| 1 | /* |
| 2 | * SPDX-License-Identifier: MIT |
| 3 | * |
| 4 | * Copyright 2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 5 | * |
| 6 | * Common Trace Format Object Stack. |
| 7 | */ |
| 8 | |
| 9 | #include <stdlib.h> |
| 10 | |
| 11 | #define BT_LOG_OUTPUT_LEVEL ctf_plugin_metadata_log_level |
| 12 | #define BT_LOG_TAG "PLUGIN/CTF/META/OBJSTACK" |
| 13 | #include "logging.hpp" |
| 14 | |
| 15 | #include "common/align.h" |
| 16 | #include "common/list.h" |
| 17 | |
| 18 | #include "objstack.hpp" |
| 19 | |
| 20 | #define OBJSTACK_ALIGN 8 /* Object stack alignment */ |
| 21 | #define OBJSTACK_INIT_LEN 128 |
| 22 | #define OBJSTACK_POISON 0xcc |
| 23 | |
| 24 | struct objstack |
| 25 | { |
| 26 | struct bt_list_head head; /* list of struct objstack_node */ |
| 27 | }; |
| 28 | |
| 29 | struct objstack_node |
| 30 | { |
| 31 | struct bt_list_head node; |
| 32 | size_t len; |
| 33 | size_t used_len; |
| 34 | char __attribute__((aligned(OBJSTACK_ALIGN))) data[]; |
| 35 | }; |
| 36 | |
| 37 | struct objstack *objstack_create(void) |
| 38 | { |
| 39 | struct objstack *objstack; |
| 40 | struct objstack_node *node; |
| 41 | |
| 42 | objstack = (struct objstack *) calloc(1, sizeof(*objstack)); |
| 43 | if (!objstack) { |
| 44 | BT_LOGE_STR("Failed to allocate one object stack."); |
| 45 | return NULL; |
| 46 | } |
| 47 | node = (objstack_node *) calloc(sizeof(struct objstack_node) + OBJSTACK_INIT_LEN, sizeof(char)); |
| 48 | if (!node) { |
| 49 | BT_LOGE_STR("Failed to allocate one object stack node."); |
| 50 | free(objstack); |
| 51 | return NULL; |
| 52 | } |
| 53 | BT_INIT_LIST_HEAD(&objstack->head); |
| 54 | bt_list_add_tail(&node->node, &objstack->head); |
| 55 | node->len = OBJSTACK_INIT_LEN; |
| 56 | return objstack; |
| 57 | } |
| 58 | |
| 59 | static void objstack_node_free(struct objstack_node *node) |
| 60 | { |
| 61 | size_t offset, len; |
| 62 | char *p; |
| 63 | |
| 64 | if (!node) |
| 65 | return; |
| 66 | p = (char *) node; |
| 67 | len = sizeof(*node) + node->len; |
| 68 | for (offset = 0; offset < len; offset++) |
| 69 | p[offset] = OBJSTACK_POISON; |
| 70 | free(node); |
| 71 | } |
| 72 | |
| 73 | void objstack_destroy(struct objstack *objstack) |
| 74 | { |
| 75 | struct objstack_node *node, *p; |
| 76 | |
| 77 | if (!objstack) |
| 78 | return; |
| 79 | bt_list_for_each_entry_safe (node, p, &objstack->head, node) { |
| 80 | bt_list_del(&node->node); |
| 81 | objstack_node_free(node); |
| 82 | } |
| 83 | free(objstack); |
| 84 | } |
| 85 | |
| 86 | static struct objstack_node *objstack_append_node(struct objstack *objstack) |
| 87 | { |
| 88 | struct objstack_node *last_node, *new_node; |
| 89 | |
| 90 | /* Get last node */ |
| 91 | last_node = bt_list_entry(objstack->head.prev, struct objstack_node, node); |
| 92 | |
| 93 | /* Allocate new node with double of size of last node */ |
| 94 | new_node = (objstack_node *) calloc(sizeof(struct objstack_node) + (last_node->len << 1), |
| 95 | sizeof(char)); |
| 96 | if (!new_node) { |
| 97 | BT_LOGE_STR("Failed to allocate one object stack node."); |
| 98 | return NULL; |
| 99 | } |
| 100 | bt_list_add_tail(&new_node->node, &objstack->head); |
| 101 | new_node->len = last_node->len << 1; |
| 102 | return new_node; |
| 103 | } |
| 104 | |
| 105 | void *objstack_alloc(struct objstack *objstack, size_t len) |
| 106 | { |
| 107 | struct objstack_node *last_node; |
| 108 | void *p; |
| 109 | |
| 110 | len = BT_ALIGN(len, OBJSTACK_ALIGN); |
| 111 | |
| 112 | /* Get last node */ |
| 113 | last_node = bt_list_entry(objstack->head.prev, struct objstack_node, node); |
| 114 | while (last_node->len - last_node->used_len < len) { |
| 115 | last_node = objstack_append_node(objstack); |
| 116 | if (!last_node) { |
| 117 | return NULL; |
| 118 | } |
| 119 | } |
| 120 | p = &last_node->data[last_node->used_len]; |
| 121 | last_node->used_len += len; |
| 122 | return p; |
| 123 | } |