memory-management

问题 This question already has answers here : Pointer to pointer clarification (16 answers) Closed last year . IMPORTANT: This tried to ask too many things at once and was misleading because I wrote it under a false assumption about how pointers can be used, and it ended up just looking like a duplicate. Please see this instead: How are variables tied to their values in C? Let's consider that there is a value 4 at address 0001 , and then we assign the address 0001 to the variable num . We could

问题 This question already has answers here : Why are the terms “automatic” and “dynamic” preferred over the terms “stack” and “heap” in C++ memory management? (6 answers) Closed 3 years ago . Just what the title says, "What is the technical definition of dynamic storage in C++?" I'm curious as to how to discuss dynamic memory allocation on the heap without making any mistakes in my explanation. 回答1: From the The C++ Programming Language: Special Edition Free store , from which memory for objects

问题 This question already has answers here : Why are the terms “automatic” and “dynamic” preferred over the terms “stack” and “heap” in C++ memory management? (6 answers) Closed 3 years ago . Just what the title says, "What is the technical definition of dynamic storage in C++?" I'm curious as to how to discuss dynamic memory allocation on the heap without making any mistakes in my explanation. 回答1: From the The C++ Programming Language: Special Edition Free store , from which memory for objects

问题 I have a problem with my delete_table function. So i have 2 structs struct _entry_ { int key; int data; struct _entry_* next; struct _entry_* prev; }; typedef struct _entry_ entry; struct _table_ { entry** entries; int size; }; typedef struct _table_ table; I initialise my table with calloc. void table_init(table* ht, int initial_size) { ht->entries = (entry**)calloc(initial_size, sizeof(entry*)); if (ht->entries) { ht->size = initial_size; } } Now my free function that i wrote void table

问题 I have some MATLAB code with mxn matrix. Initially, I put first row in it and then the code runs through a for loop which appends remaining m-1 rows one by one; one for each iteration of the loop. As expected, MATLAB recommends me to pre-allocate the matrix because it is expanding with every iteration of loop. So, if I pre-allocate zeros in all m rows, MATLAB most probably will append rows after the m rows(starting from m+1 for 1st appended row) because m rows are already filled(even though

问题 Currently I am using 'Session' to keep the datatables in memory. But after doing few R&Ds, I came to know the it is not a good practice e.g. Session("Syllabus") = RegistartionLogic.GetSyllabusInfo(Session("StudentID")) Requirement: The items of dropdown will be different based on student-type. The dropdown data will be fetched from DB and these controls are used in more than one screen. Multiple DB call is not preferred from different screens for same data. So I need to call only one DB call,

问题 I am doing a game. it requires lots of images. When using the app in normal case it will be quite running fine. But when it rash then i get the error 24 - too many files open. I searched it but , i didn't get the appropriate answer. please reply. Code from comment formatted: -(void)flowerImagesAnimate { self.flowerImage.animationImages = self.flowerArray; self.flowerArray = nil; self.flowerImage.animationDuration = 1.0; self.flowerImage.animationRepeatCount = 3; [self.flowerImage

问题 I am having trouble adding "records" at the end of a dynamically allocated string array. Before reallocating more memory for the records to be added, everything works fine, and then I basically replicate what I initially did but now with realloc. And after I am done inputting the added Records I get an error and I don't know how to go about adding records. NOTE* The posed code is really stripped down from the original. I've tried many things but to no avail, thanks for all the help in advance

问题 I'm trying to find any system functionality that would allow a process to allocate "temporary" memory - i.e. memory that is considered discardable by the process, and can be take away by the system when memory is needed, but allowing the process to benefit from available memory when possible. In other words, the process tells the system it's OK to sacrifice the block of memory when the process is not using it. Freeing the block is also preferable to swapping it out (it's more expensive, or as

问题 Here is from 3.7.4.2 N3797: The global operator delete[] with exactly two parameters, the second of which has type std::size_t, is a usual deallocation function.37 37) This deallocation function precludes use of an allocation function void operator new(std::size_t, std::size_t) as a placement allocation function This note is not clear for me. I would like to look at the real example of that preclusion. Compiler will throw a warning or we have a runtime error? I've been trying to write