/*
* Initialize shared buffer pool
*
* This is called once during shared-memory initialization (either in the
* postmaster, or in a standalone backend).
*/
void
InitBufferPool(void)
{
bool foundBufs,
foundDescs;
BufferDescriptors = (BufferDesc *)
ShmemInitStruct("Buffer Descriptors",
NBuffers * sizeof(BufferDesc), &foundDescs);
BufferBlocks = (char *)
ShmemInitStruct("Buffer Blocks",
NBuffers * (Size) BLCKSZ, &foundBufs);
if (foundDescs || foundBufs)
{
/* both should be present or neither */
Assert(foundDescs && foundBufs);
/* note: this path is only taken in EXEC_BACKEND case */
}
else
{
BufferDesc *buf;
int i;
buf = BufferDescriptors;
/*
* Initialize all the buffer headers.
*/
for (i = 0; i < NBuffers; buf++, i++)
{
CLEAR_BUFFERTAG(buf->tag);
buf->flags = 0;
buf->usage_count = 0;
buf->refcount = 0;
buf->wait_backend_pid = 0;
SpinLockInit(&buf->buf_hdr_lock);
buf->buf_id = i;
/*
* Initially link all the buffers together as unused. Subsequent
* management of this list is done by freelist.c.
*/
buf->freeNext = i + 1;
buf->io_in_progress_lock = LWLockAssign();
buf->content_lock = LWLockAssign();
}
/* Correct last entry of linked list */
BufferDescriptors[NBuffers - 1].freeNext = FREENEXT_END_OF_LIST;
}
/* Init other shared buffer-management stuff */
StrategyInitialize(!foundDescs);
}
void
InitBufferPool () {
int i;
PrivateRefCount = (long *) malloc(NBuffers * sizeof(long));
// Altered to use regular memory
BufferDescriptors = (BufferDesc *) malloc (NBuffers * sizeof(BufferDesc));
BufferBlocks = (char *) malloc (NBuffers * BLCKSZ);
ShmemBase = BufferBlocks;
// ShmemBase = (unsigned long) BufferBlocks;
if (false)
{
}
else
{
BufferDesc *buf;
buf = BufferDescriptors;
for (i = 0; i < NBuffers; buf++, i++)
{
CLEAR_BUFFERTAG(buf->tag);
buf->flags = 0;
buf->usage_count = 0;
buf->refcount = 0;
buf->wait_backend_pid = 0;
buf->freeNext = i + 1;
buf->buf_id = i;
*((char *) MAKE_PTR(i * BLCKSZ)) = '#';
buf->io_in_progress_lock = LWLockAssign();
buf->content_lock = LWLockAssign();
}
/* close the circular queue */
BufferDescriptors[NBuffers - 1].freeNext = -1;
StrategyInitialize(true);
}
}
/*
* Initialize shared buffer pool
*
* This is called once during shared-memory initialization (either in the
* postmaster, or in a standalone backend).
*/
void
InitBufferPool(void)
{
bool foundBufs,
foundDescs,
foundIOLocks,
foundBufCkpt;
/* Align descriptors to a cacheline boundary. */
BufferDescriptors = (BufferDescPadded *)
ShmemInitStruct("Buffer Descriptors",
NBuffers * sizeof(BufferDescPadded),
&foundDescs);
BufferBlocks = (char *)
ShmemInitStruct("Buffer Blocks",
NBuffers * (Size) BLCKSZ, &foundBufs);
/* Align lwlocks to cacheline boundary */
BufferIOLWLockArray = (LWLockMinimallyPadded *)
ShmemInitStruct("Buffer IO Locks",
NBuffers * (Size) sizeof(LWLockMinimallyPadded),
&foundIOLocks);
LWLockRegisterTranche(LWTRANCHE_BUFFER_IO_IN_PROGRESS, "buffer_io");
LWLockRegisterTranche(LWTRANCHE_BUFFER_CONTENT, "buffer_content");
/*
* The array used to sort to-be-checkpointed buffer ids is located in
* shared memory, to avoid having to allocate significant amounts of
* memory at runtime. As that'd be in the middle of a checkpoint, or when
* the checkpointer is restarted, memory allocation failures would be
* painful.
*/
CkptBufferIds = (CkptSortItem *)
ShmemInitStruct("Checkpoint BufferIds",
NBuffers * sizeof(CkptSortItem), &foundBufCkpt);
if (foundDescs || foundBufs || foundIOLocks || foundBufCkpt)
{
/* should find all of these, or none of them */
Assert(foundDescs && foundBufs && foundIOLocks && foundBufCkpt);
/* note: this path is only taken in EXEC_BACKEND case */
}
else
{
int i;
/*
* Initialize all the buffer headers.
*/
for (i = 0; i < NBuffers; i++)
{
BufferDesc *buf = GetBufferDescriptor(i);
CLEAR_BUFFERTAG(buf->tag);
pg_atomic_init_u32(&buf->state, 0);
buf->wait_backend_pid = 0;
buf->buf_id = i;
/*
* Initially link all the buffers together as unused. Subsequent
* management of this list is done by freelist.c.
*/
buf->freeNext = i + 1;
LWLockInitialize(BufferDescriptorGetContentLock(buf),
LWTRANCHE_BUFFER_CONTENT);
LWLockInitialize(BufferDescriptorGetIOLock(buf),
LWTRANCHE_BUFFER_IO_IN_PROGRESS);
}
/* Correct last entry of linked list */
GetBufferDescriptor(NBuffers - 1)->freeNext = FREENEXT_END_OF_LIST;
}
/* Init other shared buffer-management stuff */
StrategyInitialize(!foundDescs);
/* Initialize per-backend file flush context */
WritebackContextInit(&BackendWritebackContext,
&backend_flush_after);
}
/*
* Initialize shared buffer pool
*
* This is called once during shared-memory initialization (either in the
* postmaster, or in a standalone backend).
*/
void
InitBufferPool(void)
{
bool foundBufs,
foundDescs,
foundIOLocks;
/* Align descriptors to a cacheline boundary. */
BufferDescriptors = (BufferDescPadded *)
CACHELINEALIGN(
ShmemInitStruct("Buffer Descriptors",
NBuffers * sizeof(BufferDescPadded)
+ PG_CACHE_LINE_SIZE,
&foundDescs));
BufferBlocks = (char *)
ShmemInitStruct("Buffer Blocks",
NBuffers * (Size) BLCKSZ, &foundBufs);
/* Align lwlocks to cacheline boundary */
BufferIOLWLockArray = (LWLockMinimallyPadded *)
CACHELINEALIGN(ShmemInitStruct("Buffer IO Locks",
NBuffers * (Size) sizeof(LWLockMinimallyPadded)
+ PG_CACHE_LINE_SIZE,
&foundIOLocks));
BufferIOLWLockTranche.name = "buffer_io";
BufferIOLWLockTranche.array_base = BufferIOLWLockArray;
BufferIOLWLockTranche.array_stride = sizeof(LWLockMinimallyPadded);
LWLockRegisterTranche(LWTRANCHE_BUFFER_IO_IN_PROGRESS,
&BufferIOLWLockTranche);
BufferContentLWLockTranche.name = "buffer_content";
BufferContentLWLockTranche.array_base =
((char *) BufferDescriptors) + offsetof(BufferDesc, content_lock);
BufferContentLWLockTranche.array_stride = sizeof(BufferDescPadded);
LWLockRegisterTranche(LWTRANCHE_BUFFER_CONTENT,
&BufferContentLWLockTranche);
if (foundDescs || foundBufs || foundIOLocks)
{
/* should find all of these, or none of them */
Assert(foundDescs && foundBufs && foundIOLocks);
/* note: this path is only taken in EXEC_BACKEND case */
}
else
{
int i;
/*
* Initialize all the buffer headers.
*/
for (i = 0; i < NBuffers; i++)
{
BufferDesc *buf = GetBufferDescriptor(i);
CLEAR_BUFFERTAG(buf->tag);
buf->flags = 0;
buf->usage_count = 0;
buf->refcount = 0;
buf->wait_backend_pid = 0;
SpinLockInit(&buf->buf_hdr_lock);
buf->buf_id = i;
/*
* Initially link all the buffers together as unused. Subsequent
* management of this list is done by freelist.c.
*/
buf->freeNext = i + 1;
LWLockInitialize(BufferDescriptorGetContentLock(buf),
LWTRANCHE_BUFFER_CONTENT);
LWLockInitialize(BufferDescriptorGetIOLock(buf),
LWTRANCHE_BUFFER_IO_IN_PROGRESS);
}
/* Correct last entry of linked list */
GetBufferDescriptor(NBuffers - 1)->freeNext = FREENEXT_END_OF_LIST;
}
/* Init other shared buffer-management stuff */
StrategyInitialize(!foundDescs);
}
/*
* Initialize shared buffer pool
*
* This is called once during shared-memory initialization (either in the
* postmaster, or in a standalone backend).
*/
void
InitBufferPool(void)
{
char *BufferBlocks;
bool foundBufs,
foundDescs;
int i;
BufferDescriptors = (BufferDesc *)
ShmemInitStruct("Buffer Descriptors",
NBuffers * sizeof(BufferDesc), &foundDescs);
BufferBlocks = (char *)
ShmemInitStruct("Buffer Blocks",
NBuffers * BLCKSZ, &foundBufs);
if (foundDescs || foundBufs)
{
/* both should be present or neither */
Assert(foundDescs && foundBufs);
}
else
{
BufferDesc *buf;
char *block;
/*
* 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 problems.
*/
LWLockAcquire(BufMgrLock, LW_EXCLUSIVE);
buf = BufferDescriptors;
block = BufferBlocks;
/*
* Initialize all the buffer headers.
*/
for (i = 0; i < NBuffers; block += BLCKSZ, buf++, i++)
{
Assert(ShmemIsValid((unsigned long) block));
/*
* The bufNext fields link together all totally-unused buffers.
* Subsequent management of this list is done by
* StrategyGetBuffer().
*/
buf->bufNext = i + 1;
CLEAR_BUFFERTAG(buf->tag);
buf->buf_id = i;
buf->data = MAKE_OFFSET(block);
buf->flags = 0;
buf->refcount = 0;
buf->io_in_progress_lock = LWLockAssign();
buf->cntx_lock = LWLockAssign();
buf->cntxDirty = false;
buf->wait_backend_id = 0;
}
/* Correct last entry of linked list */
BufferDescriptors[NBuffers - 1].bufNext = -1;
LWLockRelease(BufMgrLock);
}
/* Init other shared buffer-management stuff */
StrategyInitialize(!foundDescs);
}
