From 4a4936b8af99ba8b64f8fba81c49f49ddc25ac88 Mon Sep 17 00:00:00 2001 From: Howard Chu Date: Tue, 7 Jun 2022 20:27:11 +0100 Subject: [PATCH] Fix use of rtxn without a mdb_txn_safe wrapper --- src/blockchain_db/blockchain_db.h | 16 +++--- src/blockchain_db/lmdb/db_lmdb.cpp | 86 ++++++++++++++++-------------- 2 files changed, 55 insertions(+), 47 deletions(-) diff --git a/src/blockchain_db/blockchain_db.h b/src/blockchain_db/blockchain_db.h index 263948fa2..a163ef98c 100644 --- a/src/blockchain_db/blockchain_db.h +++ b/src/blockchain_db/blockchain_db.h @@ -1883,16 +1883,18 @@ public: } virtual ~db_txn_guard() { - if (active) - stop(); + stop(); } void stop() { - if (readonly) - db->block_rtxn_stop(); - else - db->block_wtxn_stop(); - active = false; + if (active) + { + if (readonly) + db->block_rtxn_stop(); + else + db->block_wtxn_stop(); + active = false; + } } void abort() { diff --git a/src/blockchain_db/lmdb/db_lmdb.cpp b/src/blockchain_db/lmdb/db_lmdb.cpp index e2ac9df0b..1ae40dbe9 100644 --- a/src/blockchain_db/lmdb/db_lmdb.cpp +++ b/src/blockchain_db/lmdb/db_lmdb.cpp @@ -472,6 +472,32 @@ void mdb_txn_safe::increment_txns(int i) num_active_txns += i; } +#define TXN_PREFIX(flags); \ + mdb_txn_safe auto_txn; \ + mdb_txn_safe* txn_ptr = &auto_txn; \ + if (m_batch_active) \ + txn_ptr = m_write_txn; \ + else \ + { \ + if (auto mdb_res = lmdb_txn_begin(m_env, NULL, flags, auto_txn)) \ + throw0(DB_ERROR(lmdb_error(std::string("Failed to create a transaction for the db in ")+__FUNCTION__+": ", mdb_res).c_str())); \ + } \ + +#define TXN_PREFIX_RDONLY() \ + MDB_txn *m_txn; \ + mdb_txn_cursors *m_cursors; \ + mdb_txn_safe auto_txn; \ + bool my_rtxn = block_rtxn_start(&m_txn, &m_cursors); \ + if (my_rtxn) auto_txn.m_tinfo = m_tinfo.get(); \ + else auto_txn.uncheck() +#define TXN_POSTFIX_RDONLY() + +#define TXN_POSTFIX_SUCCESS() \ + do { \ + if (! m_batch_active) \ + auto_txn.commit(); \ + } while(0) + void lmdb_resized(MDB_env *env, int isactive) { mdb_txn_safe::prevent_new_txns(); @@ -720,21 +746,20 @@ uint64_t BlockchainLMDB::get_estimated_batch_size(uint64_t batch_num_blocks, uin } else { - MDB_txn *rtxn; - mdb_txn_cursors *rcurs; - bool my_rtxn = block_rtxn_start(&rtxn, &rcurs); - for (uint64_t block_num = block_start; block_num <= block_stop; ++block_num) { - // we have access to block weight, which will be greater or equal to block size, - // so use this as a proxy. If it's too much off, we might have to check actual size, - // which involves reading more data, so is not really wanted - size_t block_weight = get_block_weight(block_num); - total_block_size += block_weight; - // Track number of blocks being totalled here instead of assuming, in case - // some blocks were to be skipped for being outliers. - ++num_blocks_used; + TXN_PREFIX_RDONLY(); + for (uint64_t block_num = block_start; block_num <= block_stop; ++block_num) + { + // we have access to block weight, which will be greater or equal to block size, + // so use this as a proxy. If it's too much off, we might have to check actual size, + // which involves reading more data, so is not really wanted + size_t block_weight = get_block_weight(block_num); + total_block_size += block_weight; + // Track number of blocks being totalled here instead of assuming, in case + // some blocks were to be skipped for being outliers. + ++num_blocks_used; + } } - if (my_rtxn) block_rtxn_stop(); avg_block_size = total_block_size / (num_blocks_used ? num_blocks_used : 1); MDEBUG("average block size across recent " << num_blocks_used << " blocks: " << avg_block_size); } @@ -1714,32 +1739,6 @@ void BlockchainLMDB::unlock() check_open(); } -#define TXN_PREFIX(flags); \ - mdb_txn_safe auto_txn; \ - mdb_txn_safe* txn_ptr = &auto_txn; \ - if (m_batch_active) \ - txn_ptr = m_write_txn; \ - else \ - { \ - if (auto mdb_res = lmdb_txn_begin(m_env, NULL, flags, auto_txn)) \ - throw0(DB_ERROR(lmdb_error(std::string("Failed to create a transaction for the db in ")+__FUNCTION__+": ", mdb_res).c_str())); \ - } \ - -#define TXN_PREFIX_RDONLY() \ - MDB_txn *m_txn; \ - mdb_txn_cursors *m_cursors; \ - mdb_txn_safe auto_txn; \ - bool my_rtxn = block_rtxn_start(&m_txn, &m_cursors); \ - if (my_rtxn) auto_txn.m_tinfo = m_tinfo.get(); \ - else auto_txn.uncheck() -#define TXN_POSTFIX_RDONLY() - -#define TXN_POSTFIX_SUCCESS() \ - do { \ - if (! m_batch_active) \ - auto_txn.commit(); \ - } while(0) - // The below two macros are for DB access within block add/remove, whether // regular batch txn is in use or not. m_write_txn is used as a batch txn, even @@ -3959,13 +3958,20 @@ void BlockchainLMDB::block_rtxn_stop() const LOG_PRINT_L3("BlockchainLMDB::" << __func__); mdb_txn_reset(m_tinfo->m_ti_rtxn); memset(&m_tinfo->m_ti_rflags, 0, sizeof(m_tinfo->m_ti_rflags)); + /* cancel out the increment from rtxn_start */ + mdb_txn_safe::increment_txns(-1); } bool BlockchainLMDB::block_rtxn_start() const { MDB_txn *mtxn; mdb_txn_cursors *mcur; - return block_rtxn_start(&mtxn, &mcur); + /* auto_txn is only used for the create gate */ + mdb_txn_safe auto_txn; + bool ret = block_rtxn_start(&mtxn, &mcur); + if (ret) + auto_txn.increment_txns(1); /* remember there is an active readtxn */ + return ret; } void BlockchainLMDB::block_wtxn_start()