Thread: SQLFreeHandle() takes eons when running debug

On 12/5/14 10:56 AM, Eric Hill wrote:
> Not sure how this could be the PostgreSQL ODBC driver’s fault, but when
> I run a debug build of my application, calls to SQLFreeHandle() to free
> a statement can have for quite a long time (we’re talking a minute or
> two) before proceeding.  This is Windows, 64-bit Unicode, version
> 9.03.03 of the PG ODBC driver.   The call stack looks like this when paused:
>
>                  ntdll.dll!RtlCompareMemoryUlong()  + 0x10 bytes
>
>                 ntdll.dll!RtlpFreeHeap()  + 0x113f bytes
>
>                 ntdll.dll!RtlFreeHeap()  + 0x1df bytes
>
>                 ntdll.dll!RtlDebugFreeHeap()  + 0x23f bytes
>
>                 ntdll.dll!RtlpFreeHeap()  + 0x7d5b7 bytes
>
>                 ntdll.dll!RtlFreeHeap()  + 0x1df bytes
>
>                 msvcr100.dll!free()  + 0x1c bytes
>
>                 psqlodbc35w.dll!00007ff97bc7c827()
>
>                  [Frames below may be incorrect and/or missing, no
> symbols loaded for psqlodbc35w.dll]
>
>                 psqlodbc35w.dll!00007ff97bc7656b()
>
>                  psqlodbc35w.dll!00007ff97bc76044()
>
>                  psqlodbc35w.dll!00007ff97bc761c7()
>
>                  psqlodbc35w.dll!00007ff97bc88781()
>
>                  psqlodbc35w.dll!00007ff97bc66bda()
>
>                  odbc32.dll!FreeStmt()  + 0x2c5 bytes
>
>                 odbc32.dll!SQLFreeHandle()  + 0x2a0 bytes
>
>  >             Jmp.exe!DBContext::freeStmt(void * &
> hstmt=0x000000001f032030)  Line 1644 + 0x14 bytes      C++
>
> Running a release build, no such delay.  We don’t see anything like this
> for SQL Server, Oracle, DB2, Teradata, or MySQL ODBC drivers.  Anyone
> run into this before that can suggest a fix or workaround?

Perhaps this might be relevant (setting _NO_DEBUG_HEAP=1 env var to skip
heap validation):
http://stackoverflow.com/a/18753164

Thanks,
  Nikhil

That solved it!  Thanks, Nikhil!

Eric

-----Original Message-----
From: pgsql-odbc-owner@postgresql.org [mailto:pgsql-odbc-owner@postgresql.org] On Behalf Of Nikhil Deshpande
Sent: Friday, December 05, 2014 2:02 PM
To: pgsql-odbc@postgresql.org
Subject: Re: [ODBC] SQLFreeHandle() takes eons when running debug

On 12/5/14 10:56 AM, Eric Hill wrote:
> Not sure how this could be the PostgreSQL ODBC driver's fault, but
> when I run a debug build of my application, calls to SQLFreeHandle()
> to free a statement can have for quite a long time (we're talking a
> minute or
> two) before proceeding.  This is Windows, 64-bit Unicode, version
> 9.03.03 of the PG ODBC driver.   The call stack looks like this when paused:
>
>                  ntdll.dll!RtlCompareMemoryUlong()  + 0x10 bytes
>
>                 ntdll.dll!RtlpFreeHeap()  + 0x113f bytes
>
>                 ntdll.dll!RtlFreeHeap()  + 0x1df bytes
>
>                 ntdll.dll!RtlDebugFreeHeap()  + 0x23f bytes
>
>                 ntdll.dll!RtlpFreeHeap()  + 0x7d5b7 bytes
>
>                 ntdll.dll!RtlFreeHeap()  + 0x1df bytes
>
>                 msvcr100.dll!free()  + 0x1c bytes
>
>                 psqlodbc35w.dll!00007ff97bc7c827()
>
>                  [Frames below may be incorrect and/or missing, no
> symbols loaded for psqlodbc35w.dll]
>
>                 psqlodbc35w.dll!00007ff97bc7656b()
>
>                  psqlodbc35w.dll!00007ff97bc76044()
>
>                  psqlodbc35w.dll!00007ff97bc761c7()
>
>                  psqlodbc35w.dll!00007ff97bc88781()
>
>                  psqlodbc35w.dll!00007ff97bc66bda()
>
>                  odbc32.dll!FreeStmt()  + 0x2c5 bytes
>
>                 odbc32.dll!SQLFreeHandle()  + 0x2a0 bytes
>
>  >             Jmp.exe!DBContext::freeStmt(void * &
> hstmt=0x000000001f032030)  Line 1644 + 0x14 bytes      C++
>
> Running a release build, no such delay.  We don't see anything like
> this for SQL Server, Oracle, DB2, Teradata, or MySQL ODBC drivers.
> Anyone run into this before that can suggest a fix or workaround?

Perhaps this might be relevant (setting _NO_DEBUG_HEAP=1 env var to skip heap validation):
http://stackoverflow.com/a/18753164

Thanks,
  Nikhil


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