diff options
Diffstat (limited to 'libguile/fluids.c')
-rw-r--r-- | libguile/fluids.c | 42 |
1 files changed, 27 insertions, 15 deletions
diff --git a/libguile/fluids.c b/libguile/fluids.c index 67efd9f6a..f92c5dddc 100644 --- a/libguile/fluids.c +++ b/libguile/fluids.c @@ -68,7 +68,7 @@ grow_dynamic_state (SCM state) /* Assume the assignment below is atomic. */ len = allocated_fluids_len; - new_fluids = scm_c_make_vector (len, SCM_BOOL_F); + new_fluids = scm_c_make_vector (len, SCM_UNDEFINED); for (i = 0; i < old_len; i++) SCM_SIMPLE_VECTOR_SET (new_fluids, i, @@ -103,14 +103,14 @@ scm_i_with_fluids_print (SCM exp, SCM port, scm_print_state *pstate SCM_UNUSED) /* Return a new fluid. */ static SCM -new_fluid () +new_fluid (SCM init) { SCM fluid; size_t trial, n; - /* Fluids are pointerless cells: the first word is the type tag; the second - word is the fluid number. */ - fluid = PTR2SCM (scm_gc_malloc_pointerless (sizeof (scm_t_cell), "fluid")); + /* 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); @@ -157,7 +157,7 @@ new_fluid () } allocated_fluids[n] = SCM2PTR (fluid); - SCM_SET_CELL_WORD_1 (fluid, (scm_t_bits) n); + SCM_SET_CELL_WORD_0 (fluid, (scm_tc7_fluid | (n << 8))); GC_GENERAL_REGISTER_DISAPPEARING_LINK (&allocated_fluids[n], SCM2PTR (fluid)); @@ -166,13 +166,19 @@ new_fluid () /* Now null out values. We could (and probably should) do this when the fluid is collected instead of now. */ - scm_i_reset_fluid (n, SCM_BOOL_F); + scm_i_reset_fluid (n); return fluid; } -SCM_DEFINE (scm_make_fluid, "make-fluid", 0, 0, 0, - (), +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.\n" "Fluids are objects that can hold one\n" "value per dynamic state. That is, modifications to this value are\n" @@ -180,9 +186,9 @@ SCM_DEFINE (scm_make_fluid, "make-fluid", 0, 0, 0, "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 +#define FUNC_NAME s_scm_make_fluid_with_default { - return new_fluid (); + return new_fluid (SCM_UNBNDP (dflt) ? SCM_BOOL_F : dflt); } #undef FUNC_NAME @@ -191,9 +197,7 @@ 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 { - SCM f = new_fluid (); - scm_fluid_set_x (f, SCM_UNDEFINED); - return f; + return new_fluid (SCM_UNDEFINED); } #undef FUNC_NAME @@ -217,6 +221,7 @@ scm_is_fluid (SCM obj) 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))) @@ -227,7 +232,11 @@ fluid_ref (SCM fluid) fluids = DYNAMIC_STATE_FLUIDS (SCM_I_CURRENT_THREAD->dynamic_state); } - return SCM_SIMPLE_VECTOR_REF (fluids, FLUID_NUM (fluid)); + 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, @@ -274,6 +283,9 @@ SCM_DEFINE (scm_fluid_unset_x, "fluid-unset!", 1, 0, 0, "Unset the value associated with @var{fluid}.") #define FUNC_NAME s_scm_fluid_unset_x { + /* 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 |