Crash the dynamic memory allocation

hi
i am new to java, my prof said to crash the java prog. write simple prog. which allocate dynamic memory in C++ and Java. push the limits to see how much allocation cause the programs to crash.
how do i implement this in java.. can any one help out here.
thanks in advances.

Write a program that allocates larger and larger objects until it crashes. Make sure it prints the sizes of the objects as it runs.

Similar Messages

Queue of arrays without dynamic memory allocation

Hey folks,
I'm working on optimizing a timing critical VI. This VI is the
producer in a producer consumer architecture. I'm trying to populate
a queue from file in a manner that is as efficient as possible. My
current plan of attack is:
- read block of data from file and populate array (pre-allocated).
- add array (always of the same size) to Queue with a max size defined
(e.g. 50 elements)
- This is in a while loop as is the standard producer consumer model.
To improve the performance I would like to ensure that there is no
dynamic memory allocation on the Queue's behalf. This is easily done,
from what I understand, if the data type in the queue is of the same
type (e.g. double, int). However, since the size of an array can vary
does this mean that any queue of arrays will always dynamically
allocate memory? Is there a way to ensure that the queue will always
use the same memory as in a circular queue?
Thanks,
Steve

Duplicate.
Try to take over the world!

Templates and Dynamic Memory Allocation Templates

Hi , I was reading a detailed article about templates and I came across the following paragraph
template<class T, size_t N>
class Stack
T data[N]; // Fixed capacity is N
size_t count;
public:
void push(const T& t);
};"You must provide a compile-time constant value for the parameter N when you request an instance of this template, such as *Stack<int, 100> myFixedStack;*
Because the value of N is known at compile time, the underlying array (data) can be placed on the run time stack instead of on the free store.
This can improve runtime performance by avoiding the overhead associated with dynamic memory allocation.
Now in the above paragraph what does
"This can improve runtime performance by avoiding the overhead associated with dynamic memory allocation." mean ?? What does template over head mean ??
I am a bit puzzled and i would really appreciate it if some one could explain to me what this sentence means thanks...

The run-time memory model of a C or C++ program consists of statically allocated data, automatically allocated data, and dynamically allocated data.
Data objects (e.g. variables) declared at namespace scope (which includes global scope) are statically allocated. Data objects local to a function that are declared static are also statically allocated. Static allocation means the storage for the data is available when the program is loaded, even before it begins to run. The data remains allocated until after the program exits.
Data objects local to a function that are not declared static are automatically allocated when the function starts to run. Example:
int foo() { int i; ... } Variable i does not exist until function foo begins to run, at which time space for it appears automatically. Each new invocation of foo gets its own location for i independent of other invocations of foo. Automatic allocation is usually referred to as stack allocation, since that is the usual implementation method: an area of storage that works like a stack, referenced by a dedicated machine register. Allocating the automatic data consists of adding (or subtracting) a value to the stack register. Popping the stack involves only subtracting (or adding) a value to the stack register. When the function exits, the stack is popped, releasing storage for all its automatic data.
Dynamically allocated storage is acquired by an explicit use of a new-expression, or a call to an allocation function like malloc(). Example:
int* ip = new int[100]; // allocate space for 100 integers
double* id = (double*)malloc(100*sizeof(double)); // allocate space for 100 doublesDynamic storage is not released until you release it explicitly via a delete-expression or a call to free(). Managing the "heap", the area from where dynamic storage is acquired, and to which it is released, can be quite time-consuming.
Your example of a Stack class (not to be confused with the program stack that is part of the C or C++ implementation) uses a fixed-size (that is, fixed at the point of template instance creation) automatically-allocated array to act as a stack data type. It has the advantage of taking zero time to allocate and release the space for the array. It has the disadvantages of any fixed-size array: it can waste space, or result in a program failure when you try to put N+1 objects into it, and it cannot be re-sized once created.

Degree in Dynamic memory allocation need help!

I'm a student in the University of Bucharest in Computer-Science in the senior year. I'm looking for some specs for my degree in Dynamic memory allocation. In particular I was looking for specs about how the JVM heap and garbage collector work. Can you please direct me to someone how can help me find the necessary specs?
Thank you.

[http://java.sun.com/javase/technologies/hotspot/]
~

Problem in dynamic memory allocation

Hi,
My name is Ravi Kumar. I'm working on a project to improve organizational performance which include visual studio for simulation. I'm using dynamic memory allocation to allocate space for the array that are used in the program. Now I have run-time error
which I can't understand where it is going wrong. Can someone please help me regrading this issue.
If anyone interested in helping please leave a comment with your email id so that I will share the whole project folder.
Thanks,
Ravi

Hi Ravi,
Don is right that this is the forum to discuss questions and feedback for Microsoft Office client.
Please post in MSDN forum of Visual Studio, where you can get more experienced responses:
https://social.msdn.microsoft.com/Forums/en-US/home?forum=visualstudiogeneral
The reason why we recommend posting appropriately is you will get the most qualified pool of respondents, and other partners who read the forums regularly can either share their knowledge or learn from your interaction with us. Thank you for your understanding.
Regards,
Ethan Hua
TechNet Community Support
It's recommended to download and install
Configuration Analyzer Tool (OffCAT), which is developed by Microsoft Support teams. Once the tool is installed, you can run it at any time to scan for hundreds of known issues in Office
programs.

Guest keeps on consuming all the dynamic memory

Software:
Host: Windows Server 2012 R2 x64 fully patched
Guest: Windows 8 Update 1 x64 (Fully Patched).
I've been experience this problem for a few months and really don't know where to go from here. After starting the specific guest that is having the issue it will happen anywhere between 3-7 days. The guest will consume almost all the memory. The only way
i can log into the guest is with hyper-v manager. Remote Desktop will hang. Then when i log into the guest i can't bring up task manager or many things. Every time i have to kill the vm and restart it. Last time i thought to keep process monitor up and
running so i could inspect things. Well it happened today again. According the hyper-v manager the guest was consuming almost 24GB of memory:
here is the memory demand:
What's wierd is when i logged into the vm it was showing it only had 4GB of memory with 3.1GB used. There was hardly anything running other than a few services and they weren't using much memory. Quickly process explorer locked up on me. After logging in
for say 5-10 minutes this always happens too. After trying to diagnose the for a few minutes it will appear i have rebooted the system because i will get the following:
but i definitly did not reboot. If i come back in 24 hours it will still be at the same spot. Again i have to kill the vm but the same vicious cycle will ensue. I'm at a loss how to diagnose this. I've tried to scour the event viewer but it hasn't helped.
Sure i could just turn dynamic memory off or lower the upper threshold of the dynamic memory but i shouldn't have to do that. Thats really just masking the problem. The only default value of dynamic memory i changed was the "Startup Memory". I really
don't want to rebuild the vm but what other options do i have here?

Well i updated one of my main programs on that machine (the on that i would think used "Most" of the memory) and i "thought" it went away but nope i was wrong. It came back. Luckily i left rammap & process explorer running. I could
it when it was consuming almost 6GB rather than the 20+ GB like before. Here is a screenshot of rammap:
As you can see "Paged Pool" memory is huge. I closed almost every app running on the system hoping that would help but it really didn't. The only thing that is running at this point outside of the normal windows processes is EMET 5 & Nortan
Antivirus. I tried to stop halt "Auto Protect" & the firewall but that didn't help any.
unfortunately, though i did catch it early, most programs will fail to load. Even file explorer fails to load. As usual after interacting with process explorer for awhile i get the white screen of death out of it. Hmmmm figure out why so much pool memory
is being consumed.

Why doesn't the debugger follow dynamic memory allocations well?

Here's an example of a code block that doesn't seem to work right with the CVI compiler/debugger, but works fine with other C compilers/debuggers
struct arg_int* arg_intn(const char* shortopts,
const char* longopts,
const char *datatype,
int mincount,
int maxcount,
const char *glossary)
size_t nbytes;
struct arg_int *result;
/* foolproof things by ensuring maxcount is not less than mincount */
maxcount = (maxcount<mincount) ? mincount : maxcount;
nbytes = sizeof(struct arg_int) /* storage for struct arg_int */
+ maxcount * sizeof(int); /* storage for ival[maxcount] array */
result = (struct arg_int*)malloc(nbytes);
if (result)
/* init the arg_hdr struct */
result->hdr.flag = ARG_HASVALUE;
result->hdr.shortopts = shortopts;
result->hdr.longopts = longopts;
result->hdr.datatype = datatype ? datatype : "<int>";
result->hdr.glossary = glossary;
result->hdr.mincount = mincount;
result->hdr.maxcount = maxcount;
result->hdr.parent = result;
result->hdr.resetfn = (arg_resetfn*)resetfn;
result->hdr.scanfn = (arg_scanfn*)scanfn;
result->hdr.checkfn = (arg_checkfn*)checkfn;
result->hdr.errorfn = (arg_errorfn*)errorfn;
/* store the ival[maxcount] array immediately after the arg_int struct */
result->ival = (int*)(result+1);
result->count = 0;
/*printf("arg_intn() returns %p\n",result);*/
return result;
When I try to dereference this structure's 'ival[0]' the debugger constantly complains of a fatal runtime error and declares it out of the array bounds.
This is from the argtable2 open source library available at http://argtable.sourceforge.net/ if you want to try and reproduce it. I'm using CVI 2010 SP1.

Unfortunately, you have run into one of the inherent limitations of CVI's run-time checking. Even though it is perfectly legal in C and somewhat common practice, our run-time checking doesn't like it when you conceptually split up a block of memory and treat it as two or more separate blocks.
While I cannot fix the problem in our run-time checking without breaking other use cases, I can explain what's causing the error and how you can work around it.
When you malloc memory, we assume that the memory block is going to hold one or more instances of the type to which you're casting the memory block. In this case, CVI is treating the new memory block as an array of arg_info structures. But your new memory block is not big enough to hold more than one instance of struct arg_info, so we implicitly truncate the memory block to sizeof(struct arg_info). Because of the implicit truncation, s->values is now pointing past the end of the memory block and any access will result in an error.
#include <ansi_c.h>
struct arg_int {
char some_large_block[64];
int count;
int *values;
int main (int argc, char *argv[])
int i, n = 4;
struct arg_int *s = malloc(sizeof *s + n * sizeof *s->values);
s->count = n;
s->values = (int *)(s+1);
for (i = 0; i < n; ++i)
s->values[i] = i;
return 0;
You can avoid the implicit truncation in the original code by assigning to a (void*) first. This retains the original block size by keeping the actual type of the data in the memory block in limbo. Subsequent casts do not truncate the block. We truncate only when the cast occurs implicitly as part of a malloc. s->values points to the remainder of the block and you can access it freely, but you do not get any run-time checking on it.
#include <ansi_c.h>
struct arg_int {
char some_large_block[64];
int count;
int *values;
int main (int argc, char *argv[])
int i, n = 4;
struct arg_int *s;
void *memory = malloc(sizeof *s + n * sizeof *s->values);
s = memory;
s->count = n;
s->values = (int *)(s+1);
for (i = 0; i < n; ++i)
s->values[i] = i;
return 0;
If you want full run-time checking on s->values, you have to allocate the two components separately.
#include <ansi_c.h>
struct arg_int {
char some_large_block[64];
int count;
int *values;
int main (int argc, char *argv[])
int i, n = 4;
struct arg_int *s = malloc(sizeof *s);
s->count = n;
s->values = malloc(n * sizeof *s->values);
for (i = 0; i < n; ++i)
s->values[i] = i;
return 0;
Another option is to use an incomplete array. An incomplete array is an array of unspecified or zero size at the end of a structure definition. CVI is implicitly growing the array to fill up the rest of the allocated memory block. You do not get run-time checking for the array.
#include <ansi_c.h>
struct arg_int {
char some_large_block[64];
int count;
int values[0];
int main (int argc, char *argv[])
int i, n = 4;
struct arg_int *s = malloc(sizeof *s + n * sizeof *s->values);
s->count = n;
for (i = 0; i < n; ++i)
s->values[i] = i;
return 0;
You can also disable run-time checking for your memory block by going through a series of casts: http://zone.ni.com/reference/en-XX/help/370051K-01/cvi/disablinguserprotectionforindividualpointer/
Best regards.

Dynamic memory allocation failure

Dear reader,
We sometimes have a problem where our windows 2012 r2 RDS virtual servers, that reside on windows 2012r2 hyper-v hosts, loose their dynamic memory and only have their startup memory left to work with. Users start complaining that things are very slow etc.
If I check several screens (RDS Broker load balancing, hyper-v manager, cluster manager and the vm's task manager) it's clear that the vm only has its startup memory allocated. I'm not sure if this happens instantly or immidiatly after the nightly reboot.
To resolve the problem we have to call all users on the vm where it happens and ask them to logoff (if they are even able to), and then we reboot the machine.
I have checked the logs from the machine where the VM resides on and the logs from the vm itself. But I cannot find anything. We also have alot of windows 2008r2 vm's with dynamivc memory, but none of those have ever had this problem.
Searched the internet, but so far it seems we are only.
Can anyone give me a lead to troubleshoot this?
Best regards,
Ruud Boersma
MCITP Enterprise administrator

Hi all,
I'm going to be "one of those people" who revives dead posts for something that is relevant but obviously not fixed... sorry in advance!
We have the exact same situation, a bunch of RDSH guests with Dynamic memory turned on (60+ of them). every day between 1-8 of them will fail to allocate Dynamic memory and will be stuck on their startup RAM amount. This really hurts our users at peak
times.
I have engaged our TAM and have raised a case with PSS, Usual story "your the only one with this problem". Which obviously isn't true.
So, we have tons of free RAM on the hosts, 600GB+ on most of them, the issue affects RDSH hosts at random, across multiple hosts and clusters.
The screen shots attached are of one of our hosts from this morning. it has 8GB startup, 8GB minimum, 32GB Maximum RAM configured, with a 23% buffer. the host has 752GB RAM FREE. Notice how the perf counter "Hyper-V Dynamic Memory Integration Service"
is reporting "0", it should be reporting "32768". also under task manager on the VM we are missing "Maximum memory" which should be just below "Hardware reserved" in the bottom right hand corner.
Looks like the balloon driver is being delayed at boot time, we are going to XPerf all the servers in the hope that we can catch the critter. It's an unusual problem.
We only have Acrobat PDF viewer, word viewer, excel viewer and two custom dot.NET applications installed on the guests. Some of the servers are also just dumb RDSH hosts, with not connection broker configured, using an F5 loadbalancer for load distribution
and session management. All guests are 2012R2 patched up to March 2015, integration Services are installed and up to date (its an enlightened OS remember).

Dynamic memory allocation on HP-UX for multiple instances on one host

Hi everyone,
I was wondering what the current possibilities are nowadays on running multiple SAP instances on one very large host with regard to resource sharing. Normally, for each instance, using PHYS_MEMSIZE etc you have to set the memory to a fixed size and then optimize it.
Preferrably we would like the memory to be allocated based upon actual usage. Is that possible at all? on HP-UX? Using third party techniques?
Thank you
Marcel Rabe

Hello Marcel,
As Juan said you may not be able to change the parameters at runtime.
The only parameters that can be dynamically switched are :
ztta/roll_first
ztta/roll_extension
ztta/roll_area
abap/heap_area_dia
abap/heap_area_nondia
abap/heap_area_total
em/stat_log_size_MB
em/stat_log_timeout
These parameters would put a cap on memory allocations, however they wouldn't help increase the total addressable memory area.
I would suggest that you consider Adaptive Computing for dynamic use of resources.
Adaptive Computing
Regards,
Siddhesh

Dynamic memory allocation

Hi, guys, does anyone know whether I can use dyanmic memory allocation on the Real time system with "call library function" node. DLL is programmed using C language. Thanks.
Machman

You certainly can. LabVIEW Real-Time functionality is really not much different than what you can do on Windows. The only difference being that you can now assign priorty and timing to your execution loops; essentially, you have determinism with RT whereas with Windows, you never have a guarantee.
Thus, in regards to calling a dll, you can perform this the same way you would in LabVIEW for Windows. Here's a KnowledgeBase article on how to do this if you're not already familiar.
Cheers,
Emilie K. | Applications Engineer | National Instruments

Can any java process exceed the maximum memory allocated

Hi,
I have a basic question on the memory settings. Assume I have a java process where the memory settings are like:
-Xmx1024m
where the server capacity is say 8GB Then can the process exceed the allocated memory of 1GB and go further say upto 4 GB.
If above thing is possible, how can we limit the process not to exceed the given limit? What settings need to be used.

Krish8 wrote:
Hi,
I have a basic question on the memory settings. Assume I have a java process where the memory settings are like:
-Xmx1024m
where the server capacity is say 8GB Then can the process exceed the allocated memory of 1GB and go further say upto 4 GB.
If above thing is possible, how can we limit the process not to exceed the given limit? What settings need to be used.Yes the used memory can exceed that if you e.g. are using memory mapped files. Don't know if you can restrict it unless your OS has some kind of support for it.
Kaj

What is the default memory allocation for JVM

Hi,
Can anybody please let me know the default heap memory allocation(both min & max) for JVM, if we don't provide memory arguments (-Xms -Xmx) on 32-bit linux & windows machines having 4GB RAM?
Thanks,
Suresh

user641407 wrote:
Hi,
Can anybody please let me know the default heap memory allocation(both min & max) for JVM, if we don't provide memory arguments (-Xms -Xmx) on 32-bit linux & windows machines having 4GB RAM?
Starting with 5.0, per the Sun VM docs.
http://download.oracle.com/javase/6/docs/technotes/tools/windows/java.html
+"-Xmsn ... The default value is chosen at runtime based on system configuration."+
+"-Xmxn ... The default value is chosen at runtime based on system configuration."+
What other documentation are you looking for?

Process crashes b'cos memory allocation...Can anybody help?

It is happening randomly. The scenerio is like that I am allocating memory to pointer variable. with the core file I could find only that it is crashing in _malloc(). I am using SunOS 5.5.1 and C++ Sun compiler 4.2. Can anybody give any hint to explore it? FYI I have checked that RAM is not exauhsted.

Looks like a plugin crash, possibly Satin, or maybe one of the others.
You can try one of these.
By holding down modifier keys while you open the application, you can put Logic Pro or Logic Express into one of several troubleshooting modes. To do this, go to your Applications folder, double-click the Logic icon, then hold down the respective modifier key(s) from the table below until a dialog appears or Logic is fully loaded.
Modifier key(s)
Description
Purpose
Control
Start without Audio
This can be helpful to rule out issues with a specific Core Audio driver. In some cases, Logic may stop responding or quit unexpectedly while initializing the Core Audio driver. In these cases, start Logic Pro or Logic Express without Audio. If needed, turn on Built-In Audio for the troubleshooting.
Shift-Control
AU-Safe Mode
This will only load Audio Units that have passed the Audio Units Validation Tool which is automatically launched on the very first startup of Logic. If you have enabled Audio Units that did not pass this test, you may experience unexpected quitting or misbehavior. With this option, you may revert Logic Pro or Logic Express to a stable state.
Option
Start without Autoload/Template/LastRecent
This will start Logic Pro or Logic Express without loading a Template, Autoload, or last-opened project. This can be useful for troubleshooting any kind of issue since it excludes the possibility that an issue is specific to or caused by the currently loaded project. Choosing File > New with the Option Key held down will load an empty default project for troubleshooting.

Finding dynamic memory allocations in core file

Hi,
Is it possible to find out which data structures were allocated by analysing a core file?
I want to find out which objects are causing the memory to increase, and I have the core file of the program.
Thanks in advance,
Paulo

It's almost impossible. Anyway, it would be pure heuristics - looking at stack contents, finding familiar patterns in heap, etc, etc.

Dynamic Memory is not working all the time

We are in the process off moving our 2008R2 VM's from the 2008R2 HyperV servers to new Server 2012R2 Hosts.
We shut down the VM's copy the files and VHD's to the new CSV's en import the VM in the Hyperv Manager. Then we make them high available in the Failover Cluster Manager (Configure role - Virtual machine). We mount the integration tools and update the
VM to version 6.3.9600.16384
For a specific type of VM (mostly RDS Host servers) we always had Dynamic Memory configured (when they were hosted on de 2008R2 platform), so we are using the same settings on the 2012r2 platform. The memory settings were;
Startup memory: 1024 MB
Minimum memory: 1024 MB
Maximum memory: 12288 MB
These VM's reboot every morning, this is done for specific reasons. But now once in a while (once per week/2 weeks) we notice that the VM's are not using more memory then 1024 MB while the demand is much higher. Rebooting the server helps most of the times,
live migrating to another host also helps. In the VM we see that memory usage in the taskmanager is 99-100%, and after the move it immediately starts using more than the minimum configured amount.
Until the failover the memory usage was 1024 MB and it did not get any higher.
This happened several times. Last week we changed the Memory configuration to:
Startup memory : 2048 MB
Minimum memory: 2048 MB
Maximum memory: 12288 MB
But this morning we had a call about the performance of one of the VM's, We saw that it was only using 2 GB memory while the demand was much higher. After live migrating it to another host it started using more memory immediately.
The 2012R2 hosts are not overcommited, there is a lot of memory still available for the VM's. Those VM's never had this problem on the 2008R2 Hyperv platform.
Any idea why this happens?
Peter Camps

Peter,
I think this is a bug of some sort. I say that because the components that make up dynamic memory are as follows.
Memory Balancer(Host service, coordinates how memory changes are made.) This is also what shows the memory demand counter i believe.
Dynamic Memory Virtualization Service Provider (this is included your VMWP.exe proccess, one per VM. Essentially how it runs on the host. He listens to the Service Client for metrics)
Dynamic Memory Virtualization Service Client (this is inside the VM and reports to the Dynamic Memory Virtualizaton Service Provider.)
Since you live migrated the machine it made dynamic memory work on the other host. This means the Service Client is running in the client and shouldn't be an issue. The Memory Balancer is the server and shouldn't be the issue, so this means the "Dynamic
Memory Virtualization Service Provider" is in question. When you live migrate the machine its going to create a new VMWP.exe process on the clustered server. So now the question is it the host that couldn't listen to the service or the worker process
skipped a beat and has a bug.
Out of curiosity does it happen to both hosts? Also have you profiled the servers to see how much memory they really require on start-up? When you reboot the RDS servers, how many VM's do you reboot and is it a staggered process?

Crash the dynamic memory allocation

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