Hello,
I have a pointer to a main structure which again consists of
structures, enums, char, int, float and again complex structures.
When i free all the contents of the main structure, it takes me a lot
of time (since i have to loop determining the data type and freeing
it). Is there any idea to free all the contents of the structure in
shortest possible time. 11 2007
Or probably should i switch to static memory instead??? In that case
what care should be taken.
Pl advice
vivek wrote:
Hello,
I have a pointer to a main structure which again consists of
structures, enums, char, int, float and again complex structures.
When i free all the contents of the main structure, it takes me a lot
of time (since i have to loop determining the data type and freeing
it). Is there any idea to free all the contents of the structure in
shortest possible time.
You might try making the structure static. Or you might try having a
separate cache of all the pointers to dynamic memory for each structure
element. This will consume additional memory, but will eliminate the
need to traverse the structure to free all it's components.
In anycase, I doubt that traversing the structure is going to be your
most serious bottleneck, particularly if you do it all at once.
vivek said:
Hello,
I have a pointer to a main structure which again consists of
structures, enums, char, int, float and again complex structures.
When i free all the contents of the main structure, it takes me a lot
of time (since i have to loop determining the data type and freeing
it). Is there any idea to free all the contents of the structure in
shortest possible time.
Well, exit(0) will do it. But I'm curious to know why you think it's taking
a lot of time. Computers are pretty fast nowadays. Is this really the
bottleneck for your program? What did profiling tell you?
--
Richard Heathfield <http://www.cpax.org.uk >
Email: -http://www. +rjh@
Google users: <http://www.cpax.org.uk/prg/writings/googly.php>
"Usenet is a strange place" - dmr 29 July 1999
Oh, it is for an embedded system, where that freeing the structure
takes about 0.4 ms, which is a lot of time for an embedded
system...Thats why!!!
"you might try having a
separate cache of all the pointers to dynamic memory for each structure
element. This will consume additional memory, but will eliminate the
need to traverse the structure to free all it's components.
In anycase, I doubt that traversing the structure is going to be your
most serious bottleneck, particularly if you do it all at once"
Can you explain in detail about the caching, please? I could not
follow that part.
vivek wrote:
Oh, it is for an embedded system, where that freeing the structure
takes about 0.4 ms, which is a lot of time for an embedded
system...Thats why!!!
Okay. Some of your options are:
1. Don't free anything. Obviously this might not be feasible.
2. Use static or automatic objects. Static objects will persist
throughout the program lifetime while auto objects will be destroyed
once their scope is exited.
3. Use something like alloca. See the recent threads on this. Objects
allocated with alloca persist throughout the function and need no
explicit call to free.
4. Modify your data structures so that dynamic memory is minimised
or "clumped" together, thus minimising the number calls to free.
There may be other strategies too, though we can't tell you which one
might be suitable since the choice depends on various factors of your
program and it's host machine and what's expected of them.
Generally speaking, if you want realtime performance then malloc/free is
pretty much ruled out, but I would suggest that you actually verify
that they *are* the problem and that the time consumed *is*
unacceptable before considering other strategies.
Of course everything else is ok with the program
functionalities ...except for the time...If time is ok...thats
it..project over...
and thank u so much santhosh
On 5 Mar, 08:47, vivek <gvivek2...@gma il.comwrote:
I have a pointer to a main structure which again consists of
structures, enums, char, int, float and again complex structures.
are these nested structures or pointed to?
/* headers ommitted */
struct Main1_s
{
struct Nested_s nested;
};
struct Main2_s
{
struct Pointed_s *pointed;
};
void func (void)
{
struct Main1_s *main1_s;
struct Main2_s *main2_s;
/* should check for malloc() failures */
main1_s = malloc(sizeof *main1_s);
main2_s = malloc(sizeof *main2_s);
main2_s->pointed = malloc(sizeof (*main2_s->pointed));
/* do stuff */
/* cleanup */
delete (main1_s);
/* nested freed automatically */
delete (main2_s->pointed);
delete (main2_s);
}
When i free all the contents of the main structure, it takes me a lot
of time (since i have to loop determining the data type and freeing
it).
what sort of time? Do you mean the program takes a long time?
How do you know, have you timed it? Or is it taking a long
time to write the program? Why do you need a loop to determine the
data type. We need to see some code!
Is there any idea to free all the contents of the structure in
shortest possible time.
not sure what you mean. Could you use automatic storage?
void func (void)
{
struct Main1_s main1_s;
/* do stuff */
}
no mallocs therefore no deletes
and then vivek wrote:
Or probably should i switch to static memory instead??? In that case
what care should be taken.
I'm not sure. What lifetime does your structure need? Statics can
occupy storage unnecessarily (they go away only when the program
ends).
You may make them accessible from too much of the program.
You might have problems that there is only one copy of the struct
when logically you need many.
I need to know more about what you are doing.
Can you post a simpified example?
--
Nick Keighley
The Dinosaurs have come and gone, we Theriodonts remain
The structures are nested.
I have measured the time taken for this specific code section to run.
The lifetime of the structures would be like this.
Receive some communication data, use these structures to decode data -
allot memory...after decoding, process it ..then free memory..
then prepare a reply, encode the date(create these structures-allot
memory), send the data and free memory. This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics |
by: disco |
last post by:
I am working on this example from a book "C Primer Plus" by Prata 4th
edition - p. 672. There is no erata on this problem at the publisher's
website.
1) Is it a violation of copyright laws to post example code from a
book to a newsgroup?
2) The program crashes as it tries to free memory and I would like to
know the best way to correct THIS section of the code. By assigning
current = head, current now points to the first structure in...
|
by: Rodrigo Dominguez |
last post by:
there are sometimes that I use third party libraries, I use some functions
that returns char * or structs, etc. sometimes the memory that is returned
by those libraries, when I try to free this memory whith the function free,
it brokes my application, and sometimes it's ok, why? how do I realize when
I have to free the memory that is allocated by third party libraries and
why sometimes I don't have to free this memory?
Thank you
|
by: Fernando Cacciola |
last post by:
Help me out here please:
While watching Brad Abraham's MSDN TV talk about the Dispose pattern,
refering to:
public virtual void Dispose ( bool disposing )
{
if ( disposing )
{
<-- WHAT GOES HERE -->
|
by: Atul Sureka |
last post by:
Hi,
I want to free the object memory in C# - like we do using 'delete' keyword
in C++.
Lets say I have an object of some class and I want to explicitly free the
memory.
C# do not have any free or delete keyword to do so.
Also I don't want to wait for the GC to be called.
|
by: Amogh |
last post by:
Hi,
My question is related to setting freed pointers to NULL.
After freeing a pointer:
1) Should the freeing routine also be responsible for setting the
pointer to null?
2) Or, should the client/user code be responsible for doing it?
On what basis should a decision be made favouring either case ?
| |
by: Chris |
last post by:
I have a Bayesian simulation package that keeps running into memory
allocation problems. I have a feeling this has something to do with
Python (2.5.1.1) not freeing memory. The program essentially
iterates n times, each time proposing new arrays (numpy) of values
that are evaluated using statistical likelihoods. All variables in
the loop are re-assigned at each iteration, so there should not be
a leak. Nevertheless, at approximately the...
|
by: Berteun Damman |
last post by:
Hello,
I have programmed some python script that loads a graph (the
mathemical one with vertices and edges) into memory, does some
transformations on it, and then tries to find shortest paths in this
graph, typically several tens of thousands. This works fine.
Then I made a test for this, so I could time it, run it several times
and take a look at the best time, et cetera. But it so happens that
the first time the test is run, is...
|
by: karthikbalaguru |
last post by:
Hi,
Will 'free' return the memory Immediately to the OS ?
Thx in advans,
Karthik Balaguru
|
by: Andreas Eibach |
last post by:
Hi again,
one of the other big woes I'm having...
typedef struct perBlockStru /* (structure) Long words per block
*/
{
unsigned long *lword;
} lwperBlockStru_t;
|
by: marktang |
last post by:
ONU (Optical Network Unit) is one of the key components for providing high-speed Internet services. Its primary function is to act as an endpoint device located at the user's premises. However, people are often confused as to whether an ONU can Work As a Router. In this blog post, we’ll explore What is ONU, What Is Router, ONU & Router’s main usage, and What is the difference between ONU and Router. Let’s take a closer look !
Part I. Meaning of...
|
by: Oralloy |
last post by:
Hello folks,
I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>".
The problem is that using the GNU compilers, it seems that the internal comparison operator "<=>" tries to promote arguments from unsigned to signed.
This is as boiled down as I can make it.
Here is my compilation command:
g++-12 -std=c++20 -Wnarrowing bit_field.cpp
Here is the code in...
| |
by: jinu1996 |
last post by:
In today's digital age, having a compelling online presence is paramount for businesses aiming to thrive in a competitive landscape. At the heart of this digital strategy lies an intricately woven tapestry of website design and digital marketing. It's not merely about having a website; it's about crafting an immersive digital experience that captivates audiences and drives business growth.
The Art of Business Website Design
Your website is...
|
by: Hystou |
last post by:
Overview:
Windows 11 and 10 have less user interface control over operating system update behaviour than previous versions of Windows. In Windows 11 and 10, there is no way to turn off the Windows Update option using the Control Panel or Settings app; it automatically checks for updates and installs any it finds, whether you like it or not. For most users, this new feature is actually very convenient. If you want to control the update process,...
|
by: tracyyun |
last post by:
Dear forum friends,
With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each protocol has its own unique characteristics and advantages, but as a user who is planning to build a smart home system, I am a bit confused by the choice of these technologies. I'm particularly interested in Zigbee because I've heard it does some...
|
by: agi2029 |
last post by:
Let's talk about the concept of autonomous AI software engineers and no-code agents. These AIs are designed to manage the entire lifecycle of a software development project—planning, coding, testing, and deployment—without human intervention. Imagine an AI that can take a project description, break it down, write the code, debug it, and then launch it, all on its own....
Now, this would greatly impact the work of software developers. The idea...
|
by: conductexam |
last post by:
I have .net C# application in which I am extracting data from word file and save it in database particularly. To store word all data as it is I am converting the whole word file firstly in HTML and then checking html paragraph one by one.
At the time of converting from word file to html my equations which are in the word document file was convert into image.
Globals.ThisAddIn.Application.ActiveDocument.Select();...
|
by: TSSRALBI |
last post by:
Hello
I'm a network technician in training and I need your help.
I am currently learning how to create and manage the different types of VPNs and I have a question about LAN-to-LAN VPNs.
The last exercise I practiced was to create a LAN-to-LAN VPN between two Pfsense firewalls, by using IPSEC protocols.
I succeeded, with both firewalls in the same network. But I'm wondering if it's possible to do the same thing, with 2 Pfsense firewalls...
| |
by: bsmnconsultancy |
last post by:
In today's digital era, a well-designed website is crucial for businesses looking to succeed. Whether you're a small business owner or a large corporation in Toronto, having a strong online presence can significantly impact your brand's success. BSMN Consultancy, a leader in Website Development in Toronto offers valuable insights into creating effective websites that not only look great but also perform exceptionally well. In this comprehensive...
| |