michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #if defined(JSGC_USE_EXACT_ROOTING)
michael@0: 
michael@0: #include "js/Class.h"
michael@0: #include "jsapi-tests/tests.h"
michael@0: 
michael@0: using namespace JS;
michael@0: 
michael@0: struct BarkWhenTracedClass {
michael@0:     static int finalizeCount;
michael@0:     static int traceCount;
michael@0: 
michael@0:     static const JSClass class_;
michael@0:     static void finalize(JSFreeOp *fop, JSObject *obj) { finalizeCount++; }
michael@0:     static void trace(JSTracer *trc, JSObject *obj) { traceCount++; }
michael@0:     static void reset() { finalizeCount = 0; traceCount = 0; }
michael@0: };
michael@0: 
michael@0: int BarkWhenTracedClass::finalizeCount;
michael@0: int BarkWhenTracedClass::traceCount;
michael@0: 
michael@0: const JSClass BarkWhenTracedClass::class_ = {
michael@0:   "BarkWhenTracedClass", 0,
michael@0:   JS_PropertyStub,
michael@0:   JS_DeletePropertyStub,
michael@0:   JS_PropertyStub,
michael@0:   JS_StrictPropertyStub,
michael@0:   JS_EnumerateStub,
michael@0:   JS_ResolveStub,
michael@0:   JS_ConvertStub,
michael@0:   finalize,
michael@0:   nullptr,
michael@0:   nullptr,
michael@0:   nullptr,
michael@0:   trace
michael@0: };
michael@0: 
michael@0: struct Kennel {
michael@0:     PersistentRootedObject obj;
michael@0:     Kennel(JSContext *cx) : obj(cx) { }
michael@0:     Kennel(JSContext *cx, const HandleObject &woof) : obj(cx, woof) { };
michael@0: };
michael@0: 
michael@0: // A function for allocating a Kennel and a barker. Only allocating
michael@0: // PersistentRooteds on the heap, and in this function, helps ensure that the
michael@0: // conservative GC doesn't find stray references to the barker. Ugh.
michael@0: MOZ_NEVER_INLINE static Kennel *
michael@0: Allocate(JSContext *cx)
michael@0: {
michael@0:     RootedObject barker(cx, JS_NewObject(cx, &BarkWhenTracedClass::class_, JS::NullPtr(), JS::NullPtr()));
michael@0:     if (!barker)
michael@0:         return nullptr;
michael@0: 
michael@0:     return new Kennel(cx, barker);
michael@0: }
michael@0: 
michael@0: // Do a GC, expecting |n| barkers to be finalized.
michael@0: static bool
michael@0: GCFinalizesNBarkers(JSContext *cx, int n)
michael@0: {
michael@0:     int preGCTrace = BarkWhenTracedClass::traceCount;
michael@0:     int preGCFinalize = BarkWhenTracedClass::finalizeCount;
michael@0: 
michael@0:     JS_GC(JS_GetRuntime(cx));
michael@0: 
michael@0:     return (BarkWhenTracedClass::finalizeCount == preGCFinalize + n &&
michael@0:             BarkWhenTracedClass::traceCount > preGCTrace);
michael@0: }
michael@0: 
michael@0: // PersistentRooted instances protect their contents from being recycled.
michael@0: BEGIN_TEST(test_PersistentRooted)
michael@0: {
michael@0:     BarkWhenTracedClass::reset();
michael@0: 
michael@0:     Kennel *kennel = Allocate(cx);
michael@0:     CHECK(kennel);
michael@0: 
michael@0:     // GC should be able to find our barker.
michael@0:     CHECK(GCFinalizesNBarkers(cx, 0));
michael@0: 
michael@0:     delete(kennel);
michael@0: 
michael@0:     // Now GC should not be able to find the barker.
michael@0:     JS_GC(JS_GetRuntime(cx));
michael@0:     CHECK(BarkWhenTracedClass::finalizeCount == 1);
michael@0: 
michael@0:     return true;
michael@0: }
michael@0: END_TEST(test_PersistentRooted)
michael@0: 
michael@0: // GC should not be upset by null PersistentRooteds.
michael@0: BEGIN_TEST(test_PersistentRootedNull)
michael@0: {
michael@0:     BarkWhenTracedClass::reset();
michael@0: 
michael@0:     Kennel kennel(cx);
michael@0:     CHECK(!kennel.obj);
michael@0: 
michael@0:     JS_GC(JS_GetRuntime(cx));
michael@0:     CHECK(BarkWhenTracedClass::finalizeCount == 0);
michael@0: 
michael@0:     return true;
michael@0: }
michael@0: END_TEST(test_PersistentRootedNull)
michael@0: 
michael@0: // Copy construction works.
michael@0: BEGIN_TEST(test_PersistentRootedCopy)
michael@0: {
michael@0:     BarkWhenTracedClass::reset();
michael@0: 
michael@0:     Kennel *kennel = Allocate(cx);
michael@0:     CHECK(kennel);
michael@0: 
michael@0:     CHECK(GCFinalizesNBarkers(cx, 0));
michael@0: 
michael@0:     // Copy construction! AMAZING!
michael@0:     Kennel *newKennel = new Kennel(*kennel);
michael@0: 
michael@0:     CHECK(GCFinalizesNBarkers(cx, 0));
michael@0: 
michael@0:     delete(kennel);
michael@0: 
michael@0:     CHECK(GCFinalizesNBarkers(cx, 0));
michael@0: 
michael@0:     delete(newKennel);
michael@0: 
michael@0:     // Now that kennel and nowKennel are both deallocated, GC should not be
michael@0:     // able to find the barker.
michael@0:     JS_GC(JS_GetRuntime(cx));
michael@0:     CHECK(BarkWhenTracedClass::finalizeCount == 1);
michael@0: 
michael@0:     return true;
michael@0: }
michael@0: END_TEST(test_PersistentRootedCopy)
michael@0: 
michael@0: // Assignment works.
michael@0: BEGIN_TEST(test_PersistentRootedAssign)
michael@0: {
michael@0:     BarkWhenTracedClass::reset();
michael@0: 
michael@0:     Kennel *kennel = Allocate(cx);
michael@0:     CHECK(kennel);
michael@0: 
michael@0:     CHECK(GCFinalizesNBarkers(cx, 0));
michael@0: 
michael@0:     // Allocate a new, empty kennel.
michael@0:     Kennel *kennel2 = new Kennel(cx);
michael@0: 
michael@0:     // Assignment! ASTONISHING!
michael@0:     *kennel2 = *kennel;
michael@0: 
michael@0:     // With both kennels referring to the same barker, it is held alive.
michael@0:     CHECK(GCFinalizesNBarkers(cx, 0));
michael@0: 
michael@0:     delete(kennel2);
michael@0: 
michael@0:     // The destination of the assignment alone holds the barker alive.
michael@0:     CHECK(GCFinalizesNBarkers(cx, 0));
michael@0: 
michael@0:     // Allocate a second barker.
michael@0:     kennel2 = Allocate(cx);
michael@0:     CHECK(kennel);
michael@0: 
michael@0:     *kennel = *kennel2;
michael@0: 
michael@0:     // Nothing refers to the first kennel any more.
michael@0:     CHECK(GCFinalizesNBarkers(cx, 1));
michael@0: 
michael@0:     delete(kennel);
michael@0:     delete(kennel2);
michael@0: 
michael@0:     // Now that kennel and kennel2 are both deallocated, GC should not be
michael@0:     // able to find the barker.
michael@0:     JS_GC(JS_GetRuntime(cx));
michael@0:     CHECK(BarkWhenTracedClass::finalizeCount == 2);
michael@0: 
michael@0:     return true;
michael@0: }
michael@0: END_TEST(test_PersistentRootedAssign)
michael@0: 
michael@0: #endif // defined(JSGC_USE_EXACT_ROOTING)