[7cc8d6c] | 1 | /* |
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| 2 | * CORE Semaphore Handler |
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| 3 | * |
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| 4 | * DESCRIPTION: |
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| 5 | * |
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| 6 | * This package is the implementation of the CORE Semaphore Handler. |
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| 7 | * This core object utilizes standard Dijkstra counting semaphores to provide |
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| 8 | * synchronization and mutual exclusion capabilities. |
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| 9 | * |
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[08311cc3] | 10 | * COPYRIGHT (c) 1989-1999. |
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[7cc8d6c] | 11 | * On-Line Applications Research Corporation (OAR). |
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| 12 | * |
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| 13 | * The license and distribution terms for this file may be |
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| 14 | * found in the file LICENSE in this distribution or at |
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| 15 | * http://www.OARcorp.com/rtems/license.html. |
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| 16 | * |
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| 17 | * $Id$ |
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| 18 | */ |
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| 19 | |
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| 20 | #include <rtems/system.h> |
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| 21 | #include <rtems/score/isr.h> |
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| 22 | #include <rtems/score/coresem.h> |
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| 23 | #include <rtems/score/states.h> |
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| 24 | #include <rtems/score/thread.h> |
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| 25 | #include <rtems/score/threadq.h> |
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| 26 | #if defined(RTEMS_MULTIPROCESSING) |
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| 27 | #include <rtems/score/mpci.h> |
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| 28 | #endif |
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| 29 | |
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| 30 | /*PAGE |
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| 31 | * |
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| 32 | * _CORE_semaphore_Surrender |
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| 33 | * |
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| 34 | * Input parameters: |
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| 35 | * the_semaphore - the semaphore to be flushed |
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| 36 | * id - id of parent semaphore |
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| 37 | * api_semaphore_mp_support - api dependent MP support actions |
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| 38 | * |
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| 39 | * Output parameters: |
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| 40 | * CORE_SEMAPHORE_STATUS_SUCCESSFUL - if successful |
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| 41 | * core error code - if unsuccessful |
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| 42 | * |
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| 43 | * Output parameters: |
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| 44 | */ |
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| 45 | |
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| 46 | CORE_semaphore_Status _CORE_semaphore_Surrender( |
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| 47 | CORE_semaphore_Control *the_semaphore, |
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| 48 | Objects_Id id, |
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| 49 | CORE_semaphore_API_mp_support_callout api_semaphore_mp_support |
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| 50 | ) |
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| 51 | { |
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| 52 | Thread_Control *the_thread; |
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| 53 | ISR_Level level; |
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| 54 | CORE_semaphore_Status status; |
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| 55 | |
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| 56 | status = CORE_SEMAPHORE_STATUS_SUCCESSFUL; |
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| 57 | |
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| 58 | if ( (the_thread = _Thread_queue_Dequeue(&the_semaphore->Wait_queue)) ) { |
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| 59 | |
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| 60 | if ( !_Objects_Is_local_id( the_thread->Object.id ) ) |
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| 61 | (*api_semaphore_mp_support) ( the_thread, id ); |
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| 62 | |
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| 63 | } else { |
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| 64 | _ISR_Disable( level ); |
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| 65 | if ( the_semaphore->count <= the_semaphore->Attributes.maximum_count ) |
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| 66 | the_semaphore->count += 1; |
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| 67 | else |
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| 68 | status = CORE_SEMAPHORE_MAXIMUM_COUNT_EXCEEDED; |
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| 69 | _ISR_Enable( level ); |
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| 70 | } |
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| 71 | |
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| 72 | return status; |
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| 73 | } |
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| 74 | |
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