GC Bridge for Android scenarios

src/coreclr/clr.featuredefines.props

@@ -3,6 +3,9 @@
         <FeatureCoreCLR>true</FeatureCoreCLR>
         <FeaturePerfTracing>true</FeaturePerfTracing>
         <ProfilingSupportedBuild>true</ProfilingSupportedBuild>
+
+        <!-- !TODO-JAVA! Limit to Android build -->
+        <FeatureJavaMarshal>true</FeatureJavaMarshal>
     </PropertyGroup>
 
     <PropertyGroup Condition="'$(TargetsUnix)' == 'true'">
@@ -27,6 +30,7 @@
     </PropertyGroup>
 
     <PropertyGroup>
+        <DefineConstants Condition="'$(FeatureJavaMarshal)' == 'true'">$(DefineConstants);FEATURE_JAVAMARSHAL;FEATURE_GCBRIDGE</DefineConstants>
         <DefineConstants Condition="'$(FeatureComWrappers)' == 'true'">$(DefineConstants);FEATURE_COMWRAPPERS</DefineConstants>
         <DefineConstants Condition="'$(FeatureCominterop)' == 'true'">$(DefineConstants);FEATURE_COMINTEROP</DefineConstants>
         <DefineConstants Condition="'$(FeatureCominteropApartmentSupport)' == 'true'">$(DefineConstants);FEATURE_COMINTEROP_APARTMENT_SUPPORT</DefineConstants>

src/coreclr/clrdefinitions.cmake

@@ -161,6 +161,11 @@ if(FEATURE_OBJCMARSHAL)
   add_compile_definitions(FEATURE_OBJCMARSHAL)
 endif()
 
+if(FEATURE_JAVAMARSHAL)
+  add_compile_definitions(FEATURE_JAVAMARSHAL)
+  add_compile_definitions(FEATURE_GCBRIDGE)
+endif()
+
 add_compile_definitions($<$<NOT:$<BOOL:$<TARGET_PROPERTY:DAC_COMPONENT>>>:FEATURE_PROFAPI_ATTACH_DETACH>)
 
 add_definitions(-DFEATURE_READYTORUN)

src/coreclr/clrfeatures.cmake

@@ -47,6 +47,9 @@ if (CLR_CMAKE_TARGET_APPLE)
   set(FEATURE_OBJCMARSHAL 1)
 endif()
 
+# !TODO-JAVA! Limit to Android build
+set(FEATURE_JAVAMARSHAL 1)
+
 if (CLR_CMAKE_TARGET_WIN32)
   set(FEATURE_TYPEEQUIVALENCE 1)
 endif(CLR_CMAKE_TARGET_WIN32)

src/coreclr/debug/daccess/daccess.cpp

@@ -7705,11 +7705,18 @@ void CALLBACK DacHandleWalker::EnumCallback(PTR_UNCHECKED_OBJECTREF handle, uint
     data.Handle = TO_CDADDR(handle.GetAddr());
     data.Type = param->Type;
     if (param->Type == HNDTYPE_DEPENDENT)
+    {
         data.Secondary = GetDependentHandleSecondary(handle.GetAddr()).GetAddr();
-    else if (param->Type == HNDTYPE_WEAK_INTERIOR_POINTER)
+    }
+    else if (param->Type == HNDTYPE_WEAK_INTERIOR_POINTER
+        || param->Type == HNDTYPE_CROSSREFERENCE)
+    {
         data.Secondary = TO_CDADDR(HndGetHandleExtraInfo(handle.GetAddr()));
+    }
     else
+    {
         data.Secondary = 0;
+    }
     data.AppDomain = param->AppDomain;
     GetRefCountedHandleInfo((OBJECTREF)*handle, param->Type, &data.RefCount, &data.JupiterRefCount, &data.IsPegged, &data.StrongReference);
     data.StrongReference |= (BOOL)IsAlwaysStrongReference(param->Type);

src/coreclr/debug/daccess/request.cpp

@@ -3344,6 +3344,9 @@ HRESULT ClrDataAccess::GetHandleEnum(ISOSHandleEnum **ppHandleEnum)
 #if defined(FEATURE_COMINTEROP) || defined(FEATURE_COMWRAPPERS) || defined(FEATURE_OBJCMARSHAL)
                             HNDTYPE_REFCOUNTED,
 #endif // FEATURE_COMINTEROP || FEATURE_COMWRAPPERS || FEATURE_OBJCMARSHAL
+#if defined(FEATURE_GCBRIDGE)
+                            HNDTYPE_CROSSREFERENCE,
+#endif // FEATURE_GCBRIDGE
                             };
 
     return GetHandleEnumForTypes(types, ARRAY_SIZE(types), ppHandleEnum);

src/coreclr/gc/env/gcenv.ee.h

@@ -39,6 +39,8 @@ class GCToEEInterface
     // Promote refcounted handle callback
     static bool RefCountedHandleCallbacks(Object * pObject);
 
+    static void TriggerGCBridge(size_t sccsLen, StronglyConnectedComponent* sccs, size_t ccrsLen, ComponentCrossReference* ccrs);
+
     // Sync block cache management
     static void SyncBlockCacheWeakPtrScan(HANDLESCANPROC scanProc, uintptr_t lp1, uintptr_t lp2);
     static void SyncBlockCacheDemote(int max_gen);

src/coreclr/gc/env/gctoeeinterface.standalone.inl

@@ -49,6 +49,11 @@ namespace standalone
             return ::GCToEEInterface::RefCountedHandleCallbacks(pObject);
         }
 
+        void TriggerGCBridge(size_t sccsLen, StronglyConnectedComponent* sccs, size_t ccrsLen, ComponentCrossReference* ccrs)
+        {
+            return ::GCToEEInterface::TriggerGCBridge(sccsLen, sccs, ccrsLen, ccrs);
+        }
+
         void SyncBlockCacheWeakPtrScan(HANDLESCANPROC scanProc, uintptr_t lp1, uintptr_t lp2)
         {
             ::GCToEEInterface::SyncBlockCacheWeakPtrScan(scanProc, lp1, lp2);

src/coreclr/gc/gc.cpp

@@ -51,7 +51,7 @@ namespace SVR {
 #else // SERVER_GC
 namespace WKS {
 #endif // SERVER_GC
-    
+
 #include "gcimpl.h"
 #include "gcpriv.h"
 
@@ -6456,9 +6456,9 @@ class heap_select
         if (GCToOSInterface::CanGetCurrentProcessorNumber())
         {
             uint32_t proc_no = GCToOSInterface::GetCurrentProcessorNumber();
-            // For a 32-bit process running on a machine with > 64 procs, 
-            // even though the process can only use up to 32 procs, the processor 
-            // index can be >= 64; or in the cpu group case, if the process is not running in cpu group #0, 
+            // For a 32-bit process running on a machine with > 64 procs,
+            // even though the process can only use up to 32 procs, the processor
+            // index can be >= 64; or in the cpu group case, if the process is not running in cpu group #0,
             // the GetCurrentProcessorNumber will return a number that's >= 64.
             proc_no_to_heap_no[proc_no % MAX_SUPPORTED_CPUS] = (uint16_t)heap_number;
         }
@@ -6482,9 +6482,9 @@ class heap_select
         if (GCToOSInterface::CanGetCurrentProcessorNumber())
         {
             uint32_t proc_no = GCToOSInterface::GetCurrentProcessorNumber();
-            // For a 32-bit process running on a machine with > 64 procs, 
-            // even though the process can only use up to 32 procs, the processor 
-            // index can be >= 64; or in the cpu group case, if the process is not running in cpu group #0, 
+            // For a 32-bit process running on a machine with > 64 procs,
+            // even though the process can only use up to 32 procs, the processor
+            // index can be >= 64; or in the cpu group case, if the process is not running in cpu group #0,
             // the GetCurrentProcessorNumber will return a number that's >= 64.
             int adjusted_heap = proc_no_to_heap_no[proc_no % MAX_SUPPORTED_CPUS];
             // with dynamic heap count, need to make sure the value is in range.
@@ -30281,6 +30281,15 @@ void gc_heap::mark_phase (int condemned_gen_number)
         drain_mark_queue();
         fire_mark_event (ETW::GC_ROOT_HANDLES, current_promoted_bytes, last_promoted_bytes);
 
+#ifdef FEATURE_GCBRIDGE
+        dprintf(3,("GCBridge to mark handles"));
+        GCScan::GcScanWithBridge(GCHeap::Promote,
+                                    condemned_gen_number, max_generation,
+                                    &sc);
+        drain_mark_queue();
+        // fire_mark_event (ETW::???, current_promoted_bytes, last_promoted_bytes);
+#endif // FEATURE_GCBRIDGE
+
         if (!full_p)
         {
 #ifdef USE_REGIONS
@@ -42233,7 +42242,7 @@ void gc_heap::mark_through_cards_for_segments (card_fn fn, BOOL relocating CARD_
                 size_t card_last_obj = card_of (last_object_processed);
                 clear_cards(card, card_last_obj);
 
-                // We need to be careful of the accounting here because we could be in the situation where there are more set cards between end of 
+                // We need to be careful of the accounting here because we could be in the situation where there are more set cards between end of
                 // last set card batch and last_object_processed. We will be clearing all of them. But we can't count the set cards we haven't
                 // discovered yet or we can get a negative number for n_card_set. However, if last_object_processed lands before what end_card
                 // corresponds to, we can't count the whole batch because it will be handled by a later clear_cards.

src/coreclr/gc/gcenv.ee.standalone.inl

@@ -72,6 +72,12 @@ inline bool GCToEEInterface::RefCountedHandleCallbacks(Object * pObject)
     return g_theGCToCLR->RefCountedHandleCallbacks(pObject);
 }
 
+inline void GCToEEInterface::TriggerGCBridge(size_t sccsLen, StronglyConnectedComponent* sccs, size_t ccrsLen, ComponentCrossReference* ccrs)
+{
+    assert(g_theGCToCLR != nullptr);
+    return g_theGCToCLR->TriggerGCBridge(sccsLen, sccs, ccrsLen, ccrs);
+}
+
 inline void GCToEEInterface::SyncBlockCacheWeakPtrScan(HANDLESCANPROC scanProc, uintptr_t lp1, uintptr_t lp2)
 {
     assert(g_theGCToCLR != nullptr);

src/coreclr/gc/gchandletable.cpp

@@ -46,7 +46,7 @@ HHANDLETABLE GCHandleStore::GetTable()
     // high 16-bits are for the handle info.
     int handleInfo = (uint32_t)(ctx->alloc_count) >> 16;
 
-    // high 10 bits store the cpu index. 
+    // high 10 bits store the cpu index.
     // low 6 bits store the # of handles allocated so far (before the next reset).
     int numHandles = handleInfo & 0x3f;
     int cpuIndex = handleInfo >> 6;
@@ -213,7 +213,7 @@ Object* GCHandleManager::InterlockedCompareExchangeObjectInHandle(OBJECTHANDLE h
 HandleType GCHandleManager::HandleFetchType(OBJECTHANDLE handle)
 {
     uint32_t type = ::HandleFetchType(handle);
-    assert(type >= HNDTYPE_WEAK_SHORT && type <= HNDTYPE_WEAK_INTERIOR_POINTER);
+    assert(type >= HNDTYPE_WEAK_SHORT && type <= HNDTYPE_CROSSREFERENCE);
     return static_cast<HandleType>(type);
 }
 

src/coreclr/gc/gcinterface.ee.h

@@ -117,10 +117,10 @@ class IGCToCLREventSink
     void FireGCAllocationTick_V1(uint32_t allocationAmount, uint32_t allocationKind) PURE_VIRTUAL
 
     virtual
-    void FireGCAllocationTick_V4(uint64_t allocationAmount, 
-                                 uint32_t allocationKind, 
-                                 uint32_t heapIndex, 
-                                 void* objectAddress, 
+    void FireGCAllocationTick_V4(uint64_t allocationAmount,
+                                 uint32_t allocationKind,
+                                 uint32_t heapIndex,
+                                 void* objectAddress,
                                  uint64_t objectSize) PURE_VIRTUAL
 
     virtual
@@ -239,6 +239,9 @@ class IGCToCLR {
     virtual
     bool RefCountedHandleCallbacks(Object * pObject) PURE_VIRTUAL
 
+    virtual
+    void TriggerGCBridge(size_t sccsLen, StronglyConnectedComponent* sccs, size_t ccrsLen, ComponentCrossReference* ccrs) PURE_VIRTUAL
+
     // Performs a weak pointer scan of the sync block cache.
     virtual
     void SyncBlockCacheWeakPtrScan(HANDLESCANPROC scanProc, uintptr_t lp1, uintptr_t lp2) PURE_VIRTUAL

src/coreclr/gc/gcinterface.h

@@ -143,6 +143,19 @@ struct EtwGCSettingsInfo
     bool no_affinitize_p;
 };
 
+// These definitions are also in managed code.
+struct StronglyConnectedComponent
+{
+    size_t Count;
+    uintptr_t* Context;
+};
+
+struct ComponentCrossReference
+{
+    size_t SourceGroupIndex;
+    size_t DestinationGroupIndex;
+};
+
 // Opaque type for tracking object pointers
 #ifndef DACCESS_COMPILE
 struct OBJECTHANDLE__
@@ -506,7 +519,14 @@ typedef enum
      * have an extra pointer which points at an interior pointer into the first object.
      *
      */
-    HNDTYPE_WEAK_INTERIOR_POINTER = 10
+    HNDTYPE_WEAK_INTERIOR_POINTER = 10,
+
+    /*
+     * CROSSREFERENCE HANDLES
+     *
+     * Crossreference handles are used to track the lifetime of an object in another VM heap.
+     */
+    HNDTYPE_CROSSREFERENCE = 11
 } HandleType;
 
 typedef enum

src/coreclr/gc/gcscan.cpp

@@ -177,6 +177,17 @@ void GCScan::GcScanHandles (promote_func* fn,  int condemned, int max_gen,
     }
 }
 
+#ifdef FEATURE_GCBRIDGE
+void GCScan::GcScanWithBridge (promote_func* fn, int condemned,
+                                    int max_gen, ScanContext* sc)
+{
+    STRESS_LOG0(LF_GC|LF_GCROOTS, LL_INFO10, "GcScanWithBridge\n");
+    _ASSERTE(sc->promotion);
+    _ASSERTE(!sc->concurrent);
+    Ref_TraceGCBridge(condemned, max_gen, sc, fn);
+}
+#endif // FEATURE_GCBRIDGE
+
 /*
  * Scan all handle roots in this 'namespace' for profiling
  */

src/coreclr/gc/gcscan.h

@@ -43,6 +43,10 @@ class GCScan
     //
     static void GcScanHandles (promote_func* fn, int condemned, int max_gen, ScanContext* sc);
 
+#ifdef FEATURE_GCBRIDGE
+    static void GcScanWithBridge (promote_func* fn, int condemned, int max_gen, ScanContext* sc);
+#endif // FEATURE_GCBRIDGE
+
     static void GcRuntimeStructuresValid (BOOL bValid);
 
     static bool GetGcRuntimeStructuresValid ();

src/coreclr/gc/handletableconstants.h

@@ -14,7 +14,7 @@
 #endif
 
 #define INITIAL_HANDLE_TABLE_ARRAY_SIZE 10
-#define HANDLE_MAX_INTERNAL_TYPES       12
+#define HANDLE_MAX_INTERNAL_TYPES       16
 
 /*--------------------------------------------------------------------------*/