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C++ Singleton design pattern
... you usually do not want it to be destructed.
It will get torn down and deallocated when the program terminates, which is the normal, desired behavior for a singleton. If you want to be able to explicitly clean it, it's fairly easy to add a static method to the class that allows you to restore it ...
How to read a line from the console in C?
...ters it read. So you use fgetc:
char * getline(void) {
char * line = malloc(100), * linep = line;
size_t lenmax = 100, len = lenmax;
int c;
if(line == NULL)
return NULL;
for(;;) {
c = fgetc(stdin);
if(c == EOF)
break;
if(--len == 0)...
Is it possible to prevent an NSURLRequest from caching data or remove cached data following a reques
...e, I perform a HTTP request using NSURLRequest for a chunk of data. Object allocation spikes and I assign the data accordingly. When I finish with the data, I free it up accordingly - however instruments doesn't show any data to have been freed!
...
boost::flat_map and its performance compared to map and unordered_map
... few variations of the scenario.
A container performance is affected by:
Allocator
size of contained type
cost of implementation of copy operation, assignment operation, move operation, construction operation, of the contained type.
number of elements in the container (size of the problem)
type ha...
What's the difference between VARCHAR and CHAR?
...n hold is 255 characters.
It's 50% faster than VARCHAR.
Uses static memory allocation.
VARCHAR
Used to store variable length alphanumeric data.
The maximum this data type can hold is up to
Pre-MySQL 5.0.3: 255 characters.
Post-MySQL 5.0.3: 65,535 characters shared for the row.
It's slower tha...
How to create a memory leak in Java?
...The thread loads a class via an (optionally custom) ClassLoader.
The class allocates a large chunk of memory (e.g. new byte[1000000]), stores a strong reference to it in a static field, and then stores a reference to itself in a ThreadLocal. Allocating the extra memory is optional (leaking the clas...
iOS: Compare two dates
...STimeInterval distance
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"dd/MM/yyyy"];
[dateFormatter setLocale:[[[NSLocale alloc] initWithLocaleIdentifier:@"en_US"]
autorelease]];
NSString *stringDate = [dateFormatter stringF...
How can I send mail from an iPhone application
...:
MFMailComposeViewController* controller = [[MFMailComposeViewController alloc] init];
controller.mailComposeDelegate = self;
[controller setSubject:@"My Subject"];
[controller setMessageBody:@"Hello there." isHTML:NO];
if (controller) [self presentModalViewController:controller animated:YES];
[c...
How to find a Java Memory Leak
...t "TRACE nnnn" to see the top few frames of the stack where the object was allocated. Often, once I see where the object is allocated, I find a bug and I'm done. Also, note that you can control how many frames are recorded in the stack with the options to -Xrunhprof.
If you check out the allocation...
How can I programmatically check whether a keyboard is present in iOS app?
...tance;
}
+ (void)load
{
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
sharedInstance = [[self alloc] init];
[pool release];
}
- (BOOL)isVisible
{
return _isVisible;
}
- (void)didShow
{
_isVisible = YES;
}
- (void)didHide
{
_isVisible = NO;
}
- (id)init
{
...