/*------------------------------------------------------------------------- * * buf_internals.h-- * Internal definitions. * * * Copyright (c) 1994, Regents of the University of California * * buf_internals.h,v 1.7 1995/06/14 00:16:30 jolly Exp * * NOTE * If BUFFERPAGE0 is defined, then 0 will be used as a * valid buffer page number. * *------------------------------------------------------------------------- */ #ifndef BUFMGR_INTERNALS_H #define BUFMGR_INTERNALS_H #include "postgres.h" #include "storage/buf.h" #include "storage/ipc.h" #include "storage/shmem.h" #include "miscadmin.h" #include "storage/lmgr.h" #include "utils/rel.h" #include "utils/relcache.h" /* Buf Mgr constants */ /* in bufmgr.c */ extern int NBuffers; extern int Data_Descriptors; extern int Free_List_Descriptor; extern int Lookup_List_Descriptor; extern int Num_Descriptors; /* * Flags for buffer descriptors */ #define BM_DIRTY (1 << 0) #define BM_PRIVATE (1 << 1) #define BM_VALID (1 << 2) #define BM_DELETED (1 << 3) #define BM_FREE (1 << 4) #define BM_IO_IN_PROGRESS (1 << 5) #define BM_IO_ERROR (1 << 6) typedef bits16 BufFlags; typedef struct sbufdesc BufferDesc; typedef struct sbufdesc BufferHdr; typedef struct buftag BufferTag; /* long * so alignment will be correct */ typedef long **BufferBlock; struct buftag{ LRelId relId; BlockNumber blockNum; /* blknum relative to begin of reln */ }; #define CLEAR_BUFFERTAG(a)\ (a)->relId.dbId = InvalidOid; \ (a)->relId.relId = InvalidOid; \ (a)->blockNum = InvalidBlockNumber #define INIT_BUFFERTAG(a,xx_reln,xx_blockNum) \ { \ (a)->blockNum = xx_blockNum;\ (a)->relId = RelationGetLRelId(xx_reln); \ } #define COPY_BUFFERTAG(a,b)\ { \ (a)->blockNum = (b)->blockNum;\ LRelIdAssign(*(a),*(b));\ } #define EQUAL_BUFFERTAG(a,b) \ (((a)->blockNum == (b)->blockNum) &&\ (OID_Equal((a)->relId.relId,(b)->relId.relId))) #define BAD_BUFFER_ID(bid) ((bid<1) || (bid>(NBuffers))) #define INVALID_DESCRIPTOR (-3) /* * bletch hack -- anyplace that we declare space for relation or * database names, we just use '16', not a symbolic constant, to * specify their lengths. BM_NAMESIZE is the length of these names, * and is used in the buffer manager code. somebody with lots of * spare time should do this for all the other modules, too. */ #define BM_NAMESIZE 16 /* * struct sbufdesc -- shared buffer cache metadata for a single * shared buffer descriptor. * * We keep the name of the database and relation in which this * buffer appears in order to avoid a catalog lookup on cache * flush if we don't have the reldesc in the cache. It is also * possible that the relation to which this buffer belongs is * not visible to all backends at the time that it gets flushed. * Dbname, relname, dbid, and relid are enough to determine where * to put the buffer, for all storage managers. */ struct sbufdesc { Buffer freeNext; /* link for freelist chain */ Buffer freePrev; SHMEM_OFFSET data; /* pointer to data in buf pool */ /* tag and id must be together for table lookup to work */ BufferTag tag; /* file/block identifier */ int buf_id; /* maps global desc to local desc */ BufFlags flags; /* described below */ int16 bufsmgr; /* storage manager id for buffer */ unsigned refcount; /* # of times buffer is pinned */ char16 sb_dbname; /* name of db in which buf belongs */ char16 sb_relname; /* name of reln */ #ifdef HAS_TEST_AND_SET /* can afford a dedicated lock if test-and-set locks are available */ slock_t io_in_progress_lock; #endif /* HAS_TEST_AND_SET */ /* * I padded this structure to a power of 2 (128 bytes on a MIPS) because * BufferDescriptorGetBuffer is called a billion times and it does an * C pointer subtraction (i.e., "x - y" -> array index of x relative * to y, which is calculated using division by struct size). Integer * ".div" hits you for 35 cycles, as opposed to a 1-cycle "sra" ... * this hack cut 10% off of the time to create the Wisconsin database! * It eats up more shared memory, of course, but we're (allegedly) * going to make some of these types bigger soon anyway... -pma 1/2/93 */ #if defined(PORTNAME_ultrix4) char sb_pad[60]; /* no slock_t */ #endif /* mips */ #if defined(PORTNAME_sparc) || defined(PORTNAME_sparc_solaris) char sb_pad[56]; /* has slock_t */ #endif /* sparc */ #if defined(PORTNAME_hpux) char sb_pad[44]; /* has slock_t */ #endif /* alpha */ #if defined(PORTNAME_alpha) char sb_pad[40]; /* has slock_t */ #endif /* alpha */ }; /* * mao tracing buffer allocation */ /*#define BMTRACE*/ #ifdef BMTRACE typedef struct _bmtrace { int bmt_pid; long bmt_buf; long bmt_dbid; long bmt_relid; int bmt_blkno; int bmt_op; #define BMT_NOTUSED 0 #define BMT_ALLOCFND 1 #define BMT_ALLOCNOTFND 2 #define BMT_DEALLOC 3 } bmtrace; #endif /* BMTRACE */ /* * Bufmgr Interface: */ /* Internal routines: only called by buf.c */ /*freelist.c*/ extern void AddBufferToFreelist(BufferDesc *bf); extern void PinBuffer(BufferDesc *buf); extern void PinBuffer_Debug(String file, int line, BufferDesc *buf); extern void UnpinBuffer(BufferDesc *buf); extern void UnpinBuffer_Debug(String file, int line, BufferDesc *buf); extern BufferDesc *GetFreeBuffer(void); extern void InitFreeList(bool init); extern void DBG_FreeListCheck(int nfree); /* buf_table.c */ extern void InitBufTable(void); extern BufferDesc *BufTableLookup(BufferTag *tagPtr); extern bool BufTableDelete(BufferDesc *buf); extern bool BufTableInsert(BufferDesc *buf); extern void DBG_LookupListCheck(int nlookup); /* bufmgr.c */ extern BufferDesc *BufferDescriptors; extern BufferBlock BufferBlocks; extern long *PrivateRefCount; extern long *LastRefCount; extern SPINLOCK BufMgrLock; /* localbuf.c */ extern long *LocalRefCount; extern BufferDesc *LocalBufferDescriptors; extern int NLocBuffer; extern BufferDesc *LocalBufferAlloc(Relation reln, BlockNumber blockNum, bool *foundPtr); extern int WriteLocalBuffer(Buffer buffer, bool release); extern int FlushLocalBuffer(Buffer buffer); extern void InitLocalBuffer(); extern void LocalBufferSync(); #endif /* BUFMGR_INTERNALS_H */