SwiftArena and invoking destroy on objects as arena is destroyed (#67)

Author: ktoso

.github/workflows/pull_request.yml

@@ -57,7 +57,10 @@ jobs:
             ${{ runner.os }}-swiftpm-
       # run the actual build
       - name: Gradle build
-        run: ./gradlew build --info --no-daemon
+        run: |
+          ./gradlew build -x test --no-daemon # skip tests
+          find .
+          ./gradlew build --info --no-daemon
 
   test-swift:
     name: Swift tests (swift:${{ matrix.swift_version }} jdk:${{matrix.jdk_vendor}} os:${{ matrix.os_version }})

.gitignore

@@ -16,6 +16,9 @@ BuildLogic/out/
 **/build/
 lib/
 
+# Ignore JVM crash logs
+**/*.log
+
 # Ignore package resolved
 Package.resolved
 
@@ -27,3 +30,6 @@ Package.resolved
 
 # Cache of project
 .gradletasknamecache
+
+# Ignore files generated by jextract, we always can re-generate them
+*/**/*.java

.licenseignore

@@ -27,12 +27,12 @@ docker/*
 **/docker-compose.yaml
 **/docker/*
 **/.dockerignore
-JavaSwiftKitDemo/src/main/java/com/example/swift/generated/*
 Makefile
 **/Makefile
 **/*.html
 **/CMakeLists.txt
 **/*.jar
+**/generated/*.java
 **/generated/*.swift
 gradle/wrapper/gradle-wrapper.properties
 gradlew

Samples/SwiftKitSampleApp/src/main/java/com/example/swift/HelloJava2Swift.java

@@ -19,54 +19,36 @@
 import com.example.swift.generated.MySwiftClass;
 
 // Import javakit/swiftkit support libraries
+import org.swift.swiftkit.SwiftArena;
 import org.swift.swiftkit.SwiftKit;
-
+import org.swift.swiftkit.SwiftValueWitnessTable;
 
 import java.lang.foreign.*;
-import java.util.List;
-
 
 public class HelloJava2Swift {
 
     public static void main(String[] args) {
         boolean traceDowncalls = Boolean.getBoolean("jextract.trace.downcalls");
         System.out.println("Property: jextract.trace.downcalls = " + traceDowncalls);
 
-        final var dylibNames = List.of(
-                "swiftCore",
-                "JavaKitExample"
-        );
-
-
-        System.out.println("Loading libraries...");
-
-        for (var lib : dylibNames) {
-            System.out.printf("Loading: %s... ", lib);
-            System.loadLibrary(lib);
-            System.out.println("ok.");
-        }
+        System.out.printf("java.library.path = %s\n", System.getProperty("java.library.path"));
 
         examples();
     }
 
     static void examples() {
-        ExampleSwiftLibrary.helloWorld();
+         ExampleSwiftLibrary.helloWorld();
 
-        ExampleSwiftLibrary.globalTakeInt(1337);
+         ExampleSwiftLibrary.globalTakeInt(1337);
 
-        MySwiftClass obj = new MySwiftClass(2222, 7777);
+         MySwiftClass obj = new MySwiftClass(2222, 7777);
 
-        SwiftKit.retain(obj.$memorySegment());
-        System.out.println("[java] obj ref count = " + SwiftKit.retainCount(obj.$memorySegment()));
+         SwiftKit.retain(obj.$memorySegment());
+         System.out.println("[java] obj ref count = " + SwiftKit.retainCount(obj.$memorySegment()));
 
-        obj.voidMethod();
-        obj.takeIntMethod(42);
+         obj.voidMethod();
+         obj.takeIntMethod(42);
 
-        MemorySegment swiftType = SwiftKit.getTypeByMangledNameInEnvironment("SiSg");
-        System.out.println("Memory layout for Swift.Int?:");
-        System.out.println("  size = " + SwiftKit.sizeOfSwiftType(swiftType));
-        System.out.println("  stride = " + SwiftKit.strideOfSwiftType(swiftType));
-        System.out.println("  alignment = " + SwiftKit.alignmentOfSwiftType(swiftType));
-        System.out.println("  Java layout = " + SwiftKit.layoutOfSwiftType(swiftType));
+        System.out.println("DONE.");
     }
 }

Samples/SwiftKitSampleApp/src/main/java/com/example/swift/ManualMySwiftClass.java

@@ -27,7 +27,7 @@ public final class ManualMySwiftClass extends Manual_MySwiftClass implements Man
     // 000000000003f4a8 S type metadata for JavaKitExample.MySwiftSlice
     // strip the _$s
     // drop the N
-    public static final String TYPE_METADATA_NAME = "14JavaKitExample12MySwiftClassC";
+    public static final String TYPE_MANGLED_NAME = "14JavaKitExample12MySwiftClassC";
 
     private final MemorySegment self;
 
@@ -167,13 +167,13 @@ static MemorySegment __allocating_init_len_cap(long len, long cap) {
             if (ManualJavaKitExample.TRACE_DOWNCALLS) {
                 ManualJavaKitExample.traceDowncall("MySwiftClass.__allocating_init(len:cap:)", len, cap);
             }
-            ManualJavaKitExample.trace("type name = " + TYPE_METADATA_NAME);
+            ManualJavaKitExample.trace("type name = " + TYPE_MANGLED_NAME);
 
             // FIXME: problems with _getTypeByName because of the String memory repr
-            //  final MemorySegment type = SwiftKit.getTypeByMangledNameInEnvironment(TYPE_METADATA_NAME);
+            //  final MemorySegment type = SwiftKit.getTypeByMangledNameInEnvironment(TYPE_MANGLED_NAME);
             //  we must get a method we can call like this into SwiftKit:
 
-            MemorySegment type = ManualJavaKitExample.swiftkit_getTypeByStringByteArray(TYPE_METADATA_NAME);
+            MemorySegment type = ManualJavaKitExample.swiftkit_getTypeByStringByteArray(TYPE_MANGLED_NAME);
             ManualJavaKitExample.trace("type = " + type);
 
             var address = (MemorySegment) mh$.invokeExact(len, cap, type);

Samples/SwiftKitSampleApp/src/test/java/com/example/swift/generated/MySwiftClassTest.java

@@ -15,6 +15,7 @@
 package com.example.swift.generated;
 
 import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.condition.DisabledOnOs;
 import org.junit.jupiter.api.condition.OS;
@@ -48,9 +49,10 @@ void test_MySwiftClass_makeIntMethod() {
     }
 
     @Test
+    @Disabled // TODO: Need var mangled names in interfaces
     void test_MySwiftClass_property_len() {
         MySwiftClass o = new MySwiftClass(12, 42);
-        var got = o.makeIntMethod();
+        var got = o.getLen();
         assertEquals(12, got);
     }
 

Samples/SwiftKitSampleApp/src/test/java/org/swift/swiftkit/MySwiftClassTest.java

@@ -27,17 +27,14 @@ public class MySwiftClassTest {
 
     @BeforeAll
     static void beforeAll() {
-        System.out.printf("java.library.path = %s\n", System.getProperty("java.library.path"));
-
-        System.loadLibrary("swiftCore");
-        System.loadLibrary("ExampleSwiftLibrary");
-
-        System.setProperty("jextract.trace.downcalls", "true");
+        System.out.printf("java.library.path = %s\n", SwiftKit.getJavaLibraryPath());
+        System.out.printf("jextract.trace.downcalls = %s\n", SwiftKit.getJextractTraceDowncalls());
     }
 
     @Test
     void call_retain_retainCount_release() {
-        var obj = new MySwiftClass(1, 2);
+        var arena = SwiftArena.ofConfined();
+        var obj = new MySwiftClass(arena, 1, 2);
 
         assertEquals(1, SwiftKit.retainCount(obj.$memorySegment()));
         // TODO: test directly on SwiftHeapObject inheriting obj

Samples/SwiftKitSampleApp/src/test/java/org/swift/swiftkit/SwiftArenaTest.java

@@ -0,0 +1,78 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2024 Apple Inc. and the Swift.org project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of Swift.org project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+package org.swift.swiftkit;
+
+import com.example.swift.generated.MySwiftClass;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.DisabledIf;
+import org.swift.swiftkit.util.PlatformUtils;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.swift.swiftkit.SwiftKit.*;
+import static org.swift.swiftkit.SwiftKit.retainCount;
+
+public class SwiftArenaTest {
+
+    @BeforeAll
+    static void beforeAll() {
+        System.out.printf("java.library.path = %s\n", SwiftKit.getJavaLibraryPath());
+        System.out.printf("jextract.trace.downcalls = %s\n", SwiftKit.getJextractTraceDowncalls());
+    }
+
+    static boolean isAmd64() {
+        return PlatformUtils.isAmd64();
+    }
+
+    // FIXME: The destroy witness table call hangs on x86_64 platforms during the destroy witness table call
+    //        See: https://github.com/swiftlang/swift-java/issues/97
+    @Test
+    @DisabledIf("isAmd64")
+    public void arena_releaseClassOnClose_class_ok() {
+        try (var arena = SwiftArena.ofConfined()) {
+            var obj = new MySwiftClass(arena,1, 2);
+
+            retain(obj.$memorySegment());
+            assertEquals(2, retainCount(obj.$memorySegment()));
+
+            release(obj.$memorySegment());
+            assertEquals(1, retainCount(obj.$memorySegment()));
+        }
+
+        // TODO: should we zero out the $memorySegment perhaps?
+    }
+
+    @Test
+    public void arena_releaseClassOnClose_class_leaked() {
+        String memorySegmentDescription = "<none>";
+
+        try {
+            try (var arena = SwiftArena.ofConfined()) {
+                var obj = new MySwiftClass(arena,1, 2);
+                memorySegmentDescription = obj.$memorySegment().toString();
+
+                // Pretend that we "leaked" the class, something still holds a reference to it while we try to destroy it
+                retain(obj.$memorySegment());
+                assertEquals(2, retainCount(obj.$memorySegment()));
+            }
+
+            fail("Expected exception to be thrown while the arena is closed!");
+        } catch (Exception ex) {
+            // The message should point out which objects "leaked":
+            assertTrue(ex.getMessage().contains(memorySegmentDescription));
+        }
+
+    }
+}

Sources/ExampleSwiftLibrary/MySwiftLibrary.swift

@@ -76,6 +76,15 @@ public class MySwiftClass {
   }
 }
 
+@_silgen_name("swift_getTypeByMangledNameInEnvironment")
+public func _getTypeByMangledNameInEnvironment(
+  _ name: UnsafePointer<UInt8>,
+  _ nameLength: UInt,
+  genericEnvironment: UnsafeRawPointer?,
+  genericArguments: UnsafeRawPointer?)
+  -> Any.Type?
+
+
 // ==== Internal helpers
 
 private func p(_ msg: String, file: String = #fileID, line: UInt = #line, function: String = #function) {