1 files changed, 56 insertions, 0 deletions
diff --git a/pd/portmidi/pm_common/pmutil.h b/pd/portmidi/pm_common/pmutil.h
new file mode 100644
index 00000000..a7fb3ebf
--- /dev/null
+++ b/pd/portmidi/pm_common/pmutil.h
@@ -0,0 +1,56 @@
+/* pmutil.h -- some helpful utilities for building midi 
+               applications that use PortMidi 
+ */
+
+typedef void PmQueue;
+
+/*
+    A single-reader, single-writer queue is created by
+    Pm_QueueCreate(), which takes the number of messages and
+    the message size as parameters. The queue only accepts
+    fixed sized messages. Returns NULL if memory cannot be allocated.
+
+    Pm_QueueDestroy() destroys the queue and frees its storage.
+ */
+
+PmQueue *Pm_QueueCreate(long num_msgs, long bytes_per_msg);
+PmError Pm_QueueDestroy(PmQueue *queue);
+
+/* 
+    Pm_Dequeue() removes one item from the queue, copying it into msg.
+    Returns 1 if successful, and 0 if the queue is empty.
+    Returns pmBufferOverflow, clears the overflow flag, and does not
+    return a data item if the overflow flag is set. (This protocol
+    ensures that the reader will be notified when data is lost due 
+    to overflow.)
+ */
+PmError Pm_Dequeue(PmQueue *queue, void *msg);
+
+
+/*
+    Pm_Enqueue() inserts one item into the queue, copying it from msg.
+    Returns pmNoError if successful and pmBufferOverflow if the queue was 
+    already full. If pmBufferOverflow is returned, the overflow flag is set.
+ */
+PmError Pm_Enqueue(PmQueue *queue, void *msg);
+
+
+/*
+    Pm_QueueFull() returns non-zero if the queue is full
+    Pm_QueueEmpty() returns non-zero if the queue is empty
+
+    Either condition may change immediately because a parallel
+    enqueue or dequeue operation could be in progress.
+ */
+int Pm_QueueFull(PmQueue *queue);
+int Pm_QueueEmpty(PmQueue *queue);
+
+
+/*
+    Pm_QueuePeek() returns a pointer to the item at the head of the queue,
+    or NULL if the queue is empty. The item is not removed from the queue.
+    If queue is in an overflow state, a valid pointer is returned and the
+    queue remains in the overflow state.
+ */
+void *Pm_QueuePeek(PmQueue *queue);
+