Squashed 'third_party/pico-sdk/' content from commit 2062372d2

Change-Id: Ic20f199d3ed0ea8d3a6a1bbf513f875ec7500cc6
git-subtree-dir: third_party/pico-sdk
git-subtree-split: 2062372d203b372849d573f252cf7c6dc2800c0a
Signed-off-by: Austin Schuh <austin.linux@gmail.com>
diff --git a/src/common/pico_util/pheap.c b/src/common/pico_util/pheap.c
new file mode 100644
index 0000000..fc80435
--- /dev/null
+++ b/src/common/pico_util/pheap.c
@@ -0,0 +1,134 @@
+/*
+ * Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "pico/util/pheap.h"
+
+pheap_t *ph_create(uint max_nodes, pheap_comparator comparator, void *user_data) {
+    invalid_params_if(PHEAP, !max_nodes || max_nodes >= (1u << (8 * sizeof(pheap_node_id_t))));
+    pheap_t *heap = calloc(1, sizeof(pheap_t));
+    heap->nodes = calloc(max_nodes, sizeof(pheap_node_t));
+    ph_post_alloc_init(heap, max_nodes, comparator, user_data);
+    return heap;
+}
+
+void ph_post_alloc_init(pheap_t *heap, uint max_nodes, pheap_comparator comparator, void *user_data) {
+    invalid_params_if(PHEAP, !max_nodes || max_nodes >= (1u << (8 * sizeof(pheap_node_id_t))));
+    heap->max_nodes = (pheap_node_id_t) max_nodes;
+    heap->comparator = comparator;
+    heap->user_data = user_data;
+    ph_clear(heap);
+}
+
+void ph_clear(pheap_t *heap) {
+    heap->root_id = 0;
+    heap->free_head_id = 1;
+    heap->free_tail_id = heap->max_nodes;
+    for(pheap_node_id_t i = 1; i < heap->max_nodes; i++) {
+        ph_get_node(heap, i)->sibling = (pheap_node_id_t)(i + 1);
+    }
+    ph_get_node(heap, heap->max_nodes)->sibling = 0;
+}
+
+void ph_destroy(pheap_t *heap) {
+    free(heap->nodes);
+    free(heap);
+}
+
+pheap_node_id_t ph_merge_two_pass(pheap_t *heap, pheap_node_id_t id) {
+    if (!id || !ph_get_node(heap, id)->sibling) {
+        return id;
+    } else {
+        pheap_node_id_t a, b, new_node;
+        a = id;
+        b = ph_get_node(heap, id)->sibling;
+        new_node = ph_get_node(heap, b)->sibling;
+        ph_get_node(heap, a)->sibling = ph_get_node(heap, b)->sibling = 0;
+        return ph_merge_nodes(heap, ph_merge_nodes(heap, a, b), ph_merge_two_pass(heap, new_node));
+    }
+}
+
+static pheap_node_id_t ph_remove_any_head(pheap_t *heap, pheap_node_id_t root_id, bool free) {
+    assert(root_id);
+//    printf("Removing head %d (parent %d sibling %d)\n", root_id, ph_get_node(heap, root_id)->parent, ph_get_node(heap, root_id)->sibling);
+    assert(!ph_get_node(heap, root_id)->sibling);
+    assert(!ph_get_node(heap, root_id)->parent);
+    pheap_node_id_t new_root_id = ph_merge_two_pass(heap, ph_get_node(heap, root_id)->child);
+    if (free) {
+        if (heap->free_tail_id) {
+            ph_get_node(heap, heap->free_tail_id)->sibling = root_id;
+        }
+        heap->free_tail_id = root_id;
+    }
+    if (new_root_id) ph_get_node(heap, new_root_id)->parent = 0;
+    ph_get_node(heap, root_id)->sibling = 0;
+    return new_root_id;
+}
+
+pheap_node_id_t ph_remove_head(pheap_t *heap, bool free) {
+    pheap_node_id_t old_root_id = ph_peek_head(heap);
+    heap->root_id = ph_remove_any_head(heap, old_root_id, free);
+    return old_root_id;
+}
+
+bool ph_remove_and_free_node(pheap_t *heap, pheap_node_id_t id) {
+    // 1) trivial cases
+    if (!id) return false;
+    if (id == heap->root_id) {
+        ph_remove_and_free_head(heap);
+        return true;
+    }
+    // 2) unlink the node from the tree
+    pheap_node_t *node = ph_get_node(heap, id);
+    if (!node->parent) return false; // not in tree
+    pheap_node_t *parent = ph_get_node(heap, node->parent);
+    if (parent->child == id) {
+        parent->child = node->sibling;
+    } else {
+        pheap_node_id_t prev_sibling_id = parent->child;
+        bool __unused found = false;
+        do {
+            pheap_node_t *prev_sibling = ph_get_node(heap, prev_sibling_id);
+            if (prev_sibling->sibling == id) {
+                prev_sibling->sibling = node->sibling;
+                found = true;
+                break;
+            }
+            prev_sibling_id = prev_sibling->sibling;
+        } while (prev_sibling_id);
+        assert(found);
+    }
+    node->sibling = node->parent = 0;
+//    ph_dump(heap, NULL, NULL);
+    // 3) remove it from the head of its own subtree
+    pheap_node_id_t new_sub_tree = ph_remove_any_head(heap, id, true);
+    assert(new_sub_tree != heap->root_id);
+    heap->root_id = ph_merge_nodes(heap, heap->root_id, new_sub_tree);
+    return true;
+}
+
+static uint ph_dump_node(pheap_t *heap, pheap_node_id_t id, void (*dump_key)(pheap_node_id_t, void *), void *user_data, uint indent) {
+    uint count = 0;
+    if (id) {
+        count++;
+        for (uint i = 0; i < indent * 2; i++) {
+            putchar(' ');
+        }
+        pheap_node_t *node = ph_get_node(heap, id);
+        printf("%d (c=%d s=%d p=%d) ", id, node->child, node->sibling, node->parent);
+        if (dump_key) dump_key(id, user_data);
+        printf("\n");
+        count += ph_dump_node(heap, node->child, dump_key, user_data, indent + 1);
+        count += ph_dump_node(heap, node->sibling, dump_key, user_data, indent);
+    }
+    return count;
+}
+
+void ph_dump(pheap_t *heap, void (*dump_key)(pheap_node_id_t, void *), void *user_data) {
+    uint count = ph_dump_node(heap, heap->root_id, dump_key, user_data, 0);
+    printf("node_count %d\n", count);
+}
\ No newline at end of file