Questions tagged [memory-management]
For questions related to managing memory in programming languages, whether manually or automatically.
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What was the rationale for making realloc(ptr, 0) have UB in C23
This is the first breaking change that C made, which was making realloc(ptr, 0) have UB instead of being roughly equivalent to ...
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Are there actual languages using fat pointers to store types?
In the normal implementations of C++, while not guaranteed by the standard, there is a vtable pointer as the header of every inherited class that needs a vtable pointer. There will be multiple vtable ...
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Is there a downside to using offsets instead of raw pointers in a virtual machine?
Say I'm designing a virtual machine for a bytecode compiler/interpreter, using C as the implementation language. Some kind of “tagged” representation of values is simplest for this language, where ...
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Approaches for implementing weak references
How can weak references (weakrefs) be implemented, and how do the different approaches compare?
The most important considerations for implementing weakrefs are:
Safety ─ a weakref shouldn't allow ...
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Why did Objective-C remove `NSZone`?
NSZone is a type representing a memory allocation. NSObject implements the allocWithZone: ...
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Are there languages or compilers having optimizations to deallocate variables early?
In a scope that defines two variables a and b, the code firstly does things only on a. Then <...
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If garbage collection always sacrifice performance in multi-threaded languages, then how do some languages approch this problem?
Mark-and-Sweep garbage collection need to work over the graph of all objects in the process, and would stall threads to make the operation safe with regard to threads. I can think of no way to work ...
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To box or not to box? (how to determine if a value can be more efficiently passed by value or by reference)
I want to remove explicit addressing from my type system.
In low level languages like C or Rust, you always have a choice whether to store some data by value or by reference. There are some advantages ...
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Are there languages making addresses to have other significant meaning?
Some examples:
To support checking whether an object is of a subclass of a specific class in constant time, in a language using single inheritance, the compiler could arrange the vtables of classes ...
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Possible to mix garbage collection and manual memory management?
Do you think it is possible to have a language that uses garbage collection (GC) by default, but allows you take more control with manual memory management like C++ or Rust, in areas of the software ...
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Is it possible to extend C to have the Rust concept of ownership for memory safety?
Rust has a number of memory safety features. Is it possible to extend or enhance C or C++ to also provide similar memory safety features instead of using workarounds such as the Valgrind tool suite?
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Why might a language avoid reallocation?
In Java, the size of arrays are immutable. However, to my understanding, they are still allocated on the heap, because Java allocates almost everything on the heap. Even then, Java arrays are still ...
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X86-64 Assembly for Recursive Functions
A compiler I'm writing generates the following x86-64 assembly (AT&T syntax) for a recursive factorial function. I convert the assembly into an ELF executable using ...
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Memory layout from a native class
I think there are languages where most of the standard library is written in themselves, however with most things marked as native or ...
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Could ownership be inferred?
Rust famously has the concept of ownership vs. borrowing as part of its type system. This allows some level of automatic memory management ─ that is, heap allocations are freed when their owner goes ...
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