Real-world examples for ABA in multithreading - Stack Overflow
2022年1月10日 · The ABA-problem occurs in concurrent code when executing an atomic compare-and-swap instruction. If a thread is interrupted immediately before executing the compare-and-swap, a second thread may change change the target of the compare-and-swap from its initial value A to a different value B.
How can I prevent undefined behavior and the ABA issue in this …
2015年11月3日 · Before the second thread finishes, the caller deletes the object that was being pointed to, so the second thread is now working with deleted memory. The second issue is the classic ABA problem. The idea behind this linked list is to have it be lock-free, so I want to avoid imposing a lock within this function.
java - ABA in lock free algorithms - Stack Overflow
2013年10月29日 · The ABA problem is orthogonal to garbage collection. For instance, applications can move objects from a linked list to a free list and then reuse them back right away. Therefore the object is never actually released before it is re-used. With that said, the ABA problem can happen in this way:
c++ - ABA Race Condition - Stack Overflow
2020年5月27日 · Avoiding the ABA problem in a lock-free algorithm can be quite tricky. It is usually simplest to delegate this to an established memory reclamation scheme. My xenium library provides implementations of various reclamation schemes that can be used for just that.
c# - Avoiding the ABA problem in .NET code - Stack Overflow
2009年3月20日 · "We incur an object allocation for each Push, saving us from having to worry about so-called ABA problems." He then goes on to very briefly describe the ABA problem and mentions that this can occur in native C/C++ because the memory allocator can reuse an address as soon as it's freed. All well and good.
Need help in understanding the "ABA" problem - Stack Overflow
2010年12月9日 · If I post and explain my code it will be absolutely the same explanation as in the blog and maybe even worse, because of my not good enough english :) My source is nearly the same and it fails to work, so I want to check whether it really contains ABA problem or not. Thanks for the book :) I was looking for something interesting to read. But
algorithm - Why called "ABA_problem"? - Stack Overflow
2013年12月30日 · This is the ABA problem (well, in our case NFN). You don't notice in the first thread that your shared value has changed in-between, although this could be critical. Note that you can exchange char with some atomic type and all assignments/tests with atomic ones, the problem would still be the same.
How is this code not solving ABA problem? - Stack Overflow
2021年1月18日 · I trying to learn about the ABA problem in a lock free stack. According to Wikipedia: We have a stack A,B,C. thread_1 tries to pop A. Reads the old_value as A and next value as B. Before thread_1 starts the cas loop: thread_2 comes in and pops A, then; thread_3 comes in and pops B, then; thread_4 comes in and pushes A.
How many ABA tag bits are needed in lock-free data structures?
One popular solution to the ABA problem in lock-free data structures is to tag pointers with an additional monotonically incrementing tag. struct aba { void *ptr; uint32_t tag; }; However, this approach has a problem. It is really slow and has huge cache problems. I can obtain a speed-up of twice as much if I ditch the tag field.
Why does automatic garbage collection eliminate ABA problems?
2017年3月17日 · I have investigated ABA problem in Concurrency in practice book, in Wikipedia and I have read following post. As I understand the root cause of ABA problem that in algoritm we check that state same as was before but algorithm implies that state was untouched. Example with a stack data structure: to add element to stack we use following algorithm: