From 223388f1ad8f3e39856a1e6a01ef2acd1d820d25 Mon Sep 17 00:00:00 2001
From: Georg Holzmann <grholzi@users.sourceforge.net>
Date: Mon, 14 Nov 2005 21:06:04 +0000
Subject: initial commit

svn path=/trunk/externals/grh/; revision=3898
---
 threadlib/src/callbacks.c | 134 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 134 insertions(+)
 create mode 100755 threadlib/src/callbacks.c

(limited to 'threadlib/src/callbacks.c')

diff --git a/threadlib/src/callbacks.c b/threadlib/src/callbacks.c
new file mode 100755
index 0000000..1385992
--- /dev/null
+++ b/threadlib/src/callbacks.c
@@ -0,0 +1,134 @@
+/* 
+* 
+* callbacks.c
+* implementation of the callback FIFO
+*
+* this is the (modified) FIFO of the idle callbacks from pd_devel_0.38
+* (implemented in m_sched.c)
+*/
+
+#include "threadlib.h"
+
+// global callback fifo
+t_fifo * h_callback_fifo = NULL;
+
+// global clock callback to trigger
+// the callback fifo
+t_clock *h_callback_clock = NULL;
+
+/* linked list of callbacks 
+ * callback will be freed after returning 0 */
+typedef struct _sched_callback
+{
+  struct _sched_callback* next; /* next callback in ringbuffer / in fifo */
+  t_int (*function) (t_int* argv);
+  t_int* argv;
+  t_int argc;
+} t_sched_callback;
+
+// forward declaration
+static void h_run_callbacks();
+
+void h_init_callbacks()
+{
+  h_callback_fifo = fifo_init();
+  h_callback_clock = clock_new(NULL, (t_method)h_run_callbacks);
+}
+
+void h_free_callbacks()
+{
+  clock_free(h_callback_clock);
+  fifo_destroy(h_callback_fifo);
+}
+
+void h_set_callback(t_int (*callback) (t_int* argv), t_int* argv, t_int argc)
+{
+  t_sched_callback* new = (t_sched_callback*) getbytes
+      (sizeof(t_sched_callback));
+
+  new->function = callback;
+  new->argv = (t_int*) copybytes (argv, argc * sizeof (t_int));
+  new->argc = argc;
+  new->next = NULL;
+	
+  fifo_put(h_callback_fifo, new);
+  
+  // TODO find solution without lock
+  sys_lock();
+  clock_delay(h_callback_clock, 0);
+  sys_unlock();
+}
+
+static t_sched_callback *ringbuffer_head;
+
+void h_run_callbacks()
+{
+  t_sched_callback * new_callback;
+  
+  sys_unlock();
+  
+  /* append idle callback to ringbuffer */
+  
+  while ( (new_callback = (t_sched_callback*) fifo_get(h_callback_fifo)) )
+  {
+    t_sched_callback * next;
+    
+    /* set the next field to NULL ... it might be set in the fifo */
+    new_callback->next = NULL;
+    if (ringbuffer_head == NULL)
+    {
+      ringbuffer_head = new_callback;
+    }
+    else
+    {
+      next = ringbuffer_head;
+      while (next->next != 0)
+	next = next->next;
+      next->next = new_callback;
+    }
+  }
+
+  if (ringbuffer_head != NULL)
+  {
+    t_sched_callback * idle_callback = ringbuffer_head;
+    t_sched_callback * last = NULL;
+    t_sched_callback * next;
+
+    do
+    {
+      int status;
+    
+      sys_lock();
+      status = (idle_callback->function)(idle_callback->argv);
+      sys_unlock();
+    
+      switch (status)
+      {
+        /* callbacks returning 0 will be deleted */
+        case 0:
+          next = idle_callback->next;
+          freebytes (idle_callback->argv, idle_callback->argc);
+          freebytes ((void*)idle_callback, sizeof(t_sched_callback));
+
+          if (last == NULL)
+            ringbuffer_head = next;
+          else
+            last->next = next;
+
+          idle_callback = next;
+
+        /* callbacks returning 1 will be run again */
+        case 1:
+          break;
+
+        /* callbacks returning 2 will be run during the next idle callback */
+        case 2:
+          last = idle_callback;
+          idle_callback = idle_callback->next;
+      }
+    }
+    while (idle_callback != NULL);
+  }
+
+  sys_lock();
+}
-- 
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