> Date: Thu, 31 Mar 2011 15:01:48 +0200
> Subject: Re: cpu 100%
> From: [email protected]
> To: [email protected]
>
> On Thu, Mar 31, 2011 at 14:32, Niko Goutte <[email protected]> wrote:
> >
> > Hello,
> >
> > I developped an apache module which send small data coming from file.
> > A client request from file through a Get request and data are sent with
> > block
> > size equals to 100KB.
> > One 100KB buffer is allocated in the pool, then each buffer are used to
> > create
> > one bucket that will be sent just after being inserted into the brigade.
> > To sum up:
> > ----------------------------------------------------------------------------------------------------------------------------
> > apr_bucket_brigade *bb;
> > apr_bucket* b;
> >
> > bb = apr_brigade_create(r->pool, r->connection->bucket_alloc);
> > Buf = apr_palloc(r->pool,100KB);
> >
> > while(lastBufferToSend==false)
> > {
> > Processing(Buf);
> >
> > b = apr_bucket_pool_create(Buf ,size, r->pool,
> > r->connection->bucket_alloc) ;
> >
> > APR_BRIGADE_INSERT_TAIL(bb, b);
> > APR_BRIGADE_INSERT_TAIL(bb,apr_bucket_flush_create(bb->bucket_alloc));
> >
> > if(lastBufferToSend)
> > {
> > APR_BRIGADE_INSERT_TAIL(bb,apr_bucket_eos_create(bb->bucket_alloc));
> > }
> >
> > rv = ap_pass_brigade(r->output_filters, bb);
> > if (rv != APR_SUCCESS)
> > {
> > return HTTP_INTERNAL_SERVER_ERROR;
> > }
> >
> > apr_brigade_cleanup(bb);
> > }
> >
> > apr_brigade_destroy(bb);
> > ----------------------------------------------------------------------------------------------------------------------------
> >
> >
> > I want to call ap_pass_brigade for each buffer because I want the module to
> > send immediatly 100KB.
> >
> > Clients don't have to wait for the complete processing of the file more than
> > 2GB. They receive small blocks until the end.
> >
> > --------------------------------------------------------------------------------------------------------------------------
> >
> >
> > Apache Server is in prefork mode.
> > <IfModule prefork.c>
> > StartServers 8
> > MinSpareServers 5
> > MaxSpareServers 20
> > ServerLimit 256
> > MaxClients 256
> > MaxRequestsPerChild 4000
> > </IfModule>
> >
> > In worker mode, everything is excepted 10 bytes that are send in addition
> > including value
> > "\n256\r\n" : it is very strange because the sum of every chunk
> > corrsesponds exactly to the expected size.
> > <IfModule worker.c>
> > StartServers 2
> > MinSpareThreads 25
> > MaxSpareThreads 75
> > ThreadPerChild 64
> > MaxClients 1024
> > MaxRequestsPerChild 0
> > </IfModule>
> >
> > --------------------------------------------------------------------------------------------------------------------------
> >
> > MY PROBLEMS:
> >
> > In prefork mode, the first 8 client requests (which corresponds to the
> > StartServers = 8) are well processed. My client received all data,
> > everything is fine.
> > But the 9th freezes the module in ap_pass_brigade function. httpd is
> > freezed with 100% cpu on this process.
> >
> > In worker mode, it is ok excepted the 10 bytes added. It seems that it is
> > linked with apr_brigade_destroy or apr_bucket_delete(b).
>
>
> Are you sure that the value of lastBufferToSend changes in your while-loop?
>
> Can you post your exact code to see how you add the 10 bytes?
>
> Sorin
-------------------------------------------------------------------------------------------------------------------------------
HERE IS:
#include <httpd.h>
#include <http_config.h>
#include <http_protocol.h>
#include <http_request.h>
#include <http_log.h>
#include <ap_compat.h>
#include <apr_buckets.h>
#include <apr_strings.h>
#define ASE_FILE_SIZE 512000
#define ASE_BUFFER_SIZE 104858
module AP_MODULE_DECLARE_DATA ase_mod_module;
#define ASE_MOD_HANDLER "ase-mod.extensions"
static int ase_mod_handler(request_rec *r)
{
apr_status_t rv = APR_SUCCESS;
apr_bucket_brigade* bb = NULL;;
apr_bucket* b = NULL;;
char filename[256];
/* First, some housekeeping. */
if (((!r->handler) != 0)|| (strcmp(r->handler, ASE_MOD_HANDLER)))
{
/* r->handler wasn't "ase_mod", so it's none of our business */
ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server,"Decline processing
file %s is not %s and handler %s", r->filename,ASE_MOD_HANDLER,r->handler);
return DECLINED;
}
if (r->method_number != M_GET)
{
ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server,"Error
METHOD_NOT_ALLOWED (%d)",r->method_number);
return HTTP_METHOD_NOT_ALLOWED;
}
ap_log_error(APLOG_MARK, APLOG_INFO, 0, r->server,"%s",r->the_request);
// Construct filename
strncpy(filename, r->filename, sizeof(filename) / sizeof(char) - 1);
filename[sizeof(filename) / sizeof(char) - 1] = '\0';
ap_log_error(APLOG_MARK, APLOG_INFO, 0, r->server,"filename = %s",filename);
int DataSize = ASE_FILE_SIZE;
ap_set_content_type(r, "video/ase");
ap_update_mtime(r, r->finfo.mtime);
ap_set_last_modified(r);
apr_table_setn(r->headers_out, "Accept-Ranges", "bytes");
r->vlist_validator = apr_pstrcat(r->pool, "X",apr_itoa(r->pool, DataSize),
"\"", NULL);
ap_set_etag(r);
char content_range[64];
sprintf(content_range,"bytes %d-%d/%d",0,ASE_FILE_SIZE-1,ASE_FILE_SIZE);
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,"Add content range
%s",content_range);
apr_table_setn(r->headers_out, "Content-Range",content_range);
r->status = HTTP_OK;
bb = apr_brigade_create(r->pool, r->connection->bucket_alloc);
char* Buf;
Buf = apr_palloc(r->pool,ASE_BUFFER_SIZE);
int size = ASE_BUFFER_SIZE;
unsigned int count = 0;
while(DataSize>0)
{
if((DataSize - size)<0)
{
size = DataSize;
}
memset(Buf,count,size);
b = apr_bucket_pool_create(Buf ,size, r->pool,
r->connection->bucket_alloc) ;
APR_BRIGADE_INSERT_TAIL(bb, b);
APR_BRIGADE_INSERT_TAIL(bb,apr_bucket_flush_create(bb->bucket_alloc));
if(DataSize <= size)
{
APR_BRIGADE_INSERT_TAIL(bb,apr_bucket_eos_create(bb->bucket_alloc));
ap_log_error(APLOG_MARK, APLOG_INFO, 0,
r->server,"APR_BRIGADE_INSERT_TAIL EOS Bucket");
}
rv = ap_pass_brigade(r->output_filters, bb);
if (rv != APR_SUCCESS)
{
ap_log_error(APLOG_MARK, APLOG_ERR, 0,
r->server,"HTTP_INTERNAL_SERVER_ERROR ap_pass_brigade ");
r->status = HTTP_INTERNAL_SERVER_ERROR;
return r->status;
}
DataSize = DataSize - size;
count++;
ap_log_error(APLOG_MARK, APLOG_INFO, 0, r->server,"ap_pass_brigade,
DataSize = %d and Size = %d",DataSize, size );
apr_brigade_cleanup(bb);
}
ap_log_error(APLOG_MARK, APLOG_INFO, 0, r->server,"Out of While");
apr_bucket_delete(b);
//apr_brigade_destroy(bb);
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,"End return
%d",r->status);
return r->status;
}
static void ase_mod_hooks(apr_pool_t *pool)
{
if(pool){}
ap_hook_handler(ase_mod_handler, NULL, NULL, APR_HOOK_MIDDLE);
}
module AP_MODULE_DECLARE_DATA ase_mod_module = {
STANDARD20_MODULE_STUFF,
NULL, /*create dir config */
NULL, /*merge dir config */
NULL, /*create server config*/
NULL, /*merge server config */
NULL, /*command table */
ase_mod_hooks
};
-------------------------------------------------------------------------------------------------------------------------------
I would like to understand first why this module crashes with a segmentation
fault in prefork mode on the 9th simple request:
curl http://IP/filename.ext
where .ext is the "ase-mod.extensions"
Thank you.
