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      1 /************************************************************************
      2 Copyright (c) 2015, The Linux Foundation. All rights reserved.
      3 
      4 Redistribution and use in source and binary forms, with or without
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      9     * Redistributions in binary form must reproduce the above
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     16 
     17 THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
     18 WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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     20 ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
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     28 ************************************************************************/
     29 
     30 /**
     31  * @file datatop_linked_list.c
     32  * @brief Necessary linked_list functions created.
     33  *
     34  * Holds function which adds to or creates a linked list
     35  * used for storing dtop_data_point_gatherer's (dpg's).
     36  * Datapoints are stored in linked list for ability to
     37  * iteratively poll and print efficiently. Handles creation
     38  * and deletion of memory for linked list nodes.
     39  */
     40 
     41 #include <stdio.h>
     42 #include <string.h>
     43 #include <stdlib.h>
     44 
     45 #include "datatop_linked_list.h"
     46 
     47 /**
     48  * @brief Adds a node to the beginning of a linked list.
     49  *
     50  * @param data A void pointer which can hold any data in the node.
     51  * @param list The list that is added to.
     52  * @return Updated linked list struct.
     53  */
     54 struct dtop_linked_list *dtop_add_linked_list(void *data,
     55 				struct dtop_linked_list *list)
     56 {
     57 	struct dtop_linked_list *list_node;
     58 	list_node = malloc(sizeof(struct dtop_linked_list));
     59 
     60 	if (!list_node) {
     61 		fprintf(stderr, "failed to allocate memory.\n");
     62 		exit(EXIT_FAILURE);
     63 	}
     64 
     65 	list_node->data = data;
     66 	list_node->next_ptr = list;
     67 	list = list_node;
     68 	return list;
     69 }
     70 
     71 /**
     72  * @brief Deletes a linked list.
     73  *
     74  * @param head_ptr Pointer to the first node in the linked list that is to be deleted.
     75  */
     76 void dtop_rem_linked_list(struct dtop_linked_list *head_ptr)
     77 {
     78 	struct dtop_linked_list *tmp_ptr = NULL;
     79 	while (head_ptr) {
     80 		tmp_ptr = head_ptr;
     81 		head_ptr = head_ptr->next_ptr;
     82 		free(tmp_ptr);
     83 	}
     84 }
     85