Merge pull request #24 from thedilletante/android_multithread

[Android] Added newGuid() overloading to support multithread invocations

.gitignore

@@ -4,3 +4,4 @@ build/
 *.swp
 android/libs/
 android/obj/
+cmake_build

CMakeLists.txt

@@ -24,6 +24,8 @@ elseif(APPLE)
 	target_link_libraries(xg ${CFLIB})
 	add_definitions(-DGUID_CFUUID)
 	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -pedantic")
+elseif(ANDROID)
+	target_compile_definitions(xg PRIVATE GUID_ANDROID)
 else()
 	find_package(Libuuid REQUIRED)
 	if (NOT LIBUUID_FOUND)

Guid.cpp

@@ -39,6 +39,7 @@ THE SOFTWARE.
 
 #ifdef GUID_ANDROID
 #include <jni.h>
+#include <cassert>
 #endif
 
 BEGIN_XG_NAMESPACE
@@ -50,13 +51,16 @@ AndroidGuidInfo AndroidGuidInfo::fromJniEnv(JNIEnv *env)
 {
 	AndroidGuidInfo info;
 	info.env = env;
-	info.uuidClass = env->FindClass("java/util/UUID");
+	auto localUuidClass = env->FindClass("java/util/UUID");
+	info.uuidClass = (jclass)env->NewGlobalRef(localUuidClass);
+	env->DeleteLocalRef(localUuidClass);
 	info.newGuidMethod = env->GetStaticMethodID(
 		info.uuidClass, "randomUUID", "()Ljava/util/UUID;");
 	info.mostSignificantBitsMethod = env->GetMethodID(
 		info.uuidClass, "getMostSignificantBits", "()J");
 	info.leastSignificantBitsMethod = env->GetMethodID(
 		info.uuidClass, "getLeastSignificantBits", "()J");
+	info.initThreadId = std::this_thread::get_id();
 	return info;
 }
 
@@ -340,13 +344,15 @@ Guid newGuid()
 
 // android version that uses a call to a java api
 #ifdef GUID_ANDROID
-Guid newGuid()
+Guid newGuid(JNIEnv *env)
 {
-	jobject javaUuid = androidInfo.env->CallStaticObjectMethod(
+	assert(env != androidInfo.env || std::this_thread::get_id() == androidInfo.initThreadId);
+
+	jobject javaUuid = env->CallStaticObjectMethod(
 		androidInfo.uuidClass, androidInfo.newGuidMethod);
-	jlong mostSignificant = androidInfo.env->CallLongMethod(javaUuid,
+	jlong mostSignificant = env->CallLongMethod(javaUuid,
 		androidInfo.mostSignificantBitsMethod);
-	jlong leastSignificant = androidInfo.env->CallLongMethod(javaUuid,
+	jlong leastSignificant = env->CallLongMethod(javaUuid,
 		androidInfo.leastSignificantBitsMethod);
 
 	std::array<unsigned char, 16> bytes =
@@ -369,12 +375,18 @@ Guid newGuid()
 		(unsigned char)((leastSignificant) & 0xFF)
 	};
 
-	androidInfo.env->DeleteLocalRef(javaUuid);
+	env->DeleteLocalRef(javaUuid);
 
 	return bytes;
 }
+
+Guid newGuid()
+{
+	return newGuid(androidInfo.env);
+}
 #endif
 
+
 END_XG_NAMESPACE
 
 // Specialization for std::swap<Guid>() --

Guid.hpp

@@ -25,6 +25,7 @@ THE SOFTWARE.
 #pragma once
 
 #ifdef GUID_ANDROID
+#include <thread>
 #include <jni.h>
 #endif
 
@@ -84,11 +85,15 @@ struct AndroidGuidInfo
 	jmethodID newGuidMethod;
 	jmethodID mostSignificantBitsMethod;
 	jmethodID leastSignificantBitsMethod;
+	std::thread::id initThreadId;
 };
 
 extern AndroidGuidInfo androidInfo;
 
 void initJni(JNIEnv *env);
+
+// overloading for multi-threaded calls
+Guid newGuid(JNIEnv *env);
 #endif
 
 END_XG_NAMESPACE

README.md

@@ -207,8 +207,7 @@ following requirements:
 * Android emulator is already running (or you have physical device connected).
 * You're using bash.
 * adb is in your path.
-* ndk-build and other ndk cross-compile tools are in your path.
-* You have a jdk setup including `JAVA_HOME` environment variable.
+* You have an Android sdk setup including `ANDROID_HOME` environment variable.
 
 ## License
 

android.sh

@@ -1,10 +1,10 @@
 #!/usr/bin/env bash
 
+export LC_NUMERIC="en_US.UTF-8"
+
 pushd android
-ndk-build clean || { exit 1; }
-ndk-build || { exit 1; }
-ant debug || { exit 1; }
+./gradlew clean assembleDebug
 adb uninstall ca.graemehill.crossguid.testapp || { exit 1; }
-adb install bin/TestApp-debug.apk || { exit 1; }
+adb install app/build/outputs/apk/debug/app-debug.apk || { exit 1; }
 adb shell am start -n ca.graemehill.crossguid.testapp/ca.graemehill.crossguid.testapp.MainActivity
 popd

android/.gitignore

@@ -0,0 +1,10 @@
+*.iml
+.gradle
+/local.properties
+/.idea/workspace.xml
+/.idea/libraries
+.DS_Store
+/build
+/captures
+.externalNativeBuild
+.idea

android/app/.gitignore

@@ -0,0 +1 @@
+/build

android/app/CMakeLists.txt

@@ -0,0 +1,18 @@
+cmake_minimum_required(VERSION 3.4.1)
+
+set(LIB_NAME crossguidtest)
+set(XG_DIR ${CMAKE_CURRENT_LIST_DIR}/../..)
+set(XG_TEST_DIR ${XG_DIR}/test)
+
+add_library(${LIB_NAME} SHARED src/main/cpp/jnitest.cpp ${XG_TEST_DIR}/Test.cpp)
+
+target_include_directories(${LIB_NAME} PRIVATE
+                          ${XG_DIR}
+                          ${XG_TEST_DIR})
+
+target_compile_definitions(${LIB_NAME} PRIVATE GUID_ANDROID)
+
+set(XG_TESTS OFF CACHE BOOL "disable tests")
+add_subdirectory(${XG_DIR} ${XG_DIR}/cmake_build)
+
+target_link_libraries(${LIB_NAME} xg)

android/app/build.gradle

@@ -0,0 +1,39 @@
+apply plugin: 'com.android.application'
+
+android {
+    compileSdkVersion 25
+    buildToolsVersion "26.0.0"
+    defaultConfig {
+        applicationId "ca.graemehill.crossguid.testapp"
+        minSdkVersion 14
+        targetSdkVersion 25
+        versionCode 1
+        versionName "1.0"
+        externalNativeBuild {
+            cmake {
+                cppFlags "-std=c++11 -frtti -fexceptions"
+                arguments "-DANDROID_TOOLCHAIN=clang"
+            }
+        }
+    }
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+        }
+    }
+    externalNativeBuild {
+        cmake {
+            path "CMakeLists.txt"
+        }
+    }
+}
+
+dependencies {
+    implementation fileTree(dir: 'libs', include: ['*.jar'])
+    androidTestImplementation('com.android.support.test.espresso:espresso-core:3.0.0', {
+        exclude group: 'com.android.support', module: 'support-annotations'
+    })
+    implementation 'com.android.support:appcompat-v7:25.4.0'
+    testImplementation 'junit:junit:4.12'
+}

android/app/proguard-rules.pro

@@ -0,0 +1,25 @@
+# Add project specific ProGuard rules here.
+# By default, the flags in this file are appended to flags specified
+# in /usr/local/Cellar/android-sdk/24.4.1_1/tools/proguard/proguard-android.txt
+# You can edit the include path and order by changing the proguardFiles
+# directive in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# Add any project specific keep options here:
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile

android/AndroidManifest.xml → android/app/src/main/AndroidManifest.xml

@@ -1,9 +1,13 @@
-<?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-      package="ca.graemehill.crossguid.testapp"
-      android:versionCode="1"
-      android:versionName="1.0">
-    <application android:label="@string/app_name" android:icon="@drawable/ic_launcher">
+    package="ca.graemehill.crossguid.testapp">
+
+    <application
+        android:allowBackup="true"
+        android:icon="@mipmap/ic_launcher"
+        android:label="@string/app_name"
+        android:roundIcon="@mipmap/ic_launcher_round"
+        android:supportsRtl="true"
+        android:theme="@style/AppTheme">
         <activity android:name="MainActivity"
                   android:label="@string/app_name">
             <intent-filter>

android/app/src/main/cpp/jnitest.cpp

@@ -0,0 +1,61 @@
+#include <string>
+#include <sstream>
+#include <atomic>
+#include <iostream>
+
+#include <jni.h>
+#include "Guid.hpp"
+#include "Test.hpp"
+
+JavaVM *&javaVM() {
+    static JavaVM *jvm;
+    return jvm;
+}
+
+extern "C"
+{
+
+JNIEXPORT jint JNICALL JNI_OnLoad(JavaVM *jvm, void * /* reserved */) {
+    javaVM() = jvm;
+    return JNI_VERSION_1_6;
+}
+
+JNIEXPORT jstring JNICALL
+Java_ca_graemehill_crossguid_testapp_MainActivity_test(
+    JNIEnv *env, jobject /*thiz*/)
+{
+    std::stringstream resultStream;
+    xg::initJni(env);
+    test(resultStream);
+    return env->NewStringUTF(resultStream.str().c_str());
+}
+
+JNIEXPORT jstring JNICALL
+Java_ca_graemehill_crossguid_testapp_MainActivity_newGuid(
+    JNIEnv *env, jobject /*thiz*/) {
+    return env->NewStringUTF(xg::newGuid(env).str().c_str());
+}
+
+JNIEXPORT jstring JNICALL
+Java_ca_graemehill_crossguid_testapp_MainActivity_createGuidFromNativeThread(
+    JNIEnv *env, jobject /*thiz*/) {
+
+    // there is no promise<> in armeabi of ndk
+    // so ugly atomic_bool wait solution
+    std::atomic_bool ready { false };
+    std::string guid;
+
+    std::thread([&ready, &guid](){
+        JNIEnv *threadEnv;
+        javaVM()->AttachCurrentThread(&threadEnv, NULL);
+        guid = xg::newGuid(threadEnv);
+        javaVM()->DetachCurrentThread();
+
+        ready = true;
+    }).detach();
+
+    while (!ready);
+    return env->NewStringUTF(guid.c_str());
+}
+
+}

android/app/src/main/java/ca/graemehill/crossguid/testapp/MainActivity.java

@@ -0,0 +1,64 @@
+package ca.graemehill.crossguid.testapp;
+
+import android.app.Activity;
+import android.os.Bundle;
+import android.widget.TextView;
+
+import java.util.concurrent.CountDownLatch;
+
+public class MainActivity extends Activity {
+
+    @Override
+    public void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.main);
+
+        final TextView textView = (TextView)findViewById(R.id.mainTextView);
+        textView.setText(test());
+
+        final TextView javaThreadView = (TextView)findViewById(R.id.javaThreadView);
+        javaThreadView.setText(createGuidFromJavaThread());
+
+        final TextView nativeThreadView = (TextView)findViewById(R.id.nativeThreadView);
+        nativeThreadView.setText(createGuidFromNativeThread());
+    }
+
+    public native String test();
+
+    private static class StringCapture {
+        private String value;
+
+        public String getValue() {
+            return value;
+        }
+
+        public void setValue(String value) {
+            this.value = value;
+        }
+    }
+
+    public String createGuidFromJavaThread() {
+        final CountDownLatch created = new CountDownLatch(1);
+        final StringCapture result = new StringCapture();
+        new Thread(new Runnable() {
+            @Override
+            public void run() {
+                result.setValue(newGuid());
+                created.countDown();
+            }
+        }).start();
+        try {
+            created.await();
+        } catch (InterruptedException e) {
+            return "Could not get value: " + e.getMessage();
+        }
+        return result.getValue();
+    }
+
+    public native String newGuid();
+
+    public native String createGuidFromNativeThread();
+    static {
+        System.loadLibrary("crossguidtest");
+    }
+}