attempt to fix double task creation

src/main.cpp

@@ -45,7 +45,7 @@ void setup()
 
   static const char *bootSound = "/boot.wav";
 
-  xTaskCreate(&(Sound::buffer_refill_task), "buffer_refill_task", 4096, (void*)bootSound, 5, &xTaskSound);
+  //xTaskCreate(&(Sound::buffer_refill_task), "buffer_refill_task", 3072, (void*)bootSound, 5, &xTaskSound);
 }
 
 void loop()
@@ -56,9 +56,10 @@ void loop()
       touched = true;
         Serial.print("touch ");
         Serial.println(i, DEC);
-      if (sound.playing == false) {
-        Serial.println("new task");
-        xTaskCreate(&(Sound::buffer_refill_task), "buffer_refill_task", 4096, (void*)soundFile[i/3][i%3], 5, &xTaskSound);
+      if (Sound::playing == false) {
+        Sound::playing == true;  // ToDo: fix double task init
+        Serial.println("main loop touched==true: new task");
+        xTaskCreate(&(Sound::buffer_refill_task), "buffer_refill_task", 3072, (void*)soundFile[i/3][i%3], 5, &xTaskSound);
       }
     }
   }

src/sdcard.cpp

@@ -9,6 +9,7 @@
 #include "FS.h"
 #include "SD.h"
 #include "SPI.h"
+#include "freertos/semphr.h"
 
 #include "hardware.h"
 #include "sdcard.h"
@@ -20,10 +21,12 @@ using namespace std;
 static const char* TAG = "SDCard";
 
 unsigned char *DataSource::buffer = NULL;
+SemaphoreHandle_t xSemaphore = NULL;
 unsigned int DataSource::buf_pos = 0;
 File SDCard::file;
 
 SDCard::SDCard() {
+    xSemaphore = xSemaphoreCreateMutex();
 }
 
 void SDCard::mount() {
@@ -62,17 +65,33 @@ void SDCard::umount() {
 }
 
 void SDCard::open(const char *path) {
-    DataSource::buffer = (unsigned char *)malloc(BUF_LENGTH);
-    Serial.print("Allocated buffer at: ");   Serial.println((int)(DataSource::buffer),HEX);
-    SDCard::file = (SDCard::fs).open(path);
-    if(!SDCard::file){
-        Serial.println("Failed to open file for reading");
-        return;
+    if( xSemaphore != NULL ) {
+        if( xSemaphoreTake( xSemaphore, ( TickType_t ) 10 ) == pdTRUE ) {
+            if (DataSource::buffer != NULL) Serial.println("double malloc for buffer?");
+            DataSource::buffer = (unsigned char *)malloc(BUF_LENGTH);
+            Serial.print("Allocated buffer at: ");   Serial.println((int)(DataSource::buffer),HEX);
+            SDCard::file = (SDCard::fs).open(path);
+            if(!SDCard::file){
+                Serial.println("Failed to open file for reading");
+                return;
+            }
+        } else {
+            /* xSemaphoreTake() != pdTRUE */
+            /* could not obtain the semaphore */
+            Serial.println("sdcard: open(): could not obtain semaphore");
+        }
     }
+
+
 }
 
 void SDCard::close() {
-  free(DataSource::buffer);
+  if (DataSource::buffer != NULL) { // ToDo: really fix this
+    Serial.print("free(buffer) at: ");   Serial.println((int)(DataSource::buffer),HEX);
+    free(DataSource::buffer);
+    DataSource::buffer = NULL;
+    xSemaphoreGive( xSemaphore );
+  }
   SDCard::file.close();
 }
 

src/sound.cpp

@@ -28,7 +28,7 @@
 
 using namespace std;
 
-bool Sound::playing = false;
+volatile bool Sound::playing = false;
 
 Sound::Sound() {
 }
@@ -82,13 +82,15 @@ void Sound::init() {
 }
 
 void Sound::play() {
+  Serial.println("Sound::play()");
   i2s_start(i2s_num);
-  playing = true;
+  Sound::playing = true;
 }
 
 void Sound::stop() {
+  Serial.println("Sound::stop()");
   i2s_stop(i2s_num);
-  playing = false;
+  Sound::playing = false;
 }
 
 void Sound::end() {
@@ -96,22 +98,25 @@ void Sound::end() {
 }
 
 void Sound::buffer_refill_task(void *pvParameter) {
+//  Serial.print("initial free stack: "); Serial.println(uxTaskGetStackHighWaterMark( NULL ), DEC); // DEBUG
   char *path = (char *) pvParameter;
   Serial.println("sdcard: opening File");
   SDCard::open(path);
 
   Sound::play();
   while (SDCard::available()) {
+//  Serial.print("chunk free stack: "); Serial.println(uxTaskGetStackHighWaterMark( NULL ), DEC); // DEBUG
   // get chunk of data
   SDCard::read(); // overwrite buffer
   DataSource::buf_pos = 0;
 
   while (DataSource::buf_pos < BUF_LENGTH) {
+//    Serial.print("i2s_push free stack: "); Serial.println(uxTaskGetStackHighWaterMark( NULL ), DEC); // DEBUG
     uint16_t *buf = (uint16_t *) DataSource::buffer;
     int buf_pos = (DataSource::buf_pos)/4;
     // convert data
     //unsigned int sample = ((unsigned short) DataSource::buffer[DataSource::buf_pos] << 16 & 0xffff0000) | ((unsigned short) DataSource::buffer[DataSource::buf_pos]);
-    unsigned int sample = ((unsigned short) buf[buf_pos] << 16 & 0xffff0000) | ((unsigned short) DataSource::buffer[buf_pos]);
+    unsigned int sample = ((unsigned short) buf[buf_pos] << 16 & 0xffff0000) | ((unsigned short) buf[buf_pos]);
     // push samples
     int num_pushed_bytes = i2s_push_sample(Sound::i2s_num, (char *)&sample, 0);
     if (num_pushed_bytes == 0) {
@@ -127,6 +132,7 @@ void Sound::buffer_refill_task(void *pvParameter) {
   Serial.println("sdcard: EOF");
   SDCard::close();
   Sound::stop();
+  Serial.println("task exiting");
   vTaskDelete( NULL );
 }
 

src/sound.h

@@ -18,7 +18,7 @@ class Sound {
     static void stop();
     int render_sample_block(uint16_t *sample_buf_left, uint16_t *sample_buf_right, int num_samples);
     static const i2s_port_t i2s_num = (i2s_port_t)I2S_NUM;
-    static bool playing;
+    static volatile bool playing;
     static void buffer_refill_task(void *pvParameter);
   private:
     TaskHandle_t xTaskRefillBuffer;