ucx: src/ucx/stack.h@2f5dea574a75 (annotated)

src/ucx/stack.h@2f5dea574a75 (annotated)

src/ucx/stack.h

Sat, 28 Oct 2017 15:43:51 +0200

author: Mike Becker <universe@uap-core.de>
date: Sat, 28 Oct 2017 15:43:51 +0200
changeset 259: 2f5dea574a75
parent 251: fae240d633fc
child 301: 0f83916c1639
permissions: -rw-r--r--

modules documentation

 /*
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
  *
  * Copyright 2017 Mike Becker, Olaf Wintermann All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *   1. Redistributions of source code must retain the above copyright
  *      notice, this list of conditions and the following disclaimer.
  *
  *   2. Redistributions in binary form must reproduce the above copyright
  *      notice, this list of conditions and the following disclaimer in the
  *      documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */
 /**
  * @file stack.h
  *
  * Default stack memory allocation implementation.
  *
  * @author Mike Becker
  * @author Olaf Wintermann
  */
 #ifndef UCX_STACK_H
 #define	UCX_STACK_H
 #include "ucx.h"
 #include "allocator.h"
 #ifdef	__cplusplus
 extern "C" {
 #endif
 /**
  * UCX stack structure.
  */
 typedef struct {
     /** UcxAllocator based on this stack */
     UcxAllocator allocator;
     /** Stack size. */
     size_t size;
     /** Pointer to the bottom of the stack */
     char *space;
     /** Pointer to the top of the stack */
     char *top;
 } UcxStack;
 /**
  * Metadata for each UCX stack element.
  */
 struct ucx_stack_metadata {
     /**
      * Location of the previous element (<code>NULL</code> if this is the first)
      */
     char *prev;
     /** Size of this element */
     size_t size;
 };
 /**
  * Initializes UcxStack structure with memory.
  *
  * @param stack a pointer to an uninitialized stack structure
  * @param space the memory area that shall be managed
  * @param size size of the memory area
  * @return a new UcxStack structure
  */
 void ucx_stack_init(UcxStack *stack, char* space, size_t size);
 /**
  * Allocates stack memory.
  *
  * @param stack a pointer to the stack
  * @param n amount of memory to allocate
  * @return a pointer to the allocated memory
  * @see ucx_allocator_malloc()
  */
 void *ucx_stack_malloc(UcxStack *stack, size_t n);
 /**
  * Alias for #ucx_stack_malloc().
  * @param stack a pointer to the stack
  * @param n amount of memory to allocate
  * @return a pointer to the allocated memory
  * @see ucx_stack_malloc
  */
 #define ucx_stack_push(stack, n) ucx_stack_malloc(stack, n)
 /**
  * Allocates an array of stack memory
  *
  * The content of the allocated memory is set to zero.
  *
  * @param stack a pointer to the stack
  * @param nelem amount of elements to allocate
  * @param elsize amount of memory per element
  * @return a pointer to the allocated memory
  * @see ucx_allocator_calloc()
  */
 void *ucx_stack_calloc(UcxStack *stack, size_t nelem, size_t elsize);
 /**
  * Alias for #ucx_stack_calloc().
  *
  * @param stack a pointer to the stack
  * @param n amount of elements to allocate
  * @param elsize amount of memory per element
  * @return a pointer to the allocated memory
  * @see ucx_stack_calloc
  */
 #define ucx_stack_pusharr(stack,n,elsize) ucx_stack_calloc(stack,n,elssize)
 /**
  * Reallocates memory on the stack.
  *
  * Shrinking memory is always safe. Extending memory can be very expensive.
  *
  * @param stack the stack
  * @param ptr a pointer to the memory that shall be reallocated
  * @param n the new size of the memory
  * @return a pointer to the new location of the memory
  * @see ucx_allocator_realloc()
  */
 void *ucx_stack_realloc(UcxStack *stack, void *ptr, size_t n);
 /**
  * Frees memory on the stack.
  *
  * Freeing stack memory behaves in a special way.
  *
  * If the element, that should be freed, is the top most element of the stack,
  * it is removed from the stack. Otherwise it is marked as freed. Marked
  * elements are removed, when they become the top most elements of the stack.
  *
  * @param stack a pointer to the stack
  * @param ptr a pointer to the memory that shall be freed
  */
 void ucx_stack_free(UcxStack *stack, void *ptr);
 /**
  * Returns the size of the top most element.
  * @param stack a pointer to the stack
  * @return the size of the top most element
  */
 #define ucx_stack_topsize(stack) ((stack)->top ? ((struct ucx_stack_metadata*)\
                                   (stack)->top - 1)->size : 0)
 /**
  * Removes the top most element from the stack and copies the content to <code>
  * dest</code>, if specified.
  *
  * Use #ucx_stack_topsize()# to get the amount of memory that must be available
  * at the location of <code>dest</code>.
  *
  * @param stack a pointer to the stack
  * @param dest the location where the contents shall be written to, or <code>
  * NULL</code>, if the element shall only be removed.
  * @see ucx_stack_free
  * @see ucx_stack_popn
  */
 #define ucx_stack_pop(stack, dest) ucx_stack_popn(stack, dest, (size_t)-1)
 /**
  * Removes the top most element from the stack and copies the content to <code>
  * dest</code>.
  *
  * In contrast to #ucx_stack_pop() the <code>dest</code> pointer <code>MUST
  * NOT</code> be <code>NULL</code>.
  *
  * @param stack a pointer to the stack
  * @param dest the location where the contents shall be written to
  * @param n copies at most n elements to <code>dest</code>
  * @see ucx_stack_pop
  */
 void ucx_stack_popn(UcxStack *stack, void *dest, size_t n);
 /**
  * Returns the remaining available memory on the specified stack.
  *
  * @param stack a pointer to the stack
  * @return the remaining available memory
  */
 size_t ucx_stack_avail(UcxStack *stack);
 /**
  * Checks, if the stack is empty.
  *
  * @param stack a pointer to the stack
  * @return nonzero, if the stack is empty, zero otherwise
  */
 #define ucx_stack_empty(stack) (!(stack)->top)
 /**
  * Computes a recommended size for the stack memory area. Note, that
  * reallocations have not been taken into account, so you might need to reserve
  * twice as much memory to allow many reallocations.
  *
  * @param size the approximate payload
  * @param elems the approximate count of element allocations
  * @return a recommended size for the stack space based on the information
  * provided
  */
 #define ucx_stack_dim(size, elems) (size+sizeof(struct ucx_stack_metadata) * \
                                     (elems + 1))
 #ifdef	__cplusplus
 }
 #endif
 #endif	/* UCX_STACK_H */

Mercurial > hg > ucx / annotate

src/ucx/stack.h@2f5dea574a75 (annotated)

src/ucx/stack.h