Why is CompareAndSwap instruction considered expensive?
I read in a book:
"Memory barriers are expensive, about as
expensive as an atomic compareAndSet()
instruction."
Thanks!
Searching for answers about the "Clear Text Credential Access Enabled" field, I found a question on an oracle forum that was my exactly what I was trying to find out. Thinking that my answer would soon be found, I happily click on the link only to find zero replies. All hope was lost. I am posting the question here, hoping that someone on this site will know the answer.
Can somebody please explain the usage of "Clear Text Credential Access Enabled" checkbox under "-Security-Advanced tab for Weblogic 11g? What is the difference if we set or unset this flag? If I dont set this flag I get an exception like "Access to sensitive attribute in clear text is not allowed due to the setting of ClearTextCredentialAccessEnabled attribute in SecurityConfigurationMBean" when I try to set a value for the "Credential" field. But what should be the value for "Credential" field if I dont set the "Clear Text Credential Access Enabled"flag?
I'm building a little script that will connect to an IMAP account and grab the content of the email and also the attachments. It works well for the most part, but when a really large file comes in, it causes the script to time out. Is there any way that I can check the file size before trying to grab it? I think that would be the simplest solution. Otherwise, I may have to upgrade to a server that has more memory.
Hi,
list<Dog*> dog;
.............
............
So I added many dog objects to it.
If I call dog.pop_front();
Does memory automatically gets deallocated ?
how can i modify the method in memory so it makes new objects with that modified method?
for example i want to modify or add page_init handler on runtime for the next time the page loads?
see this also for clarification: http://stackoverflow.com/questions/3005338/page-load-another-handler
Is there a more efficient way than using numpy.asarray() to generate an array from output in the form of a list?
This appears to be copying everything in memory, which doesn't seem like it would be that efficient with very large arrays.
(Updated) Example:
import numpy as np
a1 = np.array([1,2,3,4,5,6,7,8,9,10]) # pretend this has thousands of elements
a2 = np.array([3,7,8])
results = np.asarray([np.amax(np.where(a1 > element)) for element in a2])
Hi,
I have a rdf file (file.trp) in n-triples format, where each line is:
"subject predicate object ."
I tried to use rdf_load in semweb/rdf_db to load it into memory, but failed. Here is what I tried:
?- rdf_load('file.trp').
?- rdf_load('file.trp', [format(triples]).
the manual says it supports xml and triples. But it only loads rdf xml files. How can I load such rdf triple file?
Thanks,
Li
As I remember there is a magic command line option in Java that turn on writing of operations that are currently executed to console. The output was looked like byte code. I do not mean -verbose, because it prints only class loading, while this option outputs information like memory allocation etc.
I have some questions about singletons in C++.
Under what situations is a singleton a must?
What are the pros and cons of singletons? I was told they could cause memory leaks, how is that? I was also told that initialization is a problem, is that true?
$fp_src=fopen('file','r');
$filter = stream_filter_prepend($fp_src, 'convert.iconv.ISO-8859-1/UTF-8');
while(fread($fp_src,4096)){
++$count;
if($count%1000==0) print ftell($fp_src)."\n";
}
When I run this the script ends up consuming ~ 200 MB of RAM after going through just 35MB of the file.
Running it without the stream_filter zips right through with a constant memory footprint of ~10 MB.
What gives?
I was doing some work handling a lot of information and my partner told me that I was using too many matrices to manipulate the variables of the problem. The idea was to use one dimension arrays int a[] instead of the 2 dimensional arrays int b[][], to save memory and processing speed of the algorithm. How certain is that this change will accelerate the speed of execution or compilation of my code in c ++?
I have a huge problem with ElanTech touchpad. Without the ElanTech driver both the keys can be used at the same time(R+L). This is usefull in games like Mafia2 (can't play without it). When I install their driver I get the gestures, scrolling etc. but I can't use both keys at the same time. It is a common problem.
Acer Aspire v3-571G Windows 7 x64
This didn't work at all: Synaptics 15.3.41.5
Is there any universal driver which will give me at least scrolling and simultaneous keys usage?
Is is bad practice to pass the Context to a constructor and save it as a private variable for internal use? The other option is to pass the Context as a parameter to methods that need it.
Which is the better option?
I have a feeling that passing to the constructor might result in memory leaks accidentally.
I am sorting a hash in Perl. I encountered an Out of memory error when running my Perl Script:
foreach $key (sort (keys(%hash))) {
....
}
How do I sort a hash that has tons of data?
I found OWSTIMER consume a lot of memory during create personal sites. (I have to pre-create personal sites for many users)
After googling I found some suggestion to restart OWSTIMER but it’ll grow up again after create several personal sites. So I have to restart OWSTIMER every hour.
Did you know any impact of restart OWSTIMER every hour?
Thank you
If I have a Facebook app, and my users agree to allow my app to access their information, photos, friends, etc, is it ethical to grab their information when they log in, and then saving it in memory so that the next time he goes to my app, it can load faster?
If so, what about when the user logged off? Is the right thing to do to is to delete all the cached information and photos that the user provided?
Has Facebook got any way to detect that we're doing this (saving their information, etc)?
I was wondering how Java sorts items in the Map (HashMap or Hashtable) when they are added. Are the keys sorted by the hashcode, memory reference or by allocation precedence...?
It's because I've noticed same pairs in the Map are not always sorted in the same order
Hi, I have a structs action object instance that loads a variable from a properties file.I want it to happen only the first time the action is called, so in further executions its read from memory. Any hints ? Thanks.
Hi,
I'm implementing a program which gets text from various sites and checks which ones are most relevant to a query. The problem is that when I have breakpoints in my code it works perfectly well but without it, the program just freezes. Is this a memory issue? What can I do to solve this please?
THanks
I have a class definition of the form
class X
{
public:
//class functions
private:
A_type *A;
//other class variables
};
and struct A_type is defined as
struct A_type
{
string s1,s2,s3;
};
Inside the constructor, I allocate appropriate memory for A and try A[0].s1="somestring";
It shows segmentation fault.
Is this kind of declaration invalid, or am I missing something
I'm trying to use the OpenCA library in a C++ application. However, when including the file pki_x509_data_st.h the following code fragment is encountered:
typedef struct pki_x509_callbacks_st {
/* ---------------- Memory Management -------------------- */
void * (*new) (void );
void (*free) (void *x );
void * (*dup) (void *x );
This won't compile because of the "new" pointer declaration.
How can I make it work?
I was looking at AppFog's Pricing and they appear to be giving 2GB of ram away for free, to nonpaying customers. This seems unprecedented for PAAS provodes--providers like Heroku and App Engine remove the app from memory if it has been inactive for certain amount of time. Does cloudfoundry work similarly? Am I wrong in assuming that in a few years appfog servers will be filled with inactive non paying applications?
I used strtol to convert a string to hex, now I need to print it to the screen. I'm not sure if I can use sprintf since I only have 20k of memory to use on this board. Alternatives welcome.
Basically -[UIApplication openURL:] would be perfect, if it wasn't for the fact that it doesn't work within the same application (at least on simulator -- if this works on device someone please tell me). It's not a super big deal though if it just relaunches w/o URLness since I can obviously just persist some data. The goal of this is to essentially free all memory in the application and call all of the loading procedures.