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Relax the requirement that all lwlocks be stored in a single array.

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This makes it possible to store lwlocks as part of some other data
structure in the main shared memory segment, or in a dynamic shared
memory segment.  There is still a main LWLock array and this patch does
not move anything out of it, but it provides necessary infrastructure
for doing that in the future.

This change is likely to increase the size of LWLockPadded on some
platforms, especially 32-bit platforms where it was previously only
16 bytes.

Patch by me.  Review by Andres Freund and KaiGai Kohei.
This commit is contained in:
Robert Haas
2014-01-27 11:07:44 -05:00
parent f62eba204f
commit ea9df812d8
18 changed files with 523 additions and 317 deletions
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34
src/backend/storage/lmgr/lock.c
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@@ -565,7 +565,7 @@ LockHasWaiters(const LOCKTAG *locktag, LOCKMODE lockmode, bool sessionLock)
LOCALLOCK *locallock;
LOCK *lock;
PROCLOCK *proclock;
LWLockId partitionLock;
LWLock *partitionLock;
bool hasWaiters = false;
if (lockmethodid <= 0 || lockmethodid >= lengthof(LockMethods))
@@ -702,7 +702,7 @@ LockAcquireExtended(const LOCKTAG *locktag,
bool found;
ResourceOwner owner;
uint32 hashcode;
LWLockId partitionLock;
LWLock *partitionLock;
int status;
bool log_lock = false;
@@ -1744,7 +1744,7 @@ LockRelease(const LOCKTAG *locktag, LOCKMODE lockmode, bool sessionLock)
LOCALLOCK *locallock;
LOCK *lock;
PROCLOCK *proclock;
LWLockId partitionLock;
LWLock *partitionLock;
bool wakeupNeeded;
if (lockmethodid <= 0 || lockmethodid >= lengthof(LockMethods))
@@ -2096,10 +2096,12 @@ LockReleaseAll(LOCKMETHODID lockmethodid, bool allLocks)
*/
for (partition = 0; partition < NUM_LOCK_PARTITIONS; partition++)
{
LWLockId partitionLock = FirstLockMgrLock + partition;
LWLock *partitionLock;
SHM_QUEUE *procLocks = &(MyProc->myProcLocks[partition]);
PROCLOCK *nextplock;
partitionLock = LockHashPartitionLockByIndex(partition);
/*
* If the proclock list for this partition is empty, we can skip
* acquiring the partition lock. This optimization is trickier than
@@ -2475,7 +2477,7 @@ static bool
FastPathTransferRelationLocks(LockMethod lockMethodTable, const LOCKTAG *locktag,
uint32 hashcode)
{
LWLockId partitionLock = LockHashPartitionLock(hashcode);
LWLock *partitionLock = LockHashPartitionLock(hashcode);
Oid relid = locktag->locktag_field2;
uint32 i;
@@ -2565,7 +2567,7 @@ FastPathGetRelationLockEntry(LOCALLOCK *locallock)
LockMethod lockMethodTable = LockMethods[DEFAULT_LOCKMETHOD];
LOCKTAG *locktag = &locallock->tag.lock;
PROCLOCK *proclock = NULL;
LWLockId partitionLock = LockHashPartitionLock(locallock->hashcode);
LWLock *partitionLock = LockHashPartitionLock(locallock->hashcode);
Oid relid = locktag->locktag_field2;
uint32 f;
@@ -2671,7 +2673,7 @@ GetLockConflicts(const LOCKTAG *locktag, LOCKMODE lockmode)
SHM_QUEUE *procLocks;
PROCLOCK *proclock;
uint32 hashcode;
LWLockId partitionLock;
LWLock *partitionLock;
int count = 0;
int fast_count = 0;
@@ -2883,7 +2885,7 @@ LockRefindAndRelease(LockMethod lockMethodTable, PGPROC *proc,
PROCLOCKTAG proclocktag;
uint32 hashcode;
uint32 proclock_hashcode;
LWLockId partitionLock;
LWLock *partitionLock;
bool wakeupNeeded;
hashcode = LockTagHashCode(locktag);
@@ -3159,10 +3161,12 @@ PostPrepare_Locks(TransactionId xid)
*/
for (partition = 0; partition < NUM_LOCK_PARTITIONS; partition++)
{
LWLockId partitionLock = FirstLockMgrLock + partition;
LWLock *partitionLock;
SHM_QUEUE *procLocks = &(MyProc->myProcLocks[partition]);
PROCLOCK *nextplock;
partitionLock = LockHashPartitionLockByIndex(partition);
/*
* If the proclock list for this partition is empty, we can skip
* acquiring the partition lock. This optimization is safer than the
@@ -3400,7 +3404,7 @@ GetLockStatusData(void)
* Must grab LWLocks in partition-number order to avoid LWLock deadlock.
*/
for (i = 0; i < NUM_LOCK_PARTITIONS; i++)
LWLockAcquire(FirstLockMgrLock + i, LW_SHARED);
LWLockAcquire(LockHashPartitionLockByIndex(i), LW_SHARED);
/* Now we can safely count the number of proclocks */
data->nelements = el + hash_get_num_entries(LockMethodProcLockHash);
@@ -3442,7 +3446,7 @@ GetLockStatusData(void)
* behavior inside LWLockRelease.
*/
for (i = NUM_LOCK_PARTITIONS; --i >= 0;)
LWLockRelease(FirstLockMgrLock + i);
LWLockRelease(LockHashPartitionLockByIndex(i));
Assert(el == data->nelements);
@@ -3477,7 +3481,7 @@ GetRunningTransactionLocks(int *nlocks)
* Must grab LWLocks in partition-number order to avoid LWLock deadlock.
*/
for (i = 0; i < NUM_LOCK_PARTITIONS; i++)
LWLockAcquire(FirstLockMgrLock + i, LW_SHARED);
LWLockAcquire(LockHashPartitionLockByIndex(i), LW_SHARED);
/* Now we can safely count the number of proclocks */
els = hash_get_num_entries(LockMethodProcLockHash);
@@ -3537,7 +3541,7 @@ GetRunningTransactionLocks(int *nlocks)
* behavior inside LWLockRelease.
*/
for (i = NUM_LOCK_PARTITIONS; --i >= 0;)
LWLockRelease(FirstLockMgrLock + i);
LWLockRelease(LockHashPartitionLockByIndex(i));
*nlocks = index;
return accessExclusiveLocks;
@@ -3673,7 +3677,7 @@ lock_twophase_recover(TransactionId xid, uint16 info,
uint32 hashcode;
uint32 proclock_hashcode;
int partition;
LWLockId partitionLock;
LWLock *partitionLock;
LockMethod lockMethodTable;
Assert(len == sizeof(TwoPhaseLockRecord));
@@ -4044,7 +4048,7 @@ VirtualXactLock(VirtualTransactionId vxid, bool wait)
{
PROCLOCK *proclock;
uint32 hashcode;
LWLockId partitionLock;
LWLock *partitionLock;
hashcode = LockTagHashCode(&tag);