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Diffstat (limited to 'src/gc/gcinterface.h')
| -rw-r--r-- | src/gc/gcinterface.h | 622 |
1 files changed, 622 insertions, 0 deletions
diff --git a/src/gc/gcinterface.h b/src/gc/gcinterface.h new file mode 100644 index 0000000000..1457848992 --- /dev/null +++ b/src/gc/gcinterface.h @@ -0,0 +1,622 @@ +// Licensed to the .NET Foundation under one or more agreements. +// The .NET Foundation licenses this file to you under the MIT license. +// See the LICENSE file in the project root for more information. + +#ifndef _GC_INTERFACE_H_ +#define _GC_INTERFACE_H_ + +struct ScanContext; +struct gc_alloc_context; +class CrawlFrame; + +// Callback passed to GcScanRoots. +typedef void promote_func(PTR_PTR_Object, ScanContext*, uint32_t); + +// Callback passed to GcEnumAllocContexts. +typedef void enum_alloc_context_func(gc_alloc_context*, void*); + +// Callback passed to CreateBackgroundThread. +typedef uint32_t (__stdcall *GCBackgroundThreadFunction)(void* param); + +// Struct often used as a parameter to callbacks. +typedef struct +{ + promote_func* f; + ScanContext* sc; + CrawlFrame * cf; +} GCCONTEXT; + +// SUSPEND_REASON is the reason why the GC wishes to suspend the EE, +// used as an argument to IGCToCLR::SuspendEE. +typedef enum +{ + SUSPEND_FOR_GC = 1, + SUSPEND_FOR_GC_PREP = 6 +} SUSPEND_REASON; + +typedef enum +{ + walk_for_gc = 1, + walk_for_bgc = 2, + walk_for_loh = 3 +} walk_surv_type; + +// Different operations that can be done by GCToEEInterface::StompWriteBarrier +enum class WriteBarrierOp +{ + StompResize, + StompEphemeral, + Initialize +}; + +// Arguments to GCToEEInterface::StompWriteBarrier +struct WriteBarrierParameters +{ + // The operation that StompWriteBarrier will perform. + WriteBarrierOp operation; + + // Whether or not the runtime is currently suspended. If it is not, + // the EE will need to suspend it before bashing the write barrier. + // Used for all operations. + bool is_runtime_suspended; + + // Whether or not the GC has moved the ephemeral generation to no longer + // be at the top of the heap. When the ephemeral generation is at the top + // of the heap, and the write barrier observes that a pointer is greater than + // g_ephemeral_low, it does not need to check that the pointer is less than + // g_ephemeral_high because there is nothing in the GC heap above the ephemeral + // generation. When this is not the case, however, the GC must inform the EE + // so that the EE can switch to a write barrier that checks that a pointer + // is both greater than g_ephemeral_low and less than g_ephemeral_high. + // Used for WriteBarrierOp::StompResize. + bool requires_upper_bounds_check; + + // The new card table location. May or may not be the same as the previous + // card table. Used for WriteBarrierOp::Initialize and WriteBarrierOp::StompResize. + uint32_t* card_table; + + // The heap's new low boundary. May or may not be the same as the previous + // value. Used for WriteBarrierOp::Initialize and WriteBarrierOp::StompResize. + uint8_t* lowest_address; + + // The heap's new high boundary. May or may not be the same as the previous + // value. Used for WriteBarrierOp::Initialize and WriteBarrierOp::StompResize. + uint8_t* highest_address; + + // The new start of the ephemeral generation. + // Used for WriteBarrierOp::StompEphemeral. + uint8_t* ephemeral_lo; + + // The new end of the ephemeral generation. + // Used for WriteBarrierOp::StompEphemeral. + uint8_t* ephemeral_hi; +}; + +#include "gcinterface.ee.h" + +// The allocation context must be known to the VM for use in the allocation +// fast path and known to the GC for performing the allocation. Every Thread +// has its own allocation context that it hands to the GC when allocating. +struct gc_alloc_context +{ + uint8_t* alloc_ptr; + uint8_t* alloc_limit; + int64_t alloc_bytes; //Number of bytes allocated on SOH by this context + int64_t alloc_bytes_loh; //Number of bytes allocated on LOH by this context + // These two fields are deliberately not exposed past the EE-GC interface. + void* gc_reserved_1; + void* gc_reserved_2; + int alloc_count; +public: + + void init() + { + LIMITED_METHOD_CONTRACT; + + alloc_ptr = 0; + alloc_limit = 0; + alloc_bytes = 0; + alloc_bytes_loh = 0; + gc_reserved_1 = 0; + gc_reserved_2 = 0; + alloc_count = 0; + } +}; + +// stub type to abstract a heap segment +struct gc_heap_segment_stub; +typedef gc_heap_segment_stub *segment_handle; + +struct segment_info +{ + void * pvMem; // base of the allocation, not the first object (must add ibFirstObject) + size_t ibFirstObject; // offset to the base of the first object in the segment + size_t ibAllocated; // limit of allocated memory in the segment (>= firstobject) + size_t ibCommit; // limit of committed memory in the segment (>= alllocated) + size_t ibReserved; // limit of reserved memory in the segment (>= commit) +}; + +#ifdef PROFILING_SUPPORTED +#define GC_PROFILING //Turn on profiling +#endif // PROFILING_SUPPORTED + +#define LARGE_OBJECT_SIZE ((size_t)(85000)) + +// The minimum size of an object is three pointers wide: one for the syncblock, +// one for the object header, and one for the first field in the object. +#define min_obj_size ((sizeof(uint8_t*) + sizeof(uintptr_t) + sizeof(size_t))) + +#define max_generation 2 + +class Object; +class IGCHeap; + +// Initializes the garbage collector. Should only be called +// once, during EE startup. +IGCHeap* InitializeGarbageCollector(IGCToCLR* clrToGC); + +// The runtime needs to know whether we're using workstation or server GC +// long before the GCHeap is created. This function sets the type of +// heap that will be created, before InitializeGarbageCollector is called +// and the heap is actually recated. +void InitializeHeapType(bool bServerHeap); + +#ifdef WRITE_BARRIER_CHECK +//always defined, but should be 0 in Server GC +extern uint8_t* g_GCShadow; +extern uint8_t* g_GCShadowEnd; +// saves the g_lowest_address in between GCs to verify the consistency of the shadow segment +extern uint8_t* g_shadow_lowest_address; +#endif + +// For low memory notification from host +extern int32_t g_bLowMemoryFromHost; + +extern VOLATILE(int32_t) m_GCLock; + +// !!!!!!!!!!!!!!!!!!!!!!! +// make sure you change the def in bcl\system\gc.cs +// if you change this! +enum collection_mode +{ + collection_non_blocking = 0x00000001, + collection_blocking = 0x00000002, + collection_optimized = 0x00000004, + collection_compacting = 0x00000008 +#ifdef STRESS_HEAP + , collection_gcstress = 0x80000000 +#endif // STRESS_HEAP +}; + +// !!!!!!!!!!!!!!!!!!!!!!! +// make sure you change the def in bcl\system\gc.cs +// if you change this! +enum wait_full_gc_status +{ + wait_full_gc_success = 0, + wait_full_gc_failed = 1, + wait_full_gc_cancelled = 2, + wait_full_gc_timeout = 3, + wait_full_gc_na = 4 +}; + +// !!!!!!!!!!!!!!!!!!!!!!! +// make sure you change the def in bcl\system\gc.cs +// if you change this! +enum start_no_gc_region_status +{ + start_no_gc_success = 0, + start_no_gc_no_memory = 1, + start_no_gc_too_large = 2, + start_no_gc_in_progress = 3 +}; + +enum end_no_gc_region_status +{ + end_no_gc_success = 0, + end_no_gc_not_in_progress = 1, + end_no_gc_induced = 2, + end_no_gc_alloc_exceeded = 3 +}; + +typedef BOOL (* walk_fn)(Object*, void*); +typedef void (* gen_walk_fn)(void* context, int generation, uint8_t* range_start, uint8_t* range_end, uint8_t* range_reserved); +typedef void (* record_surv_fn)(uint8_t* begin, uint8_t* end, ptrdiff_t reloc, size_t context, BOOL compacting_p, BOOL bgc_p); +typedef void (* fq_walk_fn)(BOOL, void*); +typedef void (* fq_scan_fn)(Object** ppObject, ScanContext *pSC, uint32_t dwFlags); +typedef void (* handle_scan_fn)(Object** pRef, Object* pSec, uint32_t flags, ScanContext* context, BOOL isDependent); + +// IGCHeap is the interface that the VM will use when interacting with the GC. +class IGCHeap { +public: + /* + =========================================================================== + Hosting APIs. These are used by GC hosting. The code that + calls these methods may possibly be moved behind the interface - + today, the VM handles the setting of segment size and max gen 0 size. + (See src/vm/corehost.cpp) + =========================================================================== + */ + + // Returns whether or not the given size is a valid segment size. + virtual BOOL IsValidSegmentSize(size_t size) = 0; + + // Returns whether or not the given size is a valid gen 0 max size. + virtual BOOL IsValidGen0MaxSize(size_t size) = 0; + + // Gets a valid segment size. + virtual size_t GetValidSegmentSize(BOOL large_seg = FALSE) = 0; + + // Sets the limit for reserved virtual memory. + virtual void SetReservedVMLimit(size_t vmlimit) = 0; + + /* + =========================================================================== + Concurrent GC routines. These are used in various places in the VM + to synchronize with the GC, when the VM wants to update something that + the GC is potentially using, if it's doing a background GC. + + Concrete examples of this are moving async pinned handles across appdomains + and profiling/ETW scenarios. + =========================================================================== + */ + + // Blocks until any running concurrent GCs complete. + virtual void WaitUntilConcurrentGCComplete() = 0; + + // Returns true if a concurrent GC is in progress, false otherwise. + virtual BOOL IsConcurrentGCInProgress() = 0; + + // Temporarily enables concurrent GC, used during profiling. + virtual void TemporaryEnableConcurrentGC() = 0; + + // Temporarily disables concurrent GC, used during profiling. + virtual void TemporaryDisableConcurrentGC() = 0; + + // Returns whether or not Concurrent GC is enabled. + virtual BOOL IsConcurrentGCEnabled() = 0; + + // Wait for a concurrent GC to complete if one is in progress, with the given timeout. + virtual HRESULT WaitUntilConcurrentGCCompleteAsync(int millisecondsTimeout) = 0; // Use in native threads. TRUE if succeed. FALSE if failed or timeout + + + /* + =========================================================================== + Finalization routines. These are used by the finalizer thread to communicate + with the GC. + =========================================================================== + */ + + // Finalizes an app domain by finalizing objects within that app domain. + virtual BOOL FinalizeAppDomain(AppDomain* pDomain, BOOL fRunFinalizers) = 0; + + // Finalizes all registered objects for shutdown, even if they are still reachable. + virtual void SetFinalizeQueueForShutdown(BOOL fHasLock) = 0; + + // Gets the number of finalizable objects. + virtual size_t GetNumberOfFinalizable() = 0; + + // Traditionally used by the finalizer thread on shutdown to determine + // whether or not to time out. Returns true if the GC lock has not been taken. + virtual BOOL ShouldRestartFinalizerWatchDog() = 0; + + // Gets the next finalizable object. + virtual Object* GetNextFinalizable() = 0; + + /* + =========================================================================== + BCL routines. These are routines that are directly exposed by mscorlib + as a part of the `System.GC` class. These routines behave in the same + manner as the functions on `System.GC`. + =========================================================================== + */ + + // Gets the current GC latency mode. + virtual int GetGcLatencyMode() = 0; + + // Sets the current GC latency mode. newLatencyMode has already been + // verified by mscorlib to be valid. + virtual int SetGcLatencyMode(int newLatencyMode) = 0; + + // Gets the current LOH compaction mode. + virtual int GetLOHCompactionMode() = 0; + + // Sets the current LOH compaction mode. newLOHCompactionMode has + // already been verified by mscorlib to be valid. + virtual void SetLOHCompactionMode(int newLOHCompactionMode) = 0; + + // Registers for a full GC notification, raising a notification if the gen 2 or + // LOH object heap thresholds are exceeded. + virtual BOOL RegisterForFullGCNotification(uint32_t gen2Percentage, uint32_t lohPercentage) = 0; + + // Cancels a full GC notification that was requested by `RegisterForFullGCNotification`. + virtual BOOL CancelFullGCNotification() = 0; + + // Returns the status of a registered notification for determining whether a blocking + // Gen 2 collection is about to be initiated, with the given timeout. + virtual int WaitForFullGCApproach(int millisecondsTimeout) = 0; + + // Returns the status of a registered notification for determining whether a blocking + // Gen 2 collection has completed, with the given timeout. + virtual int WaitForFullGCComplete(int millisecondsTimeout) = 0; + + // Returns the generation in which obj is found. Also used by the VM + // in some places, in particular syncblk code. + virtual unsigned WhichGeneration(Object* obj) = 0; + + // Returns the number of GCs that have transpired in the given generation + // since the beginning of the life of the process. Also used by the VM + // for debug code and app domains. + virtual int CollectionCount(int generation, int get_bgc_fgc_coutn = 0) = 0; + + // Begins a no-GC region, returning a code indicating whether entering the no-GC + // region was successful. + virtual int StartNoGCRegion(uint64_t totalSize, BOOL lohSizeKnown, uint64_t lohSize, BOOL disallowFullBlockingGC) = 0; + + // Exits a no-GC region. + virtual int EndNoGCRegion() = 0; + + // Gets the total number of bytes in use. + virtual size_t GetTotalBytesInUse() = 0; + + // Forces a garbage collection of the given generation. Also used extensively + // throughout the VM. + virtual HRESULT GarbageCollect(int generation = -1, BOOL low_memory_p = FALSE, int mode = collection_blocking) = 0; + + // Gets the largest GC generation. Also used extensively throughout the VM. + virtual unsigned GetMaxGeneration() = 0; + + // Indicates that an object's finalizer should not be run upon the object's collection. + virtual void SetFinalizationRun(Object* obj) = 0; + + // Indicates that an object's finalizer should be run upon the object's collection. + virtual bool RegisterForFinalization(int gen, Object* obj) = 0; + + /* + =========================================================================== + Miscellaneous routines used by the VM. + =========================================================================== + */ + + // Initializes the GC heap, returning whether or not the initialization + // was successful. + virtual HRESULT Initialize() = 0; + + // Returns whether nor this GC was promoted by the last GC. + virtual BOOL IsPromoted(Object* object) = 0; + + // Returns true if this pointer points into a GC heap, false otherwise. + virtual BOOL IsHeapPointer(void* object, BOOL small_heap_only = FALSE) = 0; + + // Return the generation that has been condemned by the current GC. + virtual unsigned GetCondemnedGeneration() = 0; + + // Returns whether or not a GC is in progress. + virtual BOOL IsGCInProgressHelper(BOOL bConsiderGCStart = FALSE) = 0; + + // Returns the number of GCs that have occured. Mainly used for + // sanity checks asserting that a GC has not occured. + virtual unsigned GetGcCount() = 0; + + // Sets cards after an object has been memmoved. + virtual void SetCardsAfterBulkCopy(Object** obj, size_t length) = 0; + + // Gets whether or not the home heap of this alloc context matches the heap + // associated with this thread. + virtual bool IsThreadUsingAllocationContextHeap(gc_alloc_context* acontext, int thread_number) = 0; + + // Returns whether or not this object resides in an ephemeral generation. + virtual BOOL IsEphemeral(Object* object) = 0; + + // Blocks until a GC is complete, returning a code indicating the wait was successful. + virtual uint32_t WaitUntilGCComplete(BOOL bConsiderGCStart = FALSE) = 0; + + // "Fixes" an allocation context by binding its allocation pointer to a + // location on the heap. + virtual void FixAllocContext(gc_alloc_context* acontext, BOOL lockp, void* arg, void* heap) = 0; + + // Gets the total survived size plus the total allocated bytes on the heap. + virtual size_t GetCurrentObjSize() = 0; + + // Sets whether or not a GC is in progress. + virtual void SetGCInProgress(BOOL fInProgress) = 0; + + /* + ============================================================================ + Add/RemoveMemoryPressure support routines. These are on the interface + for now, but we should move Add/RemoveMemoryPressure from the VM to the GC. + When that occurs, these three routines can be removed from the interface. + ============================================================================ + */ + + // Get the timestamp corresponding to the last GC that occured for the + // given generation. + virtual size_t GetLastGCStartTime(int generation) = 0; + + // Gets the duration of the last GC that occured for the given generation. + virtual size_t GetLastGCDuration(int generation) = 0; + + // Gets a timestamp for the current moment in time. + virtual size_t GetNow() = 0; + + /* + =========================================================================== + Allocation routines. These all call into the GC's allocator and may trigger a garbage + collection. All allocation routines return NULL when the allocation request + couldn't be serviced due to being out of memory. + =========================================================================== + */ + + // Allocates an object on the given allocation context with the given size and flags. + virtual Object* Alloc(gc_alloc_context* acontext, size_t size, uint32_t flags) = 0; + + // Allocates an object on the default allocation context with the given size and flags. + virtual Object* Alloc(size_t size, uint32_t flags) = 0; + + // Allocates an object on the large object heap with the given size and flags. + virtual Object* AllocLHeap(size_t size, uint32_t flags) = 0; + + // Allocates an object on the default allocation context, aligned to 64 bits, + // with the given size and flags. + virtual Object* AllocAlign8 (size_t size, uint32_t flags) = 0; + + // Allocates an object on the given allocation context, aligned to 64 bits, + // with the given size and flags. + virtual Object* AllocAlign8 (gc_alloc_context* acontext, size_t size, uint32_t flags) = 0; + + // This is for the allocator to indicate it's done allocating a large object during a + // background GC as the BGC threads also need to walk LOH. + virtual void PublishObject(uint8_t* obj) = 0; + + // Gets the event that suspended threads will use to wait for the + // end of a GC. + virtual CLREventStatic* GetWaitForGCEvent() = 0; + + /* + =========================================================================== + Heap verification routines. These are used during heap verification only. + =========================================================================== + */ + // Returns whether or not this object is in the fixed heap. + virtual BOOL IsObjectInFixedHeap(Object* pObj) = 0; + + // Walks an object and validates its members. + virtual void ValidateObjectMember(Object* obj) = 0; + + // Retrieves the next object after the given object. When the EE + // is not suspended, the result is not accurate - if the input argument + // is in Gen0, the function could return zeroed out memory as the next object. + virtual Object* NextObj(Object* object) = 0; + + // Given an interior pointer, return a pointer to the object + // containing that pointer. This is safe to call only when the EE is suspended. + virtual Object* GetContainingObject(void* pInteriorPtr) = 0; + + /* + =========================================================================== + Profiling routines. Used for event tracing and profiling to broadcast + information regarding the heap. + =========================================================================== + */ + + // Walks an object, invoking a callback on each member. + virtual void DiagWalkObject(Object* obj, walk_fn fn, void* context) = 0; + + // Walk the heap object by object. + virtual void DiagWalkHeap(walk_fn fn, void* context, int gen_number, BOOL walk_large_object_heap_p) = 0; + + // Walks the survivors and get the relocation information if objects have moved. + virtual void DiagWalkSurvivorsWithType(void* gc_context, record_surv_fn fn, size_t diag_context, walk_surv_type type) = 0; + + // Walks the finalization queue. + virtual void DiagWalkFinalizeQueue(void* gc_context, fq_walk_fn fn) = 0; + + // Scan roots on finalizer queue. This is a generic function. + virtual void DiagScanFinalizeQueue(fq_scan_fn fn, ScanContext* context) = 0; + + // Scan handles for profiling or ETW. + virtual void DiagScanHandles(handle_scan_fn fn, int gen_number, ScanContext* context) = 0; + + // Scan dependent handles for profiling or ETW. + virtual void DiagScanDependentHandles(handle_scan_fn fn, int gen_number, ScanContext* context) = 0; + + // Describes all generations to the profiler, invoking a callback on each generation. + virtual void DiagDescrGenerations(gen_walk_fn fn, void* context) = 0; + + // Traces all GC segments and fires ETW events with information on them. + virtual void DiagTraceGCSegments() = 0; + + /* + =========================================================================== + GC Stress routines. Used only when running under GC Stress. + =========================================================================== + */ + + // Returns TRUE if GC actually happens, otherwise FALSE + virtual BOOL StressHeap(gc_alloc_context* acontext = 0) = 0; + + /* + =========================================================================== + Routines to register read only segments for frozen objects. + Only valid if FEATURE_BASICFREEZE is defined. + =========================================================================== + */ + + // Registers a frozen segment with the GC. + virtual segment_handle RegisterFrozenSegment(segment_info *pseginfo) = 0; + + // Unregisters a frozen segment. + virtual void UnregisterFrozenSegment(segment_handle seg) = 0; + + IGCHeap() {} + virtual ~IGCHeap() {} + + typedef enum + { + GC_HEAP_INVALID = 0, + GC_HEAP_WKS = 1, + GC_HEAP_SVR = 2 + } GC_HEAP_TYPE; + +#ifdef FEATURE_SVR_GC + SVAL_DECL(uint32_t, gcHeapType); +#endif + + SVAL_DECL(uint32_t, maxGeneration); +}; + +#ifdef WRITE_BARRIER_CHECK +void updateGCShadow(Object** ptr, Object* val); +#endif + +//constants for the flags parameter to the gc call back + +#define GC_CALL_INTERIOR 0x1 +#define GC_CALL_PINNED 0x2 +#define GC_CALL_CHECK_APP_DOMAIN 0x4 + +//flags for IGCHeapAlloc(...) +#define GC_ALLOC_FINALIZE 0x1 +#define GC_ALLOC_CONTAINS_REF 0x2 +#define GC_ALLOC_ALIGN8_BIAS 0x4 +#define GC_ALLOC_ALIGN8 0x8 + +struct ScanContext +{ + Thread* thread_under_crawl; + int thread_number; + uintptr_t stack_limit; // Lowest point on the thread stack that the scanning logic is permitted to read + BOOL promotion; //TRUE: Promotion, FALSE: Relocation. + BOOL concurrent; //TRUE: concurrent scanning +#if CHECK_APP_DOMAIN_LEAKS || defined (FEATURE_APPDOMAIN_RESOURCE_MONITORING) || defined (DACCESS_COMPILE) + AppDomain *pCurrentDomain; +#endif //CHECK_APP_DOMAIN_LEAKS || FEATURE_APPDOMAIN_RESOURCE_MONITORING || DACCESS_COMPILE + +#ifndef FEATURE_REDHAWK +#if defined(GC_PROFILING) || defined (DACCESS_COMPILE) + MethodDesc *pMD; +#endif //GC_PROFILING || DACCESS_COMPILE +#endif // FEATURE_REDHAWK +#if defined(GC_PROFILING) || defined(FEATURE_EVENT_TRACE) + EtwGCRootKind dwEtwRootKind; +#endif // GC_PROFILING || FEATURE_EVENT_TRACE + + ScanContext() + { + LIMITED_METHOD_CONTRACT; + + thread_under_crawl = 0; + thread_number = -1; + stack_limit = 0; + promotion = FALSE; + concurrent = FALSE; +#ifdef GC_PROFILING + pMD = NULL; +#endif //GC_PROFILING +#ifdef FEATURE_EVENT_TRACE + dwEtwRootKind = kEtwGCRootKindOther; +#endif // FEATURE_EVENT_TRACE + } +}; + +#endif // _GC_INTERFACE_H_ |