1 | /** |
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2 | * @file |
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3 | * |
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4 | * @brief Allocate resources to use the read-write lock and Initialize 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 | * POSIX RWLock Manager -- Destroy a RWLock Instance |
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10 | * |
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11 | * COPYRIGHT (c) 1989-2006. |
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12 | * On-Line Applications Research Corporation (OAR). |
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13 | * |
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14 | * The license and distribution terms for this file may be |
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15 | * found in the file LICENSE in this distribution or at |
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16 | * http://www.rtems.org/license/LICENSE. |
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17 | */ |
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18 | |
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19 | #if HAVE_CONFIG_H |
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20 | #include "config.h" |
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21 | #endif |
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22 | |
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23 | #include <pthread.h> |
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24 | #include <errno.h> |
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25 | |
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26 | #include <rtems/system.h> |
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27 | #include <rtems/posix/rwlockimpl.h> |
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28 | |
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29 | /* |
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30 | * pthread_rwlock_init |
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31 | * |
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32 | * This directive creates a rwlock. A rwlock id is returned. |
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33 | * |
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34 | * Input parameters: |
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35 | * rwlock - pointer to rwlock id |
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36 | * attr - rwlock attributes |
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37 | * |
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38 | * Output parameters: |
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39 | * rwlock - rwlock id |
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40 | * 0 - if successful |
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41 | * error code - if unsuccessful |
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42 | */ |
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43 | |
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44 | int pthread_rwlock_init( |
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45 | pthread_rwlock_t *rwlock, |
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46 | const pthread_rwlockattr_t *attr |
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47 | ) |
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48 | { |
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49 | POSIX_RWLock_Control *the_rwlock; |
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50 | CORE_RWLock_Attributes the_attributes; |
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51 | pthread_rwlockattr_t default_attr; |
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52 | const pthread_rwlockattr_t *the_attr; |
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53 | |
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54 | /* |
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55 | * Error check parameters |
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56 | */ |
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57 | if ( !rwlock ) |
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58 | return EINVAL; |
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59 | |
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60 | /* |
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61 | * If the user passed in NULL, use the default attributes |
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62 | */ |
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63 | if ( attr ) { |
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64 | the_attr = attr; |
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65 | } else { |
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66 | (void) pthread_rwlockattr_init( &default_attr ); |
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67 | the_attr = &default_attr; |
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68 | } |
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69 | |
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70 | /* |
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71 | * Now start error checking the attributes that we are going to use |
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72 | */ |
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73 | if ( !the_attr->is_initialized ) |
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74 | return EINVAL; |
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75 | |
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76 | switch ( the_attr->process_shared ) { |
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77 | case PTHREAD_PROCESS_PRIVATE: /* only supported values */ |
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78 | break; |
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79 | case PTHREAD_PROCESS_SHARED: |
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80 | default: |
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81 | return EINVAL; |
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82 | } |
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83 | |
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84 | /* |
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85 | * Convert from POSIX attributes to Core RWLock attributes |
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86 | * |
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87 | * NOTE: Currently there are no core rwlock attributes |
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88 | */ |
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89 | _CORE_RWLock_Initialize_attributes( &the_attributes ); |
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90 | |
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91 | the_rwlock = _POSIX_RWLock_Allocate(); |
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92 | |
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93 | if ( !the_rwlock ) { |
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94 | _Objects_Allocator_unlock(); |
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95 | return EAGAIN; |
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96 | } |
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97 | |
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98 | _CORE_RWLock_Initialize( &the_rwlock->RWLock, &the_attributes ); |
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99 | |
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100 | _Objects_Open_u32( |
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101 | &_POSIX_RWLock_Information, |
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102 | &the_rwlock->Object, |
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103 | 0 |
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104 | ); |
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105 | |
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106 | *rwlock = the_rwlock->Object.id; |
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107 | |
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108 | _Objects_Allocator_unlock(); |
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109 | return 0; |
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110 | } |
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