Received: (qmail 34553 invoked by uid 501); 27 Feb 2001 22:15:58 -0000
Message-Id: <20010227221558.34552.qmail@apache.org>
Date: 27 Feb 2001 22:15:58 -0000
From: Jerry Zhou <zhou@ugsolutions.com>
Reply-To: zhou@ugsolutions.com
To: submit@bugz.apache.org
Subject: WriteClient doesn't work
X-Send-Pr-Version: 3.110

>Number:         7327
>Category:       mod_isapi
>Synopsis:       WriteClient doesn't work
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    apache
>State:          closed
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   apache
>Arrival-Date:   Tue Feb 27 14:20:00 PST 2001
>Closed-Date:    Mon Dec 03 11:59:33 PST 2001
>Last-Modified:  Mon Dec 03 11:59:33 PST 2001
>Originator:     zhou@ugsolutions.com
>Release:        2.0a9
>Organization:
>Environment:
Windows NT 4.0 Service Pack 6
Visual Studio 6.0
>Description:
First, it failed to create bucket (see code below). After I fixed the bug, WriteClient works only for buffer less than 4096 bytes. 

If I provide a buffer larger than 4096 bytes (defined as DEFAULT_BUCKET_SIZE in ap_buckets_heap.c), it will be chopped. The Content-Length is still correct, causing the client to wait for more data that will never arrive. 

If I divide the buffer into small sizes and call WriteClient multiple times, the data will be all send out, but the Content-Length was put into a bucket the first time it reaches an eos, causing the client to read only the first buffer and discard all the remaining buffers.
>How-To-Repeat:
Call WriteClient with a buffer larger than 4096 bytes.
Or, devide the buffer into small ones and call WriteClient multiple times.
>Fix:
Here is my suggestion. It works as I tested.

BOOL WINAPI WriteClient (HCONN ConnID, LPVOID Buffer, LPDWORD lpwdwBytes,
                         DWORD dwReserved)
{
    request_rec *r = ((isapi_cid *)ConnID)->r;
    ap_bucket_brigade *bb;
    ap_bucket *b;

    if (dwReserved == HSE_IO_SYNC)
        ; /* XXX: Fake it */

    bb = ap_brigade_create(r->pool);
	/***************** JJZ: Is this a bug?
    b = ap_bucket_create_transient(Buffer, (apr_size_t)lpwdwBytes);
	******************/
    b = ap_bucket_create_transient(Buffer, (apr_size_t)*lpwdwBytes);
    AP_BRIGADE_INSERT_TAIL(bb, b);
	/***************** JJZ: eos caused Content-Length less than total of WriteClient
    b = ap_bucket_create_eos();
    AP_BRIGADE_INSERT_TAIL(bb, b);
	******************/
    ap_pass_brigade(r->output_filters, bb);

    return TRUE;
}
>Release-Note:
>Audit-Trail:
State-Changed-From-To: open-feedback
State-Changed-By: rbb
State-Changed-When: Sun Mar 25 11:15:04 PST 2001
State-Changed-Why:
A lot has changed since the 2.0a9 releasae.  Could you please try the latest version of Apache with the attached patch?

I believe this will solve the problem that you are seeing.

Thank you for using Apache and working to improve it.

Index: mod_isapi.c
===================================================================
RCS file: /home/cvs/httpd-2.0/modules/arch/win32/mod_isapi.c,v
retrieving revision 1.40
diff -u -d -b -w -u -r1.40 mod_isapi.c
--- mod_isapi.c 2001/02/28 15:31:29     1.40
+++ mod_isapi.c 2001/03/25 19:13:40
@@ -649,17 +649,11 @@
 {
     request_rec *r = ((isapi_cid *)ConnID)->r;
     apr_bucket_brigade *bb;
-    apr_bucket *b;
 
     if (dwReserved == HSE_IO_SYNC)
         ; /* XXX: Fake it */
 
-    bb = apr_brigade_create(r->pool);
-    b = apr_bucket_transient_create(Buffer, (apr_size_t)lpwdwBytes);
-    APR_BRIGADE_INSERT_TAIL(bb, b);
-    b = apr_bucket_eos_create();
-    APR_BRIGADE_INSERT_TAIL(bb, b);
-    ap_pass_brigade(r->output_filters, bb);
+    ap_rwrite(r, Buffer, (apr_size_t)lpwdwBytes);
 
     return TRUE;
 }
State-Changed-From-To: feedback-closed
State-Changed-By: wrowe
State-Changed-When: Mon Dec  3 11:59:33 PST 2001
State-Changed-Why:
This should be fixed some good time ago.  The buckets API
has changed several times, at a9 it was out-of-sync with
the mod_isapi (which unix bucket hackers can't test.)

Thanks for your report and interest in the Apache 2.0 Beta!
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