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| author | TexZK <texzk@email.it> | 2015-07-08 21:57:53 +0200 |
|---|---|---|
| committer | TexZK <texzk@email.it> | 2015-07-08 21:57:53 +0200 |
| commit | 5270aa500f88e13ae2f9cebded4271d52d08706c (patch) | |
| tree | 6591594bdc3c563021aee2a0838d0dbf7a654855 /demos/STM32/RT-STM32F429-DISCOVERY-TRIBUF/main.c | |
| parent | 567cfe388f25ae32621ac3f2d7d27b94cab617be (diff) | |
| download | ChibiOS-Contrib-5270aa500f88e13ae2f9cebded4271d52d08706c.tar.gz ChibiOS-Contrib-5270aa500f88e13ae2f9cebded4271d52d08706c.tar.bz2 ChibiOS-Contrib-5270aa500f88e13ae2f9cebded4271d52d08706c.zip | |
Added descriptions and code simplified
Diffstat (limited to 'demos/STM32/RT-STM32F429-DISCOVERY-TRIBUF/main.c')
| -rw-r--r-- | demos/STM32/RT-STM32F429-DISCOVERY-TRIBUF/main.c | 40 |
1 files changed, 24 insertions, 16 deletions
diff --git a/demos/STM32/RT-STM32F429-DISCOVERY-TRIBUF/main.c b/demos/STM32/RT-STM32F429-DISCOVERY-TRIBUF/main.c index 145e068..25ffd87 100644 --- a/demos/STM32/RT-STM32F429-DISCOVERY-TRIBUF/main.c +++ b/demos/STM32/RT-STM32F429-DISCOVERY-TRIBUF/main.c @@ -66,33 +66,37 @@ static char buffer_a, buffer_b, buffer_c; static const char text[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ\r\n";
-/*
- * Reads from the front buffer.
+/**
+ * @brief Reads from the front buffer.
+ *
+ * @return Buffered character from @p text or special symbol.
+ * @retval '.' No new front buffer within timeout.
*/
static char read_front(void) {
const char *front;
msg_t error;
+ char c;
/* Wait until a new front buffer gets available with prepared data */
- chSysLock();
- error = tribufWaitReadyTimeoutS(&tribuf_handler, reader_timeout);
- if (error == MSG_TIMEOUT) {
- chSysUnlock();
- return (reader_timeout == TIME_IMMEDIATE) ? '.' : '@';
+ error = tribufWaitReadyTimeout(&tribuf_handler, reader_timeout);
+ if (error == MSG_OK) {
+ /* Retrieve the new front buffer */
+ tribufSwapFront(&tribuf_handler);
+ front = (const char *)tribufGetFront(&tribuf_handler);
+
+ /* Read data from the new front buffer */
+ c = front[0];
+ } else {
+ c = '.'; /* Timeout placeholder */
}
- chSysUnlock();
-
- /* Retrieve the new front buffer */
- tribufSwapFront(&tribuf_handler);
- front = (const char *)tribufGetFront(&tribuf_handler);
-
- /* Read data from the new front buffer */
- return front[0];
+ return c;
}
/*
- * Overwrites the back buffer with the provided character.
+ * @brief Overwrites the back buffer with the provided character.
+ *
+ * @param[in] c Character to store into the current back buffer.
*/
static void write_back(char c) {
@@ -123,9 +127,11 @@ static THD_FUNCTION(reader_thread, arg) { old_priority = chThdGetPriorityX();
for (;;) {
+ /* Read from the fron buffer and print the retrieved character */
c = read_front();
chprintf(chout, "%c", c);
+ /* Change priority, suspend or delay */
osalSysLock();
palTogglePad(GPIOG, GPIOG_LED3_GREEN);
if (old_priority != reader_priority) {
@@ -160,9 +166,11 @@ static THD_FUNCTION(writer_thread, arg) { for (;;) {
for (i = 0; i < sizeof(text); ++i) {
+ /* Write the next character on the current back buffer */
c = text[i];
write_back(c);
+ /* Change priority, suspend or delay */
osalSysLock();
palTogglePad(GPIOG, GPIOG_LED4_RED);
if (old_priority != writer_priority) {
|