[rhmessaging-commits] rhmessaging commits: r3039 - store/trunk/cpp/lib.

[rhmessaging-commits at lists.jboss.org]

Author: kpvdr
Date: 2009-01-14 07:55:30 -0500 (Wed, 14 Jan 2009)
New Revision: 3039

Modified:
   store/trunk/cpp/lib/MessageStoreImpl.cpp
Log:
Fix for BZ472937 - "TPL recoverTplStore() failed: jexception 0x0b01 txn_map::get_tdata_list() threw JERR_MAP_NOTFOUND: Key not found in map. (xid=rhm-tid0x2aac2c9b0ee0) (MessageStoreImpl.cpp:1079)".

Modified: store/trunk/cpp/lib/MessageStoreImpl.cpp
===================================================================
--- store/trunk/cpp/lib/MessageStoreImpl.cpp	2009-01-12 16:58:29 UTC (rev 3038)
+++ store/trunk/cpp/lib/MessageStoreImpl.cpp	2009-01-14 12:55:30 UTC (rev 3039)
@@ -1037,27 +1037,40 @@
                 bool is2PC = *(static_cast<char*>(dbuff)) != 0;
 
                 // Check transaction details; add to recover map
-                journal::txn_data_list txnList = tmap.get_tdata_list(xid);
-                unsigned enqCnt = 0;
-                unsigned deqCnt = 0;
-                u_int64_t rid = 0;
+                // NOTE: There is a small but finite probability that the xid read above may have been removed by
+                // another thread on one of the active queues by the time the get_tdata_list() call below is made.
+                // Since reading the TPL is not considered a high-speed operation and is used for recovery and other
+                // infrequent uses, the following try-catch will work as well as attempting to lock down the
+                // entire transaction map for this operation - but with less complixity.
+                try {
+                    journal::txn_data_list txnList = tmap.get_tdata_list(xid);
+                    unsigned enqCnt = 0;
+                    unsigned deqCnt = 0;
+                    u_int64_t rid = 0;
 
-                // Assume commit (roll forward) in cases where only prepare has been called - ie only enqueue record exists.
-                // Note: will apply to both 1PC and 2PC transactions.
-                bool commitFlag = true;
+                    // Assume commit (roll forward) in cases where only prepare has been called - ie only enqueue record exists.
+                    // Note: will apply to both 1PC and 2PC transactions.
+                    bool commitFlag = true;
 
-                for (journal::tdl_itr j = txnList.begin(); j<txnList.end(); j++) {
-                    if (j->_enq_flag) {
-                        rid = j->_rid;
-                        enqCnt++;
-                    } else {
-                        commitFlag = j->_commit_flag;
-                        deqCnt++;
+                    for (journal::tdl_itr j = txnList.begin(); j<txnList.end(); j++) {
+                        if (j->_enq_flag) {
+                            rid = j->_rid;
+                            enqCnt++;
+                        } else {
+                            commitFlag = j->_commit_flag;
+                            deqCnt++;
+                        }
                     }
+                    assert(enqCnt == 1);
+                    assert(deqCnt <= 1);
+                    tplRecoverMap.insert(TplRecoverMapPair(xid, TplRecoverStruct(rid, deqCnt == 1, commitFlag, is2PC)));
                 }
-                assert(enqCnt == 1);
-                assert(deqCnt <= 1);
-                tplRecoverMap.insert(TplRecoverMapPair(xid, TplRecoverStruct(rid, deqCnt == 1, commitFlag, is2PC)));
+                catch (const journal::jexception& e) {
+                    ::free(xidbuff);
+                    aio_sleep_cnt = 0;
+                    if (e.err_code() == journal::jerrno::JERR_MAP_NOTFOUND) break; // ignore this xid; move on
+                    throw;
+                }
 
                 ::free(xidbuff);
                 aio_sleep_cnt = 0;