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(ensure_state_size, ensure_all_state_sizes, resize_all_states):

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Collapsed ensure_state_size and ensure_all_state_sizes into one
function named resize_all_states.  Allocate new vectors outside of
single threaded region.  Do only simple things inside that region.
(scm_make_fluid, scm_make_dynamic_state): Lock fluid_admin_mutex while
adding to the global lists.
This commit is contained in:
Marius Vollmer 2005-03-09 19:20:49 +00:00
parent 443840184b
commit b5fa979ca6
1 changed files with 35 additions and 29 deletions
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64
libguile/fluids.c
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@ -80,43 +80,46 @@ static scm_t_bits tc16_dynamic_state;
static SCM all_dynamic_states = SCM_EOL;
static SCM all_fluids = SCM_EOL;
/* Make sure that the dynamic state STATE has the right size. This
must be called while being single threaded and while
fluid_admin_mutex is held.
*/
static void
ensure_state_size (SCM state)
{
SCM fluids = DYNAMIC_STATE_FLUIDS (state);
size_t len = SCM_SIMPLE_VECTOR_LENGTH (fluids), i;
if (len != allocated_fluids_len)
{
SCM new_fluids = scm_c_make_vector (allocated_fluids_len, SCM_BOOL_F);
for (i = 0; i < len; i++)
SCM_SIMPLE_VECTOR_SET (new_fluids, i,
SCM_SIMPLE_VECTOR_REF (fluids, i));
SET_DYNAMIC_STATE_FLUIDS (state, new_fluids);
}
}
/* Make sure that all states have the right size. This must be called
while fluid_admin_mutex is held.
*/
static void
ensure_all_state_sizes ()
resize_all_states ()
{
SCM state;
SCM new_vectors, state;
scm_frame_begin (0);
scm_i_frame_single_threaded ();
/* Replacing the vector of a dynamic state must be done atomically:
the old values must be copied into the new vector and the new
vector must be installed without someone modifying the old vector
concurrently. Since accessing a fluid should be lock-free, we
need to put all threads to sleep when replacing a vector.
However, when being single threaded, it is best not to do much.
Therefore, we allocate the new vectors before going single
threaded.
*/
scm_gc ();
new_vectors = SCM_EOL;
for (state = all_dynamic_states; !scm_is_null (state);
state = DYNAMIC_STATE_NEXT (state))
ensure_state_size (state);
new_vectors = scm_cons (scm_c_make_vector (allocated_fluids_len,
SCM_BOOL_F),
new_vectors);
scm_frame_end ();
scm_i_thread_put_to_sleep ();
for (state = all_dynamic_states; !scm_is_null (state);
state = DYNAMIC_STATE_NEXT (state))
{
SCM old_fluids = DYNAMIC_STATE_FLUIDS (state);
SCM new_fluids = SCM_CAR (new_vectors);
size_t i, old_len = SCM_SIMPLE_VECTOR_LENGTH (old_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);
new_vectors = SCM_CDR (new_vectors);
}
scm_i_thread_wake_up ();
}
/* This is called during GC, that is, while being single threaded.
@ -236,7 +239,7 @@ next_fluid_num ()
/* Now allocated_fluids and allocated_fluids_len are valid again
and we can allow GCs to occur.
*/
ensure_all_state_sizes ();
resize_all_states ();
}
allocated_fluids_num += 1;
@ -265,8 +268,10 @@ SCM_DEFINE (scm_make_fluid, "make-fluid", 0, 0, 0,
/* The GC must not run until the fluid is properly entered into the
list.
*/
scm_i_scm_pthread_mutex_lock (&fluid_admin_mutex);
SET_FLUID_NEXT (fluid, all_fluids);
all_fluids = fluid;
scm_i_pthread_mutex_unlock (&fluid_admin_mutex);
return fluid;
}
@ -495,10 +500,11 @@ SCM_DEFINE (scm_make_dynamic_state, "make-dynamic-state", 0, 1, 0,
/* The GC must not run until the state is properly entered into the
list.
*/
scm_i_scm_pthread_mutex_lock (&fluid_admin_mutex);
SET_DYNAMIC_STATE_NEXT (state, all_dynamic_states);
all_dynamic_states = state;
scm_i_pthread_mutex_unlock (&fluid_admin_mutex);
//fprintf (stderr, "new state %p\n", state);
return state;
}
#undef FUNC_NAME