Add exitThread() polling the exit button (#888)

* Add exitThread() polling the exit button

* Add missing includes

* Remove redundant code

libs/core/buttons.ts

@@ -159,11 +159,6 @@ namespace brick {
             if (sl[i])
                 ret |= 1 << i
         }
-        // this needs to be done in query(), which is run without the main JS execution mutex
-        // otherwise, while(true){} will lock the device
-        if (ret & DAL.BUTTON_ID_ESCAPE) {
-            control.reset()
-        }
         return ret
     }
 

libs/core/linux.cpp

@@ -14,6 +14,8 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <malloc.h>
+#include <sys/mman.h>
+#include <sys/ioctl.h>
 #include "ev3const.h"
 
 #define THREAD_DBG(...)
@@ -145,6 +147,29 @@ static void startUsb() {
     pthread_detach(pid);
 }
 
+static void *exitThread(void *) {
+    int fd = open("/dev/lms_ui", O_RDWR, 0666);
+    if (fd < 0)
+        return 0;
+    uint8_t *data =
+        (uint8_t *)mmap(NULL, NUM_BUTTONS, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+    if (data == MAP_FAILED) {
+        close(fd);
+        return 0;
+    }
+    for (;;) {
+        if (data[5])
+            target_reset();
+        sleep_core_us(50000);
+    }
+}
+
+static void startExitThread() {
+    pthread_t pid;
+    pthread_create(&pid, NULL, exitThread, NULL);
+    pthread_detach(pid);
+}
+
 void sendUsb(uint16_t code, const char *data, int len) {
     while (len > 0) {
         int sz = len;
@@ -519,6 +544,7 @@ void initRuntime() {
     DMESG("runtime starting...");
     stopLMS();
     startUsb();
+    startExitThread();
     pthread_t disp;
     pthread_create(&disp, NULL, evtDispatcher, NULL);
     pthread_detach(disp);