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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 5131 | clevermous | 1 | /* WARNING: This file was automatically generated! |
| 2 | * Original: ./src/thread/generic/SDL_syssem.c |
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| 3 | */ |
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| 4 | /* |
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| 5 | SDL - Simple DirectMedia Layer |
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| 6 | Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga |
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| 7 | |||
| 8 | This library is free software; you can redistribute it and/or |
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| 9 | modify it under the terms of the GNU Library General Public |
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| 10 | License as published by the Free Software Foundation; either |
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| 11 | version 2 of the License, or (at your option) any later version. |
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| 12 | |||
| 13 | This library is distributed in the hope that it will be useful, |
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| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 16 | Library General Public License for more details. |
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| 17 | |||
| 18 | You should have received a copy of the GNU Library General Public |
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| 19 | License along with this library; if not, write to the Free |
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| 20 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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| 21 | |||
| 22 | Sam Lantinga |
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| 23 | slouken@devolution.com |
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| 24 | */ |
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| 25 | |||
| 26 | |||
| 27 | /* An implementation of semaphores using mutexes and condition variables */ |
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| 28 | |||
| 29 | #include |
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| 30 | |||
| 31 | #include "SDL_error.h" |
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| 32 | #include "SDL_timer.h" |
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| 33 | #include "SDL_thread.h" |
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| 34 | #include "SDL_systhread_c.h" |
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| 35 | |||
| 36 | |||
| 37 | #ifdef DISABLE_THREADS |
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| 38 | |||
| 39 | SDL_sem *SDL_CreateSemaphore(Uint32 initial_value) |
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| 40 | { |
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| 41 | SDL_SetError("SDL not configured with thread support"); |
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| 42 | return (SDL_sem *)0; |
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| 43 | } |
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| 44 | |||
| 45 | void SDL_DestroySemaphore(SDL_sem *sem) |
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| 46 | { |
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| 47 | return; |
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| 48 | } |
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| 49 | |||
| 50 | int SDL_SemTryWait(SDL_sem *sem) |
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| 51 | { |
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| 52 | SDL_SetError("SDL not configured with thread support"); |
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| 53 | return -1; |
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| 54 | } |
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| 55 | |||
| 56 | int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout) |
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| 57 | { |
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| 58 | SDL_SetError("SDL not configured with thread support"); |
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| 59 | return -1; |
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| 60 | } |
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| 61 | |||
| 62 | int SDL_SemWait(SDL_sem *sem) |
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| 63 | { |
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| 64 | SDL_SetError("SDL not configured with thread support"); |
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| 65 | return -1; |
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| 66 | } |
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| 67 | |||
| 68 | Uint32 SDL_SemValue(SDL_sem *sem) |
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| 69 | { |
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| 70 | return 0; |
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| 71 | } |
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| 72 | |||
| 73 | int SDL_SemPost(SDL_sem *sem) |
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| 74 | { |
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| 75 | SDL_SetError("SDL not configured with thread support"); |
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| 76 | return -1; |
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| 77 | } |
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| 78 | |||
| 79 | #else |
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| 80 | |||
| 81 | struct SDL_semaphore |
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| 82 | { |
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| 83 | Uint32 count; |
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| 84 | Uint32 waiters_count; |
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| 85 | SDL_mutex *count_lock; |
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| 86 | SDL_cond *count_nonzero; |
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| 87 | }; |
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| 88 | |||
| 89 | SDL_sem *SDL_CreateSemaphore(Uint32 initial_value) |
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| 90 | { |
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| 91 | SDL_sem *sem; |
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| 92 | |||
| 93 | sem = (SDL_sem *)malloc(sizeof(*sem)); |
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| 94 | if ( ! sem ) { |
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| 95 | SDL_OutOfMemory(); |
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| 96 | return(0); |
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| 97 | } |
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| 98 | sem->count = initial_value; |
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| 99 | sem->waiters_count = 0; |
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| 100 | |||
| 101 | sem->count_lock = SDL_CreateMutex(); |
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| 102 | sem->count_nonzero = SDL_CreateCond(); |
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| 103 | if ( ! sem->count_lock || ! sem->count_nonzero ) { |
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| 104 | SDL_DestroySemaphore(sem); |
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| 105 | return(0); |
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| 106 | } |
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| 107 | |||
| 108 | return(sem); |
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| 109 | } |
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| 110 | |||
| 111 | /* WARNING: |
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| 112 | You cannot call this function when another thread is using the semaphore. |
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| 113 | */ |
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| 114 | void SDL_DestroySemaphore(SDL_sem *sem) |
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| 115 | { |
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| 116 | if ( sem ) { |
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| 117 | sem->count = 0xFFFFFFFF; |
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| 118 | while ( sem->waiters_count > 0) { |
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| 119 | SDL_CondSignal(sem->count_nonzero); |
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| 120 | SDL_Delay(10); |
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| 121 | } |
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| 122 | SDL_DestroyCond(sem->count_nonzero); |
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| 123 | SDL_mutexP(sem->count_lock); |
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| 124 | SDL_mutexV(sem->count_lock); |
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| 125 | SDL_DestroyMutex(sem->count_lock); |
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| 126 | free(sem); |
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| 127 | } |
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| 128 | } |
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| 129 | |||
| 130 | int SDL_SemTryWait(SDL_sem *sem) |
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| 131 | { |
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| 132 | int retval; |
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| 133 | |||
| 134 | if ( ! sem ) { |
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| 135 | SDL_SetError("Passed a NULL semaphore"); |
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| 136 | return -1; |
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| 137 | } |
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| 138 | |||
| 139 | retval = SDL_MUTEX_TIMEDOUT; |
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| 140 | SDL_LockMutex(sem->count_lock); |
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| 141 | if ( sem->count > 0 ) { |
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| 142 | --sem->count; |
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| 143 | retval = 0; |
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| 144 | } |
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| 145 | SDL_UnlockMutex(sem->count_lock); |
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| 146 | |||
| 147 | return retval; |
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| 148 | } |
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| 149 | |||
| 150 | int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout) |
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| 151 | { |
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| 152 | int retval; |
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| 153 | |||
| 154 | if ( ! sem ) { |
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| 155 | SDL_SetError("Passed a NULL semaphore"); |
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| 156 | return -1; |
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| 157 | } |
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| 158 | |||
| 159 | /* A timeout of 0 is an easy case */ |
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| 160 | if ( timeout == 0 ) { |
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| 161 | return SDL_SemTryWait(sem); |
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| 162 | } |
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| 163 | |||
| 164 | SDL_LockMutex(sem->count_lock); |
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| 165 | ++sem->waiters_count; |
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| 166 | retval = 0; |
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| 167 | while ( (sem->count == 0) && (retval != SDL_MUTEX_TIMEDOUT) ) { |
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| 168 | retval = SDL_CondWaitTimeout(sem->count_nonzero, |
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| 169 | sem->count_lock, timeout); |
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| 170 | } |
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| 171 | --sem->waiters_count; |
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| 172 | --sem->count; |
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| 173 | SDL_UnlockMutex(sem->count_lock); |
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| 174 | |||
| 175 | return retval; |
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| 176 | } |
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| 177 | |||
| 178 | int SDL_SemWait(SDL_sem *sem) |
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| 179 | { |
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| 180 | return SDL_SemWaitTimeout(sem, SDL_MUTEX_MAXWAIT); |
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| 181 | } |
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| 182 | |||
| 183 | Uint32 SDL_SemValue(SDL_sem *sem) |
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| 184 | { |
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| 185 | Uint32 value; |
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| 186 | |||
| 187 | value = 0; |
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| 188 | if ( sem ) { |
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| 189 | SDL_LockMutex(sem->count_lock); |
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| 190 | value = sem->count; |
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| 191 | SDL_UnlockMutex(sem->count_lock); |
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| 192 | } |
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| 193 | return value; |
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| 194 | } |
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| 195 | |||
| 196 | int SDL_SemPost(SDL_sem *sem) |
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| 197 | { |
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| 198 | if ( ! sem ) { |
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| 199 | SDL_SetError("Passed a NULL semaphore"); |
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| 200 | return -1; |
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| 201 | } |
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| 202 | |||
| 203 | SDL_LockMutex(sem->count_lock); |
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| 204 | if ( sem->waiters_count > 0 ) { |
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| 205 | SDL_CondSignal(sem->count_nonzero); |
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| 206 | } |
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| 207 | ++sem->count; |
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| 208 | SDL_UnlockMutex(sem->count_lock); |
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| 209 | |||
| 210 | return 0; |
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| 211 | } |
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| 212 | |||
| 213 | #endif /* DISABLE_THREADS */ |