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Posted to cvs@httpd.apache.org by ji...@apache.org on 2011/02/07 20:25:14 UTC
svn commit: r1068066 - /httpd/httpd/trunk/modules/slotmem/mod_slotmem_shm.c
Author: jim
Date: Mon Feb 7 19:25:14 2011
New Revision: 1068066
URL: http://svn.apache.org/viewvc?rev=1068066&view=rev
Log:
OK, use faster, shared version... makes sense to persist this
info since it is aligned with the actual data itself.
Modified:
httpd/httpd/trunk/modules/slotmem/mod_slotmem_shm.c
Modified: httpd/httpd/trunk/modules/slotmem/mod_slotmem_shm.c
URL: http://svn.apache.org/viewvc/httpd/httpd/trunk/modules/slotmem/mod_slotmem_shm.c?rev=1068066&r1=1068065&r2=1068066&view=diff
==============================================================================
--- httpd/httpd/trunk/modules/slotmem/mod_slotmem_shm.c (original)
+++ httpd/httpd/trunk/modules/slotmem/mod_slotmem_shm.c Mon Feb 7 19:25:14 2011
@@ -52,6 +52,7 @@ typedef struct {
} sharedslotdesc_t;
#define AP_SLOTMEM_OFFSET (APR_ALIGN_DEFAULT(sizeof(sharedslotdesc_t)))
+#define AP_UNSIGNEDINT_OFFSET (APR_ALIGN_DEFAULT(sizeof(unsigned int)))
struct ap_slotmem_instance_t {
char *name; /* per segment name */
@@ -59,6 +60,8 @@ struct ap_slotmem_instance_t {
void *base; /* data set start */
apr_pool_t *gpool; /* per segment global pool */
char *inuse; /* in-use flag table*/
+ unsigned int *num_free; /* slot free count for this instance */
+ void *persist; /* persist dataset start */
sharedslotdesc_t desc; /* per slot desc */
struct ap_slotmem_instance_t *next; /* location of next allocated segment */
};
@@ -66,7 +69,10 @@ struct ap_slotmem_instance_t {
/*
* Memory layout:
- * sharedslotdesc_t | slots | isuse array
+ * sharedslotdesc_t | num_free | slots | isuse array |
+ * ^ ^
+ * | . base
+ * . persist (also num_free)
*/
/* global pool and list of slotmem we are handling */
@@ -157,8 +163,8 @@ static void store_slotmem(ap_slotmem_ins
return;
}
nbytes = (slotmem->desc.size * slotmem->desc.num) +
- (slotmem->desc.num * sizeof(char));
- apr_file_write(fp, slotmem->base, &nbytes);
+ (slotmem->desc.num * sizeof(char)) + AP_UNSIGNEDINT_OFFSET;
+ apr_file_write(fp, slotmem->persist, &nbytes);
apr_file_close(fp);
}
}
@@ -255,7 +261,7 @@ static apr_status_t slotmem_create(ap_sl
const char *fname;
apr_shm_t *shm;
apr_size_t basesize = (item_size * item_num);
- apr_size_t size = AP_SLOTMEM_OFFSET +
+ apr_size_t size = AP_SLOTMEM_OFFSET + AP_UNSIGNEDINT_OFFSET +
(item_num * sizeof(char)) + basesize;
apr_status_t rv;
@@ -307,7 +313,7 @@ static apr_status_t slotmem_create(ap_sl
apr_shm_detach(shm);
return APR_EINVAL;
}
- ptr = ptr + AP_SLOTMEM_OFFSET;
+ ptr += AP_SLOTMEM_OFFSET;
}
else {
apr_size_t dsize = size - AP_SLOTMEM_OFFSET;
@@ -335,7 +341,7 @@ static apr_status_t slotmem_create(ap_sl
desc.num = item_num;
desc.type = type;
memcpy(ptr, &desc, sizeof(desc));
- ptr = ptr + AP_SLOTMEM_OFFSET;
+ ptr += AP_SLOTMEM_OFFSET;
memset(ptr, 0, dsize);
/*
* TODO: Error check the below... What error makes
@@ -351,6 +357,10 @@ static apr_status_t slotmem_create(ap_sl
sizeof(ap_slotmem_instance_t));
res->name = apr_pstrdup(gpool, fname);
res->shm = shm;
+ res->num_free = (unsigned int *)ptr;
+ *res->num_free = item_num;
+ res->persist = (void *)ptr;
+ ptr += AP_UNSIGNEDINT_OFFSET;
res->base = (void *)ptr;
res->desc = desc;
res->gpool = gpool;
@@ -421,13 +431,16 @@ static apr_status_t slotmem_attach(ap_sl
/* Read the description of the slotmem */
ptr = (char *)apr_shm_baseaddr_get(shm);
memcpy(&desc, ptr, sizeof(desc));
- ptr = ptr + AP_SLOTMEM_OFFSET;
+ ptr += AP_SLOTMEM_OFFSET;
/* For the chained slotmem stuff */
res = (ap_slotmem_instance_t *) apr_pcalloc(gpool,
sizeof(ap_slotmem_instance_t));
res->name = apr_pstrdup(gpool, fname);
res->shm = shm;
+ res->num_free = (unsigned int *)ptr;
+ res->persist = (void *)ptr;
+ ptr += AP_UNSIGNEDINT_OFFSET;
res->base = (void *)ptr;
res->desc = desc;
res->gpool = gpool;
@@ -521,13 +534,17 @@ static unsigned int slotmem_num_slots(ap
static unsigned int slotmem_num_free_slots(ap_slotmem_instance_t *slot)
{
- unsigned int i, counter=0;
- char *inuse = slot->inuse;
- for (i=0; i<slot->desc.num; i++, inuse++) {
- if (!*inuse)
- counter++;
+ if (AP_SLOTMEM_IS_PREGRAB(slot))
+ return *slot->num_free;
+ else {
+ unsigned int i, counter=0;
+ char *inuse = slot->inuse;
+ for (i=0; i<slot->desc.num; i++, inuse++) {
+ if (!*inuse)
+ counter++;
+ }
+ return counter;
}
- return counter;
}
static apr_size_t slotmem_slot_size(ap_slotmem_instance_t *slot)
@@ -556,6 +573,7 @@ static apr_status_t slotmem_grab(ap_slot
}
*inuse = 1;
*id = i;
+ (*slot->num_free)--;
return APR_SUCCESS;
}
@@ -574,6 +592,7 @@ static apr_status_t slotmem_release(ap_s
return APR_NOTFOUND;
}
inuse[id] = 0;
+ (*slot->num_free)++;
return APR_SUCCESS;
}
Re: svn commit: r1068066 - /httpd/httpd/trunk/modules/slotmem/mod_slotmem_shm.c
Posted by Jim Jagielski <ji...@jaguNET.com>.
On Feb 9, 2011, at 2:02 AM, Ruediger Pluem wrote:
>> + (*slot->num_free)--;
>
> Is this atomic? Don't we need to use the atomic functions from APR here?
>
>
>> return APR_SUCCESS;
>> }
>>
>> @@ -574,6 +592,7 @@ static apr_status_t slotmem_release(ap_s
>> return APR_NOTFOUND;
>> }
>> inuse[id] = 0;
>> + (*slot->num_free)++;
>
> Is this atomic? Don't we need to use the atomic functions from APR here?
>
It's not atomic, but the grab/release functions aren't either
unless mutexed.
There was some discussion long ago about whether or not slotmem itself
should automatically mutex on things that should be atomic
or whether it should be left up to the user... it was decided the
latter made more sense.
Re: svn commit: r1068066 - /httpd/httpd/trunk/modules/slotmem/mod_slotmem_shm.c
Posted by Ruediger Pluem <rp...@apache.org>.
On 02/07/2011 08:25 PM, jim@apache.org wrote:
> Author: jim
> Date: Mon Feb 7 19:25:14 2011
> New Revision: 1068066
>
> URL: http://svn.apache.org/viewvc?rev=1068066&view=rev
> Log:
> OK, use faster, shared version... makes sense to persist this
> info since it is aligned with the actual data itself.
>
> Modified:
> httpd/httpd/trunk/modules/slotmem/mod_slotmem_shm.c
>
> Modified: httpd/httpd/trunk/modules/slotmem/mod_slotmem_shm.c
> URL: http://svn.apache.org/viewvc/httpd/httpd/trunk/modules/slotmem/mod_slotmem_shm.c?rev=1068066&r1=1068065&r2=1068066&view=diff
> ==============================================================================
> --- httpd/httpd/trunk/modules/slotmem/mod_slotmem_shm.c (original)
> +++ httpd/httpd/trunk/modules/slotmem/mod_slotmem_shm.c Mon Feb 7 19:25:14 2011
> @@ -556,6 +573,7 @@ static apr_status_t slotmem_grab(ap_slot
> }
> *inuse = 1;
> *id = i;
> + (*slot->num_free)--;
Is this atomic? Don't we need to use the atomic functions from APR here?
> return APR_SUCCESS;
> }
>
> @@ -574,6 +592,7 @@ static apr_status_t slotmem_release(ap_s
> return APR_NOTFOUND;
> }
> inuse[id] = 0;
> + (*slot->num_free)++;
Is this atomic? Don't we need to use the atomic functions from APR here?
> return APR_SUCCESS;
> }
>
>
>
>
>