Solved

DLL/DPL: How to choose imagebase?

Posted on 2001-07-20
3
822 Views
Last Modified: 2008-02-01
It's about the imagebase linker param that defaults to $00400000.

For DLL's and DPL's I understand it's recommended to change it, in order to minimize load time and eventually memory consumption.

1. First of all, has anybody any experience about the efectiveness of changing this setting?
2. Can you suggest any policy for choosing the value?
3. Any potential problems when several apps are using the same DLL because it was loaded at its preferred address?
4. How do you manage the settings for different DLL's across all your pool of own-developed libraries? What about "collision" chances with other libraries already in the target system?

Thank you,
F.
0
Comment
Question by:fva
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
3 Comments
 
LVL 26

Accepted Solution

by:
Russell Libby earned 100 total points
ID: 6303276
Hi F.

1.) Unless the app uses a large number of dll's, this has little affect, and then only on the load time.

2.) Per MSDN:

The system DLLs are currently based in memory from 0x70000000 to 0x78000000 (0x68000000 to 0x78000000 on MIPS). Therefore, you should base your DLLs from 0x60000000 to 0x68000000. One possible scheme is to choose a base address based on the first letter of the DLL name.

First letter Base address
A - C 0x60000000
D - F 0x61000000
G - I 0x62000000
J - L 0x63000000
M - O 0x64000000
P - R 0x65000000
S - U 0x66000000
V - X 0x67000000
Y - Z 0x68000000

It is best to base DLLs from the top of the address range down, instead of from the bottom up. Dynamic memory is allocated from the bottom up and if a DLL tries to load where dynamic memory has been allocated, it will be relocated, just as if a DLL was loaded at that address.

3.) No.

4.) Not sure if I follow the question, but windows will rebase the dll in memory if the image base address is in conflict. Answer 2 (above) covers the addresses for system dll's.

Russell



0
 
LVL 4

Author Comment

by:fva
ID: 6308172
Hi, thanks.

I admit, 4) it's actually a rephrase of 2)

I'll let some time open this, maybe I get other opinions, too.

F.
0
 
LVL 4

Author Comment

by:fva
ID: 6326229
And here are your points since nobody else cared to add any comment.

Thanks,
F.
0

Featured Post

[Live Webinar] The Cloud Skills Gap

As Cloud technologies come of age, business leaders grapple with the impact it has on their team's skills and the gap associated with the use of a cloud platform.

Join experts from 451 Research and Concerto Cloud Services on July 27th where we will examine fact and fiction.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

The uses clause is one of those things that just tends to grow and grow. Most of the time this is in the main form, as it's from this form that all others are called. If you have a big application (including many forms), the uses clause in the in…
Creating an auto free TStringList The TStringList is a basic and frequently used object in Delphi. On many occasions, you may want to create a temporary list, process some items in the list and be done with the list. In such cases, you have to…
This is my first video review of Microsoft Bookings, I will be doing a part two with a bit more information, but wanted to get this out to you folks.
Visualize your data even better in Access queries. Given a date and a value, this lesson shows how to compare that value with the previous value, calculate the difference, and display a circle if the value is the same, an up triangle if it increased…
Suggested Courses
Course of the Month5 days, 3 hours left to enroll

635 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question