/* * Simple pointer stack * * (c) 2010 Arnaldo Carvalho de Melo <acme@redhat.com> */ #include "util.h" #include "pstack.h" #include <linux/kernel.h> #include <stdlib.h> struct pstack { unsigned short top; unsigned short max_nr_entries; void *entries[0]; }; struct pstack *pstack__new(unsigned short max_nr_entries) { struct pstack *self = zalloc((sizeof(*self) + max_nr_entries * sizeof(void *))); if (self != NULL) self->max_nr_entries = max_nr_entries; return self; } void pstack__delete(struct pstack *self) { free(self); } bool pstack__empty(const struct pstack *self) { return self->top == 0; } void pstack__remove(struct pstack *self, void *key) { unsigned short i = self->top, last_index = self->top - 1; while (i-- != 0) { if (self->entries[i] == key) { if (i < last_index) memmove(self->entries + i, self->entries + i + 1, (last_index - i) * sizeof(void *)); --self->top; return; } } pr_err("%s: %p not on the pstack!\n", __func__, key); } void pstack__push(struct pstack *self, void *key) { if (self->top == self->max_nr_entries) { pr_err("%s: top=%d, overflow!\n", __func__, self->top); return; } self->entries[self->top++] = key; } void *pstack__pop(struct pstack *self) { void *ret; if (self->top == 0) { pr_err("%s: underflow!\n", __func__); return NULL; } ret = self->entries[--self->top]; self->entries[self->top] = NULL; return ret; }