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955 | palkovsky | 1 | /* |
2 | * Copyright (C) 2006 Ondrej Palkovsky |
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3 | * All rights reserved. |
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4 | * |
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5 | * Redistribution and use in source and binary forms, with or without |
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6 | * modification, are permitted provided that the following conditions |
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7 | * are met: |
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8 | * |
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9 | * - Redistributions of source code must retain the above copyright |
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10 | * notice, this list of conditions and the following disclaimer. |
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11 | * - Redistributions in binary form must reproduce the above copyright |
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12 | * notice, this list of conditions and the following disclaimer in the |
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13 | * documentation and/or other materials provided with the distribution. |
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14 | * - The name of the author may not be used to endorse or promote products |
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15 | * derived from this software without specific prior written permission. |
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16 | * |
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17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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27 | */ |
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28 | |||
29 | /* Lock ordering |
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30 | * |
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31 | * First the answerbox, then the phone |
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32 | */ |
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33 | |||
34 | #include <synch/waitq.h> |
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35 | #include <ipc/ipc.h> |
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36 | #include <errno.h> |
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37 | #include <mm/slab.h> |
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38 | #include <arch.h> |
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39 | #include <proc/task.h> |
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40 | #include <memstr.h> |
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41 | #include <debug.h> |
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42 | |||
43 | #include <print.h> |
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44 | #include <proc/thread.h> |
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45 | |||
46 | answerbox_t *ipc_central_box; |
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47 | |||
48 | static slab_cache_t *ipc_call_slab; |
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49 | |||
50 | /** Allocate & initialize call structure |
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51 | * |
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52 | * The call is initialized, so that the reply will be directed |
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53 | * to TASK->answerbox |
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54 | */ |
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55 | call_t * ipc_call_alloc(void) |
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56 | { |
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57 | call_t *call; |
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58 | |||
59 | call = slab_alloc(ipc_call_slab, 0); |
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60 | memsetb((__address)call, sizeof(*call), 0); |
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61 | call->callerbox = &TASK->answerbox; |
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62 | |||
63 | return call; |
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64 | } |
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65 | |||
66 | /** Deallocate call stracuture */ |
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67 | void ipc_call_free(call_t *call) |
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68 | { |
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69 | slab_free(ipc_call_slab, call); |
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70 | } |
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71 | |||
72 | /** Initialize answerbox structure |
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73 | */ |
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74 | void ipc_answerbox_init(answerbox_t *box) |
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75 | { |
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76 | spinlock_initialize(&box->lock, "abox_lock"); |
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77 | waitq_initialize(&box->wq); |
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78 | list_initialize(&box->connected_phones); |
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79 | list_initialize(&box->calls); |
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80 | list_initialize(&box->dispatched_calls); |
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81 | list_initialize(&box->answers); |
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82 | } |
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83 | |||
84 | /** Initialize phone structure and connect phone to naswerbox |
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85 | */ |
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86 | void ipc_phone_init(phone_t *phone, answerbox_t *box) |
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87 | { |
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88 | spinlock_initialize(&phone->lock, "phone_lock"); |
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89 | |||
90 | phone->callee = box; |
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91 | spinlock_lock(&box->lock); |
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92 | list_append(&phone->list, &box->connected_phones); |
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93 | spinlock_unlock(&box->lock); |
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94 | } |
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95 | |||
96 | /** Disconnect phone from answerbox */ |
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97 | void ipc_phone_destroy(phone_t *phone) |
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98 | { |
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99 | answerbox_t *box = phone->callee; |
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100 | |||
101 | ASSERT(box); |
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102 | |||
103 | spinlock_lock(&box->lock); |
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104 | list_remove(&phone->list); |
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105 | spinlock_unlock(&box->lock); |
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106 | } |
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107 | |||
959 | palkovsky | 108 | /** Helper function to facilitate synchronous calls */ |
109 | void ipc_call_sync(phone_t *phone, call_t *request) |
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110 | { |
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111 | answerbox_t sync_box; |
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955 | palkovsky | 112 | |
959 | palkovsky | 113 | ipc_answerbox_init(&sync_box); |
114 | |||
115 | /* We will receive data on special box */ |
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116 | request->callerbox = &sync_box; |
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117 | |||
118 | ipc_call(phone, request); |
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119 | ipc_wait_for_call(&sync_box, 0); |
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120 | } |
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121 | |||
122 | /** Send a asynchronous request using phone to answerbox |
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955 | palkovsky | 123 | * |
124 | * @param phone Phone connected to answerbox |
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125 | * @param request Request to be sent |
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126 | */ |
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127 | void ipc_call(phone_t *phone, call_t *request) |
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128 | { |
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129 | answerbox_t *box = phone->callee; |
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130 | |||
131 | ASSERT(box); |
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132 | |||
133 | spinlock_lock(&box->lock); |
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134 | list_append(&request->list, &box->calls); |
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135 | spinlock_unlock(&box->lock); |
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136 | waitq_wakeup(&box->wq, 0); |
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137 | } |
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138 | |||
139 | /** Answer message back to phone |
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140 | * |
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141 | * @param box Answerbox that is answering the message |
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142 | * @param request Modified request that is being sent back |
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143 | */ |
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144 | void ipc_answer(answerbox_t *box, call_t *request) |
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145 | { |
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146 | answerbox_t *callerbox = request->callerbox; |
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147 | |||
148 | request->flags |= IPC_CALL_ANSWERED; |
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149 | |||
150 | spinlock_lock(&box->lock); |
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151 | spinlock_lock(&callerbox->lock); |
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152 | |||
153 | list_remove(&request->list); |
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154 | list_append(&request->list, &callerbox->answers); |
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155 | waitq_wakeup(&callerbox->wq, 0); |
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156 | |||
157 | spinlock_unlock(&callerbox->lock); |
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158 | spinlock_unlock(&box->lock); |
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159 | } |
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160 | |||
161 | /** Wait for phone call |
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162 | * |
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163 | * @return Recived message address |
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164 | * - to distinguish between call and answer, look at call->flags |
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165 | */ |
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166 | call_t * ipc_wait_for_call(answerbox_t *box, int flags) |
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167 | { |
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168 | call_t *request; |
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169 | |||
170 | if ((flags & IPC_WAIT_NONBLOCKING)) { |
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171 | if (waitq_sleep_timeout(&box->wq,SYNCH_NO_TIMEOUT,SYNCH_NON_BLOCKING) == ESYNCH_WOULD_BLOCK) |
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172 | return 0; |
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173 | } else { |
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174 | waitq_sleep(&box->wq); |
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175 | } |
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176 | |||
177 | |||
178 | // TODO - might need condition variable+mutex if we want to support |
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179 | // removing of requests from queue before dispatch |
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180 | spinlock_lock(&box->lock); |
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181 | /* Handle answers first */ |
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182 | if (!list_empty(&box->answers)) { |
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183 | request = list_get_instance(box->answers.next, call_t, list); |
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184 | list_remove(&request->list); |
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185 | } else { |
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186 | ASSERT (! list_empty(&box->calls)); |
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187 | request = list_get_instance(box->calls.next, call_t, list); |
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188 | list_remove(&request->list); |
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189 | /* Append request to dispatch queue */ |
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190 | list_append(&request->list, &box->dispatched_calls); |
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191 | } |
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192 | spinlock_unlock(&box->lock); |
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193 | |||
194 | return request; |
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195 | } |
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196 | |||
197 | /** Initilize ipc subsystem */ |
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198 | void ipc_init(void) |
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199 | { |
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200 | ipc_call_slab = slab_cache_create("ipc_call", |
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201 | sizeof(call_t), |
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202 | 0, |
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203 | NULL, NULL, 0); |
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204 | } |
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205 | |||
206 | static void ipc_phonecompany_thread(void *data) |
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207 | { |
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208 | call_t *call; |
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209 | |||
210 | printf("Phone company started.\n"); |
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211 | while (1) { |
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212 | call = ipc_wait_for_call(&TASK->answerbox, 0); |
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213 | printf("Received phone call - %P %P\n", |
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214 | call->data[0], call->data[1]); |
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959 | palkovsky | 215 | call->data[0] = 0xbabaaaee;; |
216 | call->data[1] = 0xaaaaeeee; |
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955 | palkovsky | 217 | ipc_answer(&TASK->answerbox, call); |
218 | printf("Call answered.\n"); |
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219 | } |
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220 | } |
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221 | |||
222 | void ipc_create_phonecompany(void) |
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223 | { |
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224 | thread_t *t; |
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225 | |||
226 | if ((t = thread_create(ipc_phonecompany_thread, "phonecompany", |
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227 | TASK, 0))) |
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228 | thread_ready(t); |
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229 | else |
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230 | panic("thread_create/phonecompany"); |
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231 | |||
232 | ipc_central_box = &TASK->answerbox; |
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233 | } |