Added I/O queue checks to the channels, added notes in the readme, improved the FullDuplexDriver.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@940 35acf78f-673a-0410-8e92-d51de3d6d3f4

1 files changed, 34 insertions, 0 deletions

diff --git a/src/include/channels.h b/src/include/channels.h
index d3d1f5d47..2ff20b1ad 100644
--- a/src/include/channels.h
+++ b/src/include/channels.h
@@ -32,6 +32,16 @@
  */

 struct _base_channel_methods {

   /**

+   * @brief Channel output check.

+   * @see chIOPutWouldBlock()

+   */

+  bool_t (*putwouldblock)(void *instance);

+  /**

+   * @brief Channel input check.

+   * @see chIOGetWouldBlock()

+   */

+  bool_t (*getwouldblock)(void *instance);

+  /**

    * @brief Channel put method with timeout specification.

    * @see chIOPut()

    */

@@ -77,6 +87,30 @@ typedef struct {
 } BaseChannel;

 

 /**

+ * @brief Channel output check.

+ * @details This function verifies if a subsequent @p chIOPut() would block.

+ *

+ * @param[in] ip pointer to a @p BaseChannel or derived class

+ * @return The output queue status:

+ * @retval FALSE if the output queue has space and would not block a write

+ *         operation.

+ * @retval TRUE if the output queue is full and would block a write operation.

+ */

+#define chIOPutWouldBlock(ip) ((ip)->vmt->m0.putwouldblock(ip))

+

+/**

+ * @brief Channel input check.

+ * @details This function verifies if a subsequent @p chIOGett() would block.

+ *

+ * @param[in] ip pointer to a @p BaseChannel or derived class

+ * @return The input queue status:

+ * @retval FALSE if the input queue contains data and would not block a read

+ *         operation.

+ * @retval TRUE if the input queue is empty and would block a read operation.

+ */

+#define chIOGetWouldBlock(ip) ((ip)->vmt->m0.getwouldblock(ip))

+

+/**

  * @brief Channel blocking byte write.

  * @details This function writes a byte value to a channel. If the channel

  *          is not ready to accept data then the calling thread is suspended.