NULL engine: ->commit() has side effects, make sure it always works

[fio.git] / engines / null.c

diff --git a/engines/null.c b/engines/null.c
index 7f45bd97ea4988ac84ce307d82715dfcf73e4d70..86b9cbd3929e286a36c098c65cd36278e84c794c 100644 (file)
--- a/engines/null.c
+++ b/engines/null.c
@@ -1,5 +1,8 @@
 /*
- * null engine - doesn't do any transfers. Used to test fio.
+ * null engine
+ *
+ * IO engine that doesn't do any real IO transfers, it just pretends to.
+ * The main purpose is to test fio itself.
  *
  */
 #include <stdio.h>
@@ -11,39 +14,111 @@
 #include "../fio.h"
 #include "../os.h"
 
+struct null_data {
+       struct io_u **io_us;
+       int queued;
+       int events;
+};
+
+static struct io_u *fio_null_event(struct thread_data *td, int event)
+{
+       struct null_data *nd = td->io_ops->data;
+
+       return nd->io_us[event];
+}
+
+static int fio_null_getevents(struct thread_data *td, int min_events,
+                             int fio_unused max, struct timespec fio_unused *t)
+{
+       struct null_data *nd = td->io_ops->data;
+       int ret = 0;
+       
+       if (min_events) {
+               ret = nd->events;
+               nd->events = 0;
+       }
+
+       return ret;
+}
+
+static int fio_null_commit(struct thread_data *td)
+{
+       struct null_data *nd = td->io_ops->data;
+
+       if (!nd->events) {
+               nd->events = nd->queued;
+               nd->queued = 0;
+       }
+
+       return 0;
+}
+
 static int fio_null_queue(struct thread_data fio_unused *td, struct io_u *io_u)
 {
-       io_u->resid = 0;
-       io_u->error = 0;
-       return FIO_Q_COMPLETED;
+       struct null_data *nd = td->io_ops->data;
+
+       if (td->io_ops->flags & FIO_SYNCIO)
+               return FIO_Q_COMPLETED;
+       if (nd->events)
+               return FIO_Q_BUSY;
+
+       nd->io_us[nd->queued++] = io_u;
+       return FIO_Q_QUEUED;
 }
 
 static int fio_null_setup(struct thread_data *td)
 {
        struct fio_file *f;
-       int i;
+       unsigned int i;
 
-       if (!td->total_file_size) {
+       if (!td->o.size) {
                log_err("fio: need size= set\n");
                return 1;
        }
 
-       td->io_size = td->total_file_size;
+       td->io_size = td->o.size;
        td->total_io_size = td->io_size;
 
        for_each_file(td, f, i) {
-               f->fd = dup(STDOUT_FILENO);
-               f->real_file_size = td->total_io_size / td->nr_files;
+               f->real_file_size = td->total_io_size / td->o.nr_files;
                f->file_size = f->real_file_size;
        }
 
-       td->nr_open_files = td->nr_files;
        return 0;
 }
 
 static int fio_null_open(struct thread_data fio_unused *td,
                         struct fio_file fio_unused *f)
 {
+       f->fd = 0;
+       return 0;
+}
+
+static void fio_null_cleanup(struct thread_data *td)
+{
+       struct null_data *nd = td->io_ops->data;
+
+       if (nd) {
+               if (nd->io_us)
+                       free(nd->io_us);
+               free(nd);
+               td->io_ops->data = NULL;
+       }
+}
+
+static int fio_null_init(struct thread_data *td)
+{
+       struct null_data *nd = malloc(sizeof(*nd));
+
+       memset(nd, 0, sizeof(*nd));
+
+       if (td->o.iodepth != 1) {
+               nd->io_us = malloc(td->o.iodepth * sizeof(struct io_u *));
+               memset(nd->io_us, 0, td->o.iodepth * sizeof(struct io_u *));
+       } else
+               td->io_ops->flags |= FIO_SYNCIO;
+
+       td->io_ops->data = nd;
        return 0;
 }
 
@@ -52,8 +127,13 @@ static struct ioengine_ops ioengine = {
        .version        = FIO_IOOPS_VERSION,
        .setup          = fio_null_setup,
        .queue          = fio_null_queue,
+       .commit         = fio_null_commit,
+       .getevents      = fio_null_getevents,
+       .event          = fio_null_event,
+       .init           = fio_null_init,
+       .cleanup        = fio_null_cleanup,
        .open_file      = fio_null_open,
-       .flags          = FIO_SYNCIO | FIO_DISKLESSIO,
+       .flags          = FIO_DISKLESSIO,
 };
 
 static void fio_init fio_null_register(void)