Re: IPC on win32 - additions for 6.5.2 and current trees

Hi,

Daniel Horak wrote:

> Hi,
> 
> please add the file ipc.patch (patch for the cygipc library) into src/win32
> directory and apply the patch for README.NT (readme.patch). I think it
> should go into both the 6.5.2 and current trees.
> 
> I have no reaction from the author of the cygipc library yet, so it will be
> better to include the patch into the sources of PostgreSQL

I propose more patch against cygipc. 

Hiroshi Inoue (inoue@tpf.co.jp) found another backend freezing problem.
He also found semop() in cygipc can't decrement semaphore value
correctly (Only -1 is supported).

I create follwing patch fixes these issues.


I'm sorry for my poor English.

*** sem.c.orig_    Tue Aug 17 14:19:37 1999
--- sem.c    Tue Aug 31 16:59:49 1999
***************
*** 204,210 ****     {     CloseHandle ( LHandle ) ;     }
!     LHandle = CreateSemaphore(NULL, 0, 0x7FFFFFFF, LBuff) ;     if( LHandle == NULL )     {     printf( "Creation de
Semaphore\"Sem\" impossible\n" ) ;
 
--- 204,210 ----     {     CloseHandle ( LHandle ) ;     }
!     LHandle = CreateSemaphore(NULL, 0, 1, LBuff) ;     if( LHandle == NULL )     {     printf( "Creation de Semaphore
\"Sem\"impossible\n" ) ;
 
***************
*** 374,388 **** debug_printf("do_semop : return -EACCES\n");             CYGWIN32_IPCNT_RETURN (-EACCES) ;
}
!             ReleaseSemaphore(LHandle, sop->sem_op, &LVal) ;
!                 shareadrsem->current_nb[id].current_nb[sop->sem_num] +=
!                     sop->sem_op ;             sem_deconnect() ;         } else {             if( sop->sem_flg ==
IPC_NOWAIT)             {
 
!             LRet = WaitForSingleObject(LHandle, 0) ;
!             if( LRet == WAIT_TIMEOUT )             { debug_printf("do_semop : return -EAGAIN\n");
CYGWIN32_IPCNT_RETURN(-EAGAIN) ;
 
--- 374,387 ---- debug_printf("do_semop : return -EACCES\n");             CYGWIN32_IPCNT_RETURN (-EACCES) ;
}
!             shareadrsem->current_nb[id].current_nb[sop->sem_num] +=
!                 sop->sem_op ;             sem_deconnect() ;
+             ReleaseSemaphore(LHandle, 1 , &LVal) ;         } else {             if( sop->sem_flg == IPC_NOWAIT )
      {
 
!             if( sop->sem_op + shareadrsem->current_nb[id].current_nb[sop->sem_num] <0 )             {
debug_printf("do_semop: return -EAGAIN\n");                 CYGWIN32_IPCNT_RETURN (-EAGAIN) ;
 
***************
*** 392,407 **** debug_printf("do_semop : return -EACCES\n");                 CYGWIN32_IPCNT_RETURN (-EACCES) ;
   }
 
!                 shareadrsem->current_nb[id].current_nb[sop->sem_num] -= 1 ;             sem_deconnect() ;
}else {
 
!             LRet = WaitForSingleObject(LHandle, INFINITE) ;             if (sem_connect() == 0)             {
debug_printf("do_semop: return -EACCES\n");                 CYGWIN32_IPCNT_RETURN (-EACCES) ;             }
 
!                 shareadrsem->current_nb[id].current_nb[sop->sem_num] -= 1 ;                 sem_deconnect() ;
   }         }
 
--- 391,408 ---- debug_printf("do_semop : return -EACCES\n");                 CYGWIN32_IPCNT_RETURN (-EACCES) ;
   }
 
!                 shareadrsem->current_nb[id].current_nb[sop->sem_num] += sop->sem_op;             sem_deconnect() ;
        } else {
 
!             while(sop->sem_op + shareadrsem->current_nb[id].current_nb[sop->sem_num] <0)
!                 LRet = WaitForSingleObject(LHandle, INFINITE) ;
!                          if (sem_connect() == 0)             { debug_printf("do_semop : return -EACCES\n");
     CYGWIN32_IPCNT_RETURN (-EACCES) ;             }
 
!                 shareadrsem->current_nb[id].current_nb[sop->sem_num] += sop->sem_op ;                 sem_deconnect()
;            }         }
 
***************
*** 452,458 ****     char LBuff[100] ;     HANDLE LHandle ;     long LPrevious ;
-     int LIndex;  debug_printf("semctl : semid=%X semnum=%X cmd=0x%02X arg=%p\n",semid,semnum,cmd,arg);     if (semid
<0 || semnum < 0 || cmd < 0)
 
--- 453,458 ----
***************
*** 585,606 ****         if( LHandle != NULL )         {             if( arg.val >
shareadrsem->current_nb[id].current_nb[semnum])
 
!             {
!             ReleaseSemaphore(LHandle,
!             arg.val-shareadrsem->current_nb[id].current_nb[semnum],
!             &LPrevious) ;
!             }
!             else if (arg.val <
!                      shareadrsem->current_nb[id].current_nb[semnum] )
!             {
!             for( LIndex = arg.val;
!             LIndex < shareadrsem->current_nb[id].current_nb[semnum];
!             LIndex++ )
!             {
!                 WaitForSingleObject(LHandle, 0) ;
!             }
!             }
!                     shareadrsem->current_nb[id].current_nb[semnum] = arg.val ;         } debug_printf("semctl :
SETVAL: return 0\n");         CYGWIN32_IPCNT_RETURN_DECONNECT (0);
 
--- 585,592 ----         if( LHandle != NULL )         {             if( arg.val >
shareadrsem->current_nb[id].current_nb[semnum])
 
!                 ReleaseSemaphore(LHandle,1,&LPrevious) ;
!             shareadrsem->current_nb[id].current_nb[semnum] = arg.val ;         } debug_printf("semctl : SETVAL :
return0\n");         CYGWIN32_IPCNT_RETURN_DECONNECT (0);
 



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Yutaka tanida / S34 Co., Ltd.
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yutaka@marin.or.jp(Private, or if you *HATE* Microsoft Outlook)