Improve StableObjPtr

* Rename to StableRef
* Make it more typed
* Provide more idiomatic and convenient methods
* Share more code between JVM and Native

Interop/Indexer/src/main/kotlin/org/jetbrains/kotlin/native/interop/indexer/Utils.kt

@@ -138,16 +138,15 @@ internal fun CXTranslationUnit.ensureNoCompileErrors(): CXTranslationUnit {
 internal typealias CursorVisitor = (cursor: CValue<CXCursor>, parent: CValue<CXCursor>) -> CXChildVisitResult
 
 internal fun visitChildren(parent: CValue<CXCursor>, visitor: CursorVisitor) {
-    val visitorPtr = StableObjPtr.create(visitor)
+    val visitorStableRef = StableObjPtr.create(visitor)
     try {
-        val clientData = visitorPtr.value
+        val clientData = visitorStableRef.asCPointer()
         clang_visitChildren(parent, staticCFunction { cursorIt, parentIt, clientDataIt ->
-            @Suppress("UNCHECKED_CAST")
+            val visitorIt = clientDataIt!!.asStableRef<CursorVisitor>().get()
-            val visitorIt = StableObjPtr.fromValue(clientDataIt!!).get() as CursorVisitor
             visitorIt(cursorIt, parentIt)
         }, clientData)
     } finally {
-        visitorPtr.dispose()
+        visitorStableRef.dispose()
     }
 }
 
@@ -156,19 +155,19 @@ internal fun visitChildren(translationUnit: CXTranslationUnit, visitor: CursorVi
 
 internal fun getFields(type: CValue<CXType>): List<CValue<CXCursor>> {
     val result = mutableListOf<CValue<CXCursor>>()
-    val resultPtr = StableObjPtr.create(result)
+    val resultStableRef = StableRef.create(result)
     try {
-        val clientData = resultPtr.value
+        val clientData = resultStableRef.asCPointer()
 
-        @Suppress("NAME_SHADOWING", "UNCHECKED_CAST")
+        @Suppress("NAME_SHADOWING")
         clang_Type_visitFields(type, staticCFunction { cursor, clientData ->
-            val result = StableObjPtr.fromValue(clientData!!).get() as MutableList<CValue<CXCursor>>
+            val result = clientData!!.asStableRef<MutableList<CValue<CXCursor>>>().get()
             result.add(cursor)
             CXVisitorResult.CXVisit_Continue
         }, clientData)
 
     } finally {
-        resultPtr.dispose()
+        resultStableRef.dispose()
     }
 
     return result
@@ -340,16 +339,16 @@ internal interface Indexer {
 }
 
 internal fun indexTranslationUnit(index: CXIndex, translationUnit: CXTranslationUnit, options: Int, indexer: Indexer) {
-    val indexerStablePtr = StableObjPtr.create(indexer)
+    val indexerStableRef = StableObjPtr.create(indexer)
     try {
-        val clientData = indexerStablePtr.value
+        val clientData = indexerStableRef.asCPointer()
         memScoped {
             val indexerCallbacks = alloc<IndexerCallbacks>().apply {
                 abortQuery = null
                 diagnostic = null
                 enteredMainFile = staticCFunction { clientData, mainFile, _ ->
                     @Suppress("NAME_SHADOWING")
-                    val indexer = StableObjPtr.fromValue(clientData!!).get() as Indexer
+                    val indexer = clientData!!.asStableRef<Indexer>().get()
                     indexer.enteredMainFile(mainFile!!)
                     // We must ensure only interop types exist in function signature.
                     @Suppress("USELESS_CAST")
@@ -357,7 +356,7 @@ internal fun indexTranslationUnit(index: CXIndex, translationUnit: CXTranslation
                 }
                 ppIncludedFile = staticCFunction { clientData, info ->
                     @Suppress("NAME_SHADOWING")
-                    val indexer = StableObjPtr.fromValue(clientData!!).get() as Indexer
+                    val indexer = clientData!!.asStableRef<Indexer>().get()
                     indexer.ppIncludedFile(info!!.pointed)
                     // We must ensure only interop types exist in function signature.
                     @Suppress("USELESS_CAST")
@@ -367,7 +366,7 @@ internal fun indexTranslationUnit(index: CXIndex, translationUnit: CXTranslation
                 startedTranslationUnit = null
                 indexDeclaration = staticCFunction { clientData, info ->
                     @Suppress("NAME_SHADOWING")
-                    val nativeIndex = StableObjPtr.fromValue(clientData!!).get() as Indexer
+                    val nativeIndex = clientData!!.asStableRef<Indexer>().get()
                     nativeIndex.indexDeclaration(info!!.pointed)
                 }
                 indexEntityReference = null
@@ -386,7 +385,7 @@ internal fun indexTranslationUnit(index: CXIndex, translationUnit: CXTranslation
             }
         }
     } finally {
-        indexerStablePtr.dispose()
+        indexerStableRef.dispose()
     }
 }
 

Interop/Runtime/src/jvm/kotlin/kotlinx/cinterop/JvmCallbacks.kt

@@ -25,48 +25,12 @@ import kotlin.reflect.full.declaredMemberProperties
 import kotlin.reflect.full.isSubclassOf
 import kotlin.reflect.jvm.reflect
 
-/**
+internal fun createStablePointer(any: Any): COpaquePointer = newGlobalRef(any).toCPointer()!!
- * This class provides a way to create a stable handle to any Kotlin object.
- * Its [value] can be safely passed to native code e.g. to be received in a Kotlin callback.
- *
- * Any [StableObjPtr] should be manually [disposed][dispose]
- */
-data class StableObjPtr private constructor(val value: COpaquePointer) {
 
-    companion object {
+internal fun disposeStablePointer(pointer: COpaquePointer) = deleteGlobalRef(pointer.toLong())
 
-        /**
+@PublishedApi
-         * Creates a handle for given object.
+internal fun derefStablePointer(pointer: COpaquePointer): Any = derefGlobalRef(pointer.toLong())
-         */
-        fun create(any: Any) = fromValue(newGlobalRef(any))
-
-        private fun fromValue(value: NativePtr) = fromValue(interpretCPointer(value)!!)
-
-        /**
-         * Creates [StableObjPtr] from given raw value.
-         *
-         * @param value must be a [value] of some [StableObjPtr]
-         */
-        fun fromValue(value: COpaquePointer) = StableObjPtr(value)
-
-        init {
-            loadCallbacksLibrary()
-        }
-    }
-
-    /**
-     * Disposes the handle. It must not be [used][get] after that.
-     */
-    fun dispose() {
-        deleteGlobalRef(value.rawValue)
-    }
-
-    /**
-     * Returns the object this handle was [created][create] for.
-     */
-    fun get(): Any = derefGlobalRef(value.rawValue)
-
-}
 
 private fun getFieldCType(type: KType): CType<*> {
     val classifier = type.classifier
@@ -400,6 +364,8 @@ private fun loadCallbacksLibrary() {
     System.loadLibrary("callbacks")
 }
 
+private val topLevelInitializer = loadCallbacksLibrary()
+
 
 /**
  * Reference to `ffi_type` struct instance.

Interop/Runtime/src/main/kotlin/kotlinx/cinterop/StableRef.kt

@@ -0,0 +1,77 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package kotlinx.cinterop
+
+@Deprecated("Use StableRef<T> instead", ReplaceWith("StableRef<T>"))
+typealias StableObjPtr = StableRef<*>
+
+/**
+ * This class provides a way to create a stable handle to any Kotlin object.
+ * After [converting to CPointer][asCPointer] it can be safely passed to native code e.g. to be received
+ * in a Kotlin callback.
+ *
+ * Any [StableRef] should be manually [disposed][dispose]
+ */
+data class StableRef<out T : Any> @PublishedApi internal constructor(
+        private val stablePtr: COpaquePointer,
+        private val ref: T // Note: storing the reference itself to avoid unchecked casts.
+) {
+
+    companion object {
+
+        /**
+         * Creates a handle for given object.
+         */
+        fun <T : Any> create(any: T) = StableRef<T>(createStablePointer(any), any)
+
+        /**
+         * Creates [StableRef] from given raw value.
+         *
+         * @param value must be a [value] of some [StableRef]
+         */
+        @Deprecated("Use CPointer<*>.asStableRef<T>() instead", ReplaceWith("ptr.asStableRef<T>()"))
+        fun fromValue(value: COpaquePointer) = value.asStableRef<Any>()
+    }
+
+    @Deprecated("Use .asCPointer() instead", ReplaceWith("this.asCPointer()"))
+    val value: COpaquePointer get() = this.asCPointer()
+
+    /**
+     * Converts the handle to C pointer.
+     * @see [asStableRef]
+     */
+    fun asCPointer(): COpaquePointer = this.stablePtr
+
+    /**
+     * Disposes the handle. It must not be used after that.
+     */
+    fun dispose() {
+        disposeStablePointer(this.stablePtr)
+    }
+
+    /**
+     * Returns the object this handle was [created][StableRef.create] for.
+     */
+    fun get() = this.ref
+
+}
+
+/**
+ * Converts to [StableRef] this opaque pointer produced by [StableRef.asCPointer].
+ */
+inline fun <reified T : Any> CPointer<*>.asStableRef() =
+        StableRef<T>(this, derefStablePointer(this) as T)

Interop/Runtime/src/native/kotlin/kotlinx/cinterop/NativeCallbacks.kt

@@ -1,47 +0,0 @@
-package kotlinx.cinterop
-
-/**
- * This class provides a way to create a stable handle to any Kotlin object.
- * Its [value] can be safely passed to native code e.g. to be received in a Kotlin callback.
- *
- * Any [StableObjPtr] should be manually [disposed][dispose]
- */
-data class StableObjPtr private constructor(val value: COpaquePointer) {
-
-    companion object {
-
-        /**
-         * Creates a handle for given object.
-         */
-        fun create(any: Any) = fromValue(createStablePointer(any))
-
-        /**
-         * Creates [StableObjPtr] from given raw value.
-         *
-         * @param value must be a [value] of some [StableObjPtr]
-         */
-        fun fromValue(value: COpaquePointer) = StableObjPtr(value)
-    }
-
-    /**
-     * Disposes the handle. It must not be [used][get] after that.
-     */
-    fun dispose() {
-        disposeStablePointer(value)
-    }
-
-    /**
-     * Returns the object this handle was [created][create] for.
-     */
-    fun get(): Any = derefStablePointer(value)
-
-}
-
-@SymbolName("Kotlin_Interop_createStablePointer")
-private external fun createStablePointer(any: Any): COpaquePointer
-
-@SymbolName("Kotlin_Interop_disposeStablePointer")
-private external fun disposeStablePointer(pointer: COpaquePointer)
-
-@SymbolName("Kotlin_Interop_derefStablePointer")
-private external fun derefStablePointer(pointer: COpaquePointer): Any

Interop/Runtime/src/native/kotlin/kotlinx/cinterop/NativeStableRef.kt

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package kotlinx.cinterop
+
+@SymbolName("Kotlin_Interop_createStablePointer")
+internal external fun createStablePointer(any: Any): COpaquePointer
+
+@SymbolName("Kotlin_Interop_disposeStablePointer")
+internal external fun disposeStablePointer(pointer: COpaquePointer)
+
+@PublishedApi
+@SymbolName("Kotlin_Interop_derefStablePointer")
+internal external fun derefStablePointer(pointer: COpaquePointer): Any

samples/libcurl/src/main/kotlin/org/konan/libcurl/CUrl.kt

@@ -4,7 +4,7 @@ import kotlinx.cinterop.*
 import libcurl.*
 
 class CUrl(val url: String)  {
-    val stablePtr = StableObjPtr.create(this)
+    val stableRef = StableRef.create(this)
 
     val curl = curl_easy_init();
 
@@ -12,7 +12,7 @@ class CUrl(val url: String)  {
         curl_easy_setopt(curl, CURLOPT_URL, url)
         val header = staticCFunction(::header_callback)
         curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, header)
-        curl_easy_setopt(curl, CURLOPT_HEADERDATA, stablePtr.value)
+        curl_easy_setopt(curl, CURLOPT_HEADERDATA, stableRef.asCPointer())
     }
 
     val header = Event<String>()
@@ -26,7 +26,7 @@ class CUrl(val url: String)  {
 
     fun close() {
         curl_easy_cleanup(curl)
-        stablePtr.dispose()
+        stableRef.dispose()
     }
 }
 
@@ -39,7 +39,7 @@ fun header_callback(buffer: CPointer<ByteVar>?, size: size_t, nitems: size_t, us
     if (buffer == null) return 0
     val header = buffer.toKString((size * nitems).toInt()).trim()
     if (userdata != null) {
-        val curl = StableObjPtr.fromValue(userdata).get() as CUrl
+        val curl = userdata.asStableRef<CUrl>().get()
         curl.header(header)
     }
     return size * nitems
@@ -49,7 +49,7 @@ fun header_callback(buffer: CPointer<ByteVar>?, size: size_t, nitems: size_t, us
 fun write_callback(buffer: COpaquePointer?, size: size_t, nitems: size_t, userdata: COpaquePointer?): size_t {
     if (buffer == null) return 0
     if (userdata != null) {
-        val curl = StableObjPtr.fromValue(userdata).get() as CUrl
+        val curl = userdata.asStableRef<CUrl>().get()
         curl.data(buffer.)
     }
     return size * nitems