Subversion Repositories HelenOS

Rev

Rev 1351 | Rev 1404 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
1351 palkovsky 1
/*
2
 * Copyright (C) 2006 Ondrej Palkovsky
3
 * All rights reserved.
4
 *
5
 * Redistribution and use in source and binary forms, with or without
6
 * modification, are permitted provided that the following conditions
7
 * are met:
8
 *
9
 * - Redistributions of source code must retain the above copyright
10
 *   notice, this list of conditions and the following disclaimer.
11
 * - Redistributions in binary form must reproduce the above copyright
12
 *   notice, this list of conditions and the following disclaimer in the
13
 *   documentation and/or other materials provided with the distribution.
14
 * - The name of the author may not be used to endorse or promote products
15
 *   derived from this software without specific prior written permission.
16
 *
17
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
 */
28
 
1392 palkovsky 29
/**
30
 * Asynchronous library
31
 *
32
 * The aim of this library is facilitating writing programs utilizing
33
 * the asynchronous nature of Helenos IPC, yet using a normal way
34
 * of programming.
35
 *
36
 * You should be able to write very simple multithreaded programs,
37
 * the async framework will automatically take care of most synchronization
38
 * problems.
39
 *
40
 * Default semantics:
41
 * - send() - send asynchronously. If the kernel refuses to send more
42
 *            messages, [ try to get responses from kernel, if nothing
43
 *            found, might try synchronous ]
44
 *
45
 * Example of use:
46
 *
47
 * 1) Multithreaded client application
48
 *  create_thread(thread1);
49
 *  create_thread(thread2);
50
 *  ...
51
 *  
52
 *  thread1() {
53
 *        conn = ipc_connect_me_to();
54
 *        c1 = send(conn);
55
 *        c2 = send(conn);
56
 *        wait_for(c1);
57
 *        wait_for(c2);
58
 *  }
59
 *
60
 *
61
 * 2) Multithreaded server application
62
 * main() {
63
 *      wait_for_connection(new_connection);
64
 * }
65
 *
66
 *
67
 * new_connection(int connection) {
68
 *       accept(connection);
69
 *       msg = get_msg();
70
 *       handle(msg);
71
 *       answer(msg);
72
 *
73
 *       msg = get_msg();
74
 *       ....
75
 * }
76
 */
77
#include <futex.h>
78
#include <async.h>
79
#include <psthread.h>
80
#include <stdio.h>
81
#include <libadt/hash_table.h>
82
#include <libadt/list.h>
83
#include <ipc/ipc.h>
84
#include <assert.h>
85
#include <errno.h>
86
 
87
static atomic_t conn_futex = FUTEX_INITIALIZER;
88
static hash_table_t conn_hash_table;
89
 
90
typedef struct {
91
    link_t link;
92
    ipc_callid_t callid;
93
    ipc_call_t call;
94
} msg_t;
95
 
96
typedef struct {
97
    link_t link;
98
    ipcarg_t in_phone_hash;     /**< Incoming phone hash. */
99
    link_t msg_queue;              /**< Messages that should be delivered to this thread */
100
    pstid_t ptid;                /**< Thread associated with this connection */
101
    int active;                     /**< If this thread is currently active */
102
    int opened;                    /* If the connection was accepted */
103
    /* Structures for connection opening packet */
104
    ipc_callid_t callid;
105
    ipc_call_t call;
106
} connection_t;
107
 
108
__thread connection_t *PS_connection;
109
 
110
/* Hash table functions */
111
 
112
#define ASYNC_HASH_TABLE_CHAINS 32
113
 
114
static hash_index_t conn_hash(unsigned long *key)
1351 palkovsky 115
{
1392 palkovsky 116
    assert(key);
117
    return ((*key) >> 4) % ASYNC_HASH_TABLE_CHAINS;
1351 palkovsky 118
}
119
 
1392 palkovsky 120
static int conn_compare(unsigned long key[], hash_count_t keys, link_t *item)
1351 palkovsky 121
{
1392 palkovsky 122
    connection_t *hs;
123
 
124
    hs = hash_table_get_instance(item, connection_t, link);
125
 
126
    return key[0] == hs->in_phone_hash;
1351 palkovsky 127
}
128
 
1392 palkovsky 129
static void conn_remove(link_t *item)
1351 palkovsky 130
{
1392 palkovsky 131
    free(hash_table_get_instance(item, connection_t, link));
1351 palkovsky 132
}
133
 
1392 palkovsky 134
 
135
/** Operations for NS hash table. */
136
static hash_table_operations_t conn_hash_table_ops = {
137
    .hash = conn_hash,
138
    .compare = conn_compare,
139
    .remove_callback = conn_remove
140
};
141
 
142
/** Try to route a call to an appropriate connection thread
143
 *
144
 */
145
static int route_call(ipc_callid_t callid, ipc_call_t *call)
1351 palkovsky 146
{
1392 palkovsky 147
    connection_t *conn;
148
    msg_t *msg;
149
    link_t *hlp;
150
    unsigned long key;
151
 
152
    futex_down(&conn_futex);
153
 
154
    key = call->in_phone_hash;
155
    hlp = hash_table_find(&conn_hash_table, &key);
156
    if (!hlp) {
157
        futex_up(&conn_futex);
158
        return 0;
1351 palkovsky 159
    }
1392 palkovsky 160
    conn = hash_table_get_instance(hlp, connection_t, link);
1351 palkovsky 161
 
1392 palkovsky 162
    msg = malloc(sizeof(*msg));
163
    msg->callid = callid;
164
    msg->call = *call;
165
    list_append(&msg->link, &conn->msg_queue);
166
 
167
    if (!conn->active) {
168
        conn->active = 1;
169
        psthread_add_ready(conn->ptid);
170
    }
1351 palkovsky 171
 
1392 palkovsky 172
    futex_up(&conn_futex);
173
 
174
    return 1;
175
}
176
 
177
ipc_callid_t async_get_call(ipc_call_t *call)
178
{
179
    msg_t *msg;
180
    ipc_callid_t callid;
181
    connection_t *conn;
182
 
183
    futex_down(&conn_futex);
184
 
185
    conn = PS_connection;
186
    /* If nothing in queue, wait until something appears */
187
    if (list_empty(&conn->msg_queue)) {
188
        conn->active = 0;
189
        psthread_schedule_next_adv(PS_TO_MANAGER);
1351 palkovsky 190
    }
191
 
1392 palkovsky 192
    msg = list_get_instance(conn->msg_queue.next, msg_t, link);
193
    list_remove(&msg->link);
194
    callid = msg->callid;
195
    *call = msg->call;
196
    free(msg);
197
 
198
    futex_up(&conn_futex);
199
    return callid;
1351 palkovsky 200
}
201
 
1392 palkovsky 202
void client_connection(ipc_callid_t callid, ipc_call_t *call)
203
{
204
    printf("Got connection - no handler.\n");
205
    _exit(1);
206
}
1351 palkovsky 207
 
1392 palkovsky 208
static int connection_thread(void  *arg)
1351 palkovsky 209
{
1392 palkovsky 210
    /* Setup thread local connection pointer */
211
    PS_connection = (connection_t *)arg;
212
    client_connection(PS_connection->callid, &PS_connection->call);
213
 
214
    futex_down(&conn_futex);
215
    /* TODO: remove myself from connection hash table */
216
    futex_up(&conn_futex);
217
    /* TODO: answer all unanswered messages in queue with
218
     *       EHANGUP */
1351 palkovsky 219
}
1392 palkovsky 220
 
221
/** Create new thread for a new connection
222
 *
223
 * Creates new thread for connection, fills in connection
224
 * structures and inserts it into the hash table, so that
225
 * later we can easily do routing of messages to particular
226
 * threads.
227
 */
228
static void new_connection(ipc_callid_t callid, ipc_call_t *call)
229
{
230
    pstid_t ptid;
231
    connection_t *conn;
232
    unsigned long key;
233
 
234
    conn = malloc(sizeof(*conn));
235
    if (!conn) {
236
        ipc_answer_fast(callid, ENOMEM, 0, 0);
237
        return;
238
    }
239
    conn->in_phone_hash = IPC_GET_ARG3(*call);
240
    list_initialize(&conn->msg_queue);
241
    conn->opened = 0;
242
    conn->ptid = psthread_create(connection_thread, conn);
243
    conn->callid = callid;
244
    conn->call = *call;
245
    conn->active = 1; /* We will activate it asap */
246
    list_initialize(&conn->link);
247
    if (!conn->ptid) {
248
        free(conn);
249
        ipc_answer_fast(callid, ENOMEM, 0, 0);
250
        return;
251
    }
252
    key = conn->in_phone_hash;
253
    futex_down(&conn_futex);
254
    /* Add connection to hash table */
255
    hash_table_insert(&conn_hash_table, &key, &conn->link);
256
    futex_up(&conn_futex);
257
 
258
    psthread_add_ready(conn->ptid);
259
}
260
 
261
/** Handle call to a task */
262
static void handle_call(ipc_callid_t callid, ipc_call_t *call)
263
{
264
    if (route_call(callid, call))
265
        return;
266
 
267
    switch (IPC_GET_METHOD(*call)) {
268
    case IPC_M_INTERRUPT:
269
        break;
270
    case IPC_M_CONNECT_ME_TO:
271
        /* Open new connection with thread etc. */
272
        new_connection(callid, call);
273
        break;
274
    default:
275
        ipc_answer_fast(callid, EHANGUP, 0, 0);
276
    }
277
}
278
 
279
/** Endless loop dispatching incoming calls and answers */
280
int async_manager()
281
{
282
    ipc_call_t call;
283
    ipc_callid_t callid;
284
 
285
    while (1) {
286
        if (psthread_schedule_next_adv(PS_FROM_MANAGER)) {
287
            futex_up(&conn_futex); /* conn_futex is always held
288
                        * when entering manager thread
289
                        */
290
            continue;
291
        }
292
        callid = ipc_wait_cycle(&call,SYNCH_NO_TIMEOUT,SYNCH_BLOCKING);
293
 
294
        if (callid & IPC_CALLID_ANSWERED)
295
            continue;
296
        handle_call(callid, &call);
297
    }
298
}
299
 
300
static int async_manager_thread(void *arg)
301
{
302
    futex_up(&conn_futex); /* conn_futex is always locked when entering
303
                * manager */
304
    async_manager();
305
}
306
 
307
/** Add one manager to manager list */
308
void async_create_manager(void)
309
{
310
    pstid_t ptid;
311
 
312
    ptid = psthread_create(async_manager_thread, NULL);
313
    psthread_add_manager(ptid);
314
}
315
 
316
/** Remove one manager from manager list */
317
void async_destroy_manager(void)
318
{
319
    psthread_remove_manager();
320
}
321
 
322
/** Initialize internal structures needed for async manager */
323
int _async_init(void)
324
{
325
    if (!hash_table_create(&conn_hash_table, ASYNC_HASH_TABLE_CHAINS, 1, &conn_hash_table_ops)) {
326
        printf("%s: cannot create hash table\n", "async");
327
        return ENOMEM;
328
    }
329
 
330
}