Fixed segmentation fault

main.cpp

@@ -38,11 +38,11 @@
 #include <unistd.h>
 
 bool stop = false;
-Transmitter *transmitter = NULL;
+Transmitter *transmitter = nullptr;
 
 void sigIntHandler(int sigNum)
 {
-    if (transmitter != NULL) {
+    if (transmitter != nullptr) {
         std::cout << "Stopping..." << std::endl;
         transmitter->Stop();
         stop = true;
@@ -87,8 +87,14 @@ int main(int argc, char** argv)
     signal(SIGINT, sigIntHandler);
     signal(SIGTSTP, sigIntHandler);
 
+    auto finally = [&]() {
+        delete transmitter;
+        transmitter = nullptr;
+    };
     try {
-        transmitter = &Transmitter::GetInstance();
+        transmitter = new Transmitter();
+        std::cout << "Broadcasting at " << frequency << " MHz with "
+            << bandwidth << " kHz bandwidth" << std::endl;
         do {
             std::string filename = argv[optind++];
             if ((optind == argc) && loop) {
@@ -96,8 +102,6 @@ int main(int argc, char** argv)
             }
             WaveReader reader(filename != "-" ? filename : std::string(), stop);
             WaveHeader header = reader.GetHeader();
-            std::cout << "Broadcasting at " << frequency << " MHz with "
-                << bandwidth << " kHz bandwidth" << std::endl;
             std::cout << "Playing: " << reader.GetFilename() << ", "
                 << header.sampleRate << " Hz, "
                 << header.bitsPerSample << " bits, "
@@ -106,8 +110,10 @@ int main(int argc, char** argv)
         } while (!stop && (optind < argc));
     } catch (std::exception &catched) {
         std::cout << "Error: " << catched.what() << std::endl;
+        finally();
         return 1;
     }
+    finally();
 
     return 0;
 }

makefile

@@ -1,5 +1,5 @@
 EXECUTABLE = fm_transmitter
-VERSION = 0.9.3
+VERSION = 0.9.4
 FLAGS = -Wall -O3 -std=c++11
 
 all: main.o mailbox.o sample.o wave_reader.o transmitter.o

transmitter.cpp

@@ -220,7 +220,7 @@ class ClockDevice : public Device
 {
     public:
         ClockDevice(uint32_t clockAddress, unsigned divisor) {
-            clock = reinterpret_cast<ClockRegisters *>(peripherals->GetVirtualAddress(CLK0_BASE_OFFSET));
+            clock = reinterpret_cast<ClockRegisters *>(peripherals->GetVirtualAddress(clockAddress));
             clock->ctl = (0x5a << 24) | 0x06;
             std::this_thread::sleep_for(std::chrono::microseconds(1000));
             clock->div = (0x5a << 24) | (0xffffff & divisor);
@@ -301,6 +301,8 @@ class DMAController : public Device
         volatile DMARegisters *dma;
 };
 
+bool Transmitter::transmitting = false;
+
 Transmitter::Transmitter()
     : output(nullptr), stopped(true)
 {
@@ -312,17 +314,12 @@ Transmitter::~Transmitter() {
     }
 }
 
-Transmitter &Transmitter::GetInstance()
-{
-    static Transmitter instance;
-    return instance;
-}
-
 void Transmitter::Transmit(WaveReader &reader, float frequency, float bandwidth, unsigned dmaChannel, bool preserveCarrier)
 {
-    if (!stopped) {
-        throw std::runtime_error("Cannot play, transmitter already in use");
+    if (transmitting) {
+        throw std::runtime_error("Cannot transmit, transmitter already in use");
     }
+    transmitting = true;
     stopped = false;
 
     WaveHeader header = reader.GetHeader();
@@ -339,8 +336,8 @@ void Transmitter::Transmit(WaveReader &reader, float frequency, float bandwidth,
         if (!preserveCarrier) {
             delete output;
             output = nullptr;
-            stopped = true;
         }
+        transmitting = false;
     };
     try {
         if (dmaChannel != 0xff) {
@@ -374,6 +371,7 @@ void Transmitter::TransmitViaCpu(WaveReader &reader, ClockOutput &output, unsign
     std::this_thread::sleep_for(std::chrono::microseconds(BUFFER_TIME / 2));
 
     auto finally = [&]() {
+		stopped = true;
         transmitterThread.join();
         samples.clear();
     };
@@ -458,6 +456,7 @@ void Transmitter::TransmitViaDma(WaveReader &reader, ClockOutput &output, unsign
         while (dma.GetControllBlockAddress() != 0x00000000) {
             std::this_thread::sleep_for(std::chrono::microseconds(1000));
         }
+        stopped = true;
         samples.clear();
     };
     try {

transmitter.hpp

@@ -42,19 +42,19 @@ class ClockOutput;
 class Transmitter
 {
     public:
+        Transmitter();
         virtual ~Transmitter();
         Transmitter(const Transmitter &) = delete;
         Transmitter(Transmitter &&) = delete;
         Transmitter &operator=(const Transmitter &) = delete;
-        static Transmitter &GetInstance();
         void Transmit(WaveReader &reader, float frequency, float bandwidth, unsigned dmaChannel, bool preserveCarrier);
         void Stop();
     private:
-        Transmitter();
         void TransmitViaCpu(WaveReader &reader, ClockOutput &output, unsigned sampleRate, unsigned bufferSize, unsigned clockDivisor, unsigned divisorRange);
         void TransmitViaDma(WaveReader &reader, ClockOutput &output, unsigned sampleRate, unsigned bufferSize, unsigned clockDivisor, unsigned divisorRange, unsigned dmaChannel);
         static void TransmitterThread(Transmitter *instance, ClockOutput *output, unsigned sampleRate, unsigned clockDivisor, unsigned divisorRange, unsigned *sampleOffset, std::vector<Sample> *samples);
 
+        static bool transmitting;
         ClockOutput *output;
         std::mutex access;
         bool stopped;