1 | /** |
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2 | * @file |
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3 | * |
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4 | * @brief Changes the Priority Ceiling of a Mutex and Releases it |
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5 | * @ingroup POSIXAPI |
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6 | */ |
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7 | |
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8 | /* |
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9 | * COPYRIGHT (c) 1989-2009. |
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10 | * On-Line Applications Research Corporation (OAR). |
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11 | * |
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12 | * The license and distribution terms for this file may be |
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13 | * found in the file LICENSE in this distribution or at |
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14 | * http://www.rtems.org/license/LICENSE. |
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15 | */ |
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16 | |
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17 | #if HAVE_CONFIG_H |
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18 | #include "config.h" |
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19 | #endif |
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20 | |
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21 | #include <rtems/posix/muteximpl.h> |
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22 | #include <rtems/posix/priorityimpl.h> |
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23 | |
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24 | /* |
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25 | * 13.6.2 Change the Priority Ceiling of a Mutex, P1003.1c/Draft 10, p. 131 |
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26 | */ |
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27 | |
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28 | int pthread_mutex_setprioceiling( |
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29 | pthread_mutex_t *mutex, |
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30 | int prioceiling, |
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31 | int *old_ceiling |
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32 | ) |
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33 | { |
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34 | register POSIX_Mutex_Control *the_mutex; |
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35 | Priority_Control the_priority; |
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36 | ISR_lock_Context lock_context; |
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37 | |
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38 | if ( !old_ceiling ) |
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39 | return EINVAL; |
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40 | |
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41 | if ( !_POSIX_Priority_Is_valid( prioceiling ) ) |
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42 | return EINVAL; |
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43 | |
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44 | the_priority = _POSIX_Priority_To_core( prioceiling ); |
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45 | |
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46 | /* |
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47 | * Must acquire the mutex before we can change it's ceiling. |
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48 | * POSIX says block until we acquire it. |
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49 | */ |
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50 | (void) pthread_mutex_lock( mutex ); |
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51 | |
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52 | /* |
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53 | * Do not worry about the return code from this. The Get operation |
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54 | * will also fail if it is a bad id or was deleted between the two |
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55 | * operations. |
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56 | * |
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57 | * NOTE: This makes it easier to get 100% binary coverage since the |
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58 | * bad Id case is handled by the switch. |
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59 | */ |
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60 | the_mutex = _POSIX_Mutex_Get_interrupt_disable( mutex, &lock_context ); |
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61 | |
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62 | if ( the_mutex == NULL ) { |
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63 | return EINVAL; |
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64 | } |
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65 | |
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66 | *old_ceiling = _POSIX_Priority_From_core( |
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67 | the_mutex->Mutex.Attributes.priority_ceiling |
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68 | ); |
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69 | the_mutex->Mutex.Attributes.priority_ceiling = the_priority; |
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70 | |
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71 | /* |
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72 | * We are required to unlock the mutex before we return. |
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73 | */ |
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74 | _CORE_mutex_Surrender( |
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75 | &the_mutex->Mutex, |
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76 | NULL, |
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77 | 0, |
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78 | &lock_context |
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79 | ); |
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80 | return 0; |
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81 | } |
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