Fix DeviceLauncher to measure falling edge values properly and load

libEGL.so instead of using RTLD_NEXT in Boottime-EGL.

Using RTLD_NEXT would cause the program to crash for reasons yet
unknown. This fix replaces the usage of RTLD_NEXT by loading libEGL.so
and executing the needed functions from there. This is "the correct" way
to do hooking, but unfortunately now requires libEGL.so from /usr/lib
instead of loading the next symbol dynamically.

The other fix is to DeviceLauncher. Apparently, something has changed in
the way the GPIO pin in the target device goes up/down which broke the
way DeviceLauncher worked. This is now fixed, although the solution
might need refining in the future.

Boottime-EGL/main.cpp

-#define _GNU_SOURCE
-
 #include <iostream>
 #include <fstream>
 #include <dlfcn.h>
@@ -10,14 +8,27 @@
 EGLBoolean eglBindAPI(EGLenum api)
 {
     EGLBoolean (*original_eglBindAPI)(EGLenum api);
-    original_eglBindAPI = (EGLBoolean (*)(EGLenum)) dlsym(RTLD_NEXT, "eglBindAPI");
-    EGLBoolean ok = (*original_eglBindAPI)(api);
+    EGLBoolean ok;
+
+    void *eglLib = dlopen("libEGL.so", RTLD_LAZY);
+    char *error = dlerror();
+
+    if ( error != nullptr ) {
+        std::cerr << "Could not open libEGL.so: " << error;
+        ok = EGL_FALSE;
+    } else {
+        original_eglBindAPI = reinterpret_cast<EGLBoolean (*)(EGLenum)>(dlsym(eglLib, "eglBindAPI"));
+        ok = (*original_eglBindAPI)(api);
+    }
 
     if (!BoottimeEGL::firstBindAPI && !BoottimeEGL::singleShotted) {
         BoottimeEGL::firstBindAPI = true;
         BoottimeEGL::singleShotted = true;
     }
 
+    if ( dlclose(eglLib) != 0 )
+        std::cerr << "Could not close libEGL.so: " << dlerror();
+
     return ok;
 }
 
@@ -25,8 +36,18 @@ EGLBoolean eglBindAPI(EGLenum api)
 EGLBoolean eglSwapBuffers(EGLDisplay dpy, EGLSurface surface)
 {
     EGLBoolean (*original_eglSwapBuffers)(EGLDisplay, EGLSurface);
-    original_eglSwapBuffers = (EGLBoolean (*)(EGLDisplay, EGLSurface)) dlsym(RTLD_NEXT, "eglSwapBuffers");
-    EGLBoolean ok = (*original_eglSwapBuffers)(dpy, surface);
+    EGLBoolean ok;
+
+    void *eglLib = dlopen("libEGL.so", RTLD_LAZY);
+    char *error = dlerror();
+
+    if ( error != nullptr ) {
+        std::cerr << "Could not open libEGL.so: " << error;
+        ok = EGL_FALSE;
+    } else {
+        original_eglSwapBuffers = reinterpret_cast<EGLBoolean (*)(EGLDisplay, EGLSurface)>(dlsym(eglLib, "eglSwapBuffers"));
+        ok = (*original_eglSwapBuffers)(dpy, surface);
+    }
 
     if (BoottimeEGL::firstBindAPI) {
         BoottimeEGL::firstBindAPI = false;
@@ -47,8 +68,10 @@ EGLBoolean eglSwapBuffers(EGLDisplay dpy, EGLSurface surface)
                 gpiovalue.close();
             }
         }
-
     }
 
+    if ( dlclose(eglLib) != 0 )
+        std::cerr << "Could not close libEGL.so: " << dlerror();
+
     return ok;
 }

DeviceLauncher/main.cpp

@@ -98,9 +98,7 @@ int main(int argc, char *argv[])
         lseek(fds.fd, 0, SEEK_SET);
         read(fds.fd, &buffer, 3);
 
-        bool deviceOn = false;
-
-        usleep(100000);
+        usleep(1000000);
 
         while (true) {
             int ret = poll(&fds, 1, -1);
@@ -110,13 +108,10 @@ int main(int argc, char *argv[])
                 char* end;
                 long bufferValue = strtol(buffer, &end, 10);
                 //std::cout << bufferValue << std::endl;
-                if (bufferValue == 0 && deviceOn) {
+                if (bufferValue == 0) {
                     firstFrame = std::chrono::high_resolution_clock::now();
                     break;
-                } else if (bufferValue == 1 && !deviceOn) {
-                    deviceOn = true;
                 }
-
             }
         }