Hello!

On Mon, Sep 20, 2010 at 07:32:44PM +0200, Roberto De Ioris wrote:

>
> This is a patch to add $unixtime to the http variables.
>
> It simply contains the output of time(NULL)
>
> It could be useful to measure the time between the send
> of a request to an upstream module and the time the application
> server process it.
>
> Example:
>
> uwsgi_param UWSGI_TIME $unixtime;
>
> Then in your app:
>
> if int(time.time()) - int(env['UWSGI_TIME']):
> print "*** SYSTEM IS RESPONDING SLOWLY ***"

This won't work as you expect since request to upstream is created
once and used when sending request to multiple upstream servers
(due to proxy_next_upstream/fastcgi_next_upstream/...). Logging
$upstream_response_time would be better idea.

> I do not know if it is better to name it $time instead of $unixtime...

If you just need current system time as a variable - I would
recommend moving $msec from log module to generic variables
instead. Or, probably, duplicating it - as log variable will be
more efficient during logging than generic one.

>
>
> --- src/http/ngx_http_variables.c 2010-06-23 17:31:33.000000000 +0200
> +++ ../nginx-ok/src/http/ngx_http_variables.c 2010-09-20
> 19:24:57.000000000 +0200
> @@ -93,6 +93,9 @@
> static ngx_int_t ngx_http_variable_pid(ngx_http_request_t *r,
> ngx_http_variable_value_t *v, uintptr_t data);
>
> +static ngx_int_t ngx_http_variable_unixtime(ngx_http_request_t *r,
> + ngx_http_variable_value_t *v, uintptr_t data);
> +
> /*
> * TODO:
> * Apache CGI: AUTH_TYPE, PATH_INFO (null), PATH_TRANSLATED
> @@ -254,6 +257,9 @@
> { ngx_string("pid"), NULL, ngx_http_variable_pid,
> 0, 0, 0 },
>
> + { ngx_string("unixtime"), NULL, ngx_http_variable_unixtime,
> + 0, 0, 0 },
> +
> { ngx_null_string, NULL, NULL, 0, 0, 0 }
> };
>
> @@ -1640,6 +1646,26 @@
>
>
> static ngx_int_t
> +ngx_http_variable_unixtime(ngx_http_request_t *r,
> + ngx_http_variable_value_t *v, uintptr_t data)
> +{
> + u_char *p;
> +
> + p = ngx_pnalloc(r->pool, NGX_INT64_LEN);

NGX_TIME_T_LEN should be here.

> + if (p == NULL) {
> + return NGX_ERROR;
> + }
> +
> + v->len = ngx_sprintf(p, "%T", time(NULL)) - p;

As you were already said - don't use time(). Use ngx_getimeofday()
instead.

> + v->valid = 1;
> + v->no_cacheable = 0;

If you want to print current time - you may want to mark this
variable as non-cacheable (here and in definition via
NGX_HTTP_VAR_NOCACHEABLE flag).

> + v->not_found = 0;
> + v->data = p;
> +
> + return NGX_OK;
> +}
> +
> +static ngx_int_t
> ngx_http_variable_pid(ngx_http_request_t *r,
> ngx_http_variable_value_t *v, uintptr_t data)
> {

Maxim Dounin

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