diff options
Diffstat (limited to 'src/backend/storage/buffer/buf_init.c')
| -rw-r--r-- | src/backend/storage/buffer/buf_init.c | 91 |
1 files changed, 30 insertions, 61 deletions
diff --git a/src/backend/storage/buffer/buf_init.c b/src/backend/storage/buffer/buf_init.c index a671bf9f7ff..e0aa0e93e86 100644 --- a/src/backend/storage/buffer/buf_init.c +++ b/src/backend/storage/buffer/buf_init.c @@ -8,35 +8,15 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/storage/buffer/buf_init.c,v 1.62 2004/02/12 15:06:56 wieck Exp $ + * $PostgreSQL: pgsql/src/backend/storage/buffer/buf_init.c,v 1.63 2004/04/19 23:27:17 tgl Exp $ * *------------------------------------------------------------------------- */ #include "postgres.h" -#include <sys/file.h> -#include <math.h> -#include <signal.h> - -#include "catalog/catalog.h" -#include "executor/execdebug.h" -#include "miscadmin.h" -#include "storage/buf.h" -#include "storage/buf_internals.h" #include "storage/bufmgr.h" -#include "storage/fd.h" -#include "storage/ipc.h" -#include "storage/lmgr.h" -#include "storage/shmem.h" -#include "storage/smgr.h" -#include "storage/lwlock.h" -#include "utils/builtins.h" -#include "utils/hsearch.h" -#include "utils/memutils.h" - -int ShowPinTrace = 0; +#include "storage/buf_internals.h" -int Data_Descriptors; BufferDesc *BufferDescriptors; Block *BufferBlockPointers; @@ -44,6 +24,14 @@ Block *BufferBlockPointers; long *PrivateRefCount; /* also used in freelist.c */ bits8 *BufferLocks; /* flag bits showing locks I have set */ +/* statistics counters */ +long int ReadBufferCount; +long int ReadLocalBufferCount; +long int BufferHitCount; +long int LocalBufferHitCount; +long int BufferFlushCount; +long int LocalBufferFlushCount; + /* * Data Structures: @@ -61,48 +49,35 @@ bits8 *BufferLocks; /* flag bits showing locks I have set */ * see freelist.c. A buffer cannot be replaced while in * use either by data manager or during IO. * - * WriteBufferBack: - * currently, a buffer is only written back at the time - * it is selected for replacement. It should - * be done sooner if possible to reduce latency of - * BufferAlloc(). Maybe there should be a daemon process. * * Synchronization/Locking: * * BufMgrLock lock -- must be acquired before manipulating the - * buffer queues (lookup/freelist). Must be released + * buffer search datastructures (lookup/freelist, as well as the + * flag bits of any buffer). Must be released * before exit and before doing any IO. * * IO_IN_PROGRESS -- this is a flag in the buffer descriptor. * It must be set when an IO is initiated and cleared at - * the end of the IO. It is there to make sure that one + * the end of the IO. It is there to make sure that one * process doesn't start to use a buffer while another is * faulting it in. see IOWait/IOSignal. * - * refcount -- A buffer is pinned during IO and immediately - * after a BufferAlloc(). A buffer is always either pinned - * or on the freelist but never both. The buffer must be - * released, written, or flushed before the end of - * transaction. + * refcount -- Counts the number of processes holding pins on a buffer. + * A buffer is pinned during IO and immediately after a BufferAlloc(). + * Pins must be released before end of transaction. * - * PrivateRefCount -- Each buffer also has a private refcount the keeps + * PrivateRefCount -- Each buffer also has a private refcount that keeps * track of the number of times the buffer is pinned in the current - * processes. This is used for two purposes, first, if we pin a + * process. This is used for two purposes: first, if we pin a * a buffer more than once, we only need to change the shared refcount - * once, thus only lock the buffer pool once, second, when a transaction + * once, thus only lock the shared state once; second, when a transaction * aborts, it should only unpin the buffers exactly the number of times it * has pinned them, so that it will not blow away buffers of another * backend. * */ -long int ReadBufferCount; -long int ReadLocalBufferCount; -long int BufferHitCount; -long int LocalBufferHitCount; -long int BufferFlushCount; -long int LocalBufferFlushCount; - /* * Initialize shared buffer pool @@ -118,8 +93,6 @@ InitBufferPool(void) foundDescs; int i; - Data_Descriptors = NBuffers; - /* * It's probably not really necessary to grab the lock --- if there's * anyone else attached to the shmem at this point, we've got @@ -131,7 +104,7 @@ InitBufferPool(void) BufferDescriptors = (BufferDesc *) ShmemInitStruct("Buffer Descriptors", - Data_Descriptors * sizeof(BufferDesc), &foundDescs); + NBuffers * sizeof(BufferDesc), &foundDescs); BufferBlocks = (char *) ShmemInitStruct("Buffer Blocks", @@ -152,9 +125,9 @@ InitBufferPool(void) /* * link the buffers into a single linked list. This will become the - * LiFo list of unused buffers returned by StragegyGetBuffer(). + * LIFO list of unused buffers returned by StrategyGetBuffer(). */ - for (i = 0; i < Data_Descriptors; block += BLCKSZ, buf++, i++) + for (i = 0; i < NBuffers; block += BLCKSZ, buf++, i++) { Assert(ShmemIsValid((unsigned long) block)); @@ -173,7 +146,7 @@ InitBufferPool(void) } /* Correct last entry */ - BufferDescriptors[Data_Descriptors - 1].bufNext = -1; + BufferDescriptors[NBuffers - 1].bufNext = -1; } /* Init other shared buffer-management stuff */ @@ -215,35 +188,31 @@ InitBufferPoolAccess(void) BufferBlockPointers[i] = (Block) MAKE_PTR(BufferDescriptors[i].data); } -/* ----------------------------------------------------- +/* * BufferShmemSize * * compute the size of shared memory for the buffer pool including * data pages, buffer descriptors, hash tables, etc. - * ---------------------------------------------------- */ int BufferShmemSize(void) { int size = 0; - /* size of shmem index hash table */ - size += hash_estimate_size(SHMEM_INDEX_SIZE, sizeof(ShmemIndexEnt)); - /* size of buffer descriptors */ size += MAXALIGN(NBuffers * sizeof(BufferDesc)); - /* size of the shared replacement strategy control block */ - size += MAXALIGN(sizeof(BufferStrategyControl)); - - /* size of the ARC directory blocks */ - size += MAXALIGN(NBuffers * 2 * sizeof(BufferStrategyCDB)); - /* size of data pages */ size += NBuffers * MAXALIGN(BLCKSZ); /* size of buffer hash table */ size += hash_estimate_size(NBuffers * 2, sizeof(BufferLookupEnt)); + /* size of the shared replacement strategy control block */ + size += MAXALIGN(sizeof(BufferStrategyControl)); + + /* size of the ARC directory blocks */ + size += MAXALIGN(NBuffers * 2 * sizeof(BufferStrategyCDB)); + return size; } |