Neaten tdb to sync with samba version of locking fix.

[ccan] / ccan / tdb / test / external-transaction.c

diff --git a/ccan/tdb/test/external-transaction.c b/ccan/tdb/test/external-transaction.c
new file mode 100644 (file)
index 0000000..c1442c2
--- /dev/null
+++ b/ccan/tdb/test/external-transaction.c
@@ -0,0 +1,107 @@
+#include "external-transaction.h"
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <err.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <limits.h>
+#include <string.h>
+#include <ccan/tdb/tdb.h>
+
+static volatile sig_atomic_t alarmed;
+static void do_alarm(int signum)
+{
+       alarmed++;
+}
+
+static int do_transaction(const char *name)
+{
+       TDB_DATA k = { .dptr = (void *)"a", .dsize = 1 };
+       TDB_DATA d = { .dptr = (void *)"b", .dsize = 1 };
+       struct tdb_context *tdb = tdb_open(name, 0, 0, O_RDWR, 0);
+
+       if (!tdb)
+               return -1;
+
+       alarmed = 0;
+       tdb_setalarm_sigptr(tdb, &alarmed);
+
+       alarm(1);
+       if (tdb_transaction_start(tdb) != 0)
+               goto maybe_alarmed;
+
+       if (tdb_store(tdb, k, d, 0) != 0) {
+               tdb_transaction_cancel(tdb);
+               tdb_close(tdb);
+               return -2;
+       }
+
+       if (tdb_transaction_commit(tdb) == 0) {
+               tdb_delete(tdb, k);
+               tdb_close(tdb);
+               return 1;
+       }
+
+       tdb_delete(tdb, k);
+maybe_alarmed:
+       tdb_close(tdb);
+       if (alarmed)
+               return 0;
+       return -3;
+}
+
+
+/* Do this before doing any tdb stuff.  Return handle, or -1. */
+int prepare_external_agent(void)
+{
+       int pid;
+       int command[2], response[2];
+       struct sigaction act = { .sa_handler = do_alarm };
+       char name[PATH_MAX];
+
+       if (pipe(command) != 0 || pipe(response) != 0)
+               return -1;
+
+       pid = fork();
+       if (pid < 0)
+               return -1;
+
+       if (pid != 0) {
+               close(command[0]);
+               close(response[1]);
+               /* FIXME: Make fds consective. */
+               dup2(command[1]+1, response[1]);
+               return command[1];
+       }
+
+       close(command[1]);
+       close(response[0]);
+       sigaction(SIGALRM, &act, NULL);
+
+       while (read(command[0], name, sizeof(name)) != 0) {
+               int result = do_transaction(name);
+               if (write(response[1], &result, sizeof(result))
+                   != sizeof(result))
+                       err(1, "Writing response");
+       }
+       exit(0);
+}
+
+/* Ask the external agent to try to do a transaction. */
+bool external_agent_transaction(int handle, const char *tdbname)
+{
+       int res;
+
+       if (write(handle, tdbname, strlen(tdbname)+1)
+           != strlen(tdbname)+1)
+               err(1, "Writing to agent");
+
+       if (read(handle+1, &res, sizeof(res)) != sizeof(res))
+               err(1, "Reading from agent");
+
+       if (res > 1)
+               errx(1, "Agent returned %u\n", res);
+
+       return res;
+}