lib/tdb: TDB_TRACE support (for developers)

When TDB_TRACE is defined (in tdb_private.h), verbose tracing of tdb operations is enabled.
This can be replayed using "replay_trace" from http://ccan.ozlabs.org/info/tdb.

The majority of this patch comes from moving internal functions to _<funcname> to
avoid double-tracing.  There should be no additional overhead for the normal (!TDB_TRACE)
case.

Note that the verbose traces compress really well with rzip.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 28 insertions, 6 deletions

diff --git a/lib/tdb/common/lock.c b/lib/tdb/common/lock.c
index 2c72ae1f0d..3414049cb6 100644
--- a/lib/tdb/common/lock.c
+++ b/lib/tdb/common/lock.c
@@ -422,48 +422,58 @@ static int _tdb_unlockall(struct tdb_context *tdb, int ltype)
 /* lock entire database with write lock */
 int tdb_lockall(struct tdb_context *tdb)
 {
+	tdb_trace(tdb, "tdb_lockall");
 	return _tdb_lockall(tdb, F_WRLCK, F_SETLKW);
 }
 
 /* lock entire database with write lock - mark only */
 int tdb_lockall_mark(struct tdb_context *tdb)
 {
+	tdb_trace(tdb, "tdb_lockall_mark");
 	return _tdb_lockall(tdb, F_WRLCK | TDB_MARK_LOCK, F_SETLKW);
 }
 
 /* unlock entire database with write lock - unmark only */
 int tdb_lockall_unmark(struct tdb_context *tdb)
 {
+	tdb_trace(tdb, "tdb_lockall_unmark");
 	return _tdb_unlockall(tdb, F_WRLCK | TDB_MARK_LOCK);
 }
 
 /* lock entire database with write lock - nonblocking varient */
 int tdb_lockall_nonblock(struct tdb_context *tdb)
 {
-	return _tdb_lockall(tdb, F_WRLCK, F_SETLK);
+	int ret = _tdb_lockall(tdb, F_WRLCK, F_SETLK);
+	tdb_trace_ret(tdb, "tdb_lockall_nonblock", ret);
+	return ret;
 }
 
 /* unlock entire database with write lock */
 int tdb_unlockall(struct tdb_context *tdb)
 {
+	tdb_trace(tdb, "tdb_unlockall");
 	return _tdb_unlockall(tdb, F_WRLCK);
 }
 
 /* lock entire database with read lock */
 int tdb_lockall_read(struct tdb_context *tdb)
 {
+	tdb_trace(tdb, "tdb_lockall_read");
 	return _tdb_lockall(tdb, F_RDLCK, F_SETLKW);
 }
 
 /* lock entire database with read lock - nonblock varient */
 int tdb_lockall_read_nonblock(struct tdb_context *tdb)
 {
-	return _tdb_lockall(tdb, F_RDLCK, F_SETLK);
+	int ret = _tdb_lockall(tdb, F_RDLCK, F_SETLK);
+	tdb_trace_ret(tdb, "tdb_lockall_read_nonblock", ret);
+	return ret;
 }
 
 /* unlock entire database with read lock */
 int tdb_unlockall_read(struct tdb_context *tdb)
 {
+	tdb_trace(tdb, "tdb_unlockall_read");
 	return _tdb_unlockall(tdb, F_RDLCK);
 }
 
@@ -471,7 +481,9 @@ int tdb_unlockall_read(struct tdb_context *tdb)
    contention - it cannot guarantee how many records will be locked */
 int tdb_chainlock(struct tdb_context *tdb, TDB_DATA key)
 {
-	return tdb_lock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK);
+	int ret = tdb_lock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK);
+	tdb_trace_1rec(tdb, "tdb_chainlock", key);
+	return ret;
 }
 
 /* lock/unlock one hash chain, non-blocking. This is meant to be used
@@ -479,33 +491,43 @@ int tdb_chainlock(struct tdb_context *tdb, TDB_DATA key)
    locked */
 int tdb_chainlock_nonblock(struct tdb_context *tdb, TDB_DATA key)
 {
-	return tdb_lock_nonblock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK);
+	int ret = tdb_lock_nonblock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK);
+	tdb_trace_1rec_ret(tdb, "tdb_chainlock_nonblock", key, ret);
+	return ret;
 }
 
 /* mark a chain as locked without actually locking it. Warning! use with great caution! */
 int tdb_chainlock_mark(struct tdb_context *tdb, TDB_DATA key)
 {
-	return tdb_lock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK | TDB_MARK_LOCK);
+	int ret = tdb_lock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK | TDB_MARK_LOCK);
+	tdb_trace_1rec(tdb, "tdb_chainlock_mark", key);
+	return ret;
 }
 
 /* unmark a chain as locked without actually locking it. Warning! use with great caution! */
 int tdb_chainlock_unmark(struct tdb_context *tdb, TDB_DATA key)
 {
+	tdb_trace_1rec(tdb, "tdb_chainlock_unmark", key);
 	return tdb_unlock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK | TDB_MARK_LOCK);
 }
 
 int tdb_chainunlock(struct tdb_context *tdb, TDB_DATA key)
 {
+	tdb_trace_1rec(tdb, "tdb_chainunlock", key);
 	return tdb_unlock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK);
 }
 
 int tdb_chainlock_read(struct tdb_context *tdb, TDB_DATA key)
 {
-	return tdb_lock(tdb, BUCKET(tdb->hash_fn(&key)), F_RDLCK);
+	int ret;
+	ret = tdb_lock(tdb, BUCKET(tdb->hash_fn(&key)), F_RDLCK);
+	tdb_trace_1rec(tdb, "tdb_chainlock_read", key);
+	return ret;
 }
 
 int tdb_chainunlock_read(struct tdb_context *tdb, TDB_DATA key)
 {
+	tdb_trace_1rec(tdb, "tdb_chainunlock_read", key);
 	return tdb_unlock(tdb, BUCKET(tdb->hash_fn(&key)), F_RDLCK);
 }