tdb2: add lib/tdb2 (from CCAN init-1161-g661d41f)

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

1 files changed, 180 insertions, 0 deletions

diff --git a/lib/tdb2/test/run-fork-test.c b/lib/tdb2/test/run-fork-test.c
new file mode 100644
index 00000000000..e9813e0a0f0
--- /dev/null
+++ b/lib/tdb2/test/run-fork-test.c
@@ -0,0 +1,180 @@
+/* Test forking while holding lock.
+ *
+ * There are only five ways to do this currently:
+ * (1) grab a tdb_chainlock, then fork.
+ * (2) grab a tdb_lockall, then fork.
+ * (3) grab a tdb_lockall_read, then fork.
+ * (4) start a transaction, then fork.
+ * (5) fork from inside a tdb_parse() callback.
+ *
+ * Note that we don't hold a lock across tdb_traverse callbacks, so
+ * that doesn't matter.
+ */
+#include <ccan/tdb2/tdb.c>
+#include <ccan/tdb2/open.c>
+#include <ccan/tdb2/free.c>
+#include <ccan/tdb2/lock.c>
+#include <ccan/tdb2/io.c>
+#include <ccan/tdb2/hash.c>
+#include <ccan/tdb2/check.c>
+#include <ccan/tdb2/transaction.c>
+#include <ccan/tap/tap.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include "logging.h"
+
+static enum TDB_ERROR fork_in_parse(TDB_DATA key, TDB_DATA data,
+				    struct tdb_context *tdb)
+{
+	int status;
+
+	if (fork() == 0) {
+		/* We expect this to fail. */
+		if (tdb_store(tdb, key, data, TDB_REPLACE) != TDB_ERR_LOCK)
+			exit(1);
+
+		if (tdb_fetch(tdb, key, &data) != TDB_ERR_LOCK)
+			exit(1);
+
+		if (tap_log_messages != 2)
+			exit(2);
+
+		tdb_close(tdb);
+		if (tap_log_messages != 2)
+			exit(3);
+		exit(0);
+	}
+	wait(&status);
+	ok1(WIFEXITED(status) && WEXITSTATUS(status) == 0);
+	return TDB_SUCCESS;
+}
+
+int main(int argc, char *argv[])
+{
+	unsigned int i;
+	struct tdb_context *tdb;
+	int flags[] = { TDB_DEFAULT, TDB_NOMMAP,
+			TDB_CONVERT, TDB_NOMMAP|TDB_CONVERT };
+	struct tdb_data key = tdb_mkdata("key", 3);
+	struct tdb_data data = tdb_mkdata("data", 4);
+
+	plan_tests(sizeof(flags) / sizeof(flags[0]) * 14);
+	for (i = 0; i < sizeof(flags) / sizeof(flags[0]); i++) {
+		int status;
+
+		tap_log_messages = 0;
+
+		tdb = tdb_open("run-fork-test.tdb", flags[i],
+			       O_RDWR|O_CREAT|O_TRUNC, 0600, &tap_log_attr);
+		if (!ok1(tdb))
+			continue;
+
+		/* Put a record in here. */
+		ok1(tdb_store(tdb, key, data, TDB_REPLACE) == TDB_SUCCESS);
+
+		ok1(tdb_chainlock(tdb, key) == TDB_SUCCESS);
+		if (fork() == 0) {
+			/* We expect this to fail. */
+			if (tdb_store(tdb, key, data, TDB_REPLACE) != TDB_ERR_LOCK)
+				return 1;
+
+			if (tdb_fetch(tdb, key, &data) != TDB_ERR_LOCK)
+				return 1;
+
+			if (tap_log_messages != 2)
+				return 2;
+
+			tdb_chainunlock(tdb, key);
+			if (tap_log_messages != 3)
+				return 3;
+			tdb_close(tdb);
+			if (tap_log_messages != 3)
+				return 4;
+			return 0;
+		}
+		wait(&status);
+		ok1(WIFEXITED(status) && WEXITSTATUS(status) == 0);
+		tdb_chainunlock(tdb, key);
+
+		ok1(tdb_lockall(tdb) == TDB_SUCCESS);
+		if (fork() == 0) {
+			/* We expect this to fail. */
+			if (tdb_store(tdb, key, data, TDB_REPLACE) != TDB_ERR_LOCK)
+				return 1;
+
+			if (tdb_fetch(tdb, key, &data) != TDB_ERR_LOCK)
+				return 1;
+
+			if (tap_log_messages != 2)
+				return 2;
+
+			tdb_unlockall(tdb);
+			if (tap_log_messages != 2)
+				return 3;
+			tdb_close(tdb);
+			if (tap_log_messages != 2)
+				return 4;
+			return 0;
+		}
+		wait(&status);
+		ok1(WIFEXITED(status) && WEXITSTATUS(status) == 0);
+		tdb_unlockall(tdb);
+
+		ok1(tdb_lockall_read(tdb) == TDB_SUCCESS);
+		if (fork() == 0) {
+			/* We expect this to fail. */
+			/* This would always fail anyway... */
+			if (tdb_store(tdb, key, data, TDB_REPLACE) != TDB_ERR_LOCK)
+				return 1;
+
+			if (tdb_fetch(tdb, key, &data) != TDB_ERR_LOCK)
+				return 1;
+
+			if (tap_log_messages != 2)
+				return 2;
+
+			tdb_unlockall_read(tdb);
+			if (tap_log_messages != 2)
+				return 3;
+			tdb_close(tdb);
+			if (tap_log_messages != 2)
+				return 4;
+			return 0;
+		}
+		wait(&status);
+		ok1(WIFEXITED(status) && WEXITSTATUS(status) == 0);
+		tdb_unlockall_read(tdb);
+
+		ok1(tdb_transaction_start(tdb) == TDB_SUCCESS);
+		/* If transactions is empty, noop "commit" succeeds. */
+		ok1(tdb_delete(tdb, key) == TDB_SUCCESS);
+		if (fork() == 0) {
+			/* We expect this to fail. */
+			if (tdb_store(tdb, key, data, TDB_REPLACE) != TDB_ERR_LOCK)
+				return 1;
+
+			if (tdb_fetch(tdb, key, &data) != TDB_ERR_LOCK)
+				return 1;
+
+			if (tap_log_messages != 2)
+				return 2;
+
+			if (tdb_transaction_commit(tdb) != TDB_ERR_LOCK)
+				return 3;
+
+			tdb_close(tdb);
+			if (tap_log_messages < 3)
+				return 4;
+			return 0;
+		}
+		wait(&status);
+		ok1(WIFEXITED(status) && WEXITSTATUS(status) == 0);
+		tdb_transaction_cancel(tdb);
+
+		ok1(tdb_parse_record(tdb, key, fork_in_parse, tdb)
+		    == TDB_SUCCESS);
+		tdb_close(tdb);
+		ok1(tap_log_messages == 0);
+	}
+	return exit_status();
+}