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- c - What does the free() function actually do? - Stack Overflow
Per the C standard, after free(x), the pointer x (not just the memory it points to) does not have a valid value and may be changed by the C implementation In practice what this means is that the optimizer in the compiler may recognize that a register it is using to hold x can be reused for other purposes
- How do I free memory in C? - Stack Overflow
When you call free() the memory block is placed back in the free-store as a linked-list node that indicates its an available chunk of memory If you request more memory than what is located in the free-store, the libc-runtime will again request more memory from the OS up to the limit of the OS's ability to allocate memory for running processes
- free - Freeing strings in C - Stack Overflow
A quick google search suggests objective-c which is another language :P But any unicode characters typically are not called just char Take wide characters wchar_t for example Could be wrong though, but this is what I have seen so far with the implementations I have dealt with
- c - What happens when you call free() with a pointer to the middle of . . .
When you malloc a block, it actually allocates a bit more memory than you asked for This extra memory is used to store information such as the size of the allocated block, and a link to the next free used block in a chain of blocks, and sometimes some "guard data" that helps the system to detect if you write past the end of your allocated block
- Calling free ( ) in C - Stack Overflow
If you free such a block of memory, at the end of the heap, the heap size can be reduced, thus making the memory invalid and making further accesses crash The allocator will not increase or decrease the heap size for just a few bytes though, so at that point it depends on the size of the allocation and the number of blocks freed
- Correct usage of free () function in C - Stack Overflow
char c = malloc(100) allocate 100 bytes on the heap, convert the pointer to a char, and then store it to c Call to free(c) will convert c (a char) to a pointer, and then try to free it, which will lead to system crash because (most of the time) converting a pointer to a char and back will change its value and make it an invalid pointer –
- Can a call to free () in C ever fail? - Stack Overflow
Depending on the implementation, free() could fail if there is memory corruption, such as with this: char *p = malloc(1000); *(p-1)=7; free(p); Although that is a contrived example, similar things can happen by running off the end or start of an array The first you may know of it is a protection fault in free()
- malloc - When should I use free () in C? - Stack Overflow
There needs to be a call to free() for each successful call to malloc() That doesn't necessarily mean that you need to have equal numbers of malloc() and free() calls in your code; it means that for every malloc() call that's executed when your program runs, you should call free(), passing it the pointer value you got from malloc()
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