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1 | /* |
1 | /* |
2 | * Copyright (c) 2006 Ondrej Palkovsky |
2 | * Copyright (c) 2006 Ondrej Palkovsky |
3 | * All rights reserved. |
3 | * All rights reserved. |
4 | * |
4 | * |
5 | * Redistribution and use in source and binary forms, with or without |
5 | * Redistribution and use in source and binary forms, with or without |
6 | * modification, are permitted provided that the following conditions |
6 | * modification, are permitted provided that the following conditions |
7 | * are met: |
7 | * are met: |
8 | * |
8 | * |
9 | * - Redistributions of source code must retain the above copyright |
9 | * - Redistributions of source code must retain the above copyright |
10 | * notice, this list of conditions and the following disclaimer. |
10 | * notice, this list of conditions and the following disclaimer. |
11 | * - Redistributions in binary form must reproduce the above copyright |
11 | * - Redistributions in binary form must reproduce the above copyright |
12 | * notice, this list of conditions and the following disclaimer in the |
12 | * notice, this list of conditions and the following disclaimer in the |
13 | * documentation and/or other materials provided with the distribution. |
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 |
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. |
15 | * derived from this software without specific prior written permission. |
16 | * |
16 | * |
17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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 |
18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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 |
23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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 |
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. |
26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
27 | */ |
27 | */ |
28 | 28 | ||
29 | /** @addtogroup genericipc |
29 | /** @addtogroup genericipc |
30 | * @{ |
30 | * @{ |
31 | */ |
31 | */ |
32 | /** @file |
32 | /** @file |
33 | */ |
33 | */ |
34 | 34 | ||
35 | /* IPC resources management |
35 | /* IPC resources management |
36 | * |
36 | * |
37 | * The goal of this source code is to properly manage IPC resources and allow |
37 | * The goal of this source code is to properly manage IPC resources and allow |
38 | * straight and clean clean-up procedure upon task termination. |
38 | * straight and clean clean-up procedure upon task termination. |
39 | * |
39 | * |
40 | * The pattern of usage of the resources is: |
40 | * The pattern of usage of the resources is: |
41 | * - allocate empty phone slot, connect | deallocate slot |
41 | * - allocate empty phone slot, connect | deallocate slot |
42 | * - disconnect connected phone (some messages might be on the fly) |
42 | * - disconnect connected phone (some messages might be on the fly) |
43 | * - find phone in slot and send a message using phone |
43 | * - find phone in slot and send a message using phone |
44 | * - answer message to phone |
44 | * - answer message to phone |
45 | * - hangup phone (the caller has hung up) |
45 | * - hangup phone (the caller has hung up) |
46 | * - hangup phone (the answerbox is exiting) |
46 | * - hangup phone (the answerbox is exiting) |
47 | * |
47 | * |
48 | * Locking strategy |
48 | * Locking strategy |
49 | * |
49 | * |
50 | * - To use a phone, disconnect a phone etc., the phone must be first locked and |
50 | * - To use a phone, disconnect a phone etc., the phone must be first locked and |
51 | * then checked that it is connected |
51 | * then checked that it is connected |
52 | * - To connect an allocated phone it need not be locked (assigning pointer is |
52 | * - To connect an allocated phone it need not be locked (assigning pointer is |
53 | * atomic on all platforms) |
53 | * atomic on all platforms) |
54 | * |
54 | * |
55 | * - To find an empty phone slot, the TASK must be locked |
55 | * - To find an empty phone slot, the TASK must be locked |
56 | * - To answer a message, the answerbox must be locked |
56 | * - To answer a message, the answerbox must be locked |
57 | * - The locking of phone and answerbox is done at the ipc_ level. |
57 | * - The locking of phone and answerbox is done at the ipc_ level. |
58 | * It is perfectly correct to pass unconnected phone to these functions and |
58 | * It is perfectly correct to pass unconnected phone to these functions and |
59 | * proper reply will be generated. |
59 | * proper reply will be generated. |
60 | * |
60 | * |
61 | * Locking order |
61 | * Locking order |
62 | * |
62 | * |
63 | * - first phone, then answerbox |
63 | * - first phone, then answerbox |
64 | * + Easy locking on calls |
64 | * + Easy locking on calls |
65 | * - Very hard traversing list of phones when disconnecting because the phones |
65 | * - Very hard traversing list of phones when disconnecting because the phones |
66 | * may disconnect during traversal of list of connected phones. The only |
66 | * may disconnect during traversal of list of connected phones. The only |
67 | * possibility is try_lock with restart of list traversal. |
67 | * possibility is try_lock with restart of list traversal. |
68 | * |
68 | * |
69 | * Destroying is less frequent, this approach is taken. |
69 | * Destroying is less frequent, this approach is taken. |
70 | * |
70 | * |
71 | * Phone call |
71 | * Phone call |
72 | * |
72 | * |
73 | * *** Connect_me_to *** |
73 | * *** Connect_me_to *** |
74 | * The caller sends IPC_M_CONNECT_ME_TO to an answerbox. The server receives |
74 | * The caller sends IPC_M_CONNECT_ME_TO to an answerbox. The server receives |
75 | * 'phoneid' of the connecting phone as an ARG5. If it answers with RETVAL=0, |
75 | * 'phoneid' of the connecting phone as an ARG5. If it answers with RETVAL=0, |
76 | * the phonecall is accepted, otherwise it is refused. |
76 | * the phonecall is accepted, otherwise it is refused. |
77 | * |
77 | * |
78 | * *** Connect_to_me *** |
78 | * *** Connect_to_me *** |
79 | * The caller sends IPC_M_CONNECT_TO_ME. |
79 | * The caller sends IPC_M_CONNECT_TO_ME. |
80 | * The server receives an automatically opened phoneid. If it accepts |
80 | * The server receives an automatically opened phoneid. If it accepts |
81 | * (RETVAL=0), it can use the phoneid immediately. |
81 | * (RETVAL=0), it can use the phoneid immediately. |
82 | * Possible race condition can arise, when the client receives messages from new |
82 | * Possible race condition can arise, when the client receives messages from new |
83 | * connection before getting response for connect_to_me message. Userspace |
83 | * connection before getting response for connect_to_me message. Userspace |
84 | * should implement handshake protocol that would control it. |
84 | * should implement handshake protocol that would control it. |
85 | * |
85 | * |
86 | * Phone hangup |
86 | * Phone hangup |
87 | * |
87 | * |
88 | * *** The caller hangs up (sys_ipc_hangup) *** |
88 | * *** The caller hangs up (sys_ipc_hangup) *** |
89 | * - The phone is disconnected (no more messages can be sent over this phone), |
89 | * - The phone is disconnected (no more messages can be sent over this phone), |
90 | * all in-progress messages are correctly handled. The answerbox receives |
90 | * all in-progress messages are correctly handled. The answerbox receives |
91 | * IPC_M_PHONE_HUNGUP call from the phone that hung up. When all async |
91 | * IPC_M_PHONE_HUNGUP call from the phone that hung up. When all async |
92 | * calls are answered, the phone is deallocated. |
92 | * calls are answered, the phone is deallocated. |
93 | * |
93 | * |
94 | * *** The answerbox hangs up (ipc_answer(EHANGUP)) |
94 | * *** The answerbox hangs up (ipc_answer(EHANGUP)) |
95 | * - The phone is disconnected. EHANGUP response code is sent |
95 | * - The phone is disconnected. EHANGUP response code is sent |
96 | * to the calling task. All new calls through this phone |
96 | * to the calling task. All new calls through this phone |
97 | * get a EHUNGUP error code, the task is expected to |
97 | * get a EHUNGUP error code, the task is expected to |
98 | * send an sys_ipc_hangup after cleaning up its internal structures. |
98 | * send an sys_ipc_hangup after cleaning up its internal structures. |
99 | * |
99 | * |
100 | * Call forwarding |
100 | * Call forwarding |
101 | * |
101 | * |
102 | * The call can be forwarded, so that the answer to call is passed directly |
102 | * The call can be forwarded, so that the answer to call is passed directly |
103 | * to the original sender. However, this poses special problems regarding |
103 | * to the original sender. However, this poses special problems regarding |
104 | * routing of hangup messages. |
104 | * routing of hangup messages. |
105 | * |
105 | * |
106 | * sys_ipc_hangup -> IPC_M_PHONE_HUNGUP |
106 | * sys_ipc_hangup -> IPC_M_PHONE_HUNGUP |
107 | * - this message CANNOT be forwarded |
107 | * - this message CANNOT be forwarded |
108 | * |
108 | * |
109 | * EHANGUP during forward |
109 | * EHANGUP during forward |
110 | * - The *forwarding* phone will be closed, EFORWARD is sent to receiver. |
110 | * - The *forwarding* phone will be closed, EFORWARD is sent to receiver. |
111 | * |
111 | * |
112 | * EHANGUP, ENOENT during forward |
112 | * EHANGUP, ENOENT during forward |
113 | * - EFORWARD is sent to the receiver, ipc_forward returns error code EFORWARD |
113 | * - EFORWARD is sent to the receiver, ipc_forward returns error code EFORWARD |
114 | * |
114 | * |
115 | * Cleanup strategy |
115 | * Cleanup strategy |
116 | * |
116 | * |
117 | * 1) Disconnect all our phones ('ipc_phone_hangup'). |
117 | * 1) Disconnect all our phones ('ipc_phone_hangup'). |
118 | * |
118 | * |
119 | * 2) Disconnect all phones connected to answerbox. |
119 | * 2) Disconnect all phones connected to answerbox. |
120 | * |
120 | * |
121 | * 3) Answer all messages in 'calls' and 'dispatched_calls' queues with |
121 | * 3) Answer all messages in 'calls' and 'dispatched_calls' queues with |
122 | * appropriate error code (EHANGUP, EFORWARD). |
122 | * appropriate error code (EHANGUP, EFORWARD). |
123 | * |
123 | * |
124 | * 4) Wait for all async answers to arrive and dispose of them. |
124 | * 4) Wait for all async answers to arrive and dispose of them. |
125 | * |
125 | * |
126 | */ |
126 | */ |
127 | 127 | ||
128 | #include <synch/spinlock.h> |
128 | #include <synch/spinlock.h> |
129 | #include <ipc/ipc.h> |
129 | #include <ipc/ipc.h> |
130 | #include <arch.h> |
130 | #include <arch.h> |
131 | #include <proc/task.h> |
131 | #include <proc/task.h> |
132 | #include <ipc/ipcrsc.h> |
132 | #include <ipc/ipcrsc.h> |
133 | #include <debug.h> |
133 | #include <debug.h> |
134 | 134 | ||
135 | /** Find call_t * in call table according to callid. |
135 | /** Find call_t * in call table according to callid. |
136 | * |
136 | * |
137 | * @todo Some speedup (hash table?) |
137 | * @todo Some speedup (hash table?) |
138 | * |
138 | * |
139 | * @param callid Userspace hash of the call. Currently it is the call |
139 | * @param callid Userspace hash of the call. Currently it is the call |
140 | * structure kernel address. |
140 | * structure kernel address. |
141 | * |
141 | * |
142 | * @return NULL on not found, otherwise pointer to the call |
142 | * @return NULL on not found, otherwise pointer to the call |
143 | * structure. |
143 | * structure. |
144 | */ |
144 | */ |
145 | call_t *get_call(unative_t callid) |
145 | call_t *get_call(unative_t callid) |
146 | { |
146 | { |
147 | link_t *lst; |
147 | link_t *lst; |
148 | call_t *call, *result = NULL; |
148 | call_t *call, *result = NULL; |
149 | 149 | ||
150 | spinlock_lock(&TASK->answerbox.lock); |
150 | spinlock_lock(&TASK->answerbox.lock); |
151 | for (lst = TASK->answerbox.dispatched_calls.next; |
151 | for (lst = TASK->answerbox.dispatched_calls.next; |
152 | lst != &TASK->answerbox.dispatched_calls; lst = lst->next) { |
152 | lst != &TASK->answerbox.dispatched_calls; lst = lst->next) { |
153 | call = list_get_instance(lst, call_t, link); |
153 | call = list_get_instance(lst, call_t, link); |
154 | if ((unative_t) call == callid) { |
154 | if ((unative_t) call == callid) { |
155 | result = call; |
155 | result = call; |
156 | break; |
156 | break; |
157 | } |
157 | } |
158 | } |
158 | } |
159 | spinlock_unlock(&TASK->answerbox.lock); |
159 | spinlock_unlock(&TASK->answerbox.lock); |
160 | return result; |
160 | return result; |
161 | } |
161 | } |
162 | 162 | ||
163 | /** Allocate new phone slot in the current TASK structure. |
163 | /** Allocate new phone slot in the current TASK structure. |
164 | * |
164 | * |
165 | * @return New phone handle or -1 if the phone handle limit is |
165 | * @return New phone handle or -1 if the phone handle limit is |
166 | * exceeded. |
166 | * exceeded. |
167 | */ |
167 | */ |
168 | int phone_alloc(void) |
168 | int phone_alloc(void) |
169 | { |
169 | { |
170 | int i; |
170 | int i; |
171 | 171 | ||
172 | spinlock_lock(&TASK->lock); |
172 | spinlock_lock(&TASK->lock); |
173 | - | ||
174 | for (i = 0; i < IPC_MAX_PHONES; i++) { |
173 | for (i = 0; i < IPC_MAX_PHONES; i++) { |
175 | if (TASK->phones[i].state == IPC_PHONE_HUNGUP && |
174 | if (TASK->phones[i].state == IPC_PHONE_HUNGUP && |
176 | atomic_get(&TASK->phones[i].active_calls) == 0) |
175 | atomic_get(&TASK->phones[i].active_calls) == 0) |
177 | TASK->phones[i].state = IPC_PHONE_FREE; |
176 | TASK->phones[i].state = IPC_PHONE_FREE; |
178 | 177 | ||
179 | if (TASK->phones[i].state == IPC_PHONE_FREE) { |
178 | if (TASK->phones[i].state == IPC_PHONE_FREE) { |
180 | TASK->phones[i].state = IPC_PHONE_CONNECTING; |
179 | TASK->phones[i].state = IPC_PHONE_CONNECTING; |
181 | break; |
180 | break; |
182 | } |
181 | } |
183 | } |
182 | } |
184 | spinlock_unlock(&TASK->lock); |
183 | spinlock_unlock(&TASK->lock); |
185 | 184 | ||
186 | if (i >= IPC_MAX_PHONES) |
185 | if (i == IPC_MAX_PHONES) |
187 | return -1; |
186 | return -1; |
- | 187 | ||
188 | return i; |
188 | return i; |
189 | } |
189 | } |
190 | 190 | ||
191 | /** Mark a phone structure free. |
191 | /** Mark a phone structure free. |
192 | * |
192 | * |
193 | * @param phone Phone structure to be marked free. |
193 | * @param phone Phone structure to be marked free. |
194 | */ |
194 | */ |
195 | static void phone_deallocp(phone_t *phone) |
195 | static void phone_deallocp(phone_t *phone) |
196 | { |
196 | { |
197 | ASSERT(phone->state == IPC_PHONE_CONNECTING); |
197 | ASSERT(phone->state == IPC_PHONE_CONNECTING); |
198 | 198 | ||
199 | /* atomic operation */ |
199 | /* atomic operation */ |
200 | phone->state = IPC_PHONE_FREE; |
200 | phone->state = IPC_PHONE_FREE; |
201 | } |
201 | } |
202 | 202 | ||
203 | /** Free slot from a disconnected phone. |
203 | /** Free slot from a disconnected phone. |
204 | * |
204 | * |
205 | * All already sent messages will be correctly processed. |
205 | * All already sent messages will be correctly processed. |
206 | * |
206 | * |
207 | * @param phoneid Phone handle of the phone to be freed. |
207 | * @param phoneid Phone handle of the phone to be freed. |
208 | */ |
208 | */ |
209 | void phone_dealloc(int phoneid) |
209 | void phone_dealloc(int phoneid) |
210 | { |
210 | { |
211 | phone_deallocp(&TASK->phones[phoneid]); |
211 | phone_deallocp(&TASK->phones[phoneid]); |
212 | } |
212 | } |
213 | 213 | ||
214 | /** Connect phone to a given answerbox. |
214 | /** Connect phone to a given answerbox. |
215 | * |
215 | * |
216 | * @param phoneid Phone handle to be connected. |
216 | * @param phoneid Phone handle to be connected. |
217 | * @param box Answerbox to which to connect the phone handle. |
217 | * @param box Answerbox to which to connect the phone handle. |
218 | * |
218 | * |
219 | * The procedure _enforces_ that the user first marks the phone |
219 | * The procedure _enforces_ that the user first marks the phone |
220 | * busy (e.g. via phone_alloc) and then connects the phone, otherwise |
220 | * busy (e.g. via phone_alloc) and then connects the phone, otherwise |
221 | * race condition may appear. |
221 | * race condition may appear. |
222 | */ |
222 | */ |
223 | void phone_connect(int phoneid, answerbox_t *box) |
223 | void phone_connect(int phoneid, answerbox_t *box) |
224 | { |
224 | { |
225 | phone_t *phone = &TASK->phones[phoneid]; |
225 | phone_t *phone = &TASK->phones[phoneid]; |
226 | 226 | ||
227 | ASSERT(phone->state == IPC_PHONE_CONNECTING); |
227 | ASSERT(phone->state == IPC_PHONE_CONNECTING); |
228 | ipc_phone_connect(phone, box); |
228 | ipc_phone_connect(phone, box); |
229 | } |
229 | } |
230 | 230 | ||
231 | /** @} |
231 | /** @} |
232 | */ |
232 | */ |
233 | 233 |