Migrate PGPROC's backendLock into PGPROC itself, using a new tranche.

Previously, each PGPROC's backendLock was part of the main tranche,
and the PGPROC just contained a pointer.  Now, the actual LWLock is
part of the PGPROC.

As with previous, similar patches, this makes it significantly easier
to identify these lwlocks in LWLOCK_STATS or Trace_lwlocks output
and improves modularity.

Author: Ildus Kurbangaliev
Reviewed-by: Amit Kapila, Robert Haas

diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c
index bd0c96124e3c77711365333316ce18f397875d6a..6ded0f0f1267d316d0c79ae9b093344cf8c6b548 100644 (file)
--- a/src/backend/storage/ipc/procarray.c
+++ b/src/backend/storage/ipc/procarray.c
@@ -106,6 +106,9 @@ static TransactionId *KnownAssignedXids;
 static bool *KnownAssignedXidsValid;
 static TransactionId latestObservedXid = InvalidTransactionId;
 
+/* LWLock tranche for backend locks */
+static LWLockTranche ProcLWLockTranche;
+
 /*
  * If we're in STANDBY_SNAPSHOT_PENDING state, standbySnapshotPendingXmin is
  * the highest xid that might still be running that we don't have in
@@ -261,6 +264,13 @@ CreateSharedProcArray(void)
                            mul_size(sizeof(bool), TOTAL_MAX_CACHED_SUBXIDS),
                            &found);
    }
+
+   /* Register and initialize fields of ProcLWLockTranche */
+   ProcLWLockTranche.name = "proc";
+   ProcLWLockTranche.array_base = (char *) (ProcGlobal->allProcs) +
+       offsetof(PGPROC, backendLock);
+   ProcLWLockTranche.array_stride = sizeof(PGPROC);
+   LWLockRegisterTranche(LWTRANCHE_PROC, &ProcLWLockTranche);
 }
 
 /*

diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c
index 9c2e49cc84912b69cf9dcab2a5d20001556dce58..269fe14301989b28b9ff70811db45941521b0969 100644 (file)
--- a/src/backend/storage/lmgr/lock.c
+++ b/src/backend/storage/lmgr/lock.c
@@ -825,13 +825,13 @@ LockAcquireExtended(const LOCKTAG *locktag,
         * FastPathStrongRelationLocks->counts becomes visible after we test
         * it has yet to begin to transfer fast-path locks.
         */
-       LWLockAcquire(MyProc->backendLock, LW_EXCLUSIVE);
+       LWLockAcquire(&MyProc->backendLock, LW_EXCLUSIVE);
        if (FastPathStrongRelationLocks->count[fasthashcode] != 0)
            acquired = false;
        else
            acquired = FastPathGrantRelationLock(locktag->locktag_field2,
                                                 lockmode);
-       LWLockRelease(MyProc->backendLock);
+       LWLockRelease(&MyProc->backendLock);
        if (acquired)
        {
            /*
@@ -1838,10 +1838,10 @@ LockRelease(const LOCKTAG *locktag, LOCKMODE lockmode, bool sessionLock)
         * We might not find the lock here, even if we originally entered it
         * here.  Another backend may have moved it to the main table.
         */
-       LWLockAcquire(MyProc->backendLock, LW_EXCLUSIVE);
+       LWLockAcquire(&MyProc->backendLock, LW_EXCLUSIVE);
        released = FastPathUnGrantRelationLock(locktag->locktag_field2,
                                               lockmode);
-       LWLockRelease(MyProc->backendLock);
+       LWLockRelease(&MyProc->backendLock);
        if (released)
        {
            RemoveLocalLock(locallock);
@@ -2044,7 +2044,7 @@ LockReleaseAll(LOCKMETHODID lockmethodid, bool allLocks)
             */
            if (!have_fast_path_lwlock)
            {
-               LWLockAcquire(MyProc->backendLock, LW_EXCLUSIVE);
+               LWLockAcquire(&MyProc->backendLock, LW_EXCLUSIVE);
                have_fast_path_lwlock = true;
            }
 
@@ -2061,7 +2061,7 @@ LockReleaseAll(LOCKMETHODID lockmethodid, bool allLocks)
             * transferred to the main lock table.  That's going to require
             * some extra work, so release our fast-path lock before starting.
             */
-           LWLockRelease(MyProc->backendLock);
+           LWLockRelease(&MyProc->backendLock);
            have_fast_path_lwlock = false;
 
            /*
@@ -2087,7 +2087,7 @@ LockReleaseAll(LOCKMETHODID lockmethodid, bool allLocks)
 
    /* Done with the fast-path data structures */
    if (have_fast_path_lwlock)
-       LWLockRelease(MyProc->backendLock);
+       LWLockRelease(&MyProc->backendLock);
 
    /*
     * Now, scan each lock partition separately.
@@ -2490,7 +2490,7 @@ FastPathTransferRelationLocks(LockMethod lockMethodTable, const LOCKTAG *locktag
        PGPROC     *proc = &ProcGlobal->allProcs[i];
        uint32      f;
 
-       LWLockAcquire(proc->backendLock, LW_EXCLUSIVE);
+       LWLockAcquire(&proc->backendLock, LW_EXCLUSIVE);
 
        /*
         * If the target backend isn't referencing the same database as the
@@ -2499,7 +2499,7 @@ FastPathTransferRelationLocks(LockMethod lockMethodTable, const LOCKTAG *locktag
         *
         * proc->databaseId is set at backend startup time and never changes
         * thereafter, so it might be safe to perform this test before
-        * acquiring proc->backendLock.  In particular, it's certainly safe to
+        * acquiring &proc->backendLock.  In particular, it's certainly safe to
         * assume that if the target backend holds any fast-path locks, it
         * must have performed a memory-fencing operation (in particular, an
         * LWLock acquisition) since setting proc->databaseId.  However, it's
@@ -2509,7 +2509,7 @@ FastPathTransferRelationLocks(LockMethod lockMethodTable, const LOCKTAG *locktag
         */
        if (proc->databaseId != locktag->locktag_field1)
        {
-           LWLockRelease(proc->backendLock);
+           LWLockRelease(&proc->backendLock);
            continue;
        }
 
@@ -2536,7 +2536,7 @@ FastPathTransferRelationLocks(LockMethod lockMethodTable, const LOCKTAG *locktag
                if (!proclock)
                {
                    LWLockRelease(partitionLock);
-                   LWLockRelease(proc->backendLock);
+                   LWLockRelease(&proc->backendLock);
                    return false;
                }
                GrantLock(proclock->tag.myLock, proclock, lockmode);
@@ -2547,7 +2547,7 @@ FastPathTransferRelationLocks(LockMethod lockMethodTable, const LOCKTAG *locktag
            /* No need to examine remaining slots. */
            break;
        }
-       LWLockRelease(proc->backendLock);
+       LWLockRelease(&proc->backendLock);
    }
    return true;
 }
@@ -2569,7 +2569,7 @@ FastPathGetRelationLockEntry(LOCALLOCK *locallock)
    Oid         relid = locktag->locktag_field2;
    uint32      f;
 
-   LWLockAcquire(MyProc->backendLock, LW_EXCLUSIVE);
+   LWLockAcquire(&MyProc->backendLock, LW_EXCLUSIVE);
 
    for (f = 0; f < FP_LOCK_SLOTS_PER_BACKEND; f++)
    {
@@ -2592,7 +2592,7 @@ FastPathGetRelationLockEntry(LOCALLOCK *locallock)
        if (!proclock)
        {
            LWLockRelease(partitionLock);
-           LWLockRelease(MyProc->backendLock);
+           LWLockRelease(&MyProc->backendLock);
            ereport(ERROR,
                    (errcode(ERRCODE_OUT_OF_MEMORY),
                     errmsg("out of shared memory"),
@@ -2607,7 +2607,7 @@ FastPathGetRelationLockEntry(LOCALLOCK *locallock)
        break;
    }
 
-   LWLockRelease(MyProc->backendLock);
+   LWLockRelease(&MyProc->backendLock);
 
    /* Lock may have already been transferred by some other backend. */
    if (proclock == NULL)
@@ -2732,7 +2732,7 @@ GetLockConflicts(const LOCKTAG *locktag, LOCKMODE lockmode)
            if (proc == MyProc)
                continue;
 
-           LWLockAcquire(proc->backendLock, LW_SHARED);
+           LWLockAcquire(&proc->backendLock, LW_SHARED);
 
            /*
             * If the target backend isn't referencing the same database as
@@ -2744,7 +2744,7 @@ GetLockConflicts(const LOCKTAG *locktag, LOCKMODE lockmode)
             */
            if (proc->databaseId != locktag->locktag_field1)
            {
-               LWLockRelease(proc->backendLock);
+               LWLockRelease(&proc->backendLock);
                continue;
            }
 
@@ -2782,7 +2782,7 @@ GetLockConflicts(const LOCKTAG *locktag, LOCKMODE lockmode)
                break;
            }
 
-           LWLockRelease(proc->backendLock);
+           LWLockRelease(&proc->backendLock);
        }
    }
 
@@ -3332,7 +3332,7 @@ GetLockStatusData(void)
        PGPROC     *proc = &ProcGlobal->allProcs[i];
        uint32      f;
 
-       LWLockAcquire(proc->backendLock, LW_SHARED);
+       LWLockAcquire(&proc->backendLock, LW_SHARED);
 
        for (f = 0; f < FP_LOCK_SLOTS_PER_BACKEND; ++f)
        {
@@ -3390,7 +3390,7 @@ GetLockStatusData(void)
            el++;
        }
 
-       LWLockRelease(proc->backendLock);
+       LWLockRelease(&proc->backendLock);
    }
 
    /*
@@ -3930,7 +3930,7 @@ VirtualXactLockTableInsert(VirtualTransactionId vxid)
 {
    Assert(VirtualTransactionIdIsValid(vxid));
 
-   LWLockAcquire(MyProc->backendLock, LW_EXCLUSIVE);
+   LWLockAcquire(&MyProc->backendLock, LW_EXCLUSIVE);
 
    Assert(MyProc->backendId == vxid.backendId);
    Assert(MyProc->fpLocalTransactionId == InvalidLocalTransactionId);
@@ -3939,7 +3939,7 @@ VirtualXactLockTableInsert(VirtualTransactionId vxid)
    MyProc->fpVXIDLock = true;
    MyProc->fpLocalTransactionId = vxid.localTransactionId;
 
-   LWLockRelease(MyProc->backendLock);
+   LWLockRelease(&MyProc->backendLock);
 }
 
 /*
@@ -3959,14 +3959,14 @@ VirtualXactLockTableCleanup(void)
    /*
     * Clean up shared memory state.
     */
-   LWLockAcquire(MyProc->backendLock, LW_EXCLUSIVE);
+   LWLockAcquire(&MyProc->backendLock, LW_EXCLUSIVE);
 
    fastpath = MyProc->fpVXIDLock;
    lxid = MyProc->fpLocalTransactionId;
    MyProc->fpVXIDLock = false;
    MyProc->fpLocalTransactionId = InvalidLocalTransactionId;
 
-   LWLockRelease(MyProc->backendLock);
+   LWLockRelease(&MyProc->backendLock);
 
    /*
     * If fpVXIDLock has been cleared without touching fpLocalTransactionId,
@@ -4022,13 +4022,13 @@ VirtualXactLock(VirtualTransactionId vxid, bool wait)
     * against the ones we're waiting for.  The target backend will only set
     * or clear lxid while holding this lock.
     */
-   LWLockAcquire(proc->backendLock, LW_EXCLUSIVE);
+   LWLockAcquire(&proc->backendLock, LW_EXCLUSIVE);
 
    /* If the transaction has ended, our work here is done. */
    if (proc->backendId != vxid.backendId
        || proc->fpLocalTransactionId != vxid.localTransactionId)
    {
-       LWLockRelease(proc->backendLock);
+       LWLockRelease(&proc->backendLock);
        return true;
    }
 
@@ -4038,7 +4038,7 @@ VirtualXactLock(VirtualTransactionId vxid, bool wait)
     */
    if (!wait)
    {
-       LWLockRelease(proc->backendLock);
+       LWLockRelease(&proc->backendLock);
        return false;
    }
 
@@ -4063,7 +4063,7 @@ VirtualXactLock(VirtualTransactionId vxid, bool wait)
        if (!proclock)
        {
            LWLockRelease(partitionLock);
-           LWLockRelease(proc->backendLock);
+           LWLockRelease(&proc->backendLock);
            ereport(ERROR,
                    (errcode(ERRCODE_OUT_OF_MEMORY),
                     errmsg("out of shared memory"),
@@ -4077,7 +4077,7 @@ VirtualXactLock(VirtualTransactionId vxid, bool wait)
    }
 
    /* Done with proc->fpLockBits */
-   LWLockRelease(proc->backendLock);
+   LWLockRelease(&proc->backendLock);
 
    /* Time to wait. */
    (void) LockAcquire(&tag, ShareLock, false, false);

diff --git a/src/backend/storage/lmgr/lwlock.c b/src/backend/storage/lmgr/lwlock.c
index ac61be2789ce455ee9a5b2065084a4d61d2bcdf4..5e276a08da3f859622fa522c4c8269795d70aad4 100644 (file)
--- a/src/backend/storage/lmgr/lwlock.c
+++ b/src/backend/storage/lmgr/lwlock.c
@@ -353,9 +353,6 @@ NumLWLocks(void)
    /* Predefined LWLocks */
    numLocks = NUM_FIXED_LWLOCKS;
 
-   /* proc.c needs one for each backend or auxiliary process */
-   numLocks += MaxBackends + NUM_AUXILIARY_PROCS;
-
    /* slot.c needs one for each slot */
    numLocks += max_replication_slots;
 

diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c
index 0d5e23ac4d6c638760c23e5ed6c9f175e2009063..3690753d64896fed2776f91f87ab9b26cff9691d 100644 (file)
--- a/src/backend/storage/lmgr/proc.c
+++ b/src/backend/storage/lmgr/proc.c
@@ -226,7 +226,7 @@ InitProcGlobal(void)
        {
            PGSemaphoreCreate(&(procs[i].sem));
            InitSharedLatch(&(procs[i].procLatch));
-           procs[i].backendLock = LWLockAssign();
+           LWLockInitialize(&(procs[i].backendLock), LWTRANCHE_PROC);
        }
        procs[i].pgprocno = i;
 

diff --git a/src/include/storage/lwlock.h b/src/include/storage/lwlock.h
index 5e8825ebeab328164ddd24701cba693a6315016b..3f1da5155ef14987e73a8def9747c8b8e1e5c728 100644 (file)
--- a/src/include/storage/lwlock.h
+++ b/src/include/storage/lwlock.h
@@ -213,6 +213,7 @@ typedef enum BuiltinTrancheIds
    LWTRANCHE_WAL_INSERT,
    LWTRANCHE_BUFFER_CONTENT,
    LWTRANCHE_BUFFER_IO_IN_PROGRESS,
+   LWTRANCHE_PROC,
    LWTRANCHE_FIRST_USER_DEFINED
 }  BuiltinTrancheIds;
 

diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h
index 38943a176713e88bac1d7af05bc51c549d69eb33..3441288dd0626c332f4290ea12318ffa059ec666 100644 (file)
--- a/src/include/storage/proc.h
+++ b/src/include/storage/proc.h
@@ -147,7 +147,7 @@ struct PGPROC
    TransactionId   backendLatestXid;
 
    /* Per-backend LWLock.  Protects fields below. */
-   LWLock     *backendLock;    /* protects the fields below */
+   LWLock      backendLock;
 
    /* Lock manager data, recording fast-path locks taken by this backend. */
    uint64      fpLockBits;     /* lock modes held for each fast-path slot */