Fix a gpio memory leak on shutdown

Author: mskvortsov

cores/portduino/PortduinoGPIO.cpp

@@ -18,14 +18,15 @@ int NUM_GPIOS;
 
 bool realHardware = false;
 
-std::vector<GPIOPinIf*> pins;
+std::vector<std::unique_ptr<GPIOPinIf>> pins;
 
+GPIOPinIf::~GPIOPinIf() {}
 
 /** By default we assign simulated GPIOs to all pins, later applications can customize this in portduinoSetup */
 void gpioInit(int _num_gpios) {
   NUM_GPIOS = _num_gpios;
   for(size_t i = 0; i < NUM_GPIOS; i++)
-    pins.push_back( new SimGPIOPin(i, "Unbound"));
+    pins.push_back(std::make_unique<SimGPIOPin>(i, "Unbound"));
 }
 
 void gpioIdle() {
@@ -35,20 +36,17 @@ void gpioIdle() {
 }
 
 void gpioBind(GPIOPinIf *p) {
-    assert(p->getPinNum() < NUM_GPIOS);
-    pins[p->getPinNum()] = p;
-    realHardware = true;
+  assert(p->getPinNum() < NUM_GPIOS);
+  pins[p->getPinNum()].reset(p);
+  realHardware = true;
 }
 
 /**
  * Return the specified GPIO pin or the UnboundPin pin instance */
 GPIOPinIf *getGPIO(pin_size_t n)
 {
   assert(n < NUM_GPIOS);
-  auto p = pins[n];
-
-  assert(p);
-  return p;
+  return pins[n].get();
 }
 
 void pinMode(pin_size_t pinNumber, PinMode pinMode)

cores/portduino/PortduinoGPIO.h

@@ -15,6 +15,7 @@
 class GPIOPinIf
 {
 public:
+    virtual ~GPIOPinIf() = 0;
     virtual pin_size_t getPinNum() const = 0;
 
     /** Called to read from a pin and if the pin has changed state possibly call an ISR, also changes

cores/portduino/linux/gpio/LinuxGPIOPin.cpp

@@ -104,7 +104,6 @@ static struct gpiod_chip *chip_open_by_name(const char *name)
  * Try to find the specified linux gpio line, throw exception if not found
  */
 gpiod_line *LinuxGPIOPin::getLine(const char *chipLabel, const char *linuxPinName) {
-	struct gpiod_chip *chip;
 	std::string path = "/dev/";
 	path += chipLabel;
   if (access(path.c_str(), R_OK) == 0) {
@@ -181,7 +180,6 @@ gpiod_line *LinuxGPIOPin::getLine(const char *chipLabel, const char *linuxPinNam
  * Try to find the specified linux gpio line, throw exception if not found
  */
 gpiod_line *LinuxGPIOPin::getLine(const char *chipLabel, const int linuxPinNum) {
-	struct gpiod_chip *chip;
 	std::string path = "/dev/";
 	path += chipLabel;
   if (access(path.c_str(), R_OK) == 0) {
@@ -270,7 +268,7 @@ LinuxGPIOPin::LinuxGPIOPin(pin_size_t n, const char *chipLabel,
 
 LinuxGPIOPin::~LinuxGPIOPin() { 
     gpiod_line_release(line); 
-    // FIXME must call gpiod_chip_unref(chip);
+    gpiod_chip_close(chip);
 }
 
 /// Read the low level hardware for this pin

cores/portduino/linux/gpio/LinuxGPIOPin.h

@@ -29,6 +29,9 @@ class LinuxGPIOPin : public GPIOPin {
   /// Our GPIO line
   struct gpiod_line *line;
 
+  /// Chip structure associated with the line
+  struct gpiod_chip *chip;
+
 public:
 
   /**