Example (_uopen -- Open Heap for Use) (Windows)
This example creates a fixed-size heap, then uses _uopen to open it. The program then performs operations on the heap, and closes and destroys it.
#include <windows.h> #include <stdlib.h> #include <stdio.h> #include <umalloc.h>
int main(void)
{
void *initial_block;
Heap_t myheap;
char *p;
/* Call VirtualAlloc to get the initial block of memory */
if (NULL == (initial_block =
VirtualAlloc(NULL, 65536, MEM_COMMIT|MEM_RESERVE, PAGE_READWRITE)))
{
printf("VirtualAlloc error: %d.\n", GetLastError());
exit(EXIT_FAILURE);
}
/* Create a fixed size heap starting with the block declared earlier */
if (NULL == (myheap = _ucreate(initial_block, 65536, _BLOCK_CLEAN,
_HEAP_REGULAR, NULL, NULL))) {
puts("_ucreate failed.");
exit(EXIT_FAILURE);
}
if (0 != _uopen(myheap)) {
puts("_uopen failed.");
exit(EXIT_FAILURE);
}
p = (char *)_umalloc(myheap, 100);
free(p);
if (0 != _uclose(myheap)) {
puts("_uclose failed");
exit(EXIT_FAILURE);
}
if (FALSE == VirtualFree(initial_block, 0, MEM_RELEASE)) {
printf("VirtualFree error: %d.\n", GetLastError());
exit(EXIT_FAILURE);
}
return 0;
}