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How is malloc() than free() works


How is malloc() than free() works

By : PRAVESH SAILOR
Date : September 24 2020, 04:00 AM
Hope this helps That would be a spectacularly bad implementation of memory allocation functions and, in fact, the standard (referencing C11, the current standard in force) appears to disallow it (I'm activating "language lawyer" mode here):
code :


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How do I free() after malloc() when the result of malloc() is returned by the function?

How do I free() after malloc() when the result of malloc() is returned by the function?


By : skbr
Date : March 29 2020, 07:55 AM
this will help If you do not care a minor performance loss, use an NSMutableDictionary and store the point as an NSValue:
code :
NSValue* touchOriginPointValue = [touchOriginPoints objectForKey:touch];
if (touchOriginPointValue == nil) {
   touchOriginPointValue = [NSValue valueWithCGPoint:[touch locationInView:touch.view]];
   [touchOriginPoints setObject:touchOriginPointValue forKey:touch];
}
return [touchOriginPointValue CGPointValue];
static void free_malloced_memory (CFAllocatorRef allocator, const void *value) {
   free((void*)value);
}
static const CFDictionaryValueCallBacks values_callbacks = {0, NULL, free_malloced_memory, NULL, NULL};
...
touchOriginPoints = CFDictionaryCreateMutable(NULL, 0, &kCFTypeDictionaryKeyCallBacks, & values_callbacks);
...
Getting malloc-related error from design pattern of: malloc / free / malloc / free

Getting malloc-related error from design pattern of: malloc / free / malloc / free


By : chen cw
Date : March 29 2020, 07:55 AM
Simple test of malloc and free with int pointer causes double free or corruption error

Simple test of malloc and free with int pointer causes double free or corruption error


By : Dattatraya
Date : March 29 2020, 07:55 AM
wish help you to fix your issue The pointer passed to free() must be returned from a previous call to malloc() (or calloc() or realloc()). This is not the case as p has the address of a after:
code :
p = &a;
free(p); //ERROR
// printf("p: %x\n", p); // Shall cause error, because space was freed
// printf("*p: %x\n", *p); // Shall cause error, because space was freed
printf("a: %s\n", a); /* Must be '%d' as 'a' is an 'int'. */
printf("p: %x\n", p);
Unable to properly free malloc of another malloc

Unable to properly free malloc of another malloc


By : user3622020
Date : March 29 2020, 07:55 AM
help you fix your problem Here's the snippet with issues. , In your code
code :
 RESERV[i]="Iambananananananananananana";
malloc-free-malloc and strict-aliasing

malloc-free-malloc and strict-aliasing


By : zeroplusone
Date : March 29 2020, 07:55 AM
I hope this helps . Note: This only answers initial question, not the part about custom allocators.
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