[jextract] Add async legacy mode

Samples/SwiftJavaExtractJNISampleApp/src/test/java/com/example/swift/AsyncTest.java

@@ -26,31 +26,32 @@
 import java.util.OptionalLong;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
 
 import static org.junit.jupiter.api.Assertions.*;
 
 public class AsyncTest {
     @Test
-    void asyncSum() {
-        CompletableFuture<Long> future = MySwiftLibrary.asyncSum(10, 12);
+    void asyncSum() throws Exception {
+        Future<Long> future = MySwiftLibrary.asyncSum(10, 12);
 
-        Long result = future.join();
+        Long result = future.get();
         assertEquals(22, result);
     }
 
     @Test
-    void asyncSleep() {
-        CompletableFuture<Void> future = MySwiftLibrary.asyncSleep();
-        future.join();
+    void asyncSleep() throws Exception {
+        Future<Void> future = MySwiftLibrary.asyncSleep();
+        future.get();
     }
 
     @Test
-    void asyncCopy() {
+    void asyncCopy() throws Exception {
         try (var arena = SwiftArena.ofConfined()) {
             MySwiftClass obj = MySwiftClass.init(10, 5, arena);
-            CompletableFuture<MySwiftClass> future = MySwiftLibrary.asyncCopy(obj, arena);
+            Future<MySwiftClass> future = MySwiftLibrary.asyncCopy(obj, arena);
 
-            MySwiftClass result = future.join();
+            MySwiftClass result = future.get();
 
             assertEquals(10, result.getX());
             assertEquals(5, result.getY());
@@ -59,7 +60,7 @@ void asyncCopy() {
 
     @Test
     void asyncThrows() {
-        CompletableFuture<Void> future = MySwiftLibrary.asyncThrows();
+        Future<Void> future = MySwiftLibrary.asyncThrows();
 
         ExecutionException ex = assertThrows(ExecutionException.class, future::get);
 
@@ -70,14 +71,14 @@ void asyncThrows() {
     }
 
     @Test
-    void asyncOptional() {
-        CompletableFuture<OptionalLong> future = MySwiftLibrary.asyncOptional(42);
-        assertEquals(OptionalLong.of(42), future.join());
+    void asyncOptional() throws Exception {
+        Future<OptionalLong> future = MySwiftLibrary.asyncOptional(42);
+        assertEquals(OptionalLong.of(42), future.get());
     }
 
     @Test
-    void asyncString() {
-        CompletableFuture<String> future = MySwiftLibrary.asyncString("hey");
-        assertEquals("hey", future.join());
+    void asyncString() throws Exception {
+        Future<String> future = MySwiftLibrary.asyncString("hey");
+        assertEquals("hey", future.get());
     }
 }

Samples/SwiftJavaExtractJNISampleApp/src/test/java/com/example/swift/MySwiftClassTest.java

@@ -165,10 +165,10 @@ void addXWithJavaLong() {
     }
 
     @Test
-    void getAsyncVariable() {
+    void getAsyncVariable() throws Exception {
         try (var arena = SwiftArena.ofConfined()) {
             MySwiftClass c1 = MySwiftClass.init(20, 10, arena);
-            assertEquals(42, c1.getGetAsync().join());
+            assertEquals(42, c1.getGetAsync().get());
         }
     }
 }

Sources/JExtractSwiftLib/JNI/JNISwift2JavaGenerator+JavaTranslation.swift

@@ -501,40 +501,55 @@ extension JNISwift2JavaGenerator {
       originalFunctionSignature: SwiftFunctionSignature,
       mode: JExtractAsyncFuncMode
     ) {
+      // Update translated function
+      let nativeFutureType: JavaType
+      let translatedFutureType: JavaType
+      let completeMethodID: String
+      let completeExceptionallyMethodID: String
+
       switch mode {
       case .completableFuture:
-        // Update translated function
-
-        let nativeFutureType = JavaType.completableFuture(nativeFunctionSignature.result.javaType)
+        nativeFutureType = .completableFuture(nativeFunctionSignature.result.javaType)
+        translatedFutureType = .completableFuture(translatedFunctionSignature.resultType.javaType)
+        completeMethodID = "_JNIMethodIDCache.CompletableFuture.complete"
+        completeExceptionallyMethodID = "_JNIMethodIDCache.CompletableFuture.completeExceptionally"
+
+      case .legacyFuture:
+        nativeFutureType = .simpleCompletableFuture(nativeFunctionSignature.result.javaType)
+        translatedFutureType = .future(translatedFunctionSignature.resultType.javaType)
+        completeMethodID = "_JNIMethodIDCache.SimpleCompletableFuture.complete"
+        completeExceptionallyMethodID = "_JNIMethodIDCache.SimpleCompletableFuture.completeExceptionally"
+      }
 
-        let futureOutParameter = OutParameter(
-          name: "$future",
-          type: nativeFutureType,
-          allocation: .new
-        )
+      let futureOutParameter = OutParameter(
+        name: "future$",
+        type: nativeFutureType,
+        allocation: .new
+      )
 
-        let result = translatedFunctionSignature.resultType
-        translatedFunctionSignature.resultType = TranslatedResult(
-          javaType: .completableFuture(translatedFunctionSignature.resultType.javaType),
-          annotations: result.annotations,
-          outParameters: result.outParameters + [futureOutParameter],
-          conversion: .aggregate(variable: nil, [
-            .print(.placeholder), // Make the downcall
-            .method(.constant("$future"), function: "thenApply", arguments: [
-             .lambda(args: ["futureResult$"], body: .replacingPlaceholder(result.conversion, placeholder: "futureResult$"))
-           ])
+      let result = translatedFunctionSignature.resultType
+      translatedFunctionSignature.resultType = TranslatedResult(
+        javaType: translatedFutureType,
+        annotations: result.annotations,
+        outParameters: result.outParameters + [futureOutParameter],
+        conversion: .aggregate(variable: nil, [
+          .print(.placeholder), // Make the downcall
+          .method(.constant("future$"), function: "thenApply", arguments: [
+            .lambda(args: ["futureResult$"], body: .replacingPlaceholder(result.conversion, placeholder: "futureResult$"))
           ])
-        )
+        ])
+      )
 
-        // Update native function
-        nativeFunctionSignature.result.conversion = .asyncCompleteFuture(
-          swiftFunctionResultType: originalFunctionSignature.result.type,
-          nativeFunctionSignature: nativeFunctionSignature,
-          isThrowing: originalFunctionSignature.isThrowing
-        )
-        nativeFunctionSignature.result.javaType = .void
-        nativeFunctionSignature.result.outParameters.append(.init(name: "result_future", type: nativeFutureType))
-      }
+      // Update native function
+      nativeFunctionSignature.result.conversion = .asyncCompleteFuture(
+        swiftFunctionResultType: originalFunctionSignature.result.type,
+        nativeFunctionSignature: nativeFunctionSignature,
+        isThrowing: originalFunctionSignature.isThrowing,
+        completeMethodID: completeMethodID,
+        completeExceptionallyMethodID: completeExceptionallyMethodID
+      )
+      nativeFunctionSignature.result.javaType = .void
+      nativeFunctionSignature.result.outParameters.append(.init(name: "result_future", type: nativeFutureType))
     }
 
     func translateProtocolParameter(

Sources/JExtractSwiftLib/JNI/JNISwift2JavaGenerator+NativeTranslation.swift

@@ -689,7 +689,9 @@ extension JNISwift2JavaGenerator {
     indirect case asyncCompleteFuture(
       swiftFunctionResultType: SwiftType,
       nativeFunctionSignature: NativeFunctionSignature,
-      isThrowing: Bool
+      isThrowing: Bool,
+      completeMethodID: String,
+      completeExceptionallyMethodID: String
     )
 
     /// `{ (args) -> return body }`
@@ -927,7 +929,9 @@ extension JNISwift2JavaGenerator {
       case .asyncCompleteFuture(
         let swiftFunctionResultType,
         let nativeFunctionSignature,
-        let isThrowing
+        let isThrowing,
+        let completeMethodID,
+        let completeExceptionallyMethodID
       ):
         var globalRefs: [String] = ["globalFuture"]
 
@@ -954,7 +958,7 @@ extension JNISwift2JavaGenerator {
           printer.print("environment = try! JavaVirtualMachine.shared().environment()")
           let inner = nativeFunctionSignature.result.conversion.render(&printer, "swiftResult$")
           if swiftFunctionResultType.isVoid {
-            printer.print("environment.interface.CallBooleanMethodA(environment, globalFuture, _JNIMethodIDCache.CompletableFuture.complete, [jvalue(l: nil)])")
+            printer.print("environment.interface.CallBooleanMethodA(environment, globalFuture, \(completeMethodID), [jvalue(l: nil)])")
           } else {
             let result: String
             if nativeFunctionSignature.result.javaType.requiresBoxing {
@@ -964,7 +968,7 @@ extension JNISwift2JavaGenerator {
               result = inner
             }
 
-            printer.print("environment.interface.CallBooleanMethodA(environment, globalFuture, _JNIMethodIDCache.CompletableFuture.complete, [jvalue(l: \(result))])")
+            printer.print("environment.interface.CallBooleanMethodA(environment, globalFuture, \(completeMethodID), [jvalue(l: \(result))])")
           }
         }
 
@@ -986,7 +990,7 @@ extension JNISwift2JavaGenerator {
               """
               let catchEnvironment = try! JavaVirtualMachine.shared().environment()
               let exception = catchEnvironment.interface.NewObjectA(catchEnvironment, _JNIMethodIDCache.Exception.class, _JNIMethodIDCache.Exception.constructWithMessage, [String(describing: error).getJValue(in: catchEnvironment)])
-              catchEnvironment.interface.CallBooleanMethodA(catchEnvironment, globalFuture, _JNIMethodIDCache.CompletableFuture.completeExceptionally, [jvalue(l: exception)])
+              catchEnvironment.interface.CallBooleanMethodA(catchEnvironment, globalFuture, \(completeExceptionallyMethodID), [jvalue(l: exception)])
               """
               )
             }

Sources/JExtractSwiftLib/JavaTypes/JavaType+JDK.swift

@@ -44,4 +44,9 @@ extension JavaType {
   static func completableFuture(_ T: JavaType) -> JavaType {
     .class(package: "java.util.concurrent", name: "CompletableFuture", typeParameters: [T.boxedType])
   }
+
+  /// The description of the type java.util.concurrent.Future<T>
+  static func future(_ T: JavaType) -> JavaType {
+    .class(package: "java.util.concurrent", name: "Future", typeParameters: [T.boxedType])
+  }
 }

Sources/JExtractSwiftLib/JavaTypes/JavaType+SwiftKit.swift

@@ -85,4 +85,9 @@ extension JavaType {
     }
   }
 
+  /// The description of the type org.swift.swiftkit.core.SimpleCompletableFuture<T>
+  static func simpleCompletableFuture(_ T: JavaType) -> JavaType {
+    .class(package: "org.swift.swiftkit.core", name: "SimpleCompletableFuture", typeParameters: [T.boxedType])
+  }
+
 }

Sources/SwiftJavaConfigurationShared/JExtract/JExtractAsyncFuncMode.swift

@@ -23,7 +23,7 @@ public enum JExtractAsyncFuncMode: String, Codable {
   /// Android 23 and below.
   ///
   /// - Note: Prefer using the `completableFuture` mode instead, if possible.
-//  case future
+  case legacyFuture
 }
 
 extension JExtractAsyncFuncMode {

Sources/SwiftJavaRuntimeSupport/DefaultCaches.swift → Sources/SwiftJavaRuntimeSupport/JNIMethodIDCaches.swift

@@ -47,6 +47,36 @@ extension _JNIMethodIDCache {
     }
   }
 
+  public enum SimpleCompletableFuture {
+    private static let completeMethod = Method(
+      name: "complete",
+      signature: "(Ljava/lang/Object;)Z"
+    )
+
+    private static let completeExceptionallyMethod = Method(
+      name: "completeExceptionally",
+      signature: "(Ljava/lang/Throwable;)Z"
+    )
+
+    private static let cache = _JNIMethodIDCache(
+      environment: try! JavaVirtualMachine.shared().environment(),
+      className: "org/swift/swiftkit/core/SimpleCompletableFuture",
+      methods: [completeMethod, completeExceptionallyMethod]
+    )
+
+    public static var `class`: jclass {
+      cache.javaClass
+    }
+
+    public static var complete: jmethodID {
+      cache.methods[completeMethod]!
+    }
+
+    public static var completeExceptionally: jmethodID {
+      cache.methods[completeExceptionallyMethod]!
+    }
+  }
+
   public enum Exception {
     private static let messageConstructor = Method(name: "<init>", signature: "(Ljava/lang/String;)V")