abap new debugger

ABAP255: New ABAP Debugger and Memory Inspector

Christoph Stoeck, SAP AG

© SAP AG 2004, SAP TechEd / ABAP255 / 3

Agenda, Memory Inspector

Memory Inspector

Motivation

Basics

Starting the Memory Inspector

Analyzing a Memory Snapshot

Comparing Two Memory Snapshots

Summary


Agenda, New Debugger

New ABAP Debugger

Motivation & Goals

Two Process Architecture

Starting the New Debugger

Debugger UI – Main Parts

Customizing the New Debugger UI

Debugger Tools

Breakpoints

Summary

Open Points & Outlook



Memory Inspector

Motivation

Basics




Summary


Motivation

“IT_13” is quite small.

Who wasted the memory ??


Motivation

Short-lived online SAP transactions, i.e. short-lived internal modes.

Long-lived online transactions, i.e. long-lived internal modes.

Different kinds of transactions

Former (< 6.10) Present( >= 6.10)

T1 T2 T1T3 T4 cic0

A1 A2 A3 A4

Internal modeLegend:

Memory leaks will not take effect as all memory is freed during deletion of an internal mode.

Memory leaks will take effect by summing up as the internal mode will not be deleted.


Motivation

Consequences

Overview of all memory consuming objects needed

Ability to easily identify the most memory consuming objects

Sorted by memory consumption

Analyze memory consumption from inside ABAP Debugger

Create a memory snapshot (and analyze it later)

Method for analyzing memory leaks needed

Compare memory consumption at sync points of transaction

Ability to easily identify added memory objects

Create memory snapshots

Show difference of memory snapshots



Memory Inspector

Motivation

Basics




Summary


Memory Objects

Kinds of “dynamically growing memory objects” in ABAP

Named objectsStrings and Internal Tables

Declared with statement: DATA <name> Manner-of-speaking: data object, variable

Accessible by <name>

Value semantics

Anonymous objectsInstances of classes

Created by the statement: CREATE OBJECTOO manner-of-speaking: object

Instances of data typesCreated by the statement: CREATE DATASAP manner-of-speaking: anonymous data object

Accessible only via references

Reference semantics


Dynamic memory objects with value semantics

Internal tablesNamed objects

Value semantics with “Copy on write”, i.e. table sharing with reference counting

The table body is in fact the dynamic memory object

Debugger: Access also via {T:n}, where n is the id of the internal table header

StringsNamed objects

Value semantics with “Copy on write”, i.e. string sharing with reference counting

Debugger: Access also via {S:n}, where n is the string id

Memory Objects


str1 0

Memory Objects

Example: Strings

DATA: str1 TYPE STRING,str2 TYPE STRING.

⇒str1 = ‘Hallo’.

str2 = str1.

str1 = ‘Hugo’.

str2 str1

Stringheader 2

Hallo


str1 0

Memory Objects

Example: Strings


str1 = ‘Hallo’.

⇒str2 = str1.

str1 = ‘Hugo’.

str2 0 str1

Stringheader 2

Hallo

str2


str1 0

Memory Objects

Example: Strings


str1 = ‘Hallo’.

str2 = str1.

⇒str1 = ‘Hugo’.

str2 0 str1

Stringheader 2

Hallo

str2

Stringheader 3

Hugo


str1 2 str1

Memory Objects

Example: Strings


str1 = ‘Hallo’.

str2 = str1.

⇒str1 = ‘Hugo’.

str2 0

Stringheader 2

Hallo

str2

Stringheader 3

Hugo


Memory Objects

Dynamic memory objects with reference semantics

ObjectsAnonymous objectsReference semanticsNo reference countingDebugger: Access via {O:n}, where n is the object id

Anonymous data objects Anonymous objectsReference semanticsNo reference countingDebugger: Access via {A:n}, where n is the anonymous data id


ref1 0

Memory Objects

Anonymous data objects

DATA: ref1 TYPE REF TO I,ref2 TYPE REF TO I.

⇒CREATE DATA ref1.

ref1->* = 10.

ref2 = ref1.

ref2->* = 20.

ref2

{A:1}= 0

ref1


1{r}: 0{A:1}= 10

ref1 0

Memory Objects


CREATE DATA ref1.

⇒ref1->* = 10.

ref2 = ref1.

ref2->* = 20.

ref2 ref1



ref1 0

Memory Objects


CREATE DATA ref1.

ref1->* = 10.

⇒ref2 = ref1.

ref2->* = 20.

ref2 0

{A:1}= 10

ref1 ref2



1{r}: 10{A:1}= 20

ref1 0

Memory Objects


CREATE DATA ref1.

ref1->* = 10.

ref2 = ref1.

⇒ref2->* = 20.

ref2 0 ref1 ref2




Memory Inspector

Motivation

Basics




Summary



Life analysis from inside ABAP Debugger, using the MI part of the debugger

Debugger Menu: Goto -> Status Display -> Memory Use

Stand-alone Memory Inspector, analyzing memory snapshots

Transaction “S_MEMORY_INSPECTOR”

From inside the debugger, comparing memory snapshots

Debugger Menu: Development -> Memory Analysis -> Compare Memory Snapshots

Creating memory snapshots

From inside the debugger

Debugger Menu: Development -> Memory Analysis -> Create Memory Snapshot

Command /hmusa in the command field on any screen

Call the WRITE_MEMORY_CONSUMPTION_FILE method of the CL_ABAP_MEMORY_UTILITIES class in your code. Use this option carefully to avoid running out of disk space



Motivation

Demo



Memory Inspector

Motivation

Basics




Summary



Analyzing Memory:

Bound MemoryMemory of the object “itself”

Minimum of memory that will be freed, if object is deleted

itab

oreforef

obj3

obj1 obj2

Referenced MemoryMemory of the object “itself” and all referenced objects

Maximum of memory that can be freed, if object is deleted

Dynamic memory objects’ sizes

Bound MemoryMemory of the object “itself”

Minimum of memory that will be freed, if object is deleted



… Dynamic memory objects’ sizes

Consequently 4 values:

Bound used

Bound allocated

Referenced used

Referenced allocated

Table bodies (internal tables) and strings Used memory

Memory of a table body (internal table) or a string that contains data of an application

Allocated memoryMemory of a table body (internal table) or a string that is allocated by the system

Used memory <= allocated memory



Examples:s : {Anonymous objects} Bytes size of an object or an anonymous data objectsu : {Named objects} Bytes used size of a table body (internal table) or a

string sa : {Named objects} Bytes allocated size of a table body (internal table) or

a string

s(obj4)+su(str2)

s(obj4)+sa(str2)

s(obj4)s(obj4)

s(obj1)+s(obj2)

s(obj1)+s(obj2)

s(obj1)s(obj1)

Referenced used


Bound used

Bound allocated

Rule: The size of a string or a table body is added to its father’s size if and only if the reference count is one.

obj3 str1

obj4 str2

obj5

obj1 obj2

?

s(obj3)+su(str1)

s(obj3)+sa(str1)

s(obj3)+su(str1)

s(obj3)+sa(str1)

s(obj1)+s(obj2)

s(obj1)+s(obj2)

s(obj1)s(obj1)

Referenced used


Bound used

Bound allocated

s(obj1)+s(obj2)

s(obj1)+s(obj2)

s(obj1)s(obj1)

Referenced used


Boundused

Boundallocated


Strongly Connected Components* can be treated as ONE object.


*A strongly connected component of a directed graph is a subset S of the graph such that for any nodes A and B of S exists always a path from A to B and from B to A, and S is not a subset of any larger such set.




To delete a SSC (garbage collector), simply delete all references to it.



TopN-Consumer-Lists

Filter memory objects

Sort according toBound memoryReferenced memory…

Aggregation of types (class / data type)

Find References

Identification as part of a SSC

Features in ABAP Debugger

Finding all “instances” of classes and data types with high memory consumption (e.g. trees, linear lists, etc…)

Finding “objects” with high

memory consumption:

Internal tables

Strings

Objects


Finding references to internal tables, strings, objects and anonymous data objects, keeping them alive.


Strongly Connected Component List

TopN-Consumer-List

Show all SSC objects

Show all references into the SSC

…


Finding all references to the SSC keeping it alive.

Memory consumption overview

Allocated / used

Memory areas (experts only )Heap

Roll

…



Demo


Viewing memory snapshots

Analysis in different views

Overview, sorted by kind of “objects”

TopN-Consumer-List

TopN-Consumer-List with aggregation


Memory consumption overview (experts only)

Features in Stand-Alone TA



Memory Inspector

Motivation

Basics




Summary


Comparing memory snapshots

Growth of memory objects in different views

Overview, sorted by kind of “objects”

TopN-Consumer-List

TopN-Consumer-List with aggregation


Memory consumption overview (experts only)

Newly loaded programs, classes or interfaces

Features in Stand-Alone TA


Comparing Memory Snapshots

DATA oref TYPE REF TO lcl.

DATA itab TYPE STANDARD TABLE

OF REF TO lcl.

CREATE OBJECT oref.

APPEND oref TO itab.

CREATE OBJECT oref.

APPEND oref TO itab.

oref

itab

itab

oref obj1

oref

obj1

itab

oref

obj2

oref

oref



Difference of 2 snapshots

One instance of class “lcl” was added



There are two references to the new

instance of “lcl”

The added instance comes with 100 bytes



Internal Table “itab” changed

Bound memory of “itab” grew by 8 bytes,

i.e. new line “oref” in itab

One line was added to “itab”



Referenced Memory of “itab” grew by 108 bytes,

i.e. line “oref” in itab and “obj2”



Memory Inspector

Motivation

Basics




Summary


In ABAP Debugger

TopN-Consumer-Lists

Aggregation of types (class/data)

Find references

List of Strongly Connected ComponentsShow all references into the SSC

Memory consumption overview

In Stand-Alone TA

Analyzing memory snapshots

Comparing memory snapshots

Growth of memory objects in different views

Available in Release 6.20 ( SP 29, Sept.2003 )

Memory Inspector: Features Summary


Exercise 1

Run Program ZMI_DEMO

Try to find the memory leak in the source code

Use the Memory Inspector and the ABAP Debugger

Hint: To set a watchpoint on an internal table (e.g. ‘itab’) to be alarmed when its size changes, you can set a watchpointto the header of ‘itab’, i.e. ‘*itab’.


Agenda, New ABAP Debugger

New ABAP Debugger

Motivation & Goals





Debugger Tools

Breakpoints

Summary



Motivation

We have already a powerful

ABAP Debugger.

Why do we need a newone ??


Motivation

Demo


Classic Debugger

Technology

Debugger and debuggee run in the same (internal) session

Debugger dynpros placed “in-between”

ConsequencesNot all ABAP code can be debugged (no conversion / field exits)

Not free of side effects (F1, F4 help, list output)

Implementation of new features not always straight-forward

No chance to use modern UI techniques (no ABAP allowed in the debugger !)

Classic Debugger – Current Status

We need a new ABAP debugger technology


Goals – New ABAP Debugger

Higher productivity for development & support using ABAP Debugger

More robust debugger architecture (no side effects)

Possibility to implement new features (e.g. a diff tool for

internal tables) faster and with less risks

More flexible & extensible state-of-the-art debugger UI

Use two separated sessions for the debugger and the application


New ABAP Debugger – First Impression



New ABAP Debugger

Motivation & Goals





Debugger Tools

Breakpoints

Summary




Session 1 - Debugger

ABAP VM

Session 2 - Debugger

UI

Debugger Engine

The New Debugger is attached to an “external session”

/h


Two Process Architecture - Consequences

The New Debugger is started in a separated external session, after prompting “/h”The debuggee is inactive while the debugger is active.Advantage: During debugging you still see your last screen input

/h


Two Process Architecture - Consequences

When the program is finished, the debugger is still available but inactiveThe debugger is not closed as long as the debuggee (external) session is alive !You may detach the debugger by prompting “/hx” in the debuggee sessionAdvantage: The debugger with all your settings, variables, breakpoints,…is always available, when you continue debugging !



New ABAP Debugger

Motivation & Goals





Debugger Tools

Breakpoints

Summary



Starting The New Debugger

The New Debugger can be started with same commands (/h, “Debugging” in se38 …) as the Classic Debugger.

Each user can specify his default debugger in the workbench settings.


Switching Between New <-> Classic Debugger

Some techniques and features are still missing in the New Debugger-> Easy switch between the two debugger variants is provided


Motivation

Demo



New ABAP Debugger

Motivation & Goals





Debugger Tools

Breakpoints

Summary



New Debugger UI – Main Parts

Source line / SY-FieldsControl Area

Process Info

Desktops

Tools


New Debugger UI – Desktops

The New Debugger provides:Three user specific desktops, which you can customize and save as your favorite debugger environmentSix standard desktops, which should cover most of the common working conditions in thedebugger:

Standard: Stepping through the code (Editor, Stack, Variable Fast Display)Structures: Compare structuresTables: Compare tablesObjects: Compare objectsDetailDispls: Compare strings , simple fields …Breakpoints: Maintain your breakpoints

Save current layout of the user specific desktops.The customizing of the standard desktops is NOT saved !

User specific desktops Standard desktops


New Debugger UI: Main Parts, Desktops

Demo



New ABAP Debugger

Motivation & Goals





Debugger Tools

Breakpoints

Summary



Customizing The New Debugger UI – Change Tool Size


Customizing The New Debugger UI – Number of Tools


Customizing The New Debugger UI – Toolbar

Close toolCreate new toolExchange toolFull screen modeMaximize horizontallySwap toolServices of the tool

Context menu

With the normal “Back” button (F3) you can “Undo” all your layout changes


UI – Desktops

Demo



New ABAP Debugger

Motivation & Goals





Debugger Tools

Breakpoints

Summary



Debugger Tools

Up to 4 parallel visible instances of a tool (e.g. compare 4 internal tables)

Tools are integrated in debugger framework and benefit from the providedservices to customize the UI. (Change size, position, close tool ,…)

Tools provide standard services


Debugger Tools - Services

If a tool provides services then a toolicon is displayed in the toolbar.

The standard services areDownload of the tool content to a local fileSearch in specified columns (STRG+F)

Each tool can have its own additional services

Search standard service


Debugger Tools – Standard Tools

Standard tools:

Source displayStack BreakpointsVariables

Detail viewsStructureInternal tableObjectSimple types


Debugger Tools – Detail View Tools - Navigation

Navigation between ABAP data structuresDouble-click in the Editor fills appropriate detail display and fills/opens the Variable Fast Display


Double-click in Variable Fast Display fills/opens appropriate detail display


Navigation between ABAP data structuresDouble-click in the Editor fills appropriate Detail Display and fills/opens the Variable Fast Display



Double-click in Variable Fast Display fills/opens appropriate detail display

Navigation between ABAP data structuresDouble-click in the Editor fills appropriate Detail Display and fills/opens the Variable Fast Display

Double-click in detail display exchanges current tool by appropriate detail display


Debugger Tools

Demo



New ABAP Debugger

Motivation & Goals





Debugger Tools

Breakpoints

Summary



Breakpoints

Debugger context of Classic ABAP Debugger is the “internal session”

Debugger context of New ABAP Debugger is the “external session”, i.e.

the “SAP-GUI Window”

Classic Debugger breakpoints are lost, when a new internal session is created while debugging (SUBMIT, CALL TRANSACTION,…)

New Debugger breakpoints are never lost


Breakpoints – Create A Breakpoint

Create/Deactivate/Delete a breakpoint in the Editor by double-clicking on a line

Create dynamic breakpoints


Breakpoints – Maintain Breakpoints

Create/Delete/Activate/Deactivate breakpoints

Specify how often the breakpoint shall be skipped before stopping


Breakpoints

Demo


Exercise 2

Run Program ZDBG_DEMO

Use the New ABAP Debugger

Follow the exercise comments at the breakpoints of the program



New ABAP Debugger

Motivation & Goals





Debugger Tools

Breakpoints

Summary



2 Process Architecture

Enables to debug all ABAP (incl. conversion exits)

State-of-the-art UI

All debugger settings remain unchanged during lifetime of external mode (debugger context)

New Debuger UIUp to 4 tools on one desktop

Arrange and size all your tools as you like

3 user specific and 6+ standard desktops

Each tool with standard services (save to local file, search ) and more individual services

Each tool with more features

Available in NW 04

New ABAP Debugger: Summary



New ABAP Debugger

Motivation & Goals





Debugger Tools

Breakpoints

Summary



New ABAP Debugger – Outlook


New ABAP Debugger – Outlook

Match functionality of Classic Debugger

Watchpoints

RFC, HTTP, Update debugging

Variable Fast Display

Globals

Locals : incl. procedure interface

New Tools

New Edit Control : syntax highlighting, block folding, etc ..

Data Explorer : navigate through data object graphs

Diff-Tool : navigate through differences of internal tables, structures, etc …

Loaded Programs : displays all global data of loaded programs

Trace-Tool : run SQL trace, etc from inside debugger

…


Further Information

Public Web:www.sap.com

SAP Developer Network: www.sdn.sap.comSearch for ABAP Knowledge Center

SAP Customer Services Network: www.sap.com/services/

Related SAP Education Training Opportunitieshttp://www.sap.com/education/

Related Workshops/Lectures at SAP TechEd 2004Best of ABAP

ABAP201, The Ultimate ABAP 6.40 Feature Show,2h Lecture

ABAP UNIT, CheckpointsABAP245, New Dynamic Test Tools for ABAP Developers , 4h Hands-on


Further Information

Related Workshops/Lectures at SAP TechEd 2004Shared Objects

ABAP251, ABAP Shared Objects, Shared Memory ProgrammingMade Easy,4h Hands on

Simple Transformations

ABAP252, ABAP - XML Mapping,

4h Hands-on

Generic Programming

ABAP351, Advanced & Generic Programming in ABAP,4h Hands-on

ABAP Troubleshooting

ABAP253, ABAP Troubleshooting,4h Hands on


SAP Developer Network

Look for SAP TechEd ’04 presentations and videos on the SAP Developer Network.

Coming in December.

http://www.sdn.sap.com/


Q&A

Questions?


Please complete your session evaluation.

Be courteous — deposit your trash, and do not take the handouts for the following session.

Feedback

Thank You !


No part of this publication may be reproduced or transmitted in any form or for any purpose without the express permission of SAP AG. The information contained herein may be changed without prior notice.

Some software products marketed by SAP AG and its distributors contain proprietary software components of other software vendors.

Microsoft, Windows, Outlook, and PowerPoint are registered trademarks of Microsoft Corporation.

IBM, DB2, DB2 Universal Database, OS/2, Parallel Sysplex, MVS/ESA, AIX, S/390, AS/400, OS/390, OS/400, iSeries, pSeries, xSeries, zSeries, z/OS, AFP, Intelligent Miner, WebSphere, Netfinity, Tivoli, and Informix are trademarks or registered trademarks of IBM Corporation in the United States and/or other countries.

Oracle is a registered trademark of Oracle Corporation.

UNIX, X/Open, OSF/1, and Motif are registered trademarks of the Open Group.

Citrix, ICA, Program Neighborhood, MetaFrame, WinFrame, VideoFrame, and MultiWin are trademarks or registered trademarks of Citrix Systems, Inc.

HTML, XML, XHTML and W3C are trademarks or registered trademarks of W3C®, World Wide Web Consortium, Massachusetts Institute of Technology.

Java is a registered trademark of Sun Microsystems, Inc.

JavaScript is a registered trademark of Sun Microsystems, Inc., used under license for technology invented and implemented by Netscape.

MaxDB is a trademark of MySQL AB, Sweden.

SAP, R/3, mySAP, mySAP.com, xApps, xApp, SAP NetWeaver and other SAP products and services mentioned herein as well as their respective logos are trademarks or registered trademarks of SAP AG in Germany and in several other countries all over the world. All other product and service names mentioned are the trademarks of their respective companies. Data contained in this document serves informational purposes only. National product specifications may vary.

These materials are subject to change without notice. These materials are provided by SAP AG and its affiliated companies ("SAP Group") for informational purposes only, without representation or warranty of any kind, and SAP Group shall not be liable for errors or omissions with respect to the materials. The only warranties for SAP Group products and services are those that are set forth in the express warranty statements accompanying such products and services, if any. Nothing herein should be construed as constituting an additional warranty.

Copyright 2004 SAP AG. All Rights Reserved

abap new debugger

Documents