fix: throw instead of aborting when the default audio device module fails to initialize

webrtc-jni/src/main/cpp/src/JNI_PeerConnectionFactory.cpp

@@ -28,7 +28,9 @@
 #include "JavaRef.h"
 #include "JavaString.h"
 #include "JavaUtils.h"
+#include "WebRTCContext.h"
 
+#include "api/audio/create_audio_device_module.h"
 #include "api/create_peerconnection_factory.h"
 #include "api/audio_codecs/builtin_audio_decoder_factory.h"
 #include "api/audio_codecs/builtin_audio_encoder_factory.h"
@@ -89,6 +91,25 @@ JNIEXPORT void JNICALL Java_dev_onvoid_webrtc_PeerConnectionFactory_initialize
 		webrtc::scoped_refptr<webrtc::AudioProcessing> apm(processing);
 		webrtc::scoped_refptr<webrtc::AudioDeviceModule> adm(audioDevModule);
 
+		if (!adm) {
+			// Without a module, the factory would create the platform default itself
+			// and abort the process when it fails to initialize, which happens on
+			// hosts without an audio system. Create it here instead, the same way
+			// AudioDeviceModule does, so a failure becomes an exception that the
+			// application can handle, for example by passing a module created
+			// with AudioLayer.kDummyAudio.
+			jni::WebRTCContext * context = static_cast<jni::WebRTCContext *>(javaContext);
+
+			adm = webrtc::CreateAudioDeviceModule(context->webrtcEnv, webrtc::AudioDeviceModule::kPlatformDefaultAudio);
+
+			if (!adm) {
+				throw jni::Exception("Create the default AudioDeviceModule failed");
+			}
+			if (adm->Init() != 0) {
+				throw jni::Exception("Initialize the default AudioDeviceModule failed. On a host without an audio system, pass an AudioDeviceModule created with AudioLayer.kDummyAudio.");
+			}
+		}
+
 		auto factory = webrtc::CreatePeerConnectionFactory(
 			networkThread.get(),
 			workerThread.get(),

webrtc/src/test/java/dev/onvoid/webrtc/PeerConnectionFactoryTests.java

@@ -29,6 +29,20 @@
 
 class PeerConnectionFactoryTests extends TestBase {
 
+	@Test
+	void createWithoutAudioDeviceModule() {
+		// Without a module the factory creates the platform default. On a host
+		// without an audio system that must fail with an exception, not abort
+		// the process.
+		try {
+			PeerConnectionFactory factory = new PeerConnectionFactory();
+			factory.dispose();
+		}
+		catch (Error e) {
+			assertTrue(e.getMessage().contains("AudioDeviceModule"), e.getMessage());
+		}
+	}
+
 	@Test
 	void createWithAudioDeviceModule() {
 		AudioDeviceModule audioDevModule = new AudioDeviceModule(AudioLayer.kDummyAudio);