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-rw-r--r--libguile/async.c201
1 files changed, 146 insertions, 55 deletions
diff --git a/libguile/async.c b/libguile/async.c
index 35e8a5a66..88375f577 100644
--- a/libguile/async.c
+++ b/libguile/async.c
@@ -136,39 +136,39 @@ SCM_DEFINE (scm_run_asyncs, "run-asyncs", 1, 0, 0,
+static scm_i_pthread_mutex_t async_mutex = SCM_I_PTHREAD_MUTEX_INITIALIZER;
+
/* System asyncs. */
void
scm_async_click ()
{
+ scm_i_thread *t = SCM_I_CURRENT_THREAD;
+ SCM asyncs;
+
/* Reset pending_asyncs even when asyncs are blocked and not really
- executed.
+ executed since this will avoid future futile calls to this
+ function. When asyncs are unblocked again, this function is
+ invoked even when pending_asyncs is zero.
*/
- scm_root->pending_asyncs = 0;
- if (scm_root->block_asyncs == 0)
+ scm_i_scm_pthread_mutex_lock (&async_mutex);
+ t->pending_asyncs = 0;
+ if (t->block_asyncs == 0)
{
- SCM asyncs;
- while (!scm_is_null(asyncs = scm_root->active_asyncs))
- {
- scm_root->active_asyncs = SCM_EOL;
- do
- {
- scm_call_0 (SCM_CAR (asyncs));
- asyncs = SCM_CDR (asyncs);
- }
- while (!scm_is_null(asyncs));
- }
- for (asyncs = scm_root->signal_asyncs; !scm_is_null(asyncs);
- asyncs = SCM_CDR (asyncs))
- {
- if (scm_is_true (SCM_CAR (asyncs)))
- {
- SCM proc = SCM_CAR (asyncs);
- SCM_SETCAR (asyncs, SCM_BOOL_F);
- scm_call_0 (proc);
- }
- }
+ asyncs = t->active_asyncs;
+ t->active_asyncs = SCM_EOL;
+ }
+ else
+ asyncs = SCM_EOL;
+ scm_i_pthread_mutex_unlock (&async_mutex);
+
+ while (scm_is_pair (asyncs))
+ {
+ SCM next = SCM_CDR (asyncs);
+ SCM_SETCDR (asyncs, SCM_BOOL_F);
+ scm_call_0 (SCM_CAR (asyncs));
+ asyncs = next;
}
}
@@ -190,24 +190,98 @@ SCM_DEFINE (scm_system_async, "system-async", 1, 0, 0,
#endif /* SCM_ENABLE_DEPRECATED == 1 */
void
-scm_i_queue_async_cell (SCM c, scm_root_state *root)
+scm_i_queue_async_cell (SCM c, scm_i_thread *t)
{
- SCM p = root->active_asyncs;
+ SCM sleep_object;
+ scm_i_pthread_mutex_t *sleep_mutex;
+ int sleep_fd;
+ SCM p;
+
+ scm_i_scm_pthread_mutex_lock (&async_mutex);
+ p = t->active_asyncs;
SCM_SETCDR (c, SCM_EOL);
- if (p == SCM_EOL)
- root->active_asyncs = c;
+ if (!scm_is_pair (p))
+ t->active_asyncs = c;
else
{
SCM pp;
- while ((pp = SCM_CDR(p)) != SCM_EOL)
+ while (scm_is_pair (pp = SCM_CDR (p)))
{
- if (SCM_CAR (p) == SCM_CAR (c))
- return;
+ if (scm_is_eq (SCM_CAR (p), SCM_CAR (c)))
+ {
+ scm_i_pthread_mutex_unlock (&async_mutex);
+ return;
+ }
p = pp;
}
SCM_SETCDR (p, c);
}
- root->pending_asyncs = 1;
+ t->pending_asyncs = 1;
+ sleep_object = t->sleep_object;
+ sleep_mutex = t->sleep_mutex;
+ sleep_fd = t->sleep_fd;
+ scm_i_pthread_mutex_unlock (&async_mutex);
+
+ if (sleep_mutex)
+ {
+ /* By now, the thread T might be out of its sleep already, or
+ might even be in the next, unrelated sleep. Interrupting it
+ anyway does no harm, however.
+
+ The important thing to prevent here is to signal sleep_cond
+ before T waits on it. This can not happen since T has
+ sleep_mutex locked while setting t->sleep_mutex and will only
+ unlock it again while waiting on sleep_cond.
+ */
+ scm_i_scm_pthread_mutex_lock (sleep_mutex);
+ scm_i_pthread_cond_signal (&t->sleep_cond);
+ scm_i_pthread_mutex_unlock (sleep_mutex);
+ }
+
+ if (sleep_fd >= 0)
+ {
+ char dummy = 0;
+ /* Likewise, T might already been done with sleeping here, but
+ interrupting it once too often does no harm. T might also
+ not yet have started sleeping, but this is no problem either
+ since the data written to a pipe will not be lost, unlike a
+ condition variable signal.
+ */
+ write (sleep_fd, &dummy, 1);
+ }
+
+ /* This is needed to protect sleep_mutex.
+ */
+ scm_remember_upto_here_1 (sleep_object);
+}
+
+int
+scm_i_setup_sleep (scm_i_thread *t,
+ SCM sleep_object, scm_i_pthread_mutex_t *sleep_mutex,
+ int sleep_fd)
+{
+ int pending;
+
+ scm_i_scm_pthread_mutex_lock (&async_mutex);
+ pending = t->pending_asyncs;
+ if (!pending)
+ {
+ t->sleep_object = sleep_object;
+ t->sleep_mutex = sleep_mutex;
+ t->sleep_fd = sleep_fd;
+ }
+ scm_i_pthread_mutex_unlock (&async_mutex);
+ return pending;
+}
+
+void
+scm_i_reset_sleep (scm_i_thread *t)
+{
+ scm_i_scm_pthread_mutex_lock (&async_mutex);
+ t->sleep_object = SCM_BOOL_F;
+ t->sleep_mutex = NULL;
+ t->sleep_fd = -1;
+ scm_i_pthread_mutex_unlock (&async_mutex);
}
SCM_DEFINE (scm_system_async_mark_for_thread, "system-async-mark", 1, 1, 0,
@@ -222,16 +296,24 @@ SCM_DEFINE (scm_system_async_mark_for_thread, "system-async-mark", 1, 1, 0,
"signal handlers.")
#define FUNC_NAME s_scm_system_async_mark_for_thread
{
+ /* The current thread might not have a handle yet. This can happen
+ when the GC runs immediately before allocating the handle. At
+ the end of that GC, a system async might be marked. Thus, we can
+ not use scm_current_thread here.
+ */
+
+ scm_i_thread *t;
+
if (SCM_UNBNDP (thread))
- thread = scm_current_thread ();
+ t = SCM_I_CURRENT_THREAD;
else
{
SCM_VALIDATE_THREAD (2, thread);
if (scm_c_thread_exited_p (thread))
SCM_MISC_ERROR ("thread has already exited", SCM_EOL);
+ t = SCM_I_THREAD_DATA (thread);
}
- scm_i_queue_async_cell (scm_cons (proc, SCM_BOOL_F),
- scm_i_thread_root (thread));
+ scm_i_queue_async_cell (scm_cons (proc, SCM_BOOL_F), t);
return SCM_UNSPECIFIED;
}
#undef FUNC_NAME
@@ -268,13 +350,15 @@ SCM_DEFINE (scm_unmask_signals, "unmask-signals", 0, 0, 0,
"Unmask signals. The returned value is not specified.")
#define FUNC_NAME s_scm_unmask_signals
{
+ scm_i_thread *t = SCM_I_CURRENT_THREAD;
+
scm_c_issue_deprecation_warning
("'unmask-signals' is deprecated. "
"Use 'call-with-blocked-asyncs' instead.");
- if (scm_root->block_asyncs == 0)
+ if (t->block_asyncs == 0)
SCM_MISC_ERROR ("signals already unmasked", SCM_EOL);
- scm_root->block_asyncs = 0;
+ t->block_asyncs = 0;
scm_async_click ();
return SCM_UNSPECIFIED;
}
@@ -286,12 +370,14 @@ SCM_DEFINE (scm_mask_signals, "mask-signals", 0, 0, 0,
"Mask signals. The returned value is not specified.")
#define FUNC_NAME s_scm_mask_signals
{
+ scm_i_thread *t = SCM_I_CURRENT_THREAD;
+
scm_c_issue_deprecation_warning
("'mask-signals' is deprecated. Use 'call-with-blocked-asyncs' instead.");
- if (scm_root->block_asyncs > 0)
+ if (t->block_asyncs > 0)
SCM_MISC_ERROR ("signals already masked", SCM_EOL);
- scm_root->block_asyncs = 1;
+ t->block_asyncs = 1;
return SCM_UNSPECIFIED;
}
#undef FUNC_NAME
@@ -299,16 +385,15 @@ SCM_DEFINE (scm_mask_signals, "mask-signals", 0, 0, 0,
#endif /* SCM_ENABLE_DEPRECATED == 1 */
static void
-increase_block (void *unused)
+increase_block (void *data)
{
- scm_root->block_asyncs++;
+ ((scm_i_thread *)data)->block_asyncs++;
}
static void
-decrease_block (void *unused)
+decrease_block (void *data)
{
- scm_root->block_asyncs--;
- if (scm_root->block_asyncs == 0)
+ if (--((scm_i_thread *)data)->block_asyncs == 0)
scm_async_click ();
}
@@ -322,7 +407,8 @@ SCM_DEFINE (scm_call_with_blocked_asyncs, "call-with-blocked-asyncs", 1, 0, 0,
return scm_internal_dynamic_wind (increase_block,
(scm_t_inner) scm_call_0,
decrease_block,
- (void *)proc, NULL);
+ (void *)proc,
+ SCM_I_CURRENT_THREAD);
}
#undef FUNC_NAME
@@ -332,7 +418,8 @@ scm_c_call_with_blocked_asyncs (void *(*proc) (void *data), void *data)
return (void *)scm_internal_dynamic_wind (increase_block,
(scm_t_inner) proc,
decrease_block,
- data, NULL);
+ data,
+ SCM_I_CURRENT_THREAD);
}
@@ -343,42 +430,46 @@ SCM_DEFINE (scm_call_with_unblocked_asyncs, "call-with-unblocked-asyncs", 1, 0,
"it is running. Return the value returned by @var{proc}.\n")
#define FUNC_NAME s_scm_call_with_unblocked_asyncs
{
- if (scm_root->block_asyncs == 0)
+ if (SCM_I_CURRENT_THREAD->block_asyncs == 0)
SCM_MISC_ERROR ("asyncs already unblocked", SCM_EOL);
return scm_internal_dynamic_wind (decrease_block,
(scm_t_inner) scm_call_0,
increase_block,
- (void *)proc, NULL);
+ (void *)proc,
+ SCM_I_CURRENT_THREAD);
}
#undef FUNC_NAME
void *
scm_c_call_with_unblocked_asyncs (void *(*proc) (void *data), void *data)
{
- if (scm_root->block_asyncs == 0)
+ if (SCM_I_CURRENT_THREAD->block_asyncs == 0)
scm_misc_error ("scm_c_call_with_unblocked_asyncs",
"asyncs already unblocked", SCM_EOL);
return (void *)scm_internal_dynamic_wind (decrease_block,
(scm_t_inner) proc,
increase_block,
- data, NULL);
+ data,
+ SCM_I_CURRENT_THREAD);
}
void
scm_frame_block_asyncs ()
{
- scm_frame_rewind_handler (increase_block, NULL, SCM_F_WIND_EXPLICITLY);
- scm_frame_unwind_handler (decrease_block, NULL, SCM_F_WIND_EXPLICITLY);
+ scm_i_thread *t = SCM_I_CURRENT_THREAD;
+ scm_frame_rewind_handler (increase_block, t, SCM_F_WIND_EXPLICITLY);
+ scm_frame_unwind_handler (decrease_block, t, SCM_F_WIND_EXPLICITLY);
}
void
scm_frame_unblock_asyncs ()
{
- if (scm_root->block_asyncs == 0)
+ scm_i_thread *t = SCM_I_CURRENT_THREAD;
+ if (t->block_asyncs == 0)
scm_misc_error ("scm_with_unblocked_asyncs",
"asyncs already unblocked", SCM_EOL);
- scm_frame_rewind_handler (decrease_block, NULL, SCM_F_WIND_EXPLICITLY);
- scm_frame_unwind_handler (increase_block, NULL, SCM_F_WIND_EXPLICITLY);
+ scm_frame_rewind_handler (decrease_block, t, SCM_F_WIND_EXPLICITLY);
+ scm_frame_unwind_handler (increase_block, t, SCM_F_WIND_EXPLICITLY);
}