1 files changed, 337 insertions, 0 deletions
diff --git a/system/pdp_queue.c b/system/pdp_queue.c
new file mode 100644
index 0000000..2932728
--- /dev/null
+++ b/system/pdp_queue.c
@@ -0,0 +1,337 @@
+/*
+ *   Pure Data Packet - processor queue module.
+ *   Copyright (c) by Tom Schouten <pdp@zzz.kotnet.org>
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program 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 General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+
+
+/* 
+   this is a the processor queue pdp system module 
+   it receives tasks from objects that are schedules to 
+   be computed in another thread. the object is signalled back
+   when the task is completed.
+
+   this is not a standard pd class. it is a sigleton class
+   using a standard pd clock to poll for compleded methods on 
+   every scheduler run. this is a hack to do thread synchronization 
+   in a thread unsafe pd.
+
+ */
+
+#include "pdp.h"
+#include <pthread.h>
+#include <unistd.h>
+#include <stdio.h>
+
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+#define PDP_QUEUE_SIZE 1024
+#define PDP_QUEUE_DELTIME 1.0f;
+
+
+
+
+/********************* pdp process queue data *********************/
+
+typedef void (*t_pdpmethod)(void *client);
+
+/* the process queue data record */
+typedef struct process_queue_struct
+{
+  void *x_owner;             /* the object we are dealing with */
+  t_pdpmethod x_process;     /* the process method */
+  t_pdpmethod x_callback;    /* the function to be called when finished */
+  int *x_queue_id;           /* place to store the queue id for task */
+} t_process_queue;
+
+
+
+/* clock members */
+static t_clock *pdp_clock;
+static double deltime;
+
+/* some bookkeeping vars */
+static long long ticks;
+static long long packets;
+
+/* queue members */
+static t_process_queue *q;    /* queue */
+static int mask;
+static int head;              /* last entry in queue + 1 */
+static int tail;              /* first entry in queque */
+static int curr;              /* the object currently processed in other thread */
+
+/* pthread vars */
+static pthread_mutex_t mut;
+static pthread_cond_t cond_dataready;
+static pthread_cond_t cond_processingdone;
+static pthread_t thread_id;
+    
+/* synchro pipes */
+static int pipe_fd[2];
+
+/* toggle for thread usage */
+static int use_thread;
+
+
+
+/* the methods */
+void pdp_queue_wait()
+{
+    //post("pdp_pq_wait: waiting for pdp_queue_thread to finish processing");
+    pthread_mutex_lock(&mut);
+    while(((curr - head) & mask) != 0){
+
+	  pthread_cond_wait(&cond_processingdone, &mut);
+    }
+    pthread_mutex_unlock(&mut);
+    //post("pdp_pq_wait: pdp_queue_thread has finished processing");
+
+}
+void pdp_queue_finish(int index)
+{
+
+  if (-1 == index) {
+      //post("pdp_pq_remove: index == -1");
+      return;
+  }
+  /* wait for processing thread to finish*/
+  pdp_queue_wait();
+
+  /* invalidate callback at index */
+  q[index & mask].x_callback = 0;
+  q[index & mask].x_queue_id = 0;
+
+}
+
+static void pdp_queue_signal_processor(void)
+{
+
+    pthread_mutex_lock(&mut);
+    //post("signalling process thread");
+    pthread_cond_signal(&cond_dataready);
+    pthread_mutex_unlock(&mut);
+    //post("signalling process thread done");
+
+}
+
+static void pdp_queue_wait_for_feeder(void)
+{
+
+
+    /* only use locking when there is no data */
+    if(((curr - head) & mask) == 0){
+	pthread_mutex_lock(&mut);
+
+	/* signal processing done */
+	//post("pdp_queue_thread: signalling processing is done");
+	pthread_cond_signal(&cond_processingdone);
+
+	/* wait until there is an item in the queue */
+	while(((curr - head) & mask) == 0){
+	    //post("waiting for feeder");
+	    pthread_cond_wait(&cond_dataready, &mut);
+	    //post("waiting for feeder done");
+	}
+
+	pthread_mutex_unlock(&mut);
+
+    }
+}
+
+void pdp_queue_add(void *owner, void *process, void *callback, int *queue_id)
+{
+    int i;
+
+    /* if processing is in not in thread, just call the funcs */
+    if (!use_thread){
+	//post("pdp_queue_add: calling processing routine directly");
+	*queue_id = -1;
+	((t_pdpmethod) process)(owner);
+	((t_pdpmethod) callback)(owner);
+	return;
+    }
+	
+
+
+    /* schedule method in thread queue */
+    if (1 == ((tail - head) & mask)) {
+	post("pdp_queue_add: WARNING: processing queue is full.\n");
+	post("pdp_queue_add: WARNING: skipping process method, calling callback directly.\n");
+	*queue_id = -1;
+	((t_pdpmethod) callback)(owner);
+    }
+
+
+
+    i = head & mask;
+    q[i].x_owner = owner;
+    q[i].x_process = process;
+    q[i].x_callback = callback;
+    q[i].x_queue_id = queue_id;
+    *queue_id = i;
+    //post("pdp_queue_add: added method to queue, index %d", i);
+
+      
+    // increase the packet count
+    packets++;
+  
+    // move head forward
+    head++;
+
+    pdp_queue_signal_processor();
+
+}
+
+
+/* processing thread */
+static void *pdp_queue_thread(void *dummy)
+{
+  while(1){
+
+
+      /* wait until there is data available */
+      pdp_queue_wait_for_feeder();      
+
+
+      //post("pdp_queue_thread: processing %d", curr);
+
+
+      /* call the process routine */
+      (q[curr & mask].x_process)(q[curr & mask].x_owner);
+
+      /* advance */
+      curr++;
+
+
+    }
+}
+
+
+/* call back all the callbacks */
+static void pdp_queue_callback (void)
+{
+
+  /* call callbacks for finished packets */
+  while(0 != ((curr - tail) & mask))
+    {
+      int i = tail & mask;
+      /* invalidate queue id */
+      if(q[i].x_queue_id) *q[i].x_queue_id = -1;
+      /* call callback */
+      if(q[i].x_callback) (q[i].x_callback)(q[i].x_owner);
+      //else post("pdp_pq_tick: callback %d is disabled",i );
+      tail++;
+    }
+
+}
+
+/* the clock method */
+static void pdp_queue_tick (void)
+{
+  /* do work */
+  //if (!(ticks % 1000)) post("pdp tick %d", ticks);
+
+  if (!use_thread) return;
+
+  /* call callbacks */
+  pdp_queue_callback();
+
+  /* increase counter */
+  ticks++;
+
+  /* set clock for next update */
+  clock_delay(pdp_clock, deltime);
+}
+
+
+void pdp_queue_use_thread(int t)
+{
+    /* if thread usage is being disabled, 
+       wait for thread to finish processing first */
+    if (t == 0) {
+	pdp_queue_wait();
+	use_thread = 0;
+	pdp_queue_callback();
+	clock_unset(pdp_clock);
+    }
+    else {
+	clock_unset(pdp_clock);
+	clock_delay(pdp_clock, deltime);
+	use_thread = 1;
+    }
+
+}
+
+void pdp_queue_setup(void)
+{
+  pthread_attr_t attr;
+
+  /* setup pdp queue processor object */
+  ticks = 0;
+  deltime = PDP_QUEUE_DELTIME;
+
+  /* setup queue data */
+  mask = PDP_QUEUE_SIZE - 1;
+  head = 0;
+  tail = 0;
+  curr = 0;
+  q = getbytes(PDP_QUEUE_SIZE * sizeof(*q));
+
+  /* use threads by default */
+  use_thread = 1;
+
+  /* setup synchro stuff */
+  pthread_mutex_init(&mut, NULL);
+  pthread_cond_init(&cond_dataready, NULL);
+  pthread_cond_init(&cond_processingdone, NULL);
+
+ 
+  /* allocate the clock */
+  pdp_clock = clock_new(0, (t_method)pdp_queue_tick);
+
+  /* set the clock */
+  clock_delay(pdp_clock, 0);
+
+  /* start processing thread */
+
+  /* glibc doc says SCHED_OTHER is default,
+     but it seems not to be when initiated from a RT thread
+     so we explicitly set it here */
+  pthread_attr_init (&attr);
+  //pthread_attr_setschedpolicy(&attr, SCHED_FIFO); 
+  pthread_attr_setschedpolicy(&attr, SCHED_OTHER); 
+  pthread_create(&thread_id, &attr, pdp_queue_thread, (void *)0);
+
+
+
+}
+
+
+
+
+
+
+
+#ifdef __cplusplus
+}
+#endif