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1113 | 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 | |||
1719 | decky | 29 | /** @addtogroup libc |
1653 | cejka | 30 | * @{ |
31 | */ |
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32 | /** @file |
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33 | */ |
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34 | |||
1113 | palkovsky | 35 | #include <libadt/list.h> |
36 | #include <psthread.h> |
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37 | #include <malloc.h> |
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38 | #include <unistd.h> |
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39 | #include <thread.h> |
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40 | #include <stdio.h> |
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1125 | jermar | 41 | #include <kernel/arch/faddr.h> |
1392 | palkovsky | 42 | #include <futex.h> |
43 | #include <assert.h> |
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1407 | palkovsky | 44 | #include <async.h> |
1113 | palkovsky | 45 | |
1155 | vana | 46 | #ifndef PSTHREAD_INITIAL_STACK_PAGES_NO |
47 | #define PSTHREAD_INITIAL_STACK_PAGES_NO 1 |
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48 | #endif |
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49 | |||
1113 | palkovsky | 50 | static LIST_INITIALIZE(ready_list); |
1610 | palkovsky | 51 | static LIST_INITIALIZE(serialized_list); |
1392 | palkovsky | 52 | static LIST_INITIALIZE(manager_list); |
1113 | palkovsky | 53 | |
1128 | jermar | 54 | static void psthread_main(void); |
1125 | jermar | 55 | |
1392 | palkovsky | 56 | static atomic_t psthread_futex = FUTEX_INITIALIZER; |
1610 | palkovsky | 57 | /** Count of real threads that are in async_serialized mode */ |
58 | static int serialized_threads; /* Protected by async_futex */ |
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59 | /** Thread-local count of serialization. If >0, we must not preempt */ |
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1614 | palkovsky | 60 | static __thread int serialization_count; |
1610 | palkovsky | 61 | /** Counter of threads residing in async_manager */ |
62 | static int threads_in_manager; |
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1392 | palkovsky | 63 | |
1129 | palkovsky | 64 | /** Setup PSthread information into TCB structure */ |
1392 | palkovsky | 65 | psthread_data_t * psthread_setup() |
1129 | palkovsky | 66 | { |
67 | psthread_data_t *pt; |
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1392 | palkovsky | 68 | tcb_t *tcb; |
1129 | palkovsky | 69 | |
1392 | palkovsky | 70 | tcb = __make_tls(); |
71 | if (!tcb) |
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72 | return NULL; |
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73 | |||
1129 | palkovsky | 74 | pt = malloc(sizeof(*pt)); |
75 | if (!pt) { |
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1392 | palkovsky | 76 | __free_tls(tcb); |
1129 | palkovsky | 77 | return NULL; |
78 | } |
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79 | |||
80 | tcb->pst_data = pt; |
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81 | pt->tcb = tcb; |
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82 | |||
83 | return pt; |
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84 | } |
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85 | |||
86 | void psthread_teardown(psthread_data_t *pt) |
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87 | { |
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1392 | palkovsky | 88 | __free_tls(pt->tcb); |
1129 | palkovsky | 89 | free(pt); |
90 | } |
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91 | |||
1113 | palkovsky | 92 | /** Function that is called on entry to new uspace thread */ |
1128 | jermar | 93 | void psthread_main(void) |
1113 | palkovsky | 94 | { |
1129 | palkovsky | 95 | psthread_data_t *pt = __tcb_get()->pst_data; |
96 | |||
1113 | palkovsky | 97 | pt->retval = pt->func(pt->arg); |
98 | |||
99 | pt->finished = 1; |
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100 | if (pt->waiter) |
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1128 | jermar | 101 | list_append(&pt->waiter->link, &ready_list); |
1113 | palkovsky | 102 | |
1610 | palkovsky | 103 | psthread_schedule_next_adv(PS_FROM_DEAD); |
1113 | palkovsky | 104 | } |
105 | |||
1128 | jermar | 106 | /** Schedule next userspace pseudo thread. |
107 | * |
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1427 | palkovsky | 108 | * If calling with PS_TO_MANAGER parameter, the async_futex should be |
109 | * held. |
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110 | * |
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1709 | jermar | 111 | * @param ctype Type of switch. |
1128 | jermar | 112 | * @return 0 if there is no ready pseudo thread, 1 otherwise. |
113 | */ |
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1392 | palkovsky | 114 | int psthread_schedule_next_adv(pschange_type ctype) |
1113 | palkovsky | 115 | { |
1610 | palkovsky | 116 | psthread_data_t *srcpt, *dstpt; |
1392 | palkovsky | 117 | int retval = 0; |
118 | |||
119 | futex_down(&psthread_futex); |
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1113 | palkovsky | 120 | |
1392 | palkovsky | 121 | if (ctype == PS_PREEMPT && list_empty(&ready_list)) |
122 | goto ret_0; |
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1113 | palkovsky | 123 | |
1610 | palkovsky | 124 | if (ctype == PS_FROM_MANAGER) { |
125 | if (list_empty(&ready_list) && list_empty(&serialized_list)) |
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126 | goto ret_0; |
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127 | /* Do not preempt if there is not sufficient count of thread managers */ |
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128 | if (list_empty(&serialized_list) && threads_in_manager <= serialized_threads) { |
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129 | goto ret_0; |
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130 | } |
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1392 | palkovsky | 131 | } |
1407 | palkovsky | 132 | /* If we are going to manager and none exists, create it */ |
1610 | palkovsky | 133 | if (ctype == PS_TO_MANAGER || ctype == PS_FROM_DEAD) { |
134 | while (list_empty(&manager_list)) { |
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135 | futex_up(&psthread_futex); |
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136 | async_create_manager(); |
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137 | futex_down(&psthread_futex); |
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138 | } |
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1427 | palkovsky | 139 | } |
1610 | palkovsky | 140 | |
141 | if (ctype != PS_FROM_DEAD) { |
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142 | /* Save current state */ |
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143 | srcpt = __tcb_get()->pst_data; |
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144 | if (!context_save(&srcpt->ctx)) { |
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145 | if (serialization_count) |
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146 | srcpt->flags &= ~PSTHREAD_SERIALIZED; |
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147 | return 1; // futex_up already done here |
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148 | } |
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1392 | palkovsky | 149 | |
1610 | palkovsky | 150 | /* Save myself to correct run list */ |
151 | if (ctype == PS_PREEMPT) |
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152 | list_append(&srcpt->link, &ready_list); |
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153 | else if (ctype == PS_FROM_MANAGER) { |
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154 | list_append(&srcpt->link, &manager_list); |
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155 | threads_in_manager--; |
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156 | } /* If ctype == PS_TO_MANAGER, don't save ourselves to any list, we should |
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157 | * already be somewhere, or we will be lost */ |
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1720 | palkovsky | 158 | } else |
159 | srcpt = NULL; /* Avoid GCC warning, if ctype == PS_FROM_DEAD, srcpt is not used */ |
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1392 | palkovsky | 160 | |
1610 | palkovsky | 161 | /* Choose new thread to run */ |
162 | if (ctype == PS_TO_MANAGER || ctype == PS_FROM_DEAD) { |
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163 | dstpt = list_get_instance(manager_list.next,psthread_data_t, link); |
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164 | if (serialization_count && ctype == PS_TO_MANAGER) { |
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165 | serialized_threads++; |
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166 | srcpt->flags |= PSTHREAD_SERIALIZED; |
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167 | } |
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168 | threads_in_manager++; |
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169 | } else { |
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170 | if (!list_empty(&serialized_list)) { |
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171 | dstpt = list_get_instance(serialized_list.next, psthread_data_t, link); |
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172 | serialized_threads--; |
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173 | } else |
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174 | dstpt = list_get_instance(ready_list.next, psthread_data_t, link); |
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175 | } |
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176 | list_remove(&dstpt->link); |
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1113 | palkovsky | 177 | |
1392 | palkovsky | 178 | futex_up(&psthread_futex); |
1610 | palkovsky | 179 | context_restore(&dstpt->ctx); |
1392 | palkovsky | 180 | |
181 | ret_0: |
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182 | futex_up(&psthread_futex); |
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183 | return retval; |
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1113 | palkovsky | 184 | } |
185 | |||
1128 | jermar | 186 | /** Wait for uspace pseudo thread to finish. |
187 | * |
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188 | * @param psthrid Pseudo thread to wait for. |
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189 | * |
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190 | * @return Value returned by the finished thread. |
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191 | */ |
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192 | int psthread_join(pstid_t psthrid) |
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1113 | palkovsky | 193 | { |
1719 | decky | 194 | volatile psthread_data_t *pt; |
1125 | jermar | 195 | volatile int retval; |
1113 | palkovsky | 196 | |
197 | /* Handle psthrid = Kernel address -> it is wait for call */ |
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198 | pt = (psthread_data_t *) psthrid; |
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199 | |||
1610 | palkovsky | 200 | /* TODO */ |
201 | printf("join unsupported\n"); |
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202 | _exit(1); |
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203 | |||
1113 | palkovsky | 204 | retval = pt->retval; |
205 | |||
206 | free(pt->stack); |
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1129 | palkovsky | 207 | psthread_teardown((void *)pt); |
1113 | palkovsky | 208 | |
209 | return retval; |
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210 | } |
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211 | |||
212 | /** |
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1392 | palkovsky | 213 | * Create a userspace thread |
1113 | palkovsky | 214 | * |
1128 | jermar | 215 | * @param func Pseudo thread function. |
216 | * @param arg Argument to pass to func. |
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217 | * |
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218 | * @return 0 on failure, TLS of the new pseudo thread. |
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1113 | palkovsky | 219 | */ |
220 | pstid_t psthread_create(int (*func)(void *), void *arg) |
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221 | { |
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222 | psthread_data_t *pt; |
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223 | |||
1392 | palkovsky | 224 | pt = psthread_setup(); |
225 | if (!pt) |
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1129 | palkovsky | 226 | return 0; |
1155 | vana | 227 | pt->stack = (char *) malloc(PSTHREAD_INITIAL_STACK_PAGES_NO*getpagesize()); |
1113 | palkovsky | 228 | |
229 | if (!pt->stack) { |
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1129 | palkovsky | 230 | psthread_teardown(pt); |
1113 | palkovsky | 231 | return 0; |
232 | } |
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233 | |||
234 | pt->arg= arg; |
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235 | pt->func = func; |
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236 | pt->finished = 0; |
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237 | pt->waiter = NULL; |
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1610 | palkovsky | 238 | pt->flags = 0; |
1113 | palkovsky | 239 | |
240 | context_save(&pt->ctx); |
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1719 | decky | 241 | context_set(&pt->ctx, FADDR(psthread_main), pt->stack, PSTHREAD_INITIAL_STACK_PAGES_NO*getpagesize(), pt->tcb); |
1113 | palkovsky | 242 | |
1392 | palkovsky | 243 | return (pstid_t )pt; |
244 | } |
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245 | |||
246 | /** Add a thread to ready list */ |
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247 | void psthread_add_ready(pstid_t psthrid) |
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248 | { |
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249 | psthread_data_t *pt; |
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250 | |||
251 | pt = (psthread_data_t *) psthrid; |
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252 | futex_down(&psthread_futex); |
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1610 | palkovsky | 253 | if ((pt->flags & PSTHREAD_SERIALIZED)) |
254 | list_append(&pt->link, &serialized_list); |
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255 | else |
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256 | list_append(&pt->link, &ready_list); |
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1392 | palkovsky | 257 | futex_up(&psthread_futex); |
258 | } |
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1113 | palkovsky | 259 | |
1392 | palkovsky | 260 | /** Add a thread to manager list */ |
261 | void psthread_add_manager(pstid_t psthrid) |
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262 | { |
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263 | psthread_data_t *pt; |
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264 | |||
265 | pt = (psthread_data_t *) psthrid; |
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266 | |||
267 | futex_down(&psthread_futex); |
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268 | list_append(&pt->link, &manager_list); |
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269 | futex_up(&psthread_futex); |
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1113 | palkovsky | 270 | } |
1392 | palkovsky | 271 | |
272 | /** Remove one manager from manager list */ |
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273 | void psthread_remove_manager() |
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274 | { |
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275 | futex_down(&psthread_futex); |
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276 | if (list_empty(&manager_list)) { |
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277 | futex_up(&psthread_futex); |
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278 | return; |
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279 | } |
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280 | list_remove(manager_list.next); |
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281 | futex_up(&psthread_futex); |
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282 | } |
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1427 | palkovsky | 283 | |
284 | /** Return thread id of current running thread */ |
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285 | pstid_t psthread_get_id(void) |
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286 | { |
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287 | return (pstid_t)__tcb_get()->pst_data; |
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288 | } |
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1610 | palkovsky | 289 | |
290 | /** Disable preemption |
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291 | * |
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292 | * If the thread wants to send several message in row and does not want |
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293 | * to be preempted, it should start async_serialize_start() in the beginning |
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294 | * of communication and async_serialize_end() in the end. If it is a |
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295 | * true multithreaded application, it should protect the communication channel |
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296 | * by a futex as well. Interrupt messages will can still be preempted. |
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297 | */ |
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298 | void psthread_inc_sercount(void) |
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299 | { |
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300 | serialization_count++; |
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301 | } |
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302 | |||
303 | void psthread_dec_sercount(void) |
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304 | { |
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305 | serialization_count--; |
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306 | } |
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1653 | cejka | 307 | |
308 | |||
1719 | decky | 309 | /** @} |
1653 | cejka | 310 | */ |