If you do so you will run into undefined behavior. Never try that. Although new might be implemented through malloc() and delete might be implemented through free() there’s no guarantee that they are really implemented that way and also the user can overload new and delete at his discretion. You risk running into heap corruption. … Read more
You are correct that the retain count is 2 after adding it to an array. However, you should only worry about the retain counts you add to the item explicitly. Retaining an object is a contract that says “I’m not done with you, don’t go away.” A basic rule of thumb (there are exceptions, but … Read more
copy-on-write (I think this comes for free in nearly all std::string implementations) I don’t believe this is the case any longer. Copy-on-write causes problems when you modify the strings through iterators: in particular, this either causes unwanted results (i.e. no copy, and both strings get modified) or an unnecessary overhead (since the iterators cannot be … Read more
F**/proc/<pid>/pagemap + /proc/<pid>/maps dump example program** Here is a pagemap example that converts virtual addresses to physical: Is there any API for determining the physical address from virtual address in Linux? The following program uses both /proc/<pid>/pagemap + /proc/<pid>/maps to dump page table information to show how they can be used together. Usage: sudo ./pagemap_dump.out … Read more
It’s perfectly safe to use realloc. It is the way to reallocate memory in a C program. However you should always check the return value for an error condition. Don’t fall into this common trap: p = realloc(p, new_size); // don’t do this! If this fails, realloc returns NULL and you have lost access to … Read more
It’s important to be precise in the use of the term ‘memory leak’ with respect to Java. In Java, a memory leak happens when your code holds a reference permanently, so that some object is never garbage collected. Failing to close a stream is not a memory leak in this sense. Streams that have native … Read more
Much of this is answered in the Memory Management chapter of the C API documentation. Some of the documentation is vaguer than you’re asking for. For further details, you’d have to turn to the source code. And nobody’s going to be willing to do that unless you pick a specific version. (At least 2.7.5, pre-2.7.6, … Read more
I’ve had the same problem, with a lot of the same symptoms: pointer being freed was not allocated error upgraded to Xcode 3.2 error happening in code for images If I change the build target to 3.1, the errors in the simulator go away. If I run the code on the device, the errors don’t … Read more
Imports don’t correlate with any instructions in compiled code. They establish aliases for use at compile time only. There are some reflective methods that allow the class to be loaded but not yet initialized, but in most cases, you can assume that whenever a class is referenced, it has been initialized. Static member initializers and … Read more
There’s a 2 GiB limitation on all objects in .NET, you are never allowed to create a single object that exceeds 2 GiB. If you need a bigger object you need to make sure that the objects is built from parts smaller than 2 GiB, so you cannot have an array of continuous bits larger … Read more