nest-open-source / nest-learning-thermostat / 5.8 / linux / 767a574a9e8a49b60a1184494958764b04757951 / . / linux / include / linux / prio_heap.h

#ifndef _LINUX_PRIO_HEAP_H | |

#define _LINUX_PRIO_HEAP_H | |

/* | |

* Simple insertion-only static-sized priority heap containing | |

* pointers, based on CLR, chapter 7 | |

*/ | |

#include <linux/gfp.h> | |

/** | |

* struct ptr_heap - simple static-sized priority heap | |

* @ptrs - pointer to data area | |

* @max - max number of elements that can be stored in @ptrs | |

* @size - current number of valid elements in @ptrs (in the range 0..@size-1 | |

* @gt: comparison operator, which should implement "greater than" | |

*/ | |

struct ptr_heap { | |

void **ptrs; | |

int max; | |

int size; | |

int (*gt)(void *, void *); | |

}; | |

/** | |

* heap_init - initialize an empty heap with a given memory size | |

* @heap: the heap structure to be initialized | |

* @size: amount of memory to use in bytes | |

* @gfp_mask: mask to pass to kmalloc() | |

* @gt: comparison operator, which should implement "greater than" | |

*/ | |

extern int heap_init(struct ptr_heap *heap, size_t size, gfp_t gfp_mask, | |

int (*gt)(void *, void *)); | |

/** | |

* heap_free - release a heap's storage | |

* @heap: the heap structure whose data should be released | |

*/ | |

void heap_free(struct ptr_heap *heap); | |

/** | |

* heap_insert - insert a value into the heap and return any overflowed value | |

* @heap: the heap to be operated on | |

* @p: the pointer to be inserted | |

* | |

* Attempts to insert the given value into the priority heap. If the | |

* heap is full prior to the insertion, then the resulting heap will | |

* consist of the smallest @max elements of the original heap and the | |

* new element; the greatest element will be removed from the heap and | |

* returned. Note that the returned element will be the new element | |

* (i.e. no change to the heap) if the new element is greater than all | |

* elements currently in the heap. | |

*/ | |

extern void *heap_insert(struct ptr_heap *heap, void *p); | |

#endif /* _LINUX_PRIO_HEAP_H */ |