Re: [dpdk-dev] [PATCH 2/2] timer: support EAL functions on Windows

[Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>]

On 2020-04-23 17:43 GMT+0300 Fady Bader wrote:
[snip]
> diff --git a/lib/librte_eal/windows/eal_timer.c b/lib/librte_eal/windows/eal_timer.c
> new file mode 100644
> index 000000000..73eaff948
> --- /dev/null
> +++ b/lib/librte_eal/windows/eal_timer.c
> @@ -0,0 +1,67 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright 2020 Mellanox Technologies, Ltd
> + */
> +#include <inttypes.h>
> +#include <time.h>
> +
> +#include <rte_windows.h>
> +#include <rte_common.h>
> +#include <rte_log.h>
> +#include <rte_cycles.h>
> +#include <rte_eal.h>
> +#include <rte_errno.h>
> +
> +/* The frequency of the RDTSC timer resolution */
> +static uint64_t eal_tsc_resolution_hz;
> +
> +void
> +rte_delay_us_sleep(unsigned int us)
> +{
> +	LONGLONG ns = us * 1000;
> +	HANDLE timer;
> +	LARGE_INTEGER liDueTime;

Shouldn't Windows code follow DPDK naming conventions?

> +	/* create waitable timer */
> +	timer = CreateWaitableTimer(NULL, TRUE, NULL);
> +	if(!timer){

Missing spaces. There are more styling issues below that could be detected by
running ./devtools/checkpatches.sh.

> +		/* didnt find any better errno val */
> +		rte_errno = EINVAL;
> +		return;

ENOMEM probably indicates lack of resources better. EINVAL usually implies
wrong arguments to the function. You can also use RTE_WIN32_LOG_ERR() here to
log exact error code on debug level.

> +	}
> +
> +	/* set us microseconds time for timer */
> +	liDueTime.QuadPart = -ns;

Timeout is neither in microseconds, nor in nanoseconds, it's in 100-nanosecond
intervals.

> +	if(!SetWaitableTimer(timer, &liDueTime, 0, NULL, NULL, FALSE)){
> +		CloseHandle(timer);
> +		/* didnt find any better errno val */
> +		rte_errno = EFAULT;

And here, EINVAL is probably better, because result depends on function
argument and this probably will be the most frequent source of errors.

> +		return;
> +	}
> +	/* start wait for timer for us microseconds */
> +	WaitForSingleObject(timer, INFINITE);
> +	CloseHandle(timer);
> +}
[snip]
> diff --git a/lib/librte_eal/windows/include/rte_os.h b/lib/librte_eal/windows/include/rte_os.h
> index 62805a307..951a14d72 100644
> --- a/lib/librte_eal/windows/include/rte_os.h
> +++ b/lib/librte_eal/windows/include/rte_os.h
> @@ -24,6 +24,8 @@ extern "C" {
>  #define PATH_MAX _MAX_PATH
>  #endif
>  
> +#define sleep(x) Sleep(1000 * x)

It's better to enclose "x" in parentheses or to use inline function.

-- 
Dmitry Kozlyuk