mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-08-29 22:27:19 +02:00
Because of gcc -Wmissing-prototypes, all functions in dynamically loadable modules must have a separate prototype declaration. This is meant to detect global functions that are not declared in header files, but in cases where the function is called via dfmgr, this is redundant. Besides filling up space with boilerplate, this is a frequent source of compiler warnings in extension modules. We can fix that by creating the function prototype as part of the PG_FUNCTION_INFO_V1 macro, which such modules have to use anyway. That makes the code of modules cleaner, because there is one less place where the entry points have to be listed, and creates an additional check that functions have the right prototype. Remove now redundant prototypes from contrib and other modules.
217 lines
6.2 KiB
C
217 lines
6.2 KiB
C
/*-------------------------------------------------------------------------
|
|
*
|
|
* pg_buffercache_pages.c
|
|
* display some contents of the buffer cache
|
|
*
|
|
* contrib/pg_buffercache/pg_buffercache_pages.c
|
|
*-------------------------------------------------------------------------
|
|
*/
|
|
#include "postgres.h"
|
|
|
|
#include "access/htup_details.h"
|
|
#include "catalog/pg_type.h"
|
|
#include "funcapi.h"
|
|
#include "storage/buf_internals.h"
|
|
#include "storage/bufmgr.h"
|
|
|
|
|
|
#define NUM_BUFFERCACHE_PAGES_ELEM 8
|
|
|
|
PG_MODULE_MAGIC;
|
|
|
|
|
|
/*
|
|
* Record structure holding the to be exposed cache data.
|
|
*/
|
|
typedef struct
|
|
{
|
|
uint32 bufferid;
|
|
Oid relfilenode;
|
|
Oid reltablespace;
|
|
Oid reldatabase;
|
|
ForkNumber forknum;
|
|
BlockNumber blocknum;
|
|
bool isvalid;
|
|
bool isdirty;
|
|
uint16 usagecount;
|
|
} BufferCachePagesRec;
|
|
|
|
|
|
/*
|
|
* Function context for data persisting over repeated calls.
|
|
*/
|
|
typedef struct
|
|
{
|
|
TupleDesc tupdesc;
|
|
BufferCachePagesRec *record;
|
|
} BufferCachePagesContext;
|
|
|
|
|
|
/*
|
|
* Function returning data from the shared buffer cache - buffer number,
|
|
* relation node/tablespace/database/blocknum and dirty indicator.
|
|
*/
|
|
PG_FUNCTION_INFO_V1(pg_buffercache_pages);
|
|
|
|
Datum
|
|
pg_buffercache_pages(PG_FUNCTION_ARGS)
|
|
{
|
|
FuncCallContext *funcctx;
|
|
Datum result;
|
|
MemoryContext oldcontext;
|
|
BufferCachePagesContext *fctx; /* User function context. */
|
|
TupleDesc tupledesc;
|
|
HeapTuple tuple;
|
|
|
|
if (SRF_IS_FIRSTCALL())
|
|
{
|
|
int i;
|
|
volatile BufferDesc *bufHdr;
|
|
|
|
funcctx = SRF_FIRSTCALL_INIT();
|
|
|
|
/* Switch context when allocating stuff to be used in later calls */
|
|
oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
|
|
|
|
/* Create a user function context for cross-call persistence */
|
|
fctx = (BufferCachePagesContext *) palloc(sizeof(BufferCachePagesContext));
|
|
|
|
/* Construct a tuple descriptor for the result rows. */
|
|
tupledesc = CreateTemplateTupleDesc(NUM_BUFFERCACHE_PAGES_ELEM, false);
|
|
TupleDescInitEntry(tupledesc, (AttrNumber) 1, "bufferid",
|
|
INT4OID, -1, 0);
|
|
TupleDescInitEntry(tupledesc, (AttrNumber) 2, "relfilenode",
|
|
OIDOID, -1, 0);
|
|
TupleDescInitEntry(tupledesc, (AttrNumber) 3, "reltablespace",
|
|
OIDOID, -1, 0);
|
|
TupleDescInitEntry(tupledesc, (AttrNumber) 4, "reldatabase",
|
|
OIDOID, -1, 0);
|
|
TupleDescInitEntry(tupledesc, (AttrNumber) 5, "relforknumber",
|
|
INT2OID, -1, 0);
|
|
TupleDescInitEntry(tupledesc, (AttrNumber) 6, "relblocknumber",
|
|
INT8OID, -1, 0);
|
|
TupleDescInitEntry(tupledesc, (AttrNumber) 7, "isdirty",
|
|
BOOLOID, -1, 0);
|
|
TupleDescInitEntry(tupledesc, (AttrNumber) 8, "usage_count",
|
|
INT2OID, -1, 0);
|
|
|
|
fctx->tupdesc = BlessTupleDesc(tupledesc);
|
|
|
|
/* Allocate NBuffers worth of BufferCachePagesRec records. */
|
|
fctx->record = (BufferCachePagesRec *) palloc(sizeof(BufferCachePagesRec) * NBuffers);
|
|
|
|
/* Set max calls and remember the user function context. */
|
|
funcctx->max_calls = NBuffers;
|
|
funcctx->user_fctx = fctx;
|
|
|
|
/* Return to original context when allocating transient memory */
|
|
MemoryContextSwitchTo(oldcontext);
|
|
|
|
/*
|
|
* To get a consistent picture of the buffer state, we must lock all
|
|
* partitions of the buffer map. Needless to say, this is horrible
|
|
* for concurrency. Must grab locks in increasing order to avoid
|
|
* possible deadlocks.
|
|
*/
|
|
for (i = 0; i < NUM_BUFFER_PARTITIONS; i++)
|
|
LWLockAcquire(BufMappingPartitionLockByIndex(i), LW_SHARED);
|
|
|
|
/*
|
|
* Scan though all the buffers, saving the relevant fields in the
|
|
* fctx->record structure.
|
|
*/
|
|
for (i = 0, bufHdr = BufferDescriptors; i < NBuffers; i++, bufHdr++)
|
|
{
|
|
/* Lock each buffer header before inspecting. */
|
|
LockBufHdr(bufHdr);
|
|
|
|
fctx->record[i].bufferid = BufferDescriptorGetBuffer(bufHdr);
|
|
fctx->record[i].relfilenode = bufHdr->tag.rnode.relNode;
|
|
fctx->record[i].reltablespace = bufHdr->tag.rnode.spcNode;
|
|
fctx->record[i].reldatabase = bufHdr->tag.rnode.dbNode;
|
|
fctx->record[i].forknum = bufHdr->tag.forkNum;
|
|
fctx->record[i].blocknum = bufHdr->tag.blockNum;
|
|
fctx->record[i].usagecount = bufHdr->usage_count;
|
|
|
|
if (bufHdr->flags & BM_DIRTY)
|
|
fctx->record[i].isdirty = true;
|
|
else
|
|
fctx->record[i].isdirty = false;
|
|
|
|
/* Note if the buffer is valid, and has storage created */
|
|
if ((bufHdr->flags & BM_VALID) && (bufHdr->flags & BM_TAG_VALID))
|
|
fctx->record[i].isvalid = true;
|
|
else
|
|
fctx->record[i].isvalid = false;
|
|
|
|
UnlockBufHdr(bufHdr);
|
|
}
|
|
|
|
/*
|
|
* And release locks. We do this in reverse order for two reasons:
|
|
* (1) Anyone else who needs more than one of the locks will be trying
|
|
* to lock them in increasing order; we don't want to release the
|
|
* other process until it can get all the locks it needs. (2) This
|
|
* avoids O(N^2) behavior inside LWLockRelease.
|
|
*/
|
|
for (i = NUM_BUFFER_PARTITIONS; --i >= 0;)
|
|
LWLockRelease(BufMappingPartitionLockByIndex(i));
|
|
}
|
|
|
|
funcctx = SRF_PERCALL_SETUP();
|
|
|
|
/* Get the saved state */
|
|
fctx = funcctx->user_fctx;
|
|
|
|
if (funcctx->call_cntr < funcctx->max_calls)
|
|
{
|
|
uint32 i = funcctx->call_cntr;
|
|
Datum values[NUM_BUFFERCACHE_PAGES_ELEM];
|
|
bool nulls[NUM_BUFFERCACHE_PAGES_ELEM];
|
|
|
|
values[0] = Int32GetDatum(fctx->record[i].bufferid);
|
|
nulls[0] = false;
|
|
|
|
/*
|
|
* Set all fields except the bufferid to null if the buffer is unused
|
|
* or not valid.
|
|
*/
|
|
if (fctx->record[i].blocknum == InvalidBlockNumber ||
|
|
fctx->record[i].isvalid == false)
|
|
{
|
|
nulls[1] = true;
|
|
nulls[2] = true;
|
|
nulls[3] = true;
|
|
nulls[4] = true;
|
|
nulls[5] = true;
|
|
nulls[6] = true;
|
|
nulls[7] = true;
|
|
}
|
|
else
|
|
{
|
|
values[1] = ObjectIdGetDatum(fctx->record[i].relfilenode);
|
|
nulls[1] = false;
|
|
values[2] = ObjectIdGetDatum(fctx->record[i].reltablespace);
|
|
nulls[2] = false;
|
|
values[3] = ObjectIdGetDatum(fctx->record[i].reldatabase);
|
|
nulls[3] = false;
|
|
values[4] = ObjectIdGetDatum(fctx->record[i].forknum);
|
|
nulls[4] = false;
|
|
values[5] = Int64GetDatum((int64) fctx->record[i].blocknum);
|
|
nulls[5] = false;
|
|
values[6] = BoolGetDatum(fctx->record[i].isdirty);
|
|
nulls[6] = false;
|
|
values[7] = Int16GetDatum(fctx->record[i].usagecount);
|
|
nulls[7] = false;
|
|
}
|
|
|
|
/* Build and return the tuple. */
|
|
tuple = heap_form_tuple(fctx->tupdesc, values, nulls);
|
|
result = HeapTupleGetDatum(tuple);
|
|
|
|
SRF_RETURN_NEXT(funcctx, result);
|
|
}
|
|
else
|
|
SRF_RETURN_DONE(funcctx);
|
|
}
|