Diff: BufferedSerial.cpp

Revision:

12:c7947d444267

Parent:

11:779304f9c5d2

Child:

13:b4080afc8cd5

--- a/BufferedSerial.cpp	Sun Jul 26 21:53:11 2015 +0000
+++ b/BufferedSerial.cpp	Sat Feb 13 14:14:50 2016 +0000
@@ -1,4 +1,6 @@
 /**
+ * Adapted by Benjamin Hepp (benjamin.hepp@inf.ethz.ch) to include blocking when write-buffer is full.
+ *
  * @file    BufferedSerial.cpp
  * @brief   Software Buffer - Extends mbed Serial functionallity adding irq driven TX and RX
  * @author  sam grove
@@ -23,21 +25,25 @@
 #include "BufferedSerial.h"
 #include <stdarg.h>
 
-BufferedSerial::BufferedSerial(PinName tx, PinName rx, uint32_t buf_size, uint32_t tx_multiple, const char* name)
-    : RawSerial(tx, rx) , _rxbuf(buf_size), _txbuf((uint32_t)(tx_multiple*buf_size))
+BufferedSerial::BufferedSerial(PinName tx, PinName rx, uint32_t buf_size)
+    : RawSerial(tx, rx) , _rxbuf(buf_size), _txbuf(buf_size), _buffered_bytes(0)
 {
     RawSerial::attach(this, &BufferedSerial::rxIrq, Serial::RxIrq);
     this->_buf_size = buf_size;
-    this->_tx_multiple = tx_multiple;   
-    return;
+}
+
+BufferedSerial::BufferedSerial(PinName tx, PinName rx, int baud_rate, uint32_t buf_size)
+    : RawSerial(tx, rx) , _rxbuf(buf_size), _txbuf(buf_size), _buffered_bytes(0)
+{
+    baud(baud_rate);
+    RawSerial::attach(this, &BufferedSerial::rxIrq, Serial::RxIrq);
+    this->_buf_size = buf_size;
 }
 
 BufferedSerial::~BufferedSerial(void)
 {
     RawSerial::attach(NULL, RawSerial::RxIrq);
     RawSerial::attach(NULL, RawSerial::TxIrq);
-
-    return;
 }
 
 int BufferedSerial::readable(void)
@@ -47,7 +53,7 @@
 
 int BufferedSerial::writeable(void)
 {
-    return 1;   // buffer allows overwriting by design, always true
+    _buffered_bytes < this->_buf_size;
 }
 
 int BufferedSerial::getc(void)
@@ -57,7 +63,10 @@
 
 int BufferedSerial::putc(int c)
 {
+    // Wait for free space in buffer
+    while (_buffered_bytes >= this->_buf_size) {}
     _txbuf = (char)c;
+    ++_buffered_bytes;
     BufferedSerial::prime();
 
     return c;
@@ -67,13 +76,16 @@
 {
     if (s != NULL) {
         const char* ptr = s;
-    
-        while(*(ptr) != 0) {
+
+        while (*(ptr) != 0) {
+            // Wait for free space in buffer
+            while (_buffered_bytes >= this->_buf_size) {}
             _txbuf = *(ptr++);
+            ++_buffered_bytes;
         }
         _txbuf = '\n';  // done per puts definition
         BufferedSerial::prime();
-    
+
         return (ptr - s) + 1;
     }
     return 0;
@@ -82,15 +94,15 @@
 int BufferedSerial::printf(const char* format, ...)
 {
     char buffer[this->_buf_size];
-    memset(buffer,0,this->_buf_size);
+    memset(buffer, 0, this->_buf_size);
     int r = 0;
 
     va_list arg;
     va_start(arg, format);
-    r = vsprintf(buffer, format, arg);
+    r = vsnprintf(buffer, this->_buf_size, format, arg);
     // this may not hit the heap but should alert the user anyways
     if(r > this->_buf_size) {
-        error("%s %d buffer overwrite (max_buf_size: %d exceeded: %d)!\r\n", __FILE__, __LINE__,this->_buf_size,r);
+        error("%s %d buffer to small (buf_size: %d, required: %d)!\r\n", __FILE__, __LINE__, this->_buf_size, r);
         va_end(arg);
         return 0;
     }
@@ -105,12 +117,15 @@
     if (s != NULL && length > 0) {
         const char* ptr = (const char*)s;
         const char* end = ptr + length;
-    
+
         while (ptr != end) {
+            // Wait for free space in buffer
+            while (_buffered_bytes >= this->_buf_size) {}
             _txbuf = *(ptr++);
+            ++_buffered_bytes;
         }
         BufferedSerial::prime();
-    
+
         return ptr - (const char*)s;
     }
     return 0;
@@ -120,39 +135,30 @@
 void BufferedSerial::rxIrq(void)
 {
     // read from the peripheral and make sure something is available
-    if(serial_readable(&_serial)) {
+    if (serial_readable(&_serial)) {
         _rxbuf = serial_getc(&_serial); // if so load them into a buffer
     }
-
-    return;
 }
 
 void BufferedSerial::txIrq(void)
 {
     // see if there is room in the hardware fifo and if something is in the software fifo
-    while(serial_writable(&_serial)) {
-        if(_txbuf.available()) {
+    while (serial_writable(&_serial)) {
+        if (_txbuf.available()) {
             serial_putc(&_serial, (int)_txbuf.get());
-        } else {
-            // disable the TX interrupt when there is nothing left to send
-            RawSerial::attach(NULL, RawSerial::TxIrq);
-            break;
+            --_buffered_bytes;
         }
     }
-
-    return;
 }
 
 void BufferedSerial::prime(void)
 {
     // if already busy then the irq will pick this up
-    if(serial_writable(&_serial)) {
+    if (serial_writable(&_serial)) {
         RawSerial::attach(NULL, RawSerial::TxIrq);    // make sure not to cause contention in the irq
         BufferedSerial::txIrq();                // only write to hardware in one place
         RawSerial::attach(this, &BufferedSerial::txIrq, RawSerial::TxIrq);
     }
-
-    return;
 }