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What are the differences between the threading and multiprocessing modules?
...faster to create and manage than processes (because the OS doesn't need to allocate a whole new virtual memory area), and inter-thread communication is usually faster than inter-process communication. But threads are harder to program. Threads can interfere with one another, and can write to each ot...
Which kind of pointer do I use when?
... managing memory.
The costs:
If you have a custom deleter (e.g. you use allocation pools) then this will incur overhead per pointer that may be easily avoided by manual deletion.
std::shared_ptr has the overhead of a reference count increment on copy, plus a decrement on destruction followed by a...
What is the purpose of setting a key in data.table?
...dix sorting) and memory efficient (only one extra column of type double is allocated).
When is setkey() required?
For grouping operations, setkey() was never an absolute requirement. That is, we can perform a cold-by or adhoc-by.
## "cold" by
require(data.table)
DT <- data.table(x=rep(1:5, ea...
A complete solution to LOCALLY validate an in-app receipts and bundle receipts on iOS 7
...ceipt:
{
RMAppReceiptIAP *purchase = [[RMAppReceiptIAP alloc] initWithASN1Data:data];
[purchases addObject:purchase];
break;
}
case RMAppReceiptASN1TypeOriginalAppVersion:
_originalAppVersion = RMASN1ReadUTF8String(&s, lengt...
How to automatically generate a stacktrace when my program crashes
...
What would happen if the crash comes from inside malloc? Wouldn't you then hold a lock and then get stuck as "backtrace" tries to allocate memory?
– Mattias Nilsson
Apr 17 '12 at 6:39
...
Ternary operator is twice as slow as an if-else block?
...erator. it's usage in this case just happens to cause a different register allocation. In a different case, it might be faster than if/else, as I tried to explain in my answer.
– Eren Ersönmez
Jun 27 '13 at 12:41
...
How can I record a Video in my Android App.?
...t when one is done with the object. This method releases the memory
* allocated internally.
*/
public native void release();
private native void native_setup();
private static native void native_init();
private native final void native_finalize();
@Override
protec...
Declaration/definition of variables locations in ObjectiveC?
.... #1 often you'll see extern storage specified and then the actual storage allocated in #4. #2) only usually if a subclass needs it for whatever reason. #5 not necessary to forward declare private methods anymore.
– Carl Veazey
Sep 28 '12 at 1:39
...
When is assembly faster than C?
...o understand what's going on. This allows the code to be inlined, register allocated, common subexpression elimination and constant propagation can be done as well. You'll get a huge performance improvement over the hand-written assembler code that way.
For reference: The end-result for the fixed-p...
Understanding garbage collection in .NET
...nalize Method.
When an application creates a new object, the new operator allocates the memory from the heap. If the object's type contains a Finalize method, then a pointer to the object is placed on the finalization queue.
therefore pointers to objects C, E, F, I, J gets added to finalization qu...