Make ascii-art in comments pgindent-safe, and some other formatting changes.

Kevin Grittner

diff --git a/src/backend/storage/lmgr/predicate.c b/src/backend/storage/lmgr/predicate.c
index 6facb533e0fbceb2f140742b56bc4d8bc935d09a..32124b5e5df8c047b4383a7fb9fbd0b0a76b2351 100644 (file)
--- a/src/backend/storage/lmgr/predicate.c
+++ b/src/backend/storage/lmgr/predicate.c
@@ -3814,7 +3814,7 @@ FlagRWConflict(SERIALIZABLEXACT *reader, SERIALIZABLEXACT *writer)
        SetRWConflict(reader, writer);
 }
 
-/*
+/*----------------------------------------------------------------------------
  * We are about to add a RW-edge to the dependency graph - check that we don't
  * introduce a dangerous structure by doing so, and abort one of the
  * transactions if so.
@@ -3823,13 +3823,14 @@ FlagRWConflict(SERIALIZABLEXACT *reader, SERIALIZABLEXACT *writer)
  * in the dependency graph:
  *
  *     Tin ------> Tpivot ------> Tout
- *           rw             rw
+ *           rw             rw
  *
  * Furthermore, Tout must commit first.
  *
  * One more optimization is that if Tin is declared READ ONLY (or commits
  * without writing), we can only have a problem if Tout committed before Tin
  * acquired its snapshot.
+ *----------------------------------------------------------------------------
  */
 static void
 OnConflict_CheckForSerializationFailure(const SERIALIZABLEXACT *reader,
@@ -3842,32 +3843,34 @@ OnConflict_CheckForSerializationFailure(const SERIALIZABLEXACT *reader,
 
    failure = false;
 
-   /*
+   /*------------------------------------------------------------------------
     * Check for already-committed writer with rw-conflict out flagged
     * (conflict-flag on W means that T2 committed before W):
     *
     *      R ------> W ------> T2
-    *          rw        rw
+    *          rw        rw
     *
     * That is a dangerous structure, so we must abort. (Since the writer
     * has already committed, we must be the reader)
+    *------------------------------------------------------------------------
     */
    if (SxactIsCommitted(writer)
      && (SxactHasConflictOut(writer) || SxactHasSummaryConflictOut(writer)))
        failure = true;
 
-   /*
+   /*------------------------------------------------------------------------
     * Check whether the writer has become a pivot with an out-conflict
     * committed transaction (T2), and T2 committed first:
     *
     *      R ------> W ------> T2
-    *          rw        rw
+    *          rw        rw
     *
     * Because T2 must've committed first, there is no anomaly if:
     * - the reader committed before T2
     * - the writer committed before T2
     * - the reader is a READ ONLY transaction and the reader was concurrent
     *   with T2 (= reader acquired its snapshot before T2 committed)
+    *------------------------------------------------------------------------
     */
    if (!failure)
    {
@@ -3891,7 +3894,7 @@ OnConflict_CheckForSerializationFailure(const SERIALIZABLEXACT *reader,
                && (!SxactIsCommitted(writer)
                    || t2->commitSeqNo <= writer->commitSeqNo)
                && (!SxactIsReadOnly(reader)
-                   || t2->commitSeqNo <= reader->SeqNo.lastCommitBeforeSnapshot))
+              || t2->commitSeqNo <= reader->SeqNo.lastCommitBeforeSnapshot))
            {
                failure = true;
                break;
@@ -3903,16 +3906,17 @@ OnConflict_CheckForSerializationFailure(const SERIALIZABLEXACT *reader,
        }
    }
 
-   /*
+   /*------------------------------------------------------------------------
     * Check whether the reader has become a pivot with a committed writer:
     *
     *      T0 ------> R ------> W
-    *           rw        rw
+    *           rw        rw
     *
     * Because W must've committed first for an anomaly to occur, there is no
     * anomaly if:
     * - T0 committed before the writer
     * - T0 is READ ONLY, and overlaps the writer
+    *------------------------------------------------------------------------
     */
    if (!failure && SxactIsCommitted(writer) && !SxactIsReadOnly(reader))
    {
@@ -3934,7 +3938,7 @@ OnConflict_CheckForSerializationFailure(const SERIALIZABLEXACT *reader,
                && (!SxactIsCommitted(t0)
                    || t0->commitSeqNo >= writer->commitSeqNo)
                && (!SxactIsReadOnly(t0)
-                   || t0->SeqNo.lastCommitBeforeSnapshot >= writer->commitSeqNo))
+              || t0->SeqNo.lastCommitBeforeSnapshot >= writer->commitSeqNo))
            {
                failure = true;
                break;
@@ -3950,8 +3954,8 @@ OnConflict_CheckForSerializationFailure(const SERIALIZABLEXACT *reader,
    {
        /*
         * We have to kill a transaction to avoid a possible anomaly from
-        * occurring. If the writer is us, we can just ereport() to cause
-        * a transaction abort. Otherwise we flag the writer for termination,
+        * occurring. If the writer is us, we can just ereport() to cause a
+        * transaction abort. Otherwise we flag the writer for termination,
         * causing it to abort when it tries to commit. However, if the writer
         * is a prepared transaction, already prepared, we can't abort it
         * anymore, so we have to kill the reader instead.
@@ -3962,7 +3966,7 @@ OnConflict_CheckForSerializationFailure(const SERIALIZABLEXACT *reader,
            ereport(ERROR,
                    (errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
                     errmsg("could not serialize access due to read/write dependencies among transactions"),
-           errdetail("Cancelled on identification as a pivot, during write."),
+                    errdetail("Cancelled on identification as a pivot, during write."),
                     errhint("The transaction might succeed if retried.")));
        }
        else if (SxactIsPrepared(writer))