diff options
Diffstat (limited to 'db/mork/src/morkZone.h')
| -rw-r--r-- | db/mork/src/morkZone.h | 321 |
1 files changed, 321 insertions, 0 deletions
diff --git a/db/mork/src/morkZone.h b/db/mork/src/morkZone.h new file mode 100644 index 000000000..9e5ffc54c --- /dev/null +++ b/db/mork/src/morkZone.h @@ -0,0 +1,321 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef _MORKZONE_ +#define _MORKZONE_ 1 + +#ifndef _MORK_ +#include "mork.h" +#endif + +#ifndef _MORKNODE_ +#include "morkNode.h" +#endif + +#ifndef _MORKDEQUE_ +#include "morkDeque.h" +#endif + +//3456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789 + +/*| CONFIG_DEBUG: do paranoid debug checks if defined. +|*/ +#ifdef MORK_DEBUG +#define morkZone_CONFIG_DEBUG 1 /* debug paranoid if defined */ +#endif /*MORK_DEBUG*/ + +/*| CONFIG_STATS: keep volume and usage statistics. +|*/ +#define morkZone_CONFIG_VOL_STATS 1 /* count space used by zone instance */ + +/*| CONFIG_ARENA: if this is defined, then the morkZone class will alloc big +**| blocks from the zone's heap, and suballocate from these. If undefined, +**| then morkZone will just pass all calls through to the zone's heap. +|*/ +#ifdef MORK_ENABLE_ZONE_ARENAS +#define morkZone_CONFIG_ARENA 1 /* be arena, if defined; otherwise no-op */ +#endif /*MORK_ENABLE_ZONE_ARENAS*/ + +/*| CONFIG_ALIGN_8: if this is defined, then the morkZone class will give +**| blocks 8 byte alignment instead of only 4 byte alignment. +|*/ +#ifdef MORK_CONFIG_ALIGN_8 +#define morkZone_CONFIG_ALIGN_8 1 /* ifdef: align to 8 bytes, otherwise 4 */ +#endif /*MORK_CONFIG_ALIGN_8*/ + +/*| CONFIG_PTR_SIZE_4: if this is defined, then the morkZone class will +**| assume sizeof(void*) == 4, so a tag slot for padding is needed. +|*/ +#ifdef MORK_CONFIG_PTR_SIZE_4 +#define morkZone_CONFIG_PTR_SIZE_4 1 /* ifdef: sizeof(void*) == 4 */ +#endif /*MORK_CONFIG_PTR_SIZE_4*/ + +/*| morkZone_USE_TAG_SLOT: if this is defined, then define slot mRun_Tag +**| in order to achieve eight byte alignment after the mRun_Next slot. +|*/ +#if defined(morkZone_CONFIG_ALIGN_8) && defined(morkZone_CONFIG_PTR_SIZE_4) +#define morkRun_USE_TAG_SLOT 1 /* need mRun_Tag slot inside morkRun */ +#define morkHunk_USE_TAG_SLOT 1 /* need mHunk_Tag slot inside morkHunk */ +#endif + +//3456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789 + +#define morkRun_kTag ((mork_u4) 0x6D52754E ) /* ascii 'mRuN' */ + +/*| morkRun: structure used by morkZone for sized blocks +|*/ +class morkRun { + +protected: // member variable slots +#ifdef morkRun_USE_TAG_SLOT + mork_u4 mRun_Tag; // force 8 byte alignment after mRun_Next +#endif /* morkRun_USE_TAG_SLOT */ + + morkRun* mRun_Next; + +public: // pointer interpretation of mRun_Next (when inside a list): + morkRun* RunNext() const { return mRun_Next; } + void RunSetNext(morkRun* ioNext) { mRun_Next = ioNext; } + +public: // size interpretation of mRun_Next (when not inside a list): + mork_size RunSize() const { return (mork_size) ((mork_ip) mRun_Next); } + void RunSetSize(mork_size inSize) + { mRun_Next = (morkRun*) ((mork_ip) inSize); } + +public: // maintenance and testing of optional tag magic signature slot: +#ifdef morkRun_USE_TAG_SLOT + void RunInitTag() { mRun_Tag = morkRun_kTag; } + mork_bool RunGoodTag() { return ( mRun_Tag == morkRun_kTag ); } +#endif /* morkRun_USE_TAG_SLOT */ + +public: // conversion back and forth to inline block following run instance: + void* RunAsBlock() { return (((mork_u1*) this) + sizeof(morkRun)); } + + static morkRun* BlockAsRun(void* ioBlock) + { return (morkRun*) (((mork_u1*) ioBlock) - sizeof(morkRun)); } + +public: // typing & errors + static void BadRunTagError(morkEnv* ev); + static void RunSizeAlignError(morkEnv* ev); +}; + +//3456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789 + + +/*| morkOldRun: more space to record size when run is put into old free list +|*/ +class morkOldRun : public morkRun { + +protected: // need another size field when mRun_Next is used for linkage: + mdb_size mOldRun_Size; + +public: // size getter/setter + mork_size OldSize() const { return mOldRun_Size; } + void OldSetSize(mork_size inSize) { mOldRun_Size = inSize; } + +}; + +//3456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789 + +#define morkHunk_kTag ((mork_u4) 0x68556E4B ) /* ascii 'hUnK' */ + +/*| morkHunk: structure used by morkZone for heap allocations. +|*/ +class morkHunk { + +protected: // member variable slots + +#ifdef morkHunk_USE_TAG_SLOT + mork_u4 mHunk_Tag; // force 8 byte alignment after mHunk_Next +#endif /* morkHunk_USE_TAG_SLOT */ + + morkHunk* mHunk_Next; + + morkRun mHunk_Run; + +public: // setters + void HunkSetNext(morkHunk* ioNext) { mHunk_Next = ioNext; } + +public: // getters + morkHunk* HunkNext() const { return mHunk_Next; } + + morkRun* HunkRun() { return &mHunk_Run; } + +public: // maintenance and testing of optional tag magic signature slot: +#ifdef morkHunk_USE_TAG_SLOT + void HunkInitTag() { mHunk_Tag = morkHunk_kTag; } + mork_bool HunkGoodTag() { return ( mHunk_Tag == morkHunk_kTag ); } +#endif /* morkHunk_USE_TAG_SLOT */ + +public: // typing & errors + static void BadHunkTagWarning(morkEnv* ev); + +}; + +//3456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789 + +/*| kNewHunkSize: the default size for a hunk, assuming we must allocate +**| a new one whenever the free hunk list does not already have. Note this +**| number should not be changed without also considering suitable changes +**| in the related kMaxHunkWaste and kMinHunkSize constants. +|*/ +#define morkZone_kNewHunkSize ((mork_size) (64 * 1024)) /* 64K per hunk */ + +/*| kMaxFreeVolume: some number of bytes of free space in the free hunk list +**| over which we no longer want to add more free hunks to the list, for fear +**| of accumulating too much unused, fragmented free space. This should be a +**| small multiple of kNewHunkSize, say about two to four times as great, to +**| allow for no more free hunk space than fits in a handful of new hunks. +**| This strategy will let us usefuly accumulate "some" free space in the +**| free hunk list, but without accumulating "too much" free space that way. +|*/ +#define morkZone_kMaxFreeVolume (morkZone_kNewHunkSize * 3) + +/*| kMaxHunkWaste: if a current request is larger than this, and we cannot +**| satisfy the request with the current hunk, then we just allocate the +**| block from the heap without changing the current hunk. Basically this +**| number represents the largest amount of memory we are willing to waste, +**| since a block request barely less than this can cause the current hunk +**| to be retired (with any unused space wasted) as well get a new hunk. +|*/ +#define morkZone_kMaxHunkWaste ((mork_size) 4096) /* 1/16 kNewHunkSize */ + +/*| kRound*: the algorithm for rounding up allocation sizes for caching +**| in free lists works like the following. We add kRoundAdd to any size +**| requested, and then bitwise AND with kRoundMask, and this will give us +**| the smallest multiple of kRoundSize that is at least as large as the +**| requested size. Then if we rightshift this number by kRoundBits, we +**| will have the index into the mZone_FreeRuns array which will hold any +**| cache runs of that size. So 4 bits of shift gives us a granularity +**| of 16 bytes, so that free lists will hold successive runs that are +**| 16 bytes greater than the next smaller run size. If we have 256 free +**| lists of nonzero sized runs altogether, then the largest run that can +**| be cached is 4096, or 4K (since 4096 == 16 * 256). A larger run that +**| gets freed will go in to the free hunk list (or back to the heap). +|*/ +#define morkZone_kRoundBits 4 /* bits to round-up size for free lists */ +#define morkZone_kRoundSize (1 << morkZone_kRoundBits) +#define morkZone_kRoundAdd ((1 << morkZone_kRoundBits) - 1) +#define morkZone_kRoundMask (~ ((mork_ip) morkZone_kRoundAdd)) + +#define morkZone_kBuckets 256 /* number of distinct free lists */ + +/*| kMaxCachedRun: the largest run that will be stored inside a free +**| list of old zapped runs. A run larger than this cannot be put in +**| a free list, and must be allocated from the heap at need, and put +**| into the free hunk list when discarded. +|*/ +#define morkZone_kMaxCachedRun (morkZone_kBuckets * morkZone_kRoundSize) + +#define morkDerived_kZone /*i*/ 0x5A6E /* ascii 'Zn' */ + +/*| morkZone: a pooled memory allocator like an NSPR arena. The term 'zone' +**| is roughly synonymous with 'heap'. I avoid calling this class a "heap" +**| to avoid any confusion with nsIMdbHeap, and I avoid calling this class +**| an arean to avoid confusion with NSPR usage. +|*/ +class morkZone : public morkNode, public nsIMdbHeap { + +// public: // slots inherited from morkNode (meant to inform only) + // nsIMdbHeap* mNode_Heap; + + // mork_base mNode_Base; // must equal morkBase_kNode + // mork_derived mNode_Derived; // depends on specific node subclass + + // mork_access mNode_Access; // kOpen, kClosing, kShut, or kDead + // mork_usage mNode_Usage; // kHeap, kStack, kMember, kGlobal, kNone + // mork_able mNode_Mutable; // can this node be modified? + // mork_load mNode_Load; // is this node clean or dirty? + + // mork_uses mNode_Uses; // refcount for strong refs + // mork_refs mNode_Refs; // refcount for strong refs + weak refs + +public: // state is public because the entire Mork system is private + + nsIMdbHeap* mZone_Heap; // strong ref to heap allocating all space + + mork_size mZone_HeapVolume; // total bytes allocated from heap + mork_size mZone_BlockVolume; // total bytes in all zone blocks + mork_size mZone_RunVolume; // total bytes in all zone runs + mork_size mZone_ChipVolume; // total bytes in all zone chips + + mork_size mZone_FreeOldRunVolume; // total bytes in all used hunks + + mork_count mZone_HunkCount; // total number of used hunks + mork_count mZone_FreeOldRunCount; // total free old runs + + morkHunk* mZone_HunkList; // linked list of all used hunks + morkRun* mZone_FreeOldRunList; // linked list of free old runs + + // note mZone_At is a byte pointer for single byte address arithmetic: + mork_u1* mZone_At; // current position in most recent hunk + mork_size mZone_AtSize; // number of bytes remaining in this hunk + + // kBuckets+1 so indexes zero through kBuckets are all okay to use: + + morkRun* mZone_FreeRuns[ morkZone_kBuckets + 1 ]; + // Each piece of memory stored in list mZone_FreeRuns[ i ] has an + // allocation size equal to sizeof(morkRun) + (i * kRoundSize), so + // that callers can be given a piece of memory with (i * kRoundSize) + // bytes of writeable space while reserving the first sizeof(morkRun) + // bytes to keep track of size information for later re-use. Note + // that mZone_FreeRuns[ 0 ] is unused because no run will be zero + // bytes in size (and morkZone plans to complain about zero sizes). + +protected: // zone utilities + + mork_size zone_grow_at(morkEnv* ev, mork_size inNeededSize); + + void* zone_new_chip(morkEnv* ev, mdb_size inSize); // alloc + morkHunk* zone_new_hunk(morkEnv* ev, mdb_size inRunSize); // alloc + +// { ===== begin nsIMdbHeap methods ===== +public: + NS_IMETHOD Alloc(nsIMdbEnv* ev, // allocate a piece of memory + mdb_size inSize, // requested size of new memory block + void** outBlock) override; // memory block of inSize bytes, or nil + + NS_IMETHOD Free(nsIMdbEnv* ev, // free block allocated earlier by Alloc() + void* inBlock) override; + + virtual size_t GetUsedSize() override { return mZone_Heap->GetUsedSize(); } +// } ===== end nsIMdbHeap methods ===== + +// { ===== begin morkNode interface ===== +public: // morkNode virtual methods + virtual void CloseMorkNode(morkEnv* ev) override; // CloseZone() only if open + virtual ~morkZone(); // assert that CloseMap() executed earlier + +public: // morkMap construction & destruction + morkZone(morkEnv* ev, const morkUsage& inUsage, nsIMdbHeap* ioNodeHeap, + nsIMdbHeap* ioZoneHeap); + + void CloseZone(morkEnv* ev); // called by CloseMorkNode() + +public: // dynamic type identification + mork_bool IsZone() const + { return IsNode() && mNode_Derived == morkDerived_kZone; } +// } ===== end morkNode methods ===== + +// { ===== begin morkZone methods ===== +public: // chips do not know how big they are... + void* ZoneNewChip(morkEnv* ev, mdb_size inSize); // alloc + +public: // ...but runs do indeed know how big they are + void* ZoneNewRun(morkEnv* ev, mdb_size inSize); // alloc + void ZoneZapRun(morkEnv* ev, void* ioRunBody); // free + void* ZoneGrowRun(morkEnv* ev, void* ioRunBody, mdb_size inSize); // realloc + +// } ===== end morkZone methods ===== + +public: // typing & errors + static void NonZoneTypeError(morkEnv* ev); + static void NilZoneHeapError(morkEnv* ev); + static void BadZoneTagError(morkEnv* ev); +}; + +//3456789_123456789_123456789_123456789_123456789_123456789_123456789_123456789 + +#endif /* _MORKZONE_ */ |