/*

 * windowsaio engine

 *

 * IO engine using Windows IO Completion Ports.

 */

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#include <signal.h>

#include <errno.h>

#include "../fio.h"

typedef BOOL (WINAPI *CANCELIOEX)(HANDLE hFile, LPOVERLAPPED lpOverlapped);

int geterrno_from_win_error (DWORD code, int deferrno);

struct fio_overlapped {

	OVERLAPPED o;

	struct io_u *io_u;

	BOOL io_complete;

};

struct windowsaio_data {

	struct io_u **aio_events;

	HANDLE iocp;

	HANDLE iothread;

	HANDLE iocomplete_event;

	BOOL iothread_running;

};

struct thread_ctx {

	HANDLE iocp;

	struct windowsaio_data *wd;

};

static DWORD WINAPI IoCompletionRoutine(LPVOID lpParameter);

static int fio_windowsaio_init(struct thread_data *td)

{

	struct windowsaio_data *wd;

	int rc = 0;

	wd = calloc(1, sizeof(struct windowsaio_data));

	if (wd == NULL) {

		 log_err("windowsaio: failed to allocate memory for engine data\n");

		rc = 1;

	}

	if (!rc) {

		wd->aio_events = malloc(td->o.iodepth * sizeof(struct io_u*));

		if (wd->aio_events == NULL) {

			log_err("windowsaio: failed to allocate memory for aio events list\n");

			rc = 1;

		}

	}

	if (!rc) {

		/* Create an auto-reset event */

		wd->iocomplete_event = CreateEvent(NULL, FALSE, FALSE, NULL);

		if (wd->iocomplete_event == NULL) {

			log_err("windowsaio: failed to create io complete event handle\n");

			rc = 1;

		}

	}

	if (rc) {

		if (wd != NULL) {

			if (wd->aio_events != NULL)

				free(wd->aio_events);

			free(wd);

		}

	}

	td->io_ops_data = wd;

	if (!rc) {

		struct thread_ctx *ctx;

		struct windowsaio_data *wd;

		HANDLE hFile;

		hFile = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, 0);

		if (hFile == INVALID_HANDLE_VALUE) {

			log_err("windowsaio: failed to create io completion port\n");

			rc = 1;

		}

		wd = td->io_ops_data;

		wd->iothread_running = TRUE;

		wd->iocp = hFile;

		if (!rc)

			ctx = malloc(sizeof(struct thread_ctx));

		if (!rc && ctx == NULL) {

			log_err("windowsaio: failed to allocate memory for thread context structure\n");

			CloseHandle(hFile);

			rc = 1;

		}

		if (!rc) {

			DWORD threadid;

			ctx->iocp = hFile;

			ctx->wd = wd;

			wd->iothread = CreateThread(NULL, 0, IoCompletionRoutine, ctx, 0, &threadid);

			if (wd->iothread != NULL)

				fio_setaffinity(threadid, td->o.cpumask);

			else

				log_err("windowsaio: failed to create io completion thread\n");

		}

		if (rc || wd->iothread == NULL)

			rc = 1;

	}

	return rc;

}

static void fio_windowsaio_cleanup(struct thread_data *td)

{

	struct windowsaio_data *wd;

	wd = td->io_ops_data;

	if (wd != NULL) {

		wd->iothread_running = FALSE;

		WaitForSingleObject(wd->iothread, INFINITE);

		CloseHandle(wd->iothread);

		CloseHandle(wd->iocomplete_event);

		free(wd->aio_events);

		free(wd);

		td->io_ops_data = NULL;

	}

}

static int windowsaio_invalidate_cache(struct fio_file *f)

{

	DWORD error;

	DWORD isharemode = (FILE_SHARE_DELETE | FILE_SHARE_READ |

				FILE_SHARE_WRITE);

	HANDLE ihFile;

	int rc = 0;

	/*

	 * Encourage Windows to drop cached parts of a file by temporarily

	 * opening it for non-buffered access. Note: this will only work when

	 * the following is the only thing with the file open on the whole

	 * system.

	 */

	dprint(FD_IO, "windowaio: attempt invalidate cache for %s\n",

			f->file_name);

	ihFile = CreateFile(f->file_name, 0, isharemode, NULL, OPEN_EXISTING,

			FILE_FLAG_NO_BUFFERING, NULL);

	if (ihFile != INVALID_HANDLE_VALUE) {

		if (!CloseHandle(ihFile)) {

			error = GetLastError();

			log_info("windowsaio: invalidation fd close %s "

				 "failed: error %d\n", f->file_name, error);

			rc = 1;

		}

	} else {

		error = GetLastError();

		if (error != ERROR_FILE_NOT_FOUND) {

			log_info("windowsaio: cache invalidation of %s failed: "

					"error %d\n", f->file_name, error);

			rc = 1;

		}

	}

	return rc;

}

static int fio_windowsaio_open_file(struct thread_data *td, struct fio_file *f)

{

	int rc = 0;

	DWORD flags = FILE_FLAG_POSIX_SEMANTICS | FILE_FLAG_OVERLAPPED;

	DWORD sharemode = FILE_SHARE_READ | FILE_SHARE_WRITE;

	DWORD openmode = OPEN_ALWAYS;

	DWORD access;

	dprint(FD_FILE, "fd open %s\n", f->file_name);

	if (f->filetype == FIO_TYPE_PIPE) {

		log_err("windowsaio: pipes are not supported\n");

		return 1;

	}

	if (!strcmp(f->file_name, "-")) {

		log_err("windowsaio: can't read/write to stdin/out\n");

		return 1;

	}

	if (td->o.odirect)

		flags |= FILE_FLAG_NO_BUFFERING;

	if (td->o.sync_io)

		flags |= FILE_FLAG_WRITE_THROUGH;

	/*

	 * Inform Windows whether we're going to be doing sequential or

	 * random IO so it can tune the Cache Manager

	 */

	switch (td->o.fadvise_hint) {

	case F_ADV_TYPE:

		if (td_random(td))

			flags |= FILE_FLAG_RANDOM_ACCESS;

		else

			flags |= FILE_FLAG_SEQUENTIAL_SCAN;

		break;

	case F_ADV_RANDOM:

		flags |= FILE_FLAG_RANDOM_ACCESS;

		break;

	case F_ADV_SEQUENTIAL:

		flags |= FILE_FLAG_SEQUENTIAL_SCAN;

		break;

	case F_ADV_NONE:

		break;

	default:

		log_err("fio: unknown fadvise type %d\n", td->o.fadvise_hint);

	}

	if (!td_write(td) || read_only)

		access = GENERIC_READ;

	else

		access = (GENERIC_READ | GENERIC_WRITE);

	if (td->o.create_on_open)

		openmode = OPEN_ALWAYS;

	else

		openmode = OPEN_EXISTING;

	/* If we're going to use direct I/O, Windows will try and invalidate

	 * its cache at that point so there's no need to do it here */

	if (td->o.invalidate_cache && !td->o.odirect)

		windowsaio_invalidate_cache(f);

	f->hFile = CreateFile(f->file_name, access, sharemode,

		NULL, openmode, flags, NULL);

	if (f->hFile == INVALID_HANDLE_VALUE) {

		log_err("windowsaio: failed to open file \"%s\"\n", f->file_name);

		rc = 1;

	}

	/* Only set up the completion port and thread if we're not just

	 * querying the device size */

	if (!rc && td->io_ops_data != NULL) {

		struct windowsaio_data *wd;

		wd = td->io_ops_data;

		if (CreateIoCompletionPort(f->hFile, wd->iocp, 0, 0) == NULL) {

			log_err("windowsaio: failed to create io completion port\n");

			rc = 1;

		}

	}

	return rc;

}

static int fio_windowsaio_close_file(struct thread_data fio_unused *td, struct fio_file *f)

{

	int rc = 0;

	dprint(FD_FILE, "fd close %s\n", f->file_name);

	if (f->hFile != INVALID_HANDLE_VALUE) {

		if (!CloseHandle(f->hFile)) {

			log_info("windowsaio: failed to close file handle for \"%s\"\n", f->file_name);

			rc = 1;

		}

	}

	f->hFile = INVALID_HANDLE_VALUE;

	return rc;

}

static BOOL timeout_expired(DWORD start_count, DWORD end_count)

{

	BOOL expired = FALSE;

	DWORD current_time;

	current_time = GetTickCount();

	if ((end_count > start_count) && current_time >= end_count)

		expired = TRUE;

	else if (current_time < start_count && current_time > end_count)

		expired = TRUE;

	return expired;

}

static struct io_u* fio_windowsaio_event(struct thread_data *td, int event)

{

	struct windowsaio_data *wd = td->io_ops_data;

	return wd->aio_events[event];

}

static int fio_windowsaio_getevents(struct thread_data *td, unsigned int min,

				    unsigned int max,

				    const struct timespec *t)

{

	struct windowsaio_data *wd = td->io_ops_data;

	unsigned int dequeued = 0;

	struct io_u *io_u;

	int i;

	struct fio_overlapped *fov;

	DWORD start_count = 0;

	DWORD end_count = 0;

	DWORD status;

	DWORD mswait = 250;

	if (t != NULL) {

		mswait = (t->tv_sec * 1000) + (t->tv_nsec / 1000000);

		start_count = GetTickCount();

		end_count = start_count + (t->tv_sec * 1000) + (t->tv_nsec / 1000000);

	}

	do {

		io_u_qiter(&td->io_u_all, io_u, i) {

			if (!(io_u->flags & IO_U_F_FLIGHT))

				continue;

			fov = (struct fio_overlapped*)io_u->engine_data;

			if (fov->io_complete) {

				fov->io_complete = FALSE;

				wd->aio_events[dequeued] = io_u;

				dequeued++;

			}

		}

		if (dequeued >= min)

			break;

		if (dequeued < min) {

			status = WaitForSingleObject(wd->iocomplete_event, mswait);

			if (status != WAIT_OBJECT_0 && dequeued >= min)

				break;

		}

		if (dequeued >= min ||

		    (t != NULL && timeout_expired(start_count, end_count)))

			break;

	} while (1);

	return dequeued;

}

static enum fio_q_status fio_windowsaio_queue(struct thread_data *td,

					      struct io_u *io_u)

{

	struct fio_overlapped *o = io_u->engine_data;

	LPOVERLAPPED lpOvl = &o->o;

	BOOL success = FALSE;

	int rc = FIO_Q_COMPLETED;

	fio_ro_check(td, io_u);

	lpOvl->Internal = 0;

	lpOvl->InternalHigh = 0;

	lpOvl->Offset = io_u->offset & 0xFFFFFFFF;

	lpOvl->OffsetHigh = io_u->offset >> 32;

	switch (io_u->ddir) {

	case DDIR_WRITE:

		success = WriteFile(io_u->file->hFile, io_u->xfer_buf,

					io_u->xfer_buflen, NULL, lpOvl);

		break;

	case DDIR_READ:

		success = ReadFile(io_u->file->hFile, io_u->xfer_buf,

					io_u->xfer_buflen, NULL, lpOvl);

		break;

	case DDIR_SYNC:

	case DDIR_DATASYNC:

	case DDIR_SYNC_FILE_RANGE:

		success = FlushFileBuffers(io_u->file->hFile);

		if (!success) {

			log_err("windowsaio: failed to flush file buffers\n");

			io_u->error = win_to_posix_error(GetLastError());

		}

		return FIO_Q_COMPLETED;

	case DDIR_TRIM:

		log_err("windowsaio: manual TRIM isn't supported on Windows\n");

		io_u->error = 1;

		io_u->resid = io_u->xfer_buflen;

		return FIO_Q_COMPLETED;

	default:

		assert(0);

		break;

	}

	if (success || GetLastError() == ERROR_IO_PENDING)

		rc = FIO_Q_QUEUED;

	else {

		io_u->error = win_to_posix_error(GetLastError());

		io_u->resid = io_u->xfer_buflen;

	}

	return rc;

}

/* Runs as a thread and waits for queued IO to complete */

static DWORD WINAPI IoCompletionRoutine(LPVOID lpParameter)

{

	OVERLAPPED *ovl;

	struct fio_overlapped *fov;

	struct io_u *io_u;

	struct windowsaio_data *wd;

	struct thread_ctx *ctx;

	ULONG_PTR ulKey = 0;

	DWORD bytes;

	ctx = (struct thread_ctx*)lpParameter;

	wd = ctx->wd;

	do {

		BOOL ret;

		ret = GetQueuedCompletionStatus(ctx->iocp, &bytes, &ulKey,

						&ovl, 250);

		if (!ret && ovl == NULL)

			continue;

		fov = CONTAINING_RECORD(ovl, struct fio_overlapped, o);

		io_u = fov->io_u;

		if (ovl->Internal == ERROR_SUCCESS) {

			io_u->resid = io_u->xfer_buflen - ovl->InternalHigh;

			io_u->error = 0;

		} else {

			io_u->resid = io_u->xfer_buflen;

			io_u->error = win_to_posix_error(GetLastError());

		}

		fov->io_complete = TRUE;

		SetEvent(wd->iocomplete_event);

	} while (ctx->wd->iothread_running);

	CloseHandle(ctx->iocp);

	free(ctx);

	return 0;

}

static void fio_windowsaio_io_u_free(struct thread_data *td, struct io_u *io_u)

{

	struct fio_overlapped *o = io_u->engine_data;

	if (o) {

		io_u->engine_data = NULL;

		free(o);

	}

}

static int fio_windowsaio_io_u_init(struct thread_data *td, struct io_u *io_u)

{

	struct fio_overlapped *o;

	o = malloc(sizeof(*o));

	o->io_complete = FALSE;

	o->io_u = io_u;

	o->o.hEvent = NULL;

	io_u->engine_data = o;

	return 0;

}

static struct ioengine_ops ioengine = {

	.name		= "windowsaio",

	.version	= FIO_IOOPS_VERSION,

	.init		= fio_windowsaio_init,

	.queue		= fio_windowsaio_queue,

	.getevents	= fio_windowsaio_getevents,

	.event		= fio_windowsaio_event,

	.cleanup	= fio_windowsaio_cleanup,

	.open_file	= fio_windowsaio_open_file,

	.close_file	= fio_windowsaio_close_file,

	.get_file_size	= generic_get_file_size,

	.io_u_init	= fio_windowsaio_io_u_init,

	.io_u_free	= fio_windowsaio_io_u_free,

};

static void fio_init fio_windowsaio_register(void)

{

	register_ioengine(&ioengine);

}

static void fio_exit fio_windowsaio_unregister(void)

{

	unregister_ioengine(&ioengine);

}