Load Qt libs from Qt thread

[ChangeLog][Android] The application and dependent Qt libraries are
now loaded on the same thread as main() is run on, ensuring that global
static initializers, constructor functions, and main() are all run on the
same thread. The same applies during application shutdown, for destructors
of global objects, and destructor functions.

Change-Id: Id4bfece1ed2a0532ed2e8fb7d8ffd6e55d5a10dc
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>

1 files changed, 52 insertions, 55 deletions

diff --git a/src/plugins/platforms/android/androidjnimain.cpp b/src/plugins/platforms/android/androidjnimain.cpp
index 2bdd49dc50..13d41bea99 100644
--- a/src/plugins/platforms/android/androidjnimain.cpp
+++ b/src/plugins/platforms/android/androidjnimain.cpp
@@ -59,6 +59,7 @@
 #include "qandroideventdispatcher.h"
 #include <android/api-level.h>
 
+#include <QtCore/qthread.h>
 #include <QtCore/private/qjnihelpers_p.h>
 #include <QtCore/private/qjni_p.h>
 #include <QtGui/private/qguiapplication_p.h>
@@ -99,7 +100,6 @@ extern "C" typedef int (*Main)(int, char **); //use the standard main method to
 static Main m_main = nullptr;
 static void *m_mainLibraryHnd = nullptr;
 static QList<QByteArray> m_applicationParams;
-pthread_t m_qtAppThread = 0;
 static sem_t m_exitSemaphore, m_terminateSemaphore;
 
 QHash<int, AndroidSurfaceClient *> m_surfaces;
@@ -441,57 +441,10 @@ namespace QtAndroid
 
 } // namespace QtAndroid
 
-static jboolean startQtAndroidPlugin(JNIEnv* /*env*/, jobject /*object*//*, jobject applicationAssetManager*/)
+static jboolean startQtAndroidPlugin(JNIEnv *env, jobject /*object*/, jstring paramsString, jstring environmentString)
 {
     m_androidPlatformIntegration = nullptr;
     m_androidAssetsFileEngineHandler = new AndroidAssetsFileEngineHandler();
-    return true;
-}
-
-static void *startMainMethod(void */*data*/)
-{
-    {
-        JNIEnv* env = nullptr;
-        JavaVMAttachArgs args;
-        args.version = JNI_VERSION_1_6;
-        args.name = "QtMainThread";
-        args.group = NULL;
-        JavaVM *vm = QtAndroidPrivate::javaVM();
-        if (vm != 0)
-            vm->AttachCurrentThread(&env, &args);
-    }
-
-    QVarLengthArray<const char *> params(m_applicationParams.size());
-    for (int i = 0; i < m_applicationParams.size(); i++)
-        params[i] = static_cast<const char *>(m_applicationParams[i].constData());
-
-    int ret = m_main(m_applicationParams.length(), const_cast<char **>(params.data()));
-
-    if (m_mainLibraryHnd) {
-        int res = dlclose(m_mainLibraryHnd);
-        if (res < 0)
-            qWarning() << "dlclose failed:" << dlerror();
-    }
-
-    if (m_applicationClass)
-        QJNIObjectPrivate::callStaticMethod<void>(m_applicationClass, "quitApp", "()V");
-
-    // All attached threads should be detached before returning from this function.
-    JavaVM *vm = QtAndroidPrivate::javaVM();
-    if (vm != 0)
-        vm->DetachCurrentThread();
-
-    sem_post(&m_terminateSemaphore);
-    sem_wait(&m_exitSemaphore);
-    sem_destroy(&m_exitSemaphore);
-
-    // We must call exit() to ensure that all global objects will be destructed
-    exit(ret);
-    return 0;
-}
-
-static jboolean startQtApplication(JNIEnv *env, jobject /*object*/, jstring paramsString, jstring environmentString)
-{
     m_mainLibraryHnd = nullptr;
     { // Set env. vars
         const char *nativeString = env->GetStringUTFChars(environmentString, 0);
@@ -540,14 +493,54 @@ static jboolean startQtApplication(JNIEnv *env, jobject /*object*/, jstring para
     if (sem_init(&m_terminateSemaphore, 0, 0) == -1)
         return false;
 
-    jboolean res = pthread_create(&m_qtAppThread, nullptr, startMainMethod, nullptr) == 0;
+    return true;
+}
 
+static void waitForServiceSetup(JNIEnv *env, jclass /*clazz*/)
+{
+    Q_UNUSED(env);
     // The service must wait until the QCoreApplication starts otherwise onBind will be
     // called too early
     if (m_serviceObject)
         QtAndroidPrivate::waitForServiceSetup();
+}
+
+static jboolean startQtApplication(JNIEnv */*env*/, jclass /*clazz*/)
+{
+    {
+        JNIEnv* env = nullptr;
+        JavaVMAttachArgs args;
+        args.version = JNI_VERSION_1_6;
+        args.name = "QtMainThread";
+        args.group = NULL;
+        JavaVM *vm = QtAndroidPrivate::javaVM();
+        if (vm != 0)
+            vm->AttachCurrentThread(&env, &args);
+    }
+
+    QVarLengthArray<const char *> params(m_applicationParams.size());
+    for (int i = 0; i < m_applicationParams.size(); i++)
+        params[i] = static_cast<const char *>(m_applicationParams[i].constData());
+
+    int ret = m_main(m_applicationParams.length(), const_cast<char **>(params.data()));
+
+    if (m_mainLibraryHnd) {
+        int res = dlclose(m_mainLibraryHnd);
+        if (res < 0)
+            qWarning() << "dlclose failed:" << dlerror();
+    }
 
-    return res;
+    if (m_applicationClass) {
+        qWarning("exit app 0");
+        QJNIObjectPrivate::callStaticMethod<void>(m_applicationClass, "quitApp", "()V");
+    }
+
+    sem_post(&m_terminateSemaphore);
+    sem_wait(&m_exitSemaphore);
+    sem_destroy(&m_exitSemaphore);
+
+    // We must call exit() to ensure that all global objects will be destructed
+    exit(ret);
 }
 
 static void quitQtCoreApplication(JNIEnv *env, jclass /*clazz*/)
@@ -593,7 +586,6 @@ static void terminateQt(JNIEnv *env, jclass /*clazz*/)
 
     if (!QAndroidEventDispatcherStopper::instance()->stopped()) {
         sem_post(&m_exitSemaphore);
-        pthread_join(m_qtAppThread, nullptr);
     }
 }
 
@@ -758,11 +750,12 @@ static jobject onBind(JNIEnv */*env*/, jclass /*cls*/, jobject intent)
 }
 
 static JNINativeMethod methods[] = {
-    {"startQtAndroidPlugin", "()Z", (void *)startQtAndroidPlugin},
-    {"startQtApplication", "(Ljava/lang/String;Ljava/lang/String;)V", (void *)startQtApplication},
+    {"startQtAndroidPlugin", "(Ljava/lang/String;Ljava/lang/String;)Z", (void *)startQtAndroidPlugin},
+    {"startQtApplication", "()V", (void *)startQtApplication},
     {"quitQtAndroidPlugin", "()V", (void *)quitQtAndroidPlugin},
     {"quitQtCoreApplication", "()V", (void *)quitQtCoreApplication},
     {"terminateQt", "()V", (void *)terminateQt},
+    {"waitForServiceSetup", "()V", (void *)waitForServiceSetup},
     {"setDisplayMetrics", "(IIIIDDDD)V", (void *)setDisplayMetrics},
     {"setSurface", "(ILjava/lang/Object;II)V", (void *)setSurface},
     {"updateWindow", "()V", (void *)updateWindow},
@@ -884,7 +877,6 @@ Q_DECL_EXPORT jint JNICALL JNI_OnLoad(JavaVM *vm, void */*reserved*/)
         void *venv;
     } UnionJNIEnvToVoid;
 
-    __android_log_print(ANDROID_LOG_INFO, "Qt", "qt start");
     UnionJNIEnvToVoid uenv;
     uenv.venv = nullptr;
     m_javaVM = nullptr;
@@ -906,5 +898,10 @@ Q_DECL_EXPORT jint JNICALL JNI_OnLoad(JavaVM *vm, void */*reserved*/)
     QWindowSystemInterfacePrivate::TabletEvent::setPlatformSynthesizesMouse(false);
 
     m_javaVM = vm;
+    // attach qt main thread data to this thread
+    QObject threadSetter;
+    if (threadSetter.thread())
+        threadSetter.thread()->setObjectName("QtMainLoopThread");
+    __android_log_print(ANDROID_LOG_INFO, "Qt", "qt started");
     return JNI_VERSION_1_4;
 }