X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=engines%2Fnull.c;h=4378f5e2f8ec21d3d7c51f0758b9532af13bb564;hp=695afa11af0a1ebeedade04e23c5c6d7c1b1a12a;hb=465920381b80d2a6ee472f498e7d7444a310160b;hpb=2fd233b7302603fb6fd9b7098994d2a155cf7a22

diff --git a/engines/null.c b/engines/null.c
index 695afa11..4378f5e2 100644
--- a/engines/null.c
+++ b/engines/null.c
@@ -1,5 +1,12 @@
 /*
- * 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.
+ *
+ * It also can act as external C++ engine - compiled with:
+ *
+ * g++ -O2 -g -shared -rdynamic -fPIC -o null.so null.c -DFIO_EXTERNAL_ENGINE
  *
  */
 #include <stdio.h>
@@ -9,44 +16,109 @@
 #include <assert.h>
 
 #include "../fio.h"
-#include "../os.h"
 
-static int fio_null_queue(struct thread_data fio_unused *td, struct io_u *io_u)
+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)
 {
-	io_u->resid = 0;
-	io_u->error = 0;
-	return FIO_Q_COMPLETED;
+	struct null_data *nd = (struct null_data *) td->io_ops_data;
+
+	return nd->io_us[event];
 }
 
-static int fio_null_setup(struct thread_data *td)
+static int fio_null_getevents(struct thread_data *td, unsigned int min_events,
+			      unsigned int fio_unused max,
+			      const struct timespec fio_unused *t)
 {
-	struct fio_file *f;
-	int i;
+	struct null_data *nd = (struct null_data *) td->io_ops_data;
+	int ret = 0;
+	
+	if (min_events) {
+		ret = nd->events;
+		nd->events = 0;
+	}
 
-	if (!td->total_file_size) {
-		log_err("fio: need size= set\n");
-		return 1;
+	return ret;
+}
+
+static int fio_null_commit(struct thread_data *td)
+{
+	struct null_data *nd = (struct null_data *) td->io_ops_data;
+
+	if (!nd->events) {
+#ifndef FIO_EXTERNAL_ENGINE
+		io_u_mark_submit(td, nd->queued);
+#endif
+		nd->events = nd->queued;
+		nd->queued = 0;
 	}
 
-	td->io_size = td->total_file_size;
-	td->total_io_size = td->io_size;
+	return 0;
+}
+
+static int fio_null_queue(struct thread_data *td, struct io_u *io_u)
+{
+	struct null_data *nd = (struct null_data *) td->io_ops_data;
+
+	fio_ro_check(td, io_u);
+
+	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_open(struct thread_data fio_unused *td,
+			 struct fio_file fio_unused *f)
+{
+	return 0;
+}
+
+static void fio_null_cleanup(struct thread_data *td)
+{
+	struct null_data *nd = (struct null_data *) td->io_ops_data;
 
-	for_each_file(td, f, i) {
-		f->fd = dup(STDOUT_FILENO);
-		f->real_file_size = td->total_io_size / td->nr_files;
-		f->file_size = f->real_file_size;
+	if (nd) {
+		free(nd->io_us);
+		free(nd);
 	}
+}
+
+static int fio_null_init(struct thread_data *td)
+{
+	struct null_data *nd = (struct null_data *) malloc(sizeof(*nd));
+
+	memset(nd, 0, sizeof(*nd));
 
-	td->nr_open_files = td->nr_files;
+	if (td->o.iodepth != 1) {
+		nd->io_us = (struct io_u **) 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;
 }
 
+#ifndef __cplusplus
 static struct ioengine_ops ioengine = {
 	.name		= "null",
 	.version	= FIO_IOOPS_VERSION,
-	.setup		= fio_null_setup,
 	.queue		= fio_null_queue,
-	.flags		= FIO_SYNCIO | FIO_DISKLESSIO | FIO_SELFOPEN,
+	.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_DISKLESSIO | FIO_FAKEIO,
 };
 
 static void fio_init fio_null_register(void)
@@ -58,3 +130,30 @@ static void fio_exit fio_null_unregister(void)
 {
 	unregister_ioengine(&ioengine);
 }
+
+#else
+
+#ifdef FIO_EXTERNAL_ENGINE
+extern "C" {
+void get_ioengine(struct ioengine_ops **ioengine_ptr)
+{
+	struct ioengine_ops *ioengine;
+
+	*ioengine_ptr = (struct ioengine_ops *) malloc(sizeof(struct ioengine_ops));
+	ioengine = *ioengine_ptr;
+
+	ioengine->name           = "cpp_null";
+	ioengine->version        = FIO_IOOPS_VERSION;
+	ioengine->queue          = fio_null_queue;
+	ioengine->commit         = fio_null_commit;
+	ioengine->getevents      = fio_null_getevents;
+	ioengine->event          = fio_null_event;
+	ioengine->init           = fio_null_init;
+	ioengine->cleanup        = fio_null_cleanup;
+	ioengine->open_file      = fio_null_open;
+	ioengine->flags	         = FIO_DISKLESSIO | FIO_FAKEIO;
+}
+}
+#endif /* FIO_EXTERNAL_ENGINE */
+
+#endif /* __cplusplus */