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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 | |||
29 | #include <libadt/list.h> |
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30 | #include <psthread.h> |
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31 | #include <malloc.h> |
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32 | #include <unistd.h> |
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33 | #include <thread.h> |
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34 | #include <stdio.h> |
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35 | |||
36 | static LIST_INITIALIZE(ready_list); |
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37 | |||
38 | /** Function to preempt to other thread without adding |
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39 | * currently running thread to runqueue |
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40 | */ |
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41 | static void ps_exit(void) |
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42 | { |
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43 | psthread_data_t *pt; |
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44 | |||
45 | if (list_empty(&ready_list)) { |
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46 | /* Wait on IPC queue etc... */ |
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47 | printf("Cannot exit!!!\n"); |
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48 | _exit(0); |
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49 | } |
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50 | pt = list_get_instance(ready_list.next, psthread_data_t, list); |
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51 | list_remove(&pt->list); |
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52 | context_restore(&pt->ctx); |
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53 | } |
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54 | |||
55 | /** Function that is called on entry to new uspace thread */ |
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56 | static int psthread_main(void) |
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57 | { |
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58 | psthread_data_t *pt = __tls_get(); |
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59 | pt->retval = pt->func(pt->arg); |
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60 | |||
61 | pt->finished = 1; |
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62 | if (pt->waiter) |
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63 | list_append(&pt->waiter->list, &ready_list); |
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64 | |||
65 | ps_exit(); |
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66 | } |
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67 | |||
68 | /** Do a preemption of userpace threads */ |
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69 | int ps_preempt(void) |
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70 | { |
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71 | psthread_data_t *pt; |
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72 | |||
73 | if (list_empty(&ready_list)) |
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74 | return 0; |
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75 | |||
76 | pt = __tls_get(); |
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77 | if (! context_save(&pt->ctx)) |
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78 | return 1; |
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79 | |||
80 | list_append(&pt->list, &ready_list); |
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81 | pt = list_get_instance(ready_list.next, psthread_data_t, list); |
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82 | list_remove(&pt->list); |
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83 | |||
84 | context_restore(&pt->ctx); |
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85 | } |
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86 | |||
87 | /** Wait for uspace thread to finish */ |
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88 | int ps_join(pstid_t psthrid) |
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89 | { |
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90 | psthread_data_t *pt, *mypt; |
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91 | int retval; |
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92 | |||
93 | /* Handle psthrid = Kernel address -> it is wait for call */ |
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94 | |||
95 | pt = (psthread_data_t *) psthrid; |
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96 | |||
97 | if (!pt->finished) { |
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98 | mypt = __tls_get(); |
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99 | if (context_save(&mypt->ctx)) { |
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100 | pt->waiter = mypt; |
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101 | ps_exit(); |
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102 | } |
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103 | } |
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104 | retval = pt->retval; |
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105 | |||
106 | free(pt->stack); |
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107 | __free_tls(pt); |
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108 | |||
109 | return retval; |
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110 | } |
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111 | |||
112 | /** |
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113 | * Create a userspace thread |
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114 | * |
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115 | */ |
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116 | pstid_t psthread_create(int (*func)(void *), void *arg) |
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117 | { |
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118 | psthread_data_t *pt; |
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119 | |||
120 | pt = __make_tls(); |
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121 | pt->stack = (char *) malloc(getpagesize()); |
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122 | |||
123 | if (!pt->stack) { |
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124 | return 0; |
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125 | } |
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126 | |||
127 | pt->arg= arg; |
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128 | pt->func = func; |
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129 | pt->finished = 0; |
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130 | pt->waiter = NULL; |
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131 | |||
132 | context_save(&pt->ctx); |
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133 | context_set(&pt->ctx, psthread_main, pt->stack, getpagesize(), pt); |
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134 | |||
135 | list_append(&pt->list, &ready_list); |
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136 | |||
137 | return (pstid_t )pt; |
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138 | } |
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139 |