Use two phase commit

Author: knizhnik

pg_dtm.c

@@ -632,7 +632,7 @@ static void DtmSetTransactionStatus(TransactionId xid, int nsubxids, Transaction
 				LWLockAcquire(dtm->hashLock, LW_EXCLUSIVE);
 				hash_search(xid_in_doubt, &DtmNextXid, HASH_ENTER, NULL);
 				LWLockRelease(dtm->hashLock);
-				DtmGlobalSetTransStatus(xid, status, true);
+                while (DtmGlobalSetTransStatus(xid, status, false) < 0);
 				XTM_INFO("Commit transaction %d\n", xid);
 			}
 		}

tests/dtmbench.cpp

@@ -194,6 +194,12 @@ void* writer(void* arg)
             continue;
         }
 
+        #if 1
+        exec(srcTx, "prepare transaction '%u'", xid);
+        exec(dstTx, "prepare transaction '%u'", xid);
+        exec(srcTx, "commit prepared '%u'", xid);
+        exec(dstTx, "commit prepared '%u'", xid);
+        #else
         pipeline srcPipe(srcTx);
         pipeline dstPipe(dstTx);
 
@@ -202,7 +208,7 @@ void* writer(void* arg)
 
         srcPipe.complete();
         dstPipe.complete();
-
+        #endif
         t.proceeded += 1;
     }
     return NULL;