Task7498
From GNUpdf
| Task #7498 | |
|---|---|
| Implementation of the Memory Allocation module | |
| State | TODO |
| Priority | 5 |
| Estimated effort | 4ph |
| Scheduled | 29-11-2007 |
| Deadline | 29-11-2007 |
| Start | |
| End | |
| Assigned to | |
| Savannah task | |
Contents |
Implementation of the Memory Allocation module
Overview
The memory allocation module provides system-independent heap memory allocation and deallocation. The usual malloc/free/realloc schema is used to provide this service.
Description
The module should support the following API.
- Function: char* pdf_alloc (int size)
Allocates heap memory.
- Parameters
-
- size
The requested number of octects to allocate.
If there is not enough available memory to satisfy the petition a fatal error is signaled killing the current process. An error status is returned to the operating system.
- Returns
A pointer to the newly allocated memory.
- Usage example
int *p; p = (int *) pdf_alloc (sizeof(int)); p = 666;
- Function: void pdf_dealloc (char *pointer)
Deallocates heap memory.
- Parameters
-
- pointer
A pointer pointing to the memory we want to deallocate. The memory to deallocate should have been previously allocated using
pdf_alloc.
- Returns
None.
- Usage Example
-
char *p; p = (char *) pdf_alloc (21); pdf_dealloc (p);
- Function: char* pdf_realloc (char *pointer, int size)
Reallocates memory.
- Parameters
-
- pointer
A pointer to previously allocated memory.
The memory to reallocate should have been allocated using
pdf_allocorpdf_realloc.- size
The new size of the allocated memory chunk.
If the requested size is shorter than the original size of the allocated memory then it is truncated. Any previous contents in the memory will be lost.
If the requested size is larger or equal than the original size of the allocated memory then the previous contents of the allocated memory remains. The contents of newly allocated memory are undetermined.
If there is not enough available memory to satisfy the petition a fatal error is signaled killing the current process. An error status is returned to the operating system.
- Returns
A pointer to the reallocated memory.
- Usage Example
char *p; p = (char *) pdf_alloc (4); strncpy (p, "abcd", 4); /* p now points to "abcd" */ p = (char *) pdf_realloc (5); p[4] = 'e'; /* p now points to "abcde" */ p = (char *) pdf_realloc (4); /* p now points to "abcd" */ pdf_dealloc (p);
