[Tarantool-patches] [PATCH 1/1] txn: remove TXN_IS_DONE check from txn_commit()
Vladislav Shpilevoy
v.shpilevoy at tarantool.org
Sat Jul 4 02:23:55 MSK 2020
TXN_IS_DONE was used in txn_commit() to finalize the transaction
in a case it is not finished yet. But this happens only not in
so common cases - during bootstrap and recovery. During normal
operation the transaction is always finished when WAL thread
returns it to TX thread after a disk write.
So this is a matter of journal, and should be solved here, not in
txn code with some crutch, especially in such a hot path place.
This commit makes so that after journal_write() the transaction is
always already done, i.e. txn_complete_async() was called. Nothing
changes for the normal operation mode except this is -1 'if'.
---
Branch: http://github.com/tarantool/tarantool/tree/gerold103/txn_commit-opt
I couldn't get any stable bench results on my machine. But seems
like this solution probably gives something about 1-2% perf
increase for pure 'insert' workload without anything else.
Need someone else to try too. Sergey Os.?
src/box/box.cc | 23 +++++++++++++++++++++--
src/box/journal.c | 45 +--------------------------------------------
src/box/journal.h | 11 -----------
src/box/txn.c | 6 +-----
src/box/wal.c | 2 +-
5 files changed, 24 insertions(+), 63 deletions(-)
diff --git a/src/box/box.cc b/src/box/box.cc
index 871b0d976..ca061dc4f 100644
--- a/src/box/box.cc
+++ b/src/box/box.cc
@@ -323,6 +323,7 @@ recovery_journal_write(struct journal *base,
{
struct recovery_journal *journal = (struct recovery_journal *) base;
entry->res = vclock_sum(journal->vclock);
+ journal_async_complete(base, entry);
return 0;
}
@@ -330,8 +331,7 @@ static void
recovery_journal_create(struct vclock *v)
{
static struct recovery_journal journal;
- journal_create(&journal.base, journal_no_write_async,
- journal_no_write_async_cb,
+ journal_create(&journal.base, NULL, txn_complete_async,
recovery_journal_write);
journal.vclock = v;
journal_set(&journal.base);
@@ -2017,6 +2017,14 @@ engine_init()
box_set_vinyl_timeout();
}
+static int
+bootstrap_journal_write(struct journal *base, struct journal_entry *entry)
+{
+ entry->res = 0;
+ journal_async_complete(base, entry);
+ return 0;
+}
+
/**
* Initialize the first replica of a new replica set.
*/
@@ -2438,6 +2446,14 @@ box_cfg_xc(void)
if (!cfg_geti("hot_standby") || checkpoint == NULL)
tnt_raise(ClientError, ER_ALREADY_RUNNING, cfg_gets("wal_dir"));
}
+ struct journal bootstrap_journal;
+ journal_create(&bootstrap_journal, NULL, txn_complete_async,
+ bootstrap_journal_write);
+ journal_set(&bootstrap_journal);
+ auto bootstrap_journal_guard = make_scoped_guard([] {
+ journal_set(NULL);
+ });
+
bool is_bootstrap_leader = false;
if (checkpoint != NULL) {
/* Recover the instance from the local directory */
@@ -2450,6 +2466,9 @@ box_cfg_xc(void)
}
fiber_gc();
+ bootstrap_journal_guard.is_active = false;
+ assert(current_journal != &bootstrap_journal);
+
/*
* Check for correct registration of the instance in _cluster
* The instance won't exist in _cluster space if it is an
diff --git a/src/box/journal.c b/src/box/journal.c
index d84f960d5..f1e89aaa2 100644
--- a/src/box/journal.c
+++ b/src/box/journal.c
@@ -32,50 +32,7 @@
#include <small/region.h>
#include <diag.h>
-int
-journal_no_write_async(struct journal *journal,
- struct journal_entry *entry)
-{
- (void)journal;
- assert(false);
-
- errno = EINVAL;
- diag_set(SystemError, "write_async wrong context");
-
- entry->res = -1;
- return -1;
-}
-
-void
-journal_no_write_async_cb(struct journal_entry *entry)
-{
- assert(false);
-
- errno = EINVAL;
- diag_set(SystemError, "write_async_cb wrong context");
-
- entry->res = -1;
-}
-
-/**
- * Used to load from a memtx snapshot. LSN is not used,
- * but txn_commit() must work.
- */
-static int
-dummy_journal_write(struct journal *journal, struct journal_entry *entry)
-{
- (void) journal;
- entry->res = 0;
- return 0;
-}
-
-static struct journal dummy_journal = {
- .write_async = journal_no_write_async,
- .write_async_cb = journal_no_write_async_cb,
- .write = dummy_journal_write,
-};
-
-struct journal *current_journal = &dummy_journal;
+struct journal *current_journal = NULL;
struct journal_entry *
journal_entry_new(size_t n_rows, struct region *region,
diff --git a/src/box/journal.h b/src/box/journal.h
index ebc5cb708..1a10e66c3 100644
--- a/src/box/journal.h
+++ b/src/box/journal.h
@@ -182,17 +182,6 @@ journal_create(struct journal *journal,
journal->write = write;
}
-/**
- * A stub to issue an error in case if asynchronous
- * write is diabled in the backend.
- */
-extern int
-journal_no_write_async(struct journal *journal,
- struct journal_entry *entry);
-
-extern void
-journal_no_write_async_cb(struct journal_entry *entry);
-
static inline bool
journal_is_initialized(struct journal *journal)
{
diff --git a/src/box/txn.c b/src/box/txn.c
index 123520166..e86a03447 100644
--- a/src/box/txn.c
+++ b/src/box/txn.c
@@ -652,11 +652,7 @@ txn_commit(struct txn *txn)
diag_log();
return -1;
}
-
- if (!txn_has_flag(txn, TXN_IS_DONE)) {
- txn->signature = req->res;
- txn_complete(txn);
- }
+ assert(txn_has_flag(txn, TXN_IS_DONE));
int res = txn->signature >= 0 ? 0 : -1;
if (res != 0) {
diff --git a/src/box/wal.c b/src/box/wal.c
index 74cc74684..9ee1a4e7f 100644
--- a/src/box/wal.c
+++ b/src/box/wal.c
@@ -1285,7 +1285,7 @@ wal_write_none_async(struct journal *journal,
vclock_merge(&writer->vclock, &vclock_diff);
vclock_copy(&replicaset.vclock, &writer->vclock);
entry->res = vclock_sum(&writer->vclock);
-
+ journal_async_complete(journal, entry);
return 0;
}
--
2.21.1 (Apple Git-122.3)
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