Make encoder and decoder thread-safe

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>de.maxhenkel.lame4j</groupId>
     <artifactId>lame4j</artifactId>
-    <version>2.0.2</version>
+    <version>2.0.3</version>
 
     <name>Lame Wrapper for Java</name>
     <url>https://maxhenkel.de</url>

rust/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "lame4j"
-version = "2.0.2"
+version = "2.0.3"
 edition = "2021"
 
 [dependencies]

rust/src/lame/decoder.rs

@@ -13,7 +13,7 @@ struct DecoderWrapper {
 }
 
 #[no_mangle]
-pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Decoder_createDecoder(_env: JNIEnv, _class: JClass) -> jlong {
+pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Decoder_createDecoder0(_env: JNIEnv, _class: JClass) -> jlong {
     let stream_wrapper = JavaInputStream {
         env: None,
         input_stream: None,
@@ -32,7 +32,7 @@ pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Decoder_createDecoder(_env: JNIEnv
 }
 
 #[no_mangle]
-pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Decoder_decodeNextFrame<'a>(mut env: JNIEnv<'static>, obj: JObject<'a>, stream: JObject<'static>) -> JShortArray<'a> {
+pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Decoder_decodeNextFrame0<'a>(mut env: JNIEnv<'static>, obj: JObject<'a>, stream: JObject<'static>) -> JShortArray<'a> {
     let decoder_wrapper = match get_decoder(&mut env, &obj) {
         Some(decoder) => decoder,
         None => {
@@ -85,7 +85,7 @@ pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Decoder_decodeNextFrame<'a>(mut en
 }
 
 #[no_mangle]
-pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Decoder_headerParsed(mut env: JNIEnv, obj: JObject) -> jboolean {
+pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Decoder_headerParsed0(mut env: JNIEnv, obj: JObject) -> jboolean {
     let decoder_wrapper = match get_decoder(&mut env, &obj) {
         Some(decoder) => decoder,
         None => {
@@ -96,7 +96,7 @@ pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Decoder_headerParsed(mut env: JNIE
 }
 
 #[no_mangle]
-pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Decoder_getChannelCount(mut env: JNIEnv, obj: JObject) -> jint {
+pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Decoder_getChannelCount0(mut env: JNIEnv, obj: JObject) -> jint {
     let decoder_wrapper = match get_decoder(&mut env, &obj) {
         Some(decoder) => decoder,
         None => {
@@ -107,7 +107,7 @@ pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Decoder_getChannelCount(mut env: J
 }
 
 #[no_mangle]
-pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Decoder_getBitRate(mut env: JNIEnv, obj: JObject) -> jint {
+pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Decoder_getBitRate0(mut env: JNIEnv, obj: JObject) -> jint {
     let decoder_wrapper = match get_decoder(&mut env, &obj) {
         Some(decoder) => decoder,
         None => {
@@ -118,7 +118,7 @@ pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Decoder_getBitRate(mut env: JNIEnv
 }
 
 #[no_mangle]
-pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Decoder_getSampleRate(mut env: JNIEnv, obj: JObject) -> jint {
+pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Decoder_getSampleRate0(mut env: JNIEnv, obj: JObject) -> jint {
     let decoder_wrapper = match get_decoder(&mut env, &obj) {
         Some(decoder) => decoder,
         None => {
@@ -129,7 +129,7 @@ pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Decoder_getSampleRate(mut env: JNI
 }
 
 #[no_mangle]
-pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Decoder_destroyDecoder(mut env: JNIEnv, obj: JObject) {
+pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Decoder_destroyDecoder0(mut env: JNIEnv, obj: JObject) {
     let pointer = get_pointer(&mut env, &obj);
 
     if pointer == 0 {

rust/src/lame/encoder.rs

@@ -16,7 +16,7 @@ struct LameEncoder {
 }
 
 #[no_mangle]
-pub unsafe extern "C" fn Java_de_maxhenkel_lame4j_Mp3Encoder_createEncoder(mut env: JNIEnv, _class: JClass, channels: jint, sample_rate: jint, bit_rate: jint, quality: jint) -> jlong {
+pub unsafe extern "C" fn Java_de_maxhenkel_lame4j_Mp3Encoder_createEncoder0(mut env: JNIEnv, _class: JClass, channels: jint, sample_rate: jint, bit_rate: jint, quality: jint) -> jlong {
     let lame = lame_init();
 
     lame_set_num_channels(lame, channels as i32);
@@ -42,7 +42,7 @@ pub unsafe extern "C" fn Java_de_maxhenkel_lame4j_Mp3Encoder_createEncoder(mut e
 }
 
 #[no_mangle]
-pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Encoder_writeInternal<'a>(mut env: JNIEnv<'a>, obj: JObject<'a>, input: JShortArray<'a>) -> JByteArray<'a> {
+pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Encoder_writeInternal0<'a>(mut env: JNIEnv<'a>, obj: JObject<'a>, input: JShortArray<'a>) -> JByteArray<'a> {
     let lame = match get_lame(&mut env, &obj) {
         Some(lame) => lame,
         None => {
@@ -110,7 +110,7 @@ fn estimate_mp3_buffer_size(num_samples: i32) -> usize {
 }
 
 #[no_mangle]
-pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Encoder_flush<'a>(mut env: JNIEnv<'a>, obj: JObject<'a>) -> JByteArray<'a> {
+pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Encoder_flush0<'a>(mut env: JNIEnv<'a>, obj: JObject<'a>) -> JByteArray<'a> {
     let lame = match get_lame(&mut env, &obj) {
         Some(lame) => lame,
         None => {
@@ -142,7 +142,7 @@ pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Encoder_flush<'a>(mut env: JNIEnv<
 }
 
 #[no_mangle]
-pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Encoder_destroyEncoder(mut env: JNIEnv, obj: JObject) {
+pub extern "C" fn Java_de_maxhenkel_lame4j_Mp3Encoder_destroyEncoder0(mut env: JNIEnv, obj: JObject) {
     let pointer = get_pointer(&mut env, &obj);
 
     if pointer == 0 {

src/main/java/de/maxhenkel/lame4j/Mp3Decoder.java

@@ -13,10 +13,12 @@ public class Mp3Decoder implements Audio, AutoCloseable {
     public Mp3Decoder(InputStream inputStream) throws IOException, UnknownPlatformException {
         Lame.load();
         this.inputStream = inputStream;
-        decoder = createDecoder();
+        decoder = createDecoder0();
     }
 
-    private static native long createDecoder();
+    private static native long createDecoder0();
+
+    private native short[] decodeNextFrame0(InputStream stream) throws IOException;
 
     /**
      * Decodes the next frame in the mp3 file and returns the decoded audio data as PCM samples.
@@ -27,31 +29,55 @@ public Mp3Decoder(InputStream inputStream) throws IOException, UnknownPlatformEx
      * @return the decoded audio data as PCM samples or <code>null</code> if the end of the mp3 file is reached
      * @throws IOException if an I/O error occurs
      */
-    private native short[] decodeNextFrame(InputStream stream) throws IOException;
-
     public short[] decodeNextFrame() throws IOException {
-        return decodeNextFrame(inputStream);
+        synchronized (this) {
+            return decodeNextFrame0(inputStream);
+        }
     }
 
+    private native boolean headerParsed0();
+
     /**
      * @return if the header of the mp3 file is parsed
      */
-    public native boolean headerParsed();
+    public boolean headerParsed() {
+        synchronized (this) {
+            return headerParsed0();
+        }
+    }
+
+    private native int getChannelCount0();
 
     /**
      * @return the number of channels of the decoded audio or -1 if the header of the mp3 file is not yet parsed
      */
-    public native int getChannelCount();
+    public int getChannelCount() {
+        synchronized (this) {
+            return getChannelCount0();
+        }
+    }
+
+    private native int getBitRate0();
 
     /**
      * @return the bitrate of the mp3 file or -1 if the header of the mp3 file is not yet parsed
      */
-    public native int getBitRate();
+    public int getBitRate() {
+        synchronized (this) {
+            return getBitRate0();
+        }
+    }
+
+    private native int getSampleRate0();
 
     /**
      * @return the sample rate of the decoded audio or -1 if the header of the mp3 file is not yet parsed
      */
-    public native int getSampleRate();
+    public int getSampleRate() {
+        synchronized (this) {
+            return getSampleRate0();
+        }
+    }
 
     /**
      * Creates an AudioFormat object for the decoded audio.
@@ -67,17 +93,21 @@ public AudioFormat createAudioFormat() {
         return Audio.super.createAudioFormat();
     }
 
-    private native void destroyDecoder();
+    private native void destroyDecoder0();
 
     @Override
     public void close() throws IOException {
-        destroyDecoder();
-        decoder = 0L;
-        inputStream.close();
+        synchronized (this) {
+            destroyDecoder0();
+            decoder = 0L;
+            inputStream.close();
+        }
     }
 
     public boolean isClosed() {
-        return decoder == 0L;
+        synchronized (this) {
+            return decoder == 0L;
+        }
     }
 
     /**