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

3 files changed, 67 insertions, 1 deletions

diff --git a/src/chserial.c b/src/chserial.c
index 4dac892f8..65179689d 100644
--- a/src/chserial.c
+++ b/src/chserial.c
@@ -28,6 +28,20 @@
 

 #if CH_USE_SERIAL_FULLDUPLEX

 

+/*

+ * Interface implementation, the following functions just invoke the equivalent

+ * queue-level function or macro.
+ */

+static bool_t putwouldblock(void *instance) {

+

+  return chOQIsFull(&((FullDuplexDriver *)instance)->d2.oqueue);

+}

+

+static bool_t getwouldblock(void *instance) {

+

+  return chIQIsEmpty(&((FullDuplexDriver *)instance)->d2.iqueue);

+}

+

 static msg_t put(void *instance, uint8_t b, systime_t timeout) {

 

   return chOQPutTimeout(&((FullDuplexDriver *)instance)->d2.oqueue, b, timeout);

@@ -49,7 +63,7 @@ static size_t read(void *instance, uint8_t *buffer, size_t n) {
 }

 

 static const struct FullDuplexDriverVMT vmt = {

-  {put, get},

+  {putwouldblock, getwouldblock, put, get},

   {write, read},

   {}

 };

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.

diff --git a/src/include/serial.h b/src/include/serial.h
index 9bb6c4f92..08ddf61fe 100644
--- a/src/include/serial.h
+++ b/src/include/serial.h
@@ -137,6 +137,24 @@ extern "C" {
 #endif

 

 /**

+ * @brief Direct output check on a @p FullDuplexDriver.
+ * @details This function bypasses the indirect access to the channel and

+ *          checks directly the output queue. This is faster but cannot

+ *          be used to check different channels implementations.

+ * @see chIOPutWouldBlock()

+ */

+#define chFDDPutWouldBlock(sd) chOQIsFull(&(sd)->d2.oqueue)

+

+/**

+ * @brief Direct input check on a @p FullDuplexDriver.

+ * @details This function bypasses the indirect access to the channel and

+ *          checks directly the input queue. This is faster but cannot

+ *          be used to check different channels implementations.

+ * @see chIOGetWouldBlock()

+ */

+#define chFDDGetWouldBlock(sd) chIQIsEmpty(&(sd)->d2.iqueue)

+

+/**

  * @brief Direct blocking write to a @p FullDuplexDriver.

  * @details This function bypasses the indirect access to the channel and

  *          writes directly on the output queue. This is faster but cannot