--- /dev/null
+#include <ccan/tdb2/tdb2.h>
+#include <ccan/tap/tap.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <errno.h>
+#include "logging.h"
+#include "external-agent.h"
+
+#undef alarm
+#define alarm fast_alarm
+
+/* Speed things up by doing things in milliseconds. */
+static unsigned int fast_alarm(unsigned int milli_seconds)
+{
+ struct itimerval it;
+
+ it.it_interval.tv_sec = it.it_interval.tv_usec = 0;
+ it.it_value.tv_sec = milli_seconds / 1000;
+ it.it_value.tv_usec = milli_seconds * 1000;
+ setitimer(ITIMER_REAL, &it, NULL);
+ return 0;
+}
+
+#define CatchSignal(sig, handler) signal((sig), (handler))
+
+static void do_nothing(int signum)
+{
+}
+
+/* This example code is taken from SAMBA, so try not to change it. */
+static struct flock flock_struct;
+
+/* Return a value which is none of v1, v2 or v3. */
+static inline short int invalid_value(short int v1, short int v2, short int v3)
+{
+ short int try = (v1+v2+v3)^((v1+v2+v3) << 16);
+ while (try == v1 || try == v2 || try == v3)
+ try++;
+ return try;
+}
+
+/* We invalidate in as many ways as we can, so the OS rejects it */
+static void invalidate_flock_struct(int signum)
+{
+ flock_struct.l_type = invalid_value(F_RDLCK, F_WRLCK, F_UNLCK);
+ flock_struct.l_whence = invalid_value(SEEK_SET, SEEK_CUR, SEEK_END);
+ flock_struct.l_start = -1;
+ /* A large negative. */
+ flock_struct.l_len = (((off_t)1 << (sizeof(off_t)*CHAR_BIT - 1)) + 1);
+}
+
+static int timeout_lock(int fd, int rw, off_t off, off_t len, bool waitflag,
+ void *_timeout)
+{
+ int ret, saved_errno = errno;
+ unsigned int timeout = *(unsigned int *)_timeout;
+
+ flock_struct.l_type = rw;
+ flock_struct.l_whence = SEEK_SET;
+ flock_struct.l_start = off;
+ flock_struct.l_len = len;
+
+ CatchSignal(SIGALRM, invalidate_flock_struct);
+ alarm(timeout);
+
+ for (;;) {
+ if (waitflag)
+ ret = fcntl(fd, F_SETLKW, &flock_struct);
+ else
+ ret = fcntl(fd, F_SETLK, &flock_struct);
+
+ if (ret == 0)
+ break;
+
+ /* Not signalled? Something else went wrong. */
+ if (flock_struct.l_len == len) {
+ if (errno == EAGAIN || errno == EINTR)
+ continue;
+ saved_errno = errno;
+ break;
+ } else {
+ saved_errno = EINTR;
+ break;
+ }
+ }
+
+ alarm(0);
+ errno = saved_errno;
+ return ret;
+}
+
+static int tdb_chainlock_with_timeout_internal(struct tdb_context *tdb,
+ TDB_DATA key,
+ unsigned int timeout,
+ int rw_type)
+{
+ union tdb_attribute locking;
+ enum TDB_ERROR ecode;
+
+ if (timeout) {
+ locking.base.attr = TDB_ATTRIBUTE_FLOCK;
+ ecode = tdb_get_attribute(tdb, &locking);
+ if (ecode != TDB_SUCCESS)
+ return ecode;
+
+ /* Replace locking function with our own. */
+ locking.flock.data = &timeout;
+ locking.flock.lock = timeout_lock;
+
+ ecode = tdb_set_attribute(tdb, &locking);
+ if (ecode != TDB_SUCCESS)
+ return ecode;
+ }
+ if (rw_type == F_RDLCK)
+ ecode = tdb_chainlock_read(tdb, key);
+ else
+ ecode = tdb_chainlock(tdb, key);
+
+ if (timeout) {
+ tdb_unset_attribute(tdb, TDB_ATTRIBUTE_FLOCK);
+ }
+ return ecode;
+}
+
+int main(int argc, char *argv[])
+{
+ unsigned int i;
+ struct tdb_context *tdb;
+ TDB_DATA key = tdb_mkdata("hello", 5);
+ int flags[] = { TDB_DEFAULT, TDB_NOMMAP,
+ TDB_CONVERT, TDB_NOMMAP|TDB_CONVERT,
+ TDB_VERSION1, TDB_NOMMAP|TDB_VERSION1,
+ TDB_CONVERT|TDB_VERSION1,
+ TDB_NOMMAP|TDB_CONVERT|TDB_VERSION1 };
+ struct agent *agent;
+
+ plan_tests(sizeof(flags) / sizeof(flags[0]) * 15);
+
+ agent = prepare_external_agent();
+
+ for (i = 0; i < sizeof(flags) / sizeof(flags[0]); i++) {
+ enum TDB_ERROR ecode;
+ tdb = tdb_open("run-locktimeout.tdb", flags[i],
+ O_RDWR|O_CREAT|O_TRUNC, 0600, &tap_log_attr);
+ if (!ok1(tdb))
+ break;
+
+ /* Simple cases: should succeed. */
+ ecode = tdb_chainlock_with_timeout_internal(tdb, key, 20,
+ F_RDLCK);
+ ok1(ecode == TDB_SUCCESS);
+ ok1(tap_log_messages == 0);
+
+ tdb_chainunlock_read(tdb, key);
+ ok1(tap_log_messages == 0);
+
+ ecode = tdb_chainlock_with_timeout_internal(tdb, key, 20,
+ F_WRLCK);
+ ok1(ecode == TDB_SUCCESS);
+ ok1(tap_log_messages == 0);
+
+ tdb_chainunlock(tdb, key);
+ ok1(tap_log_messages == 0);
+
+ /* OK, get agent to start transaction, then we should time out. */
+ ok1(external_agent_operation(agent, OPEN, "run-locktimeout.tdb")
+ == SUCCESS);
+ ok1(external_agent_operation(agent, TRANSACTION_START, "")
+ == SUCCESS);
+ ecode = tdb_chainlock_with_timeout_internal(tdb, key, 20,
+ F_WRLCK);
+ ok1(ecode == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 0);
+
+ /* Even if we get a different signal, should be fine. */
+ CatchSignal(SIGUSR1, do_nothing);
+ external_agent_operation(agent, SEND_SIGNAL, "");
+ ecode = tdb_chainlock_with_timeout_internal(tdb, key, 20,
+ F_WRLCK);
+ ok1(ecode == TDB_ERR_LOCK);
+ ok1(tap_log_messages == 0);
+
+ ok1(external_agent_operation(agent, TRANSACTION_COMMIT, "")
+ == SUCCESS);
+ ok1(external_agent_operation(agent, CLOSE, "")
+ == SUCCESS);
+ tdb_close(tdb);
+ }
+ free_external_agent(agent);
+ return exit_status();
+}
projects / ccan / blobdiff