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buddy.c
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buddy.c
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struct Buddy {
int free;
int space;
struct Buddy *pair;
} Buddy;
int buddyAlloc(struct Buddy *bud, int size, int address) {
if (bud == NULL) {
return -1;
}
if (bud->free != 1) {
return buddyAlloc(bud->pair, size, address + bud->space);
}
if (bud->space == size) {
bud->free = 0;
return address;
} else if (bud->space < size) {
return buddyAlloc(bud->pair, size, address + bud->space);
} else {
int newBlock = bud->space;
newBlock = newBlock / 2;
struct Buddy *temp1 = bud->pair;
bud->pair = malloc(sizeof(Buddy));
bud->free = 1;
bud->space = newBlock;
struct Buddy *temp2 = bud->pair;
temp2->pair = temp1;
temp2->free = 1;
temp2->space = newBlock;
return buddyAlloc(bud, size, address);
}
}
int buddyFree(struct Buddy *bud, int address) {
if (address == 0) {
if (bud->free != 0) {
return -1;
}
bud->free = 1;
return (1);
}
if (bud == NULL) {
return (-1);
} else {
return buddyFree(bud->pair, address - bud->space);
}
}
void mergeBuddy(struct Buddy* bud) {
if (bud == NULL) {
return;
}
mergeBuddy(bud->pair);
if (bud->pair == NULL) {
return;
}
struct Buddy *nextBud = bud->pair;
if (bud->space == nextBud->space && bud->free == nextBud->free && bud->free == 1) {
struct Buddy *temp = nextBud->pair;
free(nextBud);
bud->space = bud->space * 2;
bud->pair = temp;
mergeBuddy(bud);
return;
}
}