buffer: improve memory management

Add refcounting to buffers.
Use static memory on ports for buffer input and output memory.
Improve negotiation, let format and properties be negotiated on ports as
the data passes.
Improve some debug info.

pinos/client/buffer.c

@@ -38,8 +38,8 @@ G_STATIC_ASSERT (sizeof (PinosStackBuffer) <= sizeof (PinosBuffer));
  *
  * Initialize @buffer with @data and @size and @fds and @n_fds.
  * The memory pointer to by @data and @fds becomes property of @buffer
- * and should not be freed or modified until pinos_buffer_clear() is
- * called.
+ * and should not be freed or modified until all referenced to the buffer
+ * are gone pinos_buffer_unref().
  */
 void
 pinos_buffer_init_data (PinosBuffer       *buffer,
@@ -50,7 +50,10 @@ pinos_buffer_init_data (PinosBuffer       *buffer,
 {
   PinosStackBuffer *sb = PSB (buffer);
 
+  g_debug ("buffer %p: init", buffer);
+
   sb->magic = PSB_MAGIC;
+  sb->refcount = 1;
   sb->data = data;
   sb->size = size;
   sb->max_size = size;
@@ -61,20 +64,44 @@ pinos_buffer_init_data (PinosBuffer       *buffer,
   sb->free_fds = NULL;
 }
 
-void
-pinos_buffer_clear (PinosBuffer *buffer)
+PinosBuffer *
+pinos_buffer_ref (PinosBuffer *buffer)
 {
   PinosStackBuffer *sb = PSB (buffer);
+
+  g_return_val_if_fail (is_valid_buffer (buffer), NULL);
+
+  g_debug ("buffer %p: ref %d -> %d", buffer, sb->refcount, sb->refcount+1);
+
+  sb->refcount++;
+
+  return buffer;
+}
+
+gboolean
+pinos_buffer_unref (PinosBuffer *buffer)
+{
+  PinosStackBuffer *sb = PSB (buffer);
+  gboolean res;
   gint i;
 
-  g_return_if_fail (is_valid_buffer (buffer));
+  g_return_val_if_fail (is_valid_buffer (buffer), FALSE);
 
-  sb->magic = 0;
-  g_free (sb->free_data);
-  for (i = 0; i < sb->n_fds; i++)
-    close (sb->fds[i]);
-  g_free (sb->free_fds);
-  sb->n_fds = 0;
+  g_debug ("buffer %p: unref %d -> %d", buffer, sb->refcount, sb->refcount-1);
+
+  sb->refcount--;
+  res = sb->refcount > 0;
+  if (!res) {
+    sb->magic = 0;
+    g_free (sb->free_data);
+    for (i = 0; i < sb->n_fds; i++) {
+      g_debug ("%p: close %d %d", buffer, i, sb->fds[i]);
+      close (sb->fds[i]);
+    }
+    g_free (sb->free_fds);
+    sb->n_fds = 0;
+  }
+  return res;
 }
 
 /**
@@ -158,7 +185,8 @@ pinos_buffer_steal_data (PinosBuffer       *buffer,
   PinosStackBuffer *sb = PSB (buffer);
   gpointer data;
 
-  g_return_val_if_fail (is_valid_buffer (buffer), 0);
+  g_return_val_if_fail (is_valid_buffer (buffer), NULL);
+  g_return_val_if_fail (sb->refcount == 1, NULL);
 
   data = sb->data;
   if (size)
@@ -190,7 +218,8 @@ pinos_buffer_steal_fds (PinosBuffer       *buffer,
   PinosStackBuffer *sb = PSB (buffer);
   gint *fds;
 
-  g_return_val_if_fail (is_valid_buffer (buffer), 0);
+  g_return_val_if_fail (is_valid_buffer (buffer), NULL);
+  g_return_val_if_fail (sb->refcount == 1, NULL);
 
   fds = sb->fds;
   if (n_fds)
@@ -332,6 +361,22 @@ pinos_buffer_iter_next (PinosBufferIter *iter)
   return TRUE;
 }
 
+/**
+ * pinos_buffer_iter_done:
+ * @iter: a #PinosBufferIter
+ *
+ * End iterations on @iter.
+ */
+void
+pinos_buffer_iter_end (PinosBufferIter *iter)
+{
+  struct stack_iter *si = PPSI (iter);
+
+  g_return_if_fail (is_valid_iter (iter));
+
+  si->magic = 0;
+}
+
 PinosPacketType
 pinos_buffer_iter_get_type (PinosBufferIter *iter)
 {
@@ -408,6 +453,8 @@ pinos_buffer_builder_init_full (PinosBufferBuilder       *builder,
     sb->buf.max_size = sizeof (PinosStackHeader) + 128;
     sb->buf.data = g_malloc (sb->buf.max_size);
     sb->buf.free_data = sb->buf.data;
+    g_warning ("builder %p: realloc buffer memory %"G_GSIZE_FORMAT" -> %"G_GSIZE_FORMAT,
+        builder, max_data, sb->buf.max_size);
   } else {
     sb->buf.max_size = max_data;
     sb->buf.data = data;
@@ -493,6 +540,7 @@ pinos_buffer_builder_end (PinosBufferBuilder *builder,
   sb->sh->length = sb->buf.size - sizeof (PinosStackHeader);
 
   sbuf->magic = PSB_MAGIC;
+  sbuf->refcount = 1;
   sbuf->data = sb->buf.data;
   sbuf->size = sb->buf.size;
   sbuf->max_size = sb->buf.max_size;
@@ -502,6 +550,8 @@ pinos_buffer_builder_end (PinosBufferBuilder *builder,
   sbuf->n_fds = sb->buf.n_fds;
   sbuf->max_fds = sb->buf.max_fds;
   sbuf->free_fds = sb->buf.free_fds;
+
+  g_debug ("builder %p: buffer %p init", builder, buffer);
 }
 
 /**
@@ -524,8 +574,11 @@ pinos_buffer_builder_add_fd (PinosBufferBuilder *builder,
   g_return_val_if_fail (fd > 0, -1);
 
   if (sb->buf.n_fds >= sb->buf.max_fds) {
-    sb->buf.max_fds += 8;
-    sb->buf.free_fds = g_realloc (sb->buf.free_fds, sb->buf.max_fds * sizeof (int));
+    gint new_size = sb->buf.max_fds + 8;
+    g_warning ("builder %p: realloc buffer fds %d -> %d",
+        builder, sb->buf.max_fds, new_size);
+    sb->buf.max_fds = new_size;
+    sb->buf.free_fds = g_realloc (sb->buf.free_fds, new_size * sizeof (int));
     sb->buf.fds = sb->buf.free_fds;
   }
   index = sb->buf.n_fds;
@@ -539,8 +592,11 @@ static gpointer
 builder_ensure_size (struct stack_builder *sb, gsize size)
 {
   if (sb->buf.size + size > sb->buf.max_size) {
-    sb->buf.max_size = sb->buf.size + MAX (size, 1024);
-    sb->buf.free_data = g_realloc (sb->buf.free_data, sb->buf.max_size);
+    gsize new_size = sb->buf.size + MAX (size, 1024);
+    g_warning ("builder %p: realloc buffer memory %"G_GSIZE_FORMAT" -> %"G_GSIZE_FORMAT,
+        sb, sb->buf.max_size, new_size);
+    sb->buf.max_size = new_size;
+    sb->buf.free_data = g_realloc (sb->buf.free_data, new_size);
     sb->sh = sb->buf.data = sb->buf.free_data;
   }
   return (guint8 *) sb->buf.data + sb->buf.size;