tdb2: add --summary and logging to tools/speed.

[ccan] / ccan / tdb2 / lock.c

diff --git a/ccan/tdb2/lock.c b/ccan/tdb2/lock.c
index 82fcdf17d1e6dfd0126d17232826cc53391329ee..5b04c0d243d9b29f2a5104af3f7836a5a47e8f40 100644 (file)
--- a/ccan/tdb2/lock.c
+++ b/ccan/tdb2/lock.c
@@ -30,13 +30,33 @@
 #include <ccan/build_assert/build_assert.h>
 
 /* If we were threaded, we could wait for unlock, but we're not, so fail. */
-static bool owner_conflict(struct tdb_context *tdb, struct tdb_lock *lock)
+static enum TDB_ERROR owner_conflict(struct tdb_context *tdb, const char *call)
 {
-       if (lock->owner != tdb) {
-               tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR,
-                          "Lock already owned by another opener");
+       return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR,
+                         "%s: lock owned by another tdb in this process.",
+                         call);
+}
+
+/* If we fork, we no longer really own locks. */
+static bool check_lock_pid(struct tdb_context *tdb,
+                          const char *call, bool log)
+{
+       /* No locks?  No problem! */
+       if (tdb->file->allrecord_lock.count == 0
+           && tdb->file->num_lockrecs == 0) {
+               return true;
+       }
+
+       /* No fork?  No problem! */
+       if (tdb->file->locker == getpid()) {
                return true;
        }
+
+       if (log) {
+               tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR,
+                          "%s: fork() detected after lock acquisition!"
+                          " (%u vs %u)", call, tdb->file->locker, getpid());
+       }
        return false;
 }
 
@@ -51,6 +71,11 @@ static int fcntl_lock(struct tdb_context *tdb,
        fl.l_len = len;
        fl.l_pid = 0;
 
+       if (tdb->file->allrecord_lock.count == 0
+           && tdb->file->num_lockrecs == 0) {
+               tdb->file->locker = getpid();
+       }
+
        add_stat(tdb, lock_lowlevel, 1);
        if (waitflag)
                return fcntl(tdb->file->fd, F_SETLKW, &fl);
@@ -193,7 +218,8 @@ static enum TDB_ERROR tdb_brunlock(struct tdb_context *tdb,
                ret = fcntl_unlock(tdb, rw_type, offset, len);
        } while (ret == -1 && errno == EINTR);
 
-       if (ret == -1) {
+       /* If we fail, *then* we verify that we owned the lock.  If not, ok. */
+       if (ret == -1 && check_lock_pid(tdb, "tdb_brunlock", false)) {
                return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR,
                                  "tdb_brunlock failed (fd=%d) at offset %zu"
                                  " rw_type=%d len=%zu",
@@ -213,6 +239,9 @@ enum TDB_ERROR tdb_allrecord_upgrade(struct tdb_context *tdb)
 {
        int count = 1000;
 
+       if (!check_lock_pid(tdb, "tdb_transaction_prepare_commit", true))
+               return TDB_ERR_LOCK;
+
        if (tdb->file->allrecord_lock.count != 1) {
                return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR,
                                  "tdb_allrecord_upgrade failed:"
@@ -226,6 +255,10 @@ enum TDB_ERROR tdb_allrecord_upgrade(struct tdb_context *tdb)
                                  " already upgraded?");
        }
 
+       if (tdb->file->allrecord_lock.owner != tdb) {
+               return owner_conflict(tdb, "tdb_allrecord_upgrade");
+       }
+
        while (count--) {
                struct timeval tv;
                if (tdb_brlock(tdb, F_WRLCK,
@@ -266,6 +299,9 @@ enum TDB_ERROR tdb_lock_and_recover(struct tdb_context *tdb)
 {
        enum TDB_ERROR ecode;
 
+       if (!check_lock_pid(tdb, "tdb_transaction_prepare_commit", true))
+               return TDB_ERR_LOCK;
+
        ecode = tdb_allrecord_lock(tdb, F_WRLCK, TDB_LOCK_WAIT|TDB_LOCK_NOCHECK,
                                   false);
        if (ecode != TDB_SUCCESS) {
@@ -302,12 +338,17 @@ static enum TDB_ERROR tdb_nest_lock(struct tdb_context *tdb,
        if (tdb->flags & TDB_NOLOCK)
                return TDB_SUCCESS;
 
+       if (!check_lock_pid(tdb, "tdb_nest_lock", true)) {
+               return TDB_ERR_LOCK;
+       }
+
        add_stat(tdb, locks, 1);
 
        new_lck = find_nestlock(tdb, offset, NULL);
        if (new_lck) {
-               if (owner_conflict(tdb, new_lck))
-                       return -1;
+               if (new_lck->owner != tdb) {
+                       return owner_conflict(tdb, "tdb_nest_lock");
+               }
 
                if (new_lck->ltype == F_RDLCK && ltype == F_WRLCK) {
                        return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR,
@@ -470,14 +511,24 @@ enum TDB_ERROR tdb_allrecord_lock(struct tdb_context *tdb, int ltype,
        enum TDB_ERROR ecode;
        tdb_bool_err berr;
 
-       if (tdb->file->allrecord_lock.count
-           && (ltype == F_RDLCK
-               || tdb->file->allrecord_lock.ltype == F_WRLCK)) {
-               tdb->file->allrecord_lock.count++;
+       if (tdb->flags & TDB_NOLOCK)
                return TDB_SUCCESS;
+
+       if (!check_lock_pid(tdb, "tdb_allrecord_lock", true)) {
+               return TDB_ERR_LOCK;
        }
 
        if (tdb->file->allrecord_lock.count) {
+               if (tdb->file->allrecord_lock.owner != tdb) {
+                       return owner_conflict(tdb, "tdb_allrecord_lock");
+               }
+
+               if (ltype == F_RDLCK
+                   || tdb->file->allrecord_lock.ltype == F_WRLCK) {
+                       tdb->file->allrecord_lock.count++;
+                       return TDB_SUCCESS;
+               }
+
                /* a global lock of a different type exists */
                return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR,
                                  "tdb_allrecord_lock: already have %s lock",
@@ -582,6 +633,9 @@ void tdb_unlock_expand(struct tdb_context *tdb, int ltype)
 /* unlock entire db */
 void tdb_allrecord_unlock(struct tdb_context *tdb, int ltype)
 {
+       if (tdb->flags & TDB_NOLOCK)
+               return;
+
        if (tdb->file->allrecord_lock.count == 0) {
                tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR,
                           "tdb_allrecord_unlock: not locked!");
@@ -658,12 +712,17 @@ enum TDB_ERROR tdb_lock_hashes(struct tdb_context *tdb,
                + (hash_lock >> (64 - TDB_HASH_LOCK_RANGE_BITS));
 
        /* a allrecord lock allows us to avoid per chain locks */
-       if (tdb->file->allrecord_lock.count &&
-           (ltype == tdb->file->allrecord_lock.ltype || ltype == F_RDLCK)) {
-               return TDB_SUCCESS;
-       }
-
        if (tdb->file->allrecord_lock.count) {
+               if (!check_lock_pid(tdb, "tdb_lock_hashes", true))
+                       return TDB_ERR_LOCK;
+
+               if (tdb->file->allrecord_lock.owner != tdb)
+                       return owner_conflict(tdb, "tdb_lock_hashes");
+               if (ltype == tdb->file->allrecord_lock.ltype
+                   || ltype == F_RDLCK) {
+                       return TDB_SUCCESS;
+               }
+
                return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_USE_ERROR,
                                  "tdb_lock_hashes:"
                                  " already have %s allrecordlock",
@@ -729,6 +788,9 @@ enum TDB_ERROR tdb_lock_free_bucket(struct tdb_context *tdb, tdb_off_t b_off,
 
        /* a allrecord lock allows us to avoid per chain locks */
        if (tdb->file->allrecord_lock.count) {
+               if (!check_lock_pid(tdb, "tdb_lock_free_bucket", true))
+                       return TDB_ERR_LOCK;
+
                if (tdb->file->allrecord_lock.ltype == F_WRLCK)
                        return 0;
                return tdb_logerr(tdb, TDB_ERR_LOCK, TDB_LOG_ERROR,
@@ -755,7 +817,27 @@ void tdb_unlock_free_bucket(struct tdb_context *tdb, tdb_off_t b_off)
        tdb_nest_unlock(tdb, free_lock_off(b_off), F_WRLCK);
 }
 
-void tdb_unlock_all(struct tdb_context *tdb)
+enum TDB_ERROR tdb_lockall(struct tdb_context *tdb)
+{
+       return tdb_allrecord_lock(tdb, F_WRLCK, TDB_LOCK_WAIT, false);
+}
+
+void tdb_unlockall(struct tdb_context *tdb)
+{
+       tdb_allrecord_unlock(tdb, F_WRLCK);
+}
+
+enum TDB_ERROR tdb_lockall_read(struct tdb_context *tdb)
+{
+       return tdb_allrecord_lock(tdb, F_RDLCK, TDB_LOCK_WAIT, false);
+}
+
+void tdb_unlockall_read(struct tdb_context *tdb)
+{
+       tdb_allrecord_unlock(tdb, F_RDLCK);
+}
+
+void tdb_lock_cleanup(struct tdb_context *tdb)
 {
        unsigned int i;