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/*
* Copyright (c) 2009 Martin Decky
* Copyright (c) 2009 Jiri Svoboda
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - 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.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
/** @addtogroup ns
* @{
*/
#include <ipc/ipc.h>
#include <adt/hash_table.h>
#include <bool.h>
#include <errno.h>
#include <assert.h>
#include <stdio.h>
#include <macros.h>
#include "task.h"
#include "ns.h"
#define TASK_HASH_TABLE_CHAINS 256
#define P2I_HASH_TABLE_CHAINS 256
static int get_id_by_phone(ipcarg_t phone_hash, task_id_t *id);
/* TODO:
*
* As there is currently no convention that each task has to be waited
* for, the NS can leak memory because of the zombie tasks.
*
*/
/** Task hash table item. */
typedef struct {
link_t link;
task_id_t id; /**< Task ID. */
bool finished; /**< Task is done. */
bool have_rval; /**< Task returned a value. */
int retval; /**< The return value. */
} hashed_task_t;
/** Compute hash index into task hash table.
*
* @param key Pointer keys. However, only the first key (i.e. truncated task
* number) is used to compute the hash index.
*
* @return Hash index corresponding to key[0].
*
*/
static hash_index_t task_hash(unsigned long *key)
{
assert(key);
return (LOWER32(*key) % TASK_HASH_TABLE_CHAINS);
}
/** Compare a key with hashed item.
*
* @param key Array of keys.
* @param keys Must be less than or equal to 2.
* @param item Pointer to a hash table item.
*
* @return Non-zero if the key matches the item, zero otherwise.
*
*/
static int task_compare(unsigned long key[], hash_count_t keys, link_t *item)
{
assert(key);
assert(keys <= 2);
assert(item);
hashed_task_t *ht = hash_table_get_instance(item, hashed_task_t, link);
if (keys == 2)
return ((LOWER32(key[1]) == UPPER32(ht->id))
&& (LOWER32(key[0]) == LOWER32(ht->id)));
else
return (LOWER32(key[0]) == LOWER32(ht->id));
}
/** Perform actions after removal of item from the hash table.
*
* @param item Item that was removed from the hash table.
*
*/
static void task_remove(link_t *item)
{
assert(item);
free(hash_table_get_instance(item, hashed_task_t, link));
}
/** Operations for task hash table. */
static hash_table_operations_t task_hash_table_ops = {
.hash = task_hash,
.compare = task_compare,
.remove_callback = task_remove
};
/** Task hash table structure. */
static hash_table_t task_hash_table;
typedef struct {
link_t link;
ipcarg_t phash; /**< Task ID. */
task_id_t id; /**< Task ID. */
} p2i_entry_t;
/** Compute hash index into task hash table.
*
* @param key Array of keys.
* @return Hash index corresponding to key[0].
*
*/
static hash_index_t p2i_hash(unsigned long *key)
{
assert(key);
return (*key % TASK_HASH_TABLE_CHAINS);
}
/** Compare a key with hashed item.
*
* @param key Array of keys.
* @param keys Must be less than or equal to 1.
* @param item Pointer to a hash table item.
*
* @return Non-zero if the key matches the item, zero otherwise.
*
*/
static int p2i_compare(unsigned long key[], hash_count_t keys, link_t *item)
{
assert(key);
assert(keys == 1);
assert(item);
p2i_entry_t *e = hash_table_get_instance(item, p2i_entry_t, link);
return (key[0] == e->phash);
}
/** Perform actions after removal of item from the hash table.
*
* @param item Item that was removed from the hash table.
*
*/
static void p2i_remove(link_t *item)
{
assert(item);
free(hash_table_get_instance(item, p2i_entry_t, link));
}
/** Operations for task hash table. */
static hash_table_operations_t p2i_ops = {
.hash = p2i_hash,
.compare = p2i_compare,
.remove_callback = p2i_remove
};
/** Map phone hash to task ID */
static hash_table_t phone_to_id;
/** Pending task wait structure. */
typedef struct {
link_t link;
task_id_t id; /**< Task ID. */
ipc_callid_t callid; /**< Call ID waiting for the connection */
} pending_wait_t;
static link_t pending_wait;
int task_init(void)
{
if (!hash_table_create(&task_hash_table, TASK_HASH_TABLE_CHAINS,
2, &task_hash_table_ops)) {
printf(NAME ": No memory available for tasks\n");
return ENOMEM;
}
if (!hash_table_create(&phone_to_id, P2I_HASH_TABLE_CHAINS,
1, &p2i_ops)) {
printf(NAME ": No memory available for tasks\n");
return ENOMEM;
}
list_initialize(&pending_wait);
return EOK;
}
/** Process pending wait requests */
void process_pending_wait(void)
{
link_t *cur;
task_exit_t texit;
loop:
for (cur = pending_wait.next; cur != &pending_wait; cur = cur->next) {
pending_wait_t *pr = list_get_instance(cur, pending_wait_t, link);
unsigned long keys[2] = {
LOWER32(pr->id),
UPPER32(pr->id)
};
link_t *link = hash_table_find(&task_hash_table, keys);
if (!link)
continue;
hashed_task_t *ht = hash_table_get_instance(link, hashed_task_t, link);
if (!ht->finished)
continue;
if (!(pr->callid & IPC_CALLID_NOTIFICATION)) {
texit = ht->have_rval ? TASK_EXIT_NORMAL :
TASK_EXIT_UNEXPECTED;
ipc_answer_2(pr->callid, EOK, texit,
ht->retval);
}
hash_table_remove(&task_hash_table, keys, 2);
list_remove(cur);
free(pr);
goto loop;
}
}
void wait_for_task(task_id_t id, ipc_call_t *call, ipc_callid_t callid)
{
ipcarg_t retval;
task_exit_t texit;
unsigned long keys[2] = {
LOWER32(id),
UPPER32(id)
};
link_t *link = hash_table_find(&task_hash_table, keys);
hashed_task_t *ht = (link != NULL) ?
hash_table_get_instance(link, hashed_task_t, link) : NULL;
if (ht == NULL) {
/* No such task exists. */
retval = ENOENT;
goto out;
}
if (!ht->finished) {
/* Add to pending list */
pending_wait_t *pr =
(pending_wait_t *) malloc(sizeof(pending_wait_t));
if (!pr) {
retval = ENOMEM;
goto out;
}
pr->id = id;
pr->callid = callid;
list_append(&pr->link, &pending_wait);
return;
}
hash_table_remove(&task_hash_table, keys, 2);
retval = EOK;
out:
if (!(callid & IPC_CALLID_NOTIFICATION)) {
texit = ht->have_rval ? TASK_EXIT_NORMAL : TASK_EXIT_UNEXPECTED;
ipc_answer_2(callid, retval, texit, ht->retval);
}
}
int ns_task_id_intro(ipc_call_t *call)
{
task_id_t id;
unsigned long keys[2];
link_t *link;
p2i_entry_t *e;
hashed_task_t *ht;
id = MERGE_LOUP32(IPC_GET_ARG1(*call), IPC_GET_ARG2(*call));
keys[0] = call->in_phone_hash;
link = hash_table_find(&phone_to_id, keys);
if (link != NULL)
return EEXISTS;
e = (p2i_entry_t *) malloc(sizeof(p2i_entry_t));
if (e == NULL)
return ENOMEM;
ht = (hashed_task_t *) malloc(sizeof(hashed_task_t));
if (ht == NULL)
return ENOMEM;
/* Insert to phone-to-id map. */
link_initialize(&e->link);
e->phash = call->in_phone_hash;
e->id = id;
hash_table_insert(&phone_to_id, keys, &e->link);
/* Insert to main table. */
keys[0] = LOWER32(id);
keys[1] = UPPER32(id);
link_initialize(&ht->link);
ht->id = id;
ht->finished = false;
ht->have_rval = false;
ht->retval = -1;
hash_table_insert(&task_hash_table, keys, &ht->link);
return EOK;
}
int ns_task_retval(ipc_call_t *call)
{
task_id_t id;
unsigned long keys[2];
int rc;
rc = get_id_by_phone(call->in_phone_hash, &id);
if (rc != EOK)
return rc;
keys[0] = LOWER32(id);
keys[1] = UPPER32(id);
link_t *link = hash_table_find(&task_hash_table, keys);
hashed_task_t *ht = (link != NULL) ?
hash_table_get_instance(link, hashed_task_t, link) : NULL;
if ((ht == NULL) || ht->finished)
return EINVAL;
ht->finished = true;
ht->have_rval = true;
ht->retval = IPC_GET_ARG1(*call);
return EOK;
}
int ns_task_disconnect(ipc_call_t *call)
{
unsigned long keys[2];
task_id_t id;
int rc;
rc = get_id_by_phone(call->in_phone_hash, &id);
if (rc != EOK)
return rc;
/* Delete from phone-to-id map. */
keys[0] = call->in_phone_hash;
hash_table_remove(&phone_to_id, keys, 1);
/* Mark task as finished. */
keys[0] = LOWER32(id);
keys[1] = UPPER32(id);
link_t *link = hash_table_find(&task_hash_table, keys);
hashed_task_t *ht =
hash_table_get_instance(link, hashed_task_t, link);
if (ht == NULL)
return EOK;
ht->finished = true;
return EOK;
}
static int get_id_by_phone(ipcarg_t phone_hash, task_id_t *id)
{
unsigned long keys[1];
link_t *link;
p2i_entry_t *e;
keys[0] = phone_hash;
link = hash_table_find(&phone_to_id, keys);
if (link == NULL)
return ENOENT;
e = hash_table_get_instance(link, p2i_entry_t, link);
*id = e->id;
return EOK;
}
/**
* @}
*/