Postgres95 1.01 Distribution - Virgin SourcesPG95-1_01

1 files changed, 126 insertions, 0 deletions

diff --git a/src/backend/storage/sinvaladt.h b/src/backend/storage/sinvaladt.h
new file mode 100644
index 00000000000..06029978980
--- /dev/null
+++ b/src/backend/storage/sinvaladt.h
@@ -0,0 +1,126 @@
+/*-------------------------------------------------------------------------
+ *
+ * sinvaladt.h--
+ *    POSTGRES shared cache invalidation segment definitions.
+ *
+ *
+ * Copyright (c) 1994, Regents of the University of California
+ *
+ * $Id: sinvaladt.h,v 1.1.1.1 1996/07/09 06:21:53 scrappy Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef SINVALADT_H
+#define SINVALADT_H
+
+#include "postgres.h"	/* XXX */
+
+#include "storage/ipc.h"
+#include "storage/itemptr.h"
+#include "storage/sinval.h"
+ 
+/*
+ * The structure of the shared cache invaidation segment
+ *
+ */
+/*
+A------------- Header info --------------
+    criticalSectionSemaphoreId
+    generalSemaphoreId
+    startEntrySection   (offset a)
+    endEntrySection     (offset a + b)
+    startFreeSpace      (offset relative to B)
+    startEntryChain     (offset relatiev to B)
+    endEntryChain       (offset relative to B)
+    numEntries
+    maxNumEntries
+    procState[MaxBackendId] --> limit
+				resetState (bool)
+a				tag (POSTID)
+B------------- Start entry section -------
+    SISegEntry  --> entryData --> ... (see  SharedInvalidData!)
+                    isfree  (bool)
+                    next  (offset to next entry in chain )
+b     .... (dynamically growing down)
+C----------------End shared segment -------  
+
+*/
+
+/* Parameters (configurable)  *******************************************/
+#define MaxBackendId 32      	    /* maximum number of backends   	*/
+#define MAXNUMMESSAGES 1000 	    /* maximum number of messages in seg*/
+
+
+#define	InvalidOffset	1000000000  /* a invalid offset  (End of chain)	*/
+
+typedef struct ProcState {
+    int 	limit;      	/* the number of read messages	    	*/
+    bool 	resetState; 	/* true, if backend has to reset its state */
+    int		tag;		/* special tag, recieved from the postmaster */
+} ProcState;
+
+
+typedef struct SISeg {
+    IpcSemaphoreId  	criticalSectionSemaphoreId; /* semaphore id     */
+    IpcSemaphoreId  	generalSemaphoreId; 	    /* semaphore id     */
+    Offset      startEntrySection;  	/* (offset a)	    	    	*/
+    Offset      endEntrySection;    	/* (offset a + b)   	    	*/
+    Offset      startFreeSpace;	    	/* (offset relative to B)   	*/
+    Offset      startEntryChain;    	/* (offset relative to B)   	*/
+    Offset      endEntryChain;          /* (offset relative to B)   	*/
+    int         numEntries;
+    int         maxNumEntries;
+    ProcState   procState[MaxBackendId]; /* reflects the invalidation state */
+    /* here starts the entry section, controlled by offsets */
+} SISeg;
+#define SizeSISeg     sizeof(SISeg)
+
+typedef struct SharedInvalidData {
+    int	    	    	cacheId;    /* XXX */
+    Index   	    	hashIndex;
+    ItemPointerData 	pointerData;
+} SharedInvalidData;
+
+typedef SharedInvalidData   *SharedInvalid;
+
+
+typedef struct SISegEntry {
+    SharedInvalidData	entryData;  	    	    /* the message data */
+    bool                isfree;	    	    	    /* entry free? */
+    Offset  	    	next;	    	    	    /* offset to next entry*/
+} SISegEntry;
+
+#define SizeOfOneSISegEntry   sizeof(SISegEntry)
+    
+typedef struct SISegOffsets {
+    Offset  startSegment;   	    	/* always 0 (for now) */
+    Offset  offsetToFirstEntry;         /* A + a = B */
+    Offset  offsetToEndOfSegemnt;       /* A + a + b */
+} SISegOffsets;
+
+
+/****************************************************************************/
+/* synchronization of the shared buffer access	    	    	    	    */
+/*    access to the buffer is synchronized by the lock manager !!   	    */
+/****************************************************************************/
+
+#define SI_LockStartValue  255
+#define SI_SharedLock     (-1)
+#define SI_ExclusiveLock  (-255)
+
+extern SISeg *shmInvalBuffer;	
+
+/*
+ * prototypes for functions in sinvaladt.c
+ */
+extern int SIBackendInit(SISeg *segInOutP);
+extern int SISegmentInit(bool killExistingSegment, IPCKey key);
+
+extern bool SISetDataEntry(SISeg *segP, SharedInvalidData  *data);
+extern void SISetProcStateInvalid(SISeg *segP);
+extern bool SIDelDataEntry(SISeg *segP);
+extern void SIReadEntryData(SISeg *segP, int backendId,
+		void (*invalFunction)(), void (*resetFunction)());
+extern void SIDelExpiredDataEntries(SISeg *segP);
+
+#endif	/* SINVALADT_H */