1 | /* SPDX-License-Identifier: BSD-2-Clause */ |
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2 | |
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3 | /** |
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4 | * @file |
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5 | * |
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6 | * @ingroup POSIX_SEMAPHORE POSIX Semaphores Support |
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7 | * |
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8 | * @brief Lock a Semaphore |
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9 | */ |
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10 | |
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11 | /* |
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12 | * COPYRIGHT (c) 1989-2008. |
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13 | * On-Line Applications Research Corporation (OAR). |
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14 | * |
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15 | * Redistribution and use in source and binary forms, with or without |
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16 | * modification, are permitted provided that the following conditions |
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17 | * are met: |
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18 | * 1. Redistributions of source code must retain the above copyright |
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19 | * notice, this list of conditions and the following disclaimer. |
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20 | * 2. Redistributions in binary form must reproduce the above copyright |
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21 | * notice, this list of conditions and the following disclaimer in the |
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22 | * documentation and/or other materials provided with the distribution. |
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23 | * |
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24 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
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25 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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26 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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27 | * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
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28 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
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29 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
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30 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
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31 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
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32 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
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33 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
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34 | * POSSIBILITY OF SUCH DAMAGE. |
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35 | */ |
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36 | |
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37 | #ifdef HAVE_CONFIG_H |
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38 | #include "config.h" |
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39 | #endif |
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40 | |
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41 | #include <rtems/posix/semaphoreimpl.h> |
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42 | #include <rtems/score/todimpl.h> |
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43 | |
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44 | /* |
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45 | * 11.2.6 Lock a Semaphore, P1003.1b-1993, p.226 |
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46 | * |
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47 | * NOTE: P1003.4b/D8 adds sem_timedwait(), p. 27 |
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48 | */ |
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49 | |
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50 | int sem_timedwait( |
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51 | sem_t *__restrict _sem, |
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52 | const struct timespec *__restrict abstime |
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53 | ) |
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54 | { |
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55 | Sem_Control *sem; |
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56 | Thread_queue_Context queue_context; |
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57 | ISR_Level level; |
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58 | Thread_Control *executing; |
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59 | unsigned int count; |
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60 | |
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61 | POSIX_SEMAPHORE_VALIDATE_OBJECT( _sem ); |
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62 | |
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63 | sem = _Sem_Get( &_sem->_Semaphore ); |
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64 | _Thread_queue_Context_initialize( &queue_context ); |
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65 | _Thread_queue_Context_ISR_disable( &queue_context, level ); |
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66 | executing = _Sem_Queue_acquire_critical( sem, &queue_context ); |
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67 | |
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68 | count = sem->count; |
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69 | if ( RTEMS_PREDICT_TRUE( count > 0 ) ) { |
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70 | sem->count = count - 1; |
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71 | _Sem_Queue_release( sem, level, &queue_context ); |
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72 | return 0; |
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73 | } else { |
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74 | Status_Control status; |
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75 | |
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76 | _Thread_queue_Context_set_thread_state( |
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77 | &queue_context, |
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78 | STATES_WAITING_FOR_SEMAPHORE |
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79 | ); |
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80 | _Thread_queue_Context_set_enqueue_timeout_realtime_timespec( |
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81 | &queue_context, |
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82 | abstime, |
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83 | true |
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84 | ); |
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85 | _Thread_queue_Context_set_ISR_level( &queue_context, level ); |
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86 | _Thread_queue_Enqueue( |
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87 | &sem->Queue.Queue, |
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88 | SEMAPHORE_TQ_OPERATIONS, |
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89 | executing, |
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90 | &queue_context |
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91 | ); |
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92 | status = _Thread_Wait_get_status( executing ); |
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93 | return _POSIX_Zero_or_minus_one_plus_errno( status ); |
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94 | } |
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95 | } |
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