Edit report at http://bugs.php.net/bug.php?id=52077&edit=1
ID: 52077
Comment by: wajim at mail dot ru
Reported by: wajim at mail dot ru
Summary: SNMP GET/WALK may hangs FOREVER
Status: Open
Type: Bug
Package: SNMP related
Operating System: Win XP SP3
PHP Version: 5.2.13
New Comment:
static int _sess_read(void *sessp, fd_set *fdset){
[cut]
unsigned long unblock; //WAJIM
[cut]
unblock = 1; ioctlsocket(isp->sd, FIONBIO, &unblock); //WAJIM
length = recvfrom(isp->sd, (char *)packet, PACKET_LENGTH, 0, (struct
sockaddr *)&from, &fromlength);
unblock = 0; ioctlsocket(isp->sd, FIONBIO, &unblock); //WAJIM
[cut]
}
Those my 3 lines in snmp_api.c (ucd-snmp-4.2.7.1) fixes threads hanging.
:-)
Previous Comments:
------------------------------------------------------------------------
[2010-06-19 15:03:22] larryjadams at comcast dot net
Stupid WINSock does not support send and receive timeout socket options.
It's a poorly implemented socket api. The net-snmp guys will have to
implement with an alarm. It can not be solved here. But nice catch.
------------------------------------------------------------------------
[2010-06-13 21:41:34] wajim at mail dot ru
Description:
------------
Under a heavy GET/WALK-ing (form localhost to localhost) php may hangs
forever -> apache's threads becomes zombies with CLOSE_WAIT sates even
all timeouts (php and apache) are elapsed many times.
Call-stack of a one zombie-thread:
ntoskrnl.exe!KiUnlockDispatcherDatabase+0x77
ntoskrnl.exe!KeSetEvent+0x74
ntoskrnl.exe!PspGetSetContextSpecialApc+0x4e
ntoskrnl.exe!KiDeliverApc+0xb3
ntoskrnl.exe!KiSwapThread+0x64
ntoskrnl.exe!KeWaitForSingleObject+0x1c2
ntoskrnl.exe!NtWaitForSingleObject+0x9a
ntoskrnl.exe!KiFastCallEntry+0xf8
ntdll.dll!KiFastSystemCallRet
ntdll.dll!ZwWaitForSingleObject+0xc
mswsock.dll!SockWaitForSingleObject+0x1a0
mswsock.dll!WSPRecvFrom+0x1f0
WS2_32.dll!recvfrom+0x89
php_snmp.dll!snmp_sess_read+0x21f
php_snmp.dll!snmp_sess_read+0x10
php_snmp.dll!snmp_read+0x17
php_snmp.dll!snmp_synch_response_cb+0xe8
php_snmp.dll!snmp_synch_response+0x19
php_snmp.dll!php_snmp_internal+0x267
php_snmp.dll!php_snmp+0x6da
php_snmp.dll!zif_snmp2_get+0x27
php5ts.dll!zend_do_fcall_common_helper_SPEC+0x7ab
php5ts.dll!ZEND_DO_FCALL_SPEC_CONST_HANDLER+0xe5
php5ts.dll!execute+0x1c5
php5ts.dll!zend_do_fcall_common_helper_SPEC+0x8ca
php5ts.dll!ZEND_DO_FCALL_BY_NAME_SPEC_HANDLER+0x15
php5ts.dll!execute+0x1c5
php5ts.dll!zend_do_fcall_common_helper_SPEC+0x8ca
php5ts.dll!ZEND_DO_FCALL_BY_NAME_SPEC_HANDLER+0x15
php5ts.dll!execute+0x1c5
php5ts.dll!zend_execute_scripts+0x107
php5ts.dll!php_execute_script+0x21d
php5apache.dll!apache_php_module_main+0x91
php5apache.dll!send_php+0x265
php5apache.dll!send_parsed_php+0x10
ApacheCore.dll!ap_invoke_handler+0x87
ApacheCore.dll!ap_process_request+0x2b4
ApacheCore.dll!ap_process_request+0x26
ApacheCore.dll!ap_start_restart+0x37f
WS2_32.dll!WSASocketW+0x119
IMHO bad call "WS2_32.dll!recvfrom" in buggy ucd-snmp library may hangs.
There are no socket option like "setsockopt(sd, SOL_SOCKET, SO_RCVTIMEO,
..." before recvfrom call.
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/bug.php?id=52077&edit=1
