCM fluids, SCM vals)
+SCM_DEFINE (scm_fluid_bound_p, "fluid-bound?", 1, 0, 0,
+ (SCM fluid),
+ "Return @code{#t} iff @var{fluid} is bound to a value.\n"
+ "Throw an error if @var{fluid} is not a fluid.")
+#define FUNC_NAME s_scm_fluid_bound_p
{
- if (!SCM_NULL_OR_NIL_P (fluids))
- {
- SCM fl, old_val;
-
- scm_swap_fluids_reverse (SCM_CDR (fluids), SCM_CDR (vals));
- fl = SCM_CAR (fluids);
- old_val = scm_fluid_ref (fl);
- scm_fluid_set_x (fl, SCM_CAR (vals));
- SCM_SETCAR (vals, old_val);
- }
+ SCM val;
+ SCM_VALIDATE_FLUID (1, fluid);
+ val = fluid_ref (fluid);
+ return scm_from_bool (! (SCM_UNBNDP (val)));
}
-
+#undef FUNC_NAME
static SCM
apply_thunk (void *thunk)
return scm_call_0 (SCM_PACK (thunk));
}
+SCM
+scm_i_make_with_fluids (size_t n, SCM *fluids, SCM *vals)
+{
+ SCM ret;
+
+ /* Ensure that there are no duplicates in the fluids set -- an N^2 operation,
+ but N will usually be small, so perhaps that's OK. */
+ {
+ size_t i, j;
+
+ for (j = n; j--;)
+ for (i = j; i--;)
+ if (scm_is_eq (fluids[i], fluids[j]))
+ {
+ vals[i] = vals[j]; /* later bindings win */
+ n--;
+ fluids[j] = fluids[n];
+ vals[j] = vals[n];
+ break;
+ }
+ }
+
+ ret = scm_words (scm_tc7_with_fluids | (n << 8), 1 + n*2);
+ SCM_SET_CELL_WORD_1 (ret, n);
+
+ while (n--)
+ {
+ if (SCM_UNLIKELY (!IS_FLUID (fluids[n])))
+ scm_wrong_type_arg ("with-fluids", 0, fluids[n]);
+ SCM_SET_CELL_OBJECT (ret, 1 + n * 2, fluids[n]);
+ SCM_SET_CELL_OBJECT (ret, 2 + n * 2, vals[n]);
+ }
+
+ return ret;
+}
+
+void
+scm_i_swap_with_fluids (SCM wf, SCM dynstate)
+{
+ SCM fluids;
+ size_t i, max = 0;
+
+ fluids = DYNAMIC_STATE_FLUIDS (dynstate);
+
+ /* We could cache the max in the with-fluids, but that would take more mem,
+ and we're touching all the fluids anyway, so this per-swap traversal should
+ be OK. */
+ for (i = 0; i < SCM_WITH_FLUIDS_LEN (wf); i++)
+ {
+ size_t num = FLUID_NUM (SCM_WITH_FLUIDS_NTH_FLUID (wf, i));
+ max = (max > num) ? max : num;
+ }
+
+ if (SCM_UNLIKELY (max >= SCM_SIMPLE_VECTOR_LENGTH (fluids)))
+ {
+ /* Lazily grow the current thread's dynamic state. */
+ grow_dynamic_state (dynstate);
+
+ fluids = DYNAMIC_STATE_FLUIDS (dynstate);
+ }
+
+ /* Bind the fluids. Order doesn't matter, as all fluids are distinct. */
+ for (i = 0; i < SCM_WITH_FLUIDS_LEN (wf); i++)
+ {
+ size_t fluid_num;
+ SCM x;
+
+ fluid_num = FLUID_NUM (SCM_WITH_FLUIDS_NTH_FLUID (wf, i));
+ x = SCM_SIMPLE_VECTOR_REF (fluids, fluid_num);
+ SCM_SIMPLE_VECTOR_SET (fluids, fluid_num,
+ SCM_WITH_FLUIDS_NTH_VAL (wf, i));
+ SCM_WITH_FLUIDS_SET_NTH_VAL (wf, i, x);
+ }
+}
+
SCM_DEFINE (scm_with_fluids, "with-fluids*", 3, 0, 0,
(SCM fluids, SCM values, SCM thunk),
"Set @var{fluids} to @var{values} temporary, and call @var{thunk}.\n"
"one after another. @var{thunk} must be a procedure with no argument.")
#define FUNC_NAME s_scm_with_fluids
{
- return scm_c_with_fluids (fluids, values, apply_thunk, (void *) SCM_UNPACK (thunk));
+ return scm_c_with_fluids (fluids, values,
+ apply_thunk, (void *) SCM_UNPACK (thunk));
}
#undef FUNC_NAME
scm_c_with_fluids (SCM fluids, SCM values, SCM (*cproc) (), void *cdata)
#define FUNC_NAME "scm_c_with_fluids"
{
- SCM ans;
- long flen, vlen;
+ SCM wf, ans;
+ long flen, vlen, i;
+ SCM *fluidsv, *valuesv;
SCM_VALIDATE_LIST_COPYLEN (1, fluids, flen);
SCM_VALIDATE_LIST_COPYLEN (2, values, vlen);
if (flen != vlen)
scm_out_of_range (s_scm_with_fluids, values);
- scm_swap_fluids (fluids, values);
- scm_dynwinds = scm_acons (fluids, values, scm_dynwinds);
+ if (SCM_UNLIKELY (flen == 0))
+ return cproc (cdata);
+
+ fluidsv = alloca (sizeof(SCM)*flen);
+ valuesv = alloca (sizeof(SCM)*flen);
+
+ for (i = 0; i < flen; i++)
+ {
+ fluidsv[i] = SCM_CAR (fluids);
+ fluids = SCM_CDR (fluids);
+ valuesv[i] = SCM_CAR (values);
+ values = SCM_CDR (values);
+ }
+
+ wf = scm_i_make_with_fluids (flen, fluidsv, valuesv);
+ scm_i_swap_with_fluids (wf, SCM_I_CURRENT_THREAD->dynamic_state);
+ scm_i_set_dynwinds (scm_cons (wf, scm_i_dynwinds ()));
ans = cproc (cdata);
- scm_dynwinds = SCM_CDR (scm_dynwinds);
- scm_swap_fluids_reverse (fluids, values);
+ scm_i_swap_with_fluids (wf, SCM_I_CURRENT_THREAD->dynamic_state);
+ scm_i_set_dynwinds (scm_cdr (scm_i_dynwinds ()));
+
return ans;
}
#undef FUNC_NAME
+SCM_DEFINE (scm_with_fluid, "with-fluid*", 3, 0, 0,
+ (SCM fluid, SCM value, SCM thunk),
+ "Set @var{fluid} to @var{value} temporarily, and call @var{thunk}.\n"
+ "@var{thunk} must be a procedure with no argument.")
+#define FUNC_NAME s_scm_with_fluid
+{
+ return scm_c_with_fluid (fluid, value,
+ apply_thunk, (void *) SCM_UNPACK (thunk));
+}
+#undef FUNC_NAME
+
SCM
scm_c_with_fluid (SCM fluid, SCM value, SCM (*cproc) (), void *cdata)
#define FUNC_NAME "scm_c_with_fluid"
{
- return scm_c_with_fluids (scm_list_1 (fluid), scm_list_1 (value),
- cproc, cdata);
+ SCM ans, wf;
+
+ wf = scm_i_make_with_fluids (1, &fluid, &value);
+ scm_i_swap_with_fluids (wf, SCM_I_CURRENT_THREAD->dynamic_state);
+ scm_i_set_dynwinds (scm_cons (wf, scm_i_dynwinds ()));
+ ans = cproc (cdata);
+ scm_i_swap_with_fluids (wf, SCM_I_CURRENT_THREAD->dynamic_state);
+ scm_i_set_dynwinds (scm_cdr (scm_i_dynwinds ()));
+
+ return ans;
+}
+#undef FUNC_NAME
+
+static void
+swap_fluid (SCM data)
+{
+ SCM f = SCM_CAR (data);
+ SCM t = fluid_ref (f);
+ scm_fluid_set_x (f, SCM_CDR (data));
+ SCM_SETCDR (data, t);
+}
+
+void
+scm_dynwind_fluid (SCM fluid, SCM value)
+{
+ SCM data = scm_cons (fluid, value);
+ scm_dynwind_rewind_handler_with_scm (swap_fluid, data, SCM_F_WIND_EXPLICITLY);
+ scm_dynwind_unwind_handler_with_scm (swap_fluid, data, SCM_F_WIND_EXPLICITLY);
+}
+
+SCM
+scm_i_make_initial_dynamic_state ()
+{
+ SCM fluids = scm_c_make_vector (allocated_fluids_len, SCM_BOOL_F);
+ return scm_cell (scm_tc7_dynamic_state, SCM_UNPACK (fluids));
+}
+
+SCM_DEFINE (scm_make_dynamic_state, "make-dynamic-state", 0, 1, 0,
+ (SCM parent),
+ "Return a copy of the dynamic state object @var{parent}\n"
+ "or of the current dynamic state when @var{parent} is omitted.")
+#define FUNC_NAME s_scm_make_dynamic_state
+{
+ SCM fluids;
+
+ if (SCM_UNBNDP (parent))
+ parent = scm_current_dynamic_state ();
+
+ SCM_ASSERT (IS_DYNAMIC_STATE (parent), parent, SCM_ARG1, FUNC_NAME);
+ fluids = scm_vector_copy (DYNAMIC_STATE_FLUIDS (parent));
+ return scm_cell (scm_tc7_dynamic_state, SCM_UNPACK (fluids));
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_dynamic_state_p, "dynamic-state?", 1, 0, 0,
+ (SCM obj),
+ "Return @code{#t} if @var{obj} is a dynamic state object;\n"
+ "return @code{#f} otherwise")
+#define FUNC_NAME s_scm_dynamic_state_p
+{
+ return scm_from_bool (IS_DYNAMIC_STATE (obj));
+}
+#undef FUNC_NAME
+
+int
+scm_is_dynamic_state (SCM obj)
+{
+ return IS_DYNAMIC_STATE (obj);
+}
+
+SCM_DEFINE (scm_current_dynamic_state, "current-dynamic-state", 0, 0, 0,
+ (),
+ "Return the current dynamic state object.")
+#define FUNC_NAME s_scm_current_dynamic_state
+{
+ return SCM_I_CURRENT_THREAD->dynamic_state;
}
#undef FUNC_NAME
+SCM_DEFINE (scm_set_current_dynamic_state, "set-current-dynamic-state", 1,0,0,
+ (SCM state),
+ "Set the current dynamic state object to @var{state}\n"
+ "and return the previous current dynamic state object.")
+#define FUNC_NAME s_scm_set_current_dynamic_state
+{
+ scm_i_thread *t = SCM_I_CURRENT_THREAD;
+ SCM old = t->dynamic_state;
+ SCM_ASSERT (IS_DYNAMIC_STATE (state), state, SCM_ARG1, FUNC_NAME);
+ t->dynamic_state = state;
+ return old;
+}
+#undef FUNC_NAME
+
+static void
+swap_dynamic_state (SCM loc)
+{
+ SCM_SETCAR (loc, scm_set_current_dynamic_state (SCM_CAR (loc)));
+}
+
+void
+scm_dynwind_current_dynamic_state (SCM state)
+{
+ SCM loc = scm_cons (state, SCM_EOL);
+ SCM_ASSERT (IS_DYNAMIC_STATE (state), state, SCM_ARG1, NULL);
+ scm_dynwind_rewind_handler_with_scm (swap_dynamic_state, loc,
+ SCM_F_WIND_EXPLICITLY);
+ scm_dynwind_unwind_handler_with_scm (swap_dynamic_state, loc,
+ SCM_F_WIND_EXPLICITLY);
+}
+
+void *
+scm_c_with_dynamic_state (SCM state, void *(*func)(void *), void *data)
+{
+ void *result;
+ scm_dynwind_begin (SCM_F_DYNWIND_REWINDABLE);
+ scm_dynwind_current_dynamic_state (state);
+ result = func (data);
+ scm_dynwind_end ();
+ return result;
+}
+
+SCM_DEFINE (scm_with_dynamic_state, "with-dynamic-state", 2, 0, 0,
+ (SCM state, SCM proc),
+ "Call @var{proc} while @var{state} is the current dynamic\n"
+ "state object.")
+#define FUNC_NAME s_scm_with_dynamic_state
+{
+ SCM result;
+ scm_dynwind_begin (SCM_F_DYNWIND_REWINDABLE);
+ scm_dynwind_current_dynamic_state (state);
+ result = scm_call_0 (proc);
+ scm_dynwind_end ();
+ return result;
+}
+#undef FUNC_NAME
+
+
void
scm_init_fluids ()
{
- scm_tc16_fluid = scm_make_smob_type ("fluid", 0);
- scm_set_smob_print (scm_tc16_fluid, fluid_print);
#include "libguile/fluids.x"
}