problem with shared memory and directives for httpd

[nik600 <nik600@xxxxxxxxx>]

Dear all

i'm experiencing a problem with shared memory and i'm not able to figure it out.

i've got a segment of shared memory in my module config and seen that if set some settings for the module in my configuration this memory isn't available in the request process.

i've also attached an example (very simplified and without any mutex, just to show the case).

i've noticed that if i have in my server configuration:

 <IfModule mod_kcache.c>

      KcacheEnabled On

</IfModule>

The memory segment is not availabe:

>>[Thu Dec 04 15:26:15 2014] [crit] [client 127.0.0.1] kcache_return_result invalid  config->s

But if i comment this directive:

 <IfModule mod_kcache.c>

#      KcacheEnabled On

</IfModule>

The memory segment is available and gets updated:

>>[Thu Dec 04 15:24:47 2014] [debug] src/mod_kcache.c(96): [client 127.0.0.1] config->s->counter=68

>>[Thu Dec 04 15:24:48 2014] [debug] src/mod_kcache.c(96): [client 127.0.0.1] config->s->counter=69

>>[Thu Dec 04 15:24:48 2014] [debug] src/mod_kcache.c(96): [client 127.0.0.1] config->s->counter=70

...

i've attached the full example (100 lines of code) 

I'll appreciate any help, thank all in advance

--

/*************/
nik600
http://www.kumbe.it

#include <httpd.h>
#include <http_protocol.h>
#include <http_config.h>
#include <http_log.h>
#include <sys/stat.h>
#include <apr_shm.h>

typedef struct {
	apr_size_t counter; /* my counter */
} kcache_config_stat;

typedef struct {
	int enabled;
	apr_shm_t *counters_shm; /* the APR shared segment object*/
	kcache_config_stat *s;/*my stats*/
} kcache_config;

void *create_server_conf(apr_pool_t *p, server_rec *s);
static void register_hooks(apr_pool_t *pool);

const char *kcache_set_enabled(cmd_parms *cmd, void *cfg, const char *arg);

static const command_rec kcache_directives[] = {
		AP_INIT_TAKE1("KcacheEnabled",
		kcache_set_enabled, NULL, RSRC_CONF,
		"KcacheEnabled must have Off or On value"), { NULL } };

module AP_MODULE_DECLARE_DATA kcache_module = { STANDARD20_MODULE_STUFF, NULL,
		NULL, create_server_conf, NULL, kcache_directives, register_hooks };

/*
 * creating the server cfg
 */
void *create_server_conf(apr_pool_t *pool, server_rec *s) {
	kcache_config *cfg = apr_pcalloc(pool, sizeof(kcache_config));
	return cfg;
}
;
const char *kcache_set_enabled(cmd_parms *cmd, void *cfg, const char *arg) {
	/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
	kcache_config *conf = (kcache_config *) ap_get_module_config(
			cmd->server->module_config, &kcache_module);
	/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/

	if (conf) {
		if (!strcasecmp(arg, "on"))
			conf->enabled = 1;
		else
			conf->enabled = 0;

	}
	return NULL;
}

/*
 * init child
 */
static void kcache_child_init(apr_pool_t *p, server_rec *s) {

	kcache_config *scfg =
			ap_get_module_config(s->module_config, &kcache_module);

	scfg->s = apr_shm_baseaddr_get(scfg->counters_shm);

}
/*
 * create the shm
 */
static int kcache_post_config(apr_pool_t *pconf, apr_pool_t *plog,
		apr_pool_t *ptemp, server_rec *s) {

	kcache_config *scfg = ap_get_module_config(s->module_config, &kcache_module);

	apr_shm_create(&scfg->counters_shm, sizeof(*scfg->s), NULL, pconf);

	scfg->s = apr_shm_baseaddr_get(scfg->counters_shm);
	scfg->s->counter = 0;

	return DECLINED;
}

static int kcache_handler_translate_files(request_rec* r) {

	/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
	kcache_config *config = (kcache_config *) ap_get_module_config(
			r->server->module_config, &kcache_module);
	/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/

	if (!config->s) {
		ap_log_rerror(APLOG_MARK, APLOG_CRIT, 0, r,
				"kcache_return_result invalid  config->s");
		return DECLINED;
	}

	config->s->counter++;
	ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r,
				"config->s->counter=%"APR_SIZE_T_FMT,config->s->counter);

	return DECLINED;

}

static void register_hooks(apr_pool_t* pool) {

	static const char *succ[] = { "mod_proxy.c", "mod_alias.c",
			"mod_userdir.c", NULL };
	ap_hook_child_init(kcache_child_init, NULL, NULL, APR_HOOK_REALLY_FIRST);
	ap_hook_post_config(kcache_post_config, NULL, NULL, APR_HOOK_REALLY_FIRST);
	ap_hook_translate_name(kcache_handler_translate_files, NULL, succ,
			APR_HOOK_REALLY_FIRST);
}

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