/*
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* Copyright (c) 2014, Linaro Limited
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <stdlib.h>
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#include <string.h>
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#include "handle.h"
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/*
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* Define the initial capacity of the database. It should be a low number
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* multiple of 2 since some databases a likely to only use a few handles.
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* Since the algorithm is to doubles up when growing it shouldn't cause a
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* noticable overhead on large databases.
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*/
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#define HANDLE_DB_INITIAL_MAX_PTRS 4
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static void mutex_lock(struct handle_db *db)
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{
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if (db->mu)
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pthread_mutex_lock(db->mu);
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}
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static void mutex_unlock(struct handle_db *db)
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{
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if (db->mu)
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pthread_mutex_unlock(db->mu);
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}
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void handle_db_set_mutex(struct handle_db *db, pthread_mutex_t *mu)
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{
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db->mu = mu;
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}
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void handle_db_destroy(struct handle_db *db)
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{
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if (db) {
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mutex_lock(db);
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free(db->ptrs);
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db->ptrs = NULL;
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db->max_ptrs = 0;
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mutex_unlock(db);
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}
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}
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int handle_get(struct handle_db *db, void *ptr)
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{
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size_t n;
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void *p;
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size_t new_max_ptrs;
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int ret;
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if (!db || !ptr)
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return -1;
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mutex_lock(db);
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/* Try to find an empty location */
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for (n = 0; n < db->max_ptrs; n++) {
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if (!db->ptrs[n]) {
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db->ptrs[n] = ptr;
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ret = n;
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goto out;
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}
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}
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/* No location available, grow the ptrs array */
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if (db->max_ptrs)
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new_max_ptrs = db->max_ptrs * 2;
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else
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new_max_ptrs = HANDLE_DB_INITIAL_MAX_PTRS;
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p = realloc(db->ptrs, new_max_ptrs * sizeof(void *));
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if (!p) {
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ret = -1;
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goto out;
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}
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db->ptrs = p;
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memset(db->ptrs + db->max_ptrs, 0,
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(new_max_ptrs - db->max_ptrs) * sizeof(void *));
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db->max_ptrs = new_max_ptrs;
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/* Since n stopped at db->max_ptrs there is an empty location there */
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db->ptrs[n] = ptr;
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ret = n;
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out:
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mutex_unlock(db);
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return ret;
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}
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void *handle_put(struct handle_db *db, int handle)
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{
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void *p;
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if (!db || handle < 0)
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return NULL;
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mutex_lock(db);
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if ((size_t)handle >= db->max_ptrs) {
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p = NULL;
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goto out;
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}
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p = db->ptrs[handle];
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db->ptrs[handle] = NULL;
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out:
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mutex_unlock(db);
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return p;
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}
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void *handle_lookup(struct handle_db *db, int handle)
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{
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void *p;
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if (!db || handle < 0)
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return NULL;
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mutex_lock(db);
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if ((size_t)handle >= db->max_ptrs) {
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p = NULL;
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goto out;
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}
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p = db->ptrs[handle];
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out:
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mutex_unlock(db);
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return p;
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}
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void handle_foreach_put(struct handle_db *db,
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void (*cb)(int handle, void *ptr, void *arg),
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void *arg)
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{
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size_t n;
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if (!db || !cb)
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return;
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mutex_lock(db);
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for (n = 0; n < db->max_ptrs; n++) {
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if (db->ptrs[n]) {
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cb(n, db->ptrs[n], arg);
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db->ptrs[n] = NULL;
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}
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}
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mutex_unlock(db);
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}
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