1 | /* |
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2 | ------------------------------------------------------------------------ |
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3 | $Id$ |
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4 | ------------------------------------------------------------------------ |
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5 | |
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6 | COPYRIGHT (c) 1997 |
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7 | Objective Design Systems Ltd Pty (ODS) |
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8 | All rights reserved (R) Objective Design Systems Ltd Pty |
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9 | |
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10 | The license and distribution terms for this file may be found in the |
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11 | file LICENSE in this distribution or at |
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12 | http://www.OARcorp.com/rtems/license.html. |
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13 | |
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14 | ------------------------------------------------------------------------ |
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15 | |
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16 | rtemsSemaphore class. |
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17 | |
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18 | This class allows the user to create a RTEMS semaphore, or to use an |
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19 | already existing semaphore. The type of semaphore is decitated by |
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20 | the constructor used. |
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21 | |
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22 | The first constructor with the semaphore parameters creates a RTEMS |
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23 | semaphore object. The destructor of this object also deletes the |
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24 | semaphore object. The last status code should be checked after |
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25 | construction to see if the semaphore create was successfull. |
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26 | |
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27 | The second constructor connects to an existing. The last status code |
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28 | should be checked after construction to see if the semaphore |
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29 | existed. |
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30 | |
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31 | The third constructor is a copy constructor. Connects to an existing |
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32 | object which is in scope. |
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33 | |
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34 | ------------------------------------------------------------------------ */ |
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35 | |
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36 | #if !defined(_rtemsSemaphore_h_) |
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37 | #define _rtemsSemaphore_h_ |
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38 | |
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39 | #include <rtems++/rtemsStatusCode.h> |
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40 | |
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41 | /* ---- |
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42 | rtemsSemaphore |
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43 | */ |
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44 | |
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45 | class rtemsSemaphore |
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46 | : public rtemsStatusCode |
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47 | { |
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48 | public: |
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49 | // attribute a semaphore can have |
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50 | enum WaitMode { wait_by_fifo = RTEMS_FIFO, |
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51 | wait_by_priority = RTEMS_PRIORITY }; |
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52 | enum Type { binary = RTEMS_BINARY_SEMAPHORE, |
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53 | counting = RTEMS_COUNTING_SEMAPHORE }; |
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54 | enum Priority { no_priority_inherit = RTEMS_NO_INHERIT_PRIORITY, |
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55 | inherit_priority = RTEMS_INHERIT_PRIORITY }; |
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56 | enum Ceiling { no_priority_ceiling = RTEMS_NO_PRIORITY_CEILING, |
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57 | priority_ceiling = RTEMS_PRIORITY_CEILING }; |
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58 | enum Scope { local = RTEMS_LOCAL, |
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59 | global = RTEMS_GLOBAL }; |
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60 | |
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61 | // only the first 4 characters of the name are taken, |
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62 | // the counter must be set to 1 for binary semaphores |
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63 | |
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64 | // create a semaphore object |
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65 | rtemsSemaphore(const char* name, |
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66 | const Scope scope = local, |
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67 | const rtems_unsigned32 counter = 1, |
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68 | const WaitMode wait_mode = wait_by_fifo, |
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69 | const Type type = binary, |
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70 | const Priority priority = no_priority_inherit, |
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71 | const Ceiling ceiling = no_priority_ceiling, |
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72 | const rtems_task_priority priority_ceiling = 0); |
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73 | |
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74 | // connect to an existing semaphore object by name |
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75 | rtemsSemaphore(const char *name, const rtems_unsigned32 node); |
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76 | |
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77 | // attach this object to an other objects semaphore |
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78 | rtemsSemaphore(const rtemsSemaphore& semaphore); |
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79 | rtemsSemaphore(); |
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80 | |
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81 | // only the creator's destructor will delete the actual object |
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82 | virtual ~rtemsSemaphore(); |
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83 | |
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84 | // create or destroy (delete) a semaphore |
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85 | virtual const rtems_status_code create(const char* name, |
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86 | const Scope scope = local, |
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87 | const rtems_unsigned32 counter = 1, |
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88 | const WaitMode wait_mode = wait_by_fifo, |
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89 | const Type type = binary, |
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90 | const Priority priority = no_priority_inherit, |
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91 | const Ceiling ceiling = no_priority_ceiling, |
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92 | const rtems_task_priority priority_ceiling = 0); |
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93 | virtual const rtems_status_code destroy(); |
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94 | |
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95 | // connect to an existing semaphore object, will not be the owner |
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96 | const rtemsSemaphore& operator=(const rtemsSemaphore& semaphore); |
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97 | virtual const rtems_status_code connect(const char *name, rtems_unsigned32 node); |
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98 | |
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99 | // obtain the semaphore, timeout is in micro-seconds |
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100 | inline const rtems_status_code obtain(bool wait = true, |
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101 | const rtems_unsigned32 micro_secs = RTEMS_NO_TIMEOUT); |
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102 | |
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103 | // release the semaphore, blocks threads eligble |
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104 | inline const rtems_status_code release(); |
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105 | |
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106 | // object id, and name |
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107 | const rtems_id id_is() const { return id; } |
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108 | const rtems_name name_is() const { return name; } |
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109 | const char *name_string() const { return name_str; } |
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110 | |
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111 | private: |
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112 | |
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113 | // make the object reference no valid RTEMS object |
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114 | void make_invalid(); |
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115 | |
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116 | // semaphore name |
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117 | rtems_name name; |
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118 | char name_str[5]; |
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119 | |
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120 | // owner, true if this object owns the semaphore |
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121 | // will delete the semaphore when it destructs |
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122 | bool owner; |
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123 | |
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124 | // the rtems id, object handle |
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125 | rtems_id id; |
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126 | }; |
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127 | |
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128 | const rtems_status_code rtemsSemaphore::obtain(const bool wait, |
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129 | const rtems_unsigned32 micro_secs) |
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130 | { |
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131 | rtems_interval usecs = |
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132 | micro_secs && (micro_secs < _TOD_Microseconds_per_tick) ? |
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133 | _TOD_Microseconds_per_tick : micro_secs; |
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134 | return |
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135 | set_status_code(rtems_semaphore_obtain(id, |
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136 | wait ? RTEMS_WAIT : RTEMS_NO_WAIT, |
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137 | TOD_MICROSECONDS_TO_TICKS(usecs))); |
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138 | } |
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139 | |
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140 | const rtems_status_code rtemsSemaphore::release(void) |
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141 | { |
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142 | return set_status_code(rtems_semaphore_release(id)); |
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143 | } |
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144 | |
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145 | #endif // _rtemsSemaphore_h_ |
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