WPILib Reorganization

This is a major restructuring of the WPILib repository to simply build
procedures and remove the remnants of Maven from everything except the
eclipse plugins. Gradle files have been largely simplified or rewritten,
taking advantage of splitting up parts of the build into separate build
files for ease of reading.

The eclipse plugins are now in a separate project, as is ntcore. All
dependencies are resolved via Maven dependencies, with the
Jenkins-maintained WPILib repo. Project structures have also been
simplified: we no longer have separate subprojects inside wpilibc and
wpilibj. Where possible, these changes hav been done with git renames,
to make sure we still have full history for all repositories. Other
unrelated subprojects have also been broken out: OutlineViewer is now a
separate project.

Change-Id: Ib4e2a6e1a2f66427a14f16612b0e0d69ed661878

wpilibj/src/athena/cpp/lib/NotifierJNI.cpp

@@ -0,0 +1,132 @@
+#include <jni.h>
+#include <assert.h>
+#include <functional>
+#include <stdio.h>
+#include "Log.hpp"
+#include "edu_wpi_first_wpilibj_hal_NotifierJNI.h"
+#include "HAL/Notifier.hpp"
+#include "HALUtil.h"
+
+// set the logging level
+TLogLevel notifierJNILogLevel = logWARNING;
+
+#define NOTIFIERJNI_LOG(level) \
+    if (level > notifierJNILogLevel) ; \
+    else Log().Get(level)
+
+// These two are used to pass information to the notifierHandler without using
+// up function parameters.
+// See below for more information.
+static jobject func_global;
+static jmethodID mid_global;
+
+// The arguments are unused by the HAL Notifier; they just satisfy a particular
+// function signature.
+void notifierHandler(uint32_t mask, void* param) {
+  jobject handler_obj = func_global;
+  jmethodID mid = mid_global;
+
+	NOTIFIERJNI_LOG(logDEBUG) << "Calling NOTIFIERJNI notifierHandler";
+
+	//Because this is a callback in a new thread we must attach it to the JVM.
+	JNIEnv *env;
+  jint rs;
+  // Check to see if we are already part of a JVM thread or if we need to attach
+  // ourselves.
+  int getEnvStat = jvm->GetEnv((void **)&env, JNI_VERSION_1_8);
+  if (getEnvStat == JNI_EDETACHED) {
+    rs = jvm->AttachCurrentThread((void**)&env, NULL);
+    assert (rs == JNI_OK);
+  }
+	NOTIFIERJNI_LOG(logDEBUG) << "Attached to thread. Object is: " << handler_obj;
+
+  // Actuall call the user function.
+	env->CallVoidMethod(handler_obj, mid);
+	if (env->ExceptionCheck()) {
+		env->ExceptionDescribe();
+	}
+
+  // Only detach if we needed to attach oursleves in the first place.
+  if (getEnvStat == JNI_EDETACHED) {
+    rs = jvm->DetachCurrentThread();
+    assert (rs == JNI_OK);
+  }
+	NOTIFIERJNI_LOG(logDEBUG) << "Leaving NOTIFIERJNI notifierHandler";
+}
+
+extern "C" {
+
+/*
+ * Class:     edu_wpi_first_wpilibj_hal_NotifierJNI
+ * Method:    initializeNotifier
+ * Signature: (Ljava/lang/Runnable;)J
+ */
+JNIEXPORT jlong JNICALL Java_edu_wpi_first_wpilibj_hal_NotifierJNI_initializeNotifier
+  (JNIEnv *env, jclass, jobject func)
+{
+	NOTIFIERJNI_LOG(logDEBUG) << "Calling NOTIFIERJNI initializeNotifier";
+
+  jclass cls = env->GetObjectClass(func);
+  jmethodID mid = env->GetMethodID(cls, "run", "()V");
+
+  // In order to pass the user's Runnable to the notifierHandler, we have to use
+  // something other than the function arguments (because the function arguments
+  // are dictated by the callback format). As such, we instead use a couple of
+  // global variables to pass around the object reference.
+  // This is not ideal, but the only other option that came to mind was to use
+  // lambda function captures, but, unfortunately, it turns out that using
+  // captures in a lambda changes the function signature such that it can no
+  // long be used as a standared C-style function pointer.
+  // Need to set as global ref to avoid seg faults when referring to it later.
+  func_global = env->NewGlobalRef(func);
+  mid_global = mid;
+
+	int32_t status = 0;
+	void *notifierPtr = initializeNotifier(notifierHandler, &status);
+
+	NOTIFIERJNI_LOG(logDEBUG) << "Notifier Ptr = " << notifierPtr;
+	NOTIFIERJNI_LOG(logDEBUG) << "Status = " << status;
+
+	CheckStatus(env, status);
+	return (jlong)notifierPtr;
+}
+
+/*
+ * Class:     edu_wpi_first_wpilibj_hal_NotifierJNI
+ * Method:    cleanNotifier
+ * Signature: (J)V
+ */
+JNIEXPORT void JNICALL Java_edu_wpi_first_wpilibj_hal_NotifierJNI_cleanNotifier
+  (JNIEnv *env, jclass, jlong notifierPtr)
+{
+	NOTIFIERJNI_LOG(logDEBUG) << "Calling NOTIFIERJNI cleanNotifier";
+
+	NOTIFIERJNI_LOG(logDEBUG) << "Notifier Ptr = " << (void*)notifierPtr;
+
+  int32_t status = 0;
+  cleanNotifier((void*)notifierPtr, &status);
+	NOTIFIERJNI_LOG(logDEBUG) << "Status = " << status;
+	CheckStatus(env, status);
+}
+
+/*
+ * Class:     edu_wpi_first_wpilibj_hal_NotifierJNI
+ * Method:    updateNotifierAlarm
+ * Signature: (JI)V
+ */
+JNIEXPORT void JNICALL Java_edu_wpi_first_wpilibj_hal_NotifierJNI_updateNotifierAlarm
+  (JNIEnv *env, jclass cls, jlong notifierPtr, jint triggerTime)
+{
+	NOTIFIERJNI_LOG(logDEBUG) << "Calling NOTIFIERJNI updateNotifierAlarm";
+
+	NOTIFIERJNI_LOG(logDEBUG) << "Notifier Ptr = " << (void*)notifierPtr;
+
+  NOTIFIERJNI_LOG(logDEBUG) << "triggerTime Ptr = " << &triggerTime;
+
+  int32_t status = 0;
+  updateNotifierAlarm((void*)notifierPtr, (uint32_t)triggerTime, &status);
+	NOTIFIERJNI_LOG(logDEBUG) << "Status = " << status;
+	CheckStatus(env, status);
+}
+
+}  // extern "C"