WebSVN – HelenOS-historic – Diff – /kernel/trunk/generic/include/adt/fifo.h

 /*
  * Copyright (C) 2006 Jakub Jermar
  * All rights reserved.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
+ *
  * - Redistributions of source code must retain the above copyright
  *   notice, this list of conditions and the following disclaimer.
  * - Redistributions in binary form must reproduce the above copyright
  *   notice, this list of conditions and the following disclaimer in the
  *   documentation and/or other materials provided with the distribution.
  * - The name of the author may not be used to endorse or promote products
  *   derived from this software without specific prior written permission.
+ *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 /*
- * This implementation of FIFO stores values in a statically
+ * This implementation of FIFO stores values in an array
- * allocated array created on each FIFO's initialization.
- * As such, these FIFOs have upper bound on number of values
+ * (static or dynamic). As such, these FIFOs have upper bound
- * they can store. Push and pop operations are done via accessing
+ * on number of values they can store. Push and pop operations
- * the array through head and tail indices. Because of better
+ * are done via accessing the array through head and tail indices.
- * operation ordering in fifo_pop(), the access policy for these
+ * Because of better operation ordering in fifo_pop(), the access
- * two indices is to 'increment (mod size of FIFO) and use'.
+ * policy for these two indices is to 'increment (mod size of FIFO)
+ * and use'.
  */
 #ifndef __FIFO_H__
 #define __FIFO_H__
 #include <typedefs.h>
+#include <mm/slab.h>
-/** Create and initialize FIFO.
+/** Create and initialize static FIFO.
+ *
+ * FIFO is allocated statically.
+ * This macro is suitable for creating smaller FIFOs.
+ *
  * @param name Name of FIFO.
  * @param t Type of values stored in FIFO.
  * @param itms Number of items that can be stored in FIFO.
  */
-#define FIFO_INITIALIZE(name, t, itms)          \
+#define FIFO_INITIALIZE_STATIC(name, t, itms)       \
     struct {                    \
         t fifo[(itms)];             \
         count_t items;              \
         index_t head;               \
         index_t tail;               \
     } name = {                  \
         .items = (itms),            \
         .head = 0,              \
         .tail = 0               \
+    }
+/** Create and prepare dynamic FIFO.
+ *
+ * FIFO is allocated dynamically.
+ * This macro is suitable for creating larger FIFOs.
+ *
+ * @param name Name of FIFO.
+ * @param t Type of values stored in FIFO.
+ * @param itms Number of items that can be stored in FIFO.
+ */
+#define FIFO_INITIALIZE_DYNAMIC(name, t, itms)      \
+    struct {                    \
+        t *fifo;                \
+        count_t items;              \
+        index_t head;               \
+        index_t tail;               \
+    } name = {                  \
+        .fifo = NULL,               \
+        .items = (itms),            \
+        .head = 0,              \
+        .tail = 0               \
+    }
 /** Pop value from head of FIFO.
+ *
  * @param name FIFO name.
+ *
  * @return Leading value in FIFO.
  */
 #define fifo_pop(name) \
     name.fifo[name.head = (name.head + 1) < name.items ? (name.head + 1) : 0]
 /** Push value to tail of FIFO.
+ *
  * @param name FIFO name.
  * @param value Value to be appended to FIFO.
+ *
  */
 #define fifo_push(name, value) \
     name.fifo[name.tail = (name.tail + 1) < name.items ? (name.tail + 1) : 0] = (value)
+/** Allocate memory for dynamic FIFO.
+ *
+ * @param name FIFO name.
+ */
+#define fifo_create(name) \
+    name.fifo = malloc(sizeof(*name.fifo) * name.items, 0)
 #endif

Subversion Repositories HelenOS-historic

(root)/kernel/trunk/generic/include/adt/fifo.h @ 1702 – Rev 788 → 830