tdb2: allow multiple chain locks.

[ccan] / ccan / tdb2 / test / external-agent.c

diff --git a/ccan/tdb2/test/external-agent.c b/ccan/tdb2/test/external-agent.c
index 79c299a088047ccbbc7d495548d89e4c34fade89..081b8500a0fb206ab2ec239e94d9bb333f399516 100644 (file)
--- a/ccan/tdb2/test/external-agent.c
+++ b/ccan/tdb2/test/external-agent.c
@@ -17,22 +17,46 @@
 
 static struct tdb_context *tdb;
 
+static enum TDB_ERROR clear_if_first(int fd, void *arg)
+{
+/* We hold a lock offset 63 always, so we can tell if anyone is holding it. */
+       struct flock fl;
+
+       fl.l_type = F_WRLCK;
+       fl.l_whence = SEEK_SET;
+       fl.l_start = 63;
+       fl.l_len = 1;
+
+       if (fcntl(fd, F_SETLK, &fl) == 0) {
+               /* We must be first ones to open it! */
+               diag("agent truncating file!");
+               if (ftruncate(fd, 0) != 0) {
+                       return TDB_ERR_IO;
+               }
+       }
+       fl.l_type = F_RDLCK;
+       if (fcntl(fd, F_SETLKW, &fl) != 0) {
+               return TDB_ERR_IO;
+       }
+       return TDB_SUCCESS;
+}
+
 static enum agent_return do_operation(enum operation op, const char *name)
 {
        TDB_DATA k;
        enum agent_return ret;
        TDB_DATA data;
        enum TDB_ERROR ecode;
+       union tdb_attribute cif;
 
-       if (op != OPEN && !tdb) {
+       if (op != OPEN && op != OPEN_WITH_HOOK && !tdb) {
                diag("external: No tdb open!");
                return OTHER_FAILURE;
        }
 
        diag("external: %s", operation_name(op));
 
-       k.dptr = (void *)name;
-       k.dsize = strlen(name);
+       k = tdb_mkdata(name, strlen(name));
 
        locking_would_block = 0;
        switch (op) {
@@ -50,6 +74,23 @@ static enum agent_return do_operation(enum operation op, const char *name)
                } else
                        ret = SUCCESS;
                break;
+       case OPEN_WITH_HOOK:
+               if (tdb) {
+                       diag("Already have tdb %s open", tdb->name);
+                       return OTHER_FAILURE;
+               }
+               cif.openhook.base.attr = TDB_ATTRIBUTE_OPENHOOK;
+               cif.openhook.base.next = &tap_log_attr;
+               cif.openhook.fn = clear_if_first;
+               tdb = tdb_open(name, TDB_DEFAULT, O_RDWR, 0, &cif);
+               if (!tdb) {
+                       if (!locking_would_block)
+                               diag("Opening tdb gave %s", strerror(errno));
+                       forget_locking();
+                       ret = OTHER_FAILURE;
+               } else
+                       ret = SUCCESS;
+               break;
        case FETCH:
                ecode = tdb_fetch(tdb, k, &data);
                if (ecode == TDB_ERR_NOEXIST) {
@@ -177,6 +218,7 @@ const char *operation_name(enum operation op)
 {
        switch (op) {
        case OPEN: return "OPEN";
+       case OPEN_WITH_HOOK: return "OPEN_WITH_HOOK";
        case FETCH: return "FETCH";
        case STORE: return "STORE";
        case CHECK: return "CHECK";