1 /**************************************************************************/ 2 /* */ 3 /* Copyright (c) Microsoft Corporation. All rights reserved. */ 4 /* */ 5 /* This software is licensed under the Microsoft Software License */ 6 /* Terms for Microsoft Azure RTOS. Full text of the license can be */ 7 /* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */ 8 /* and in the root directory of this software. */ 9 /* */ 10 /**************************************************************************/ 11 12 13 /**************************************************************************/ 14 /**************************************************************************/ 15 /** */ 16 /** ThreadX Component */ 17 /** */ 18 /** Semaphore */ 19 /** */ 20 /**************************************************************************/ 21 /**************************************************************************/ 22 23 #define TX_SOURCE_CODE 24 25 26 /* Include necessary system files. */ 27 28 #include "tx_api.h" 29 #include "tx_thread.h" 30 #include "tx_timer.h" 31 #include "tx_semaphore.h" 32 33 34 /**************************************************************************/ 35 /* */ 36 /* FUNCTION RELEASE */ 37 /* */ 38 /* _txe_semaphore_get PORTABLE C */ 39 /* 6.1 */ 40 /* AUTHOR */ 41 /* */ 42 /* William E. Lamie, Microsoft Corporation */ 43 /* */ 44 /* DESCRIPTION */ 45 /* */ 46 /* This function checks for errors in the semaphore get function call. */ 47 /* */ 48 /* INPUT */ 49 /* */ 50 /* semaphore_ptr Pointer to semaphore control block*/ 51 /* wait_option Suspension option */ 52 /* */ 53 /* OUTPUT */ 54 /* */ 55 /* TX_SEMAPHORE_ERROR Invalid semaphore pointer */ 56 /* TX_WAIT_ERROR Invalid wait option */ 57 /* status Actual completion status */ 58 /* */ 59 /* CALLS */ 60 /* */ 61 /* _tx_semaphore_get Actual get semaphore function */ 62 /* */ 63 /* CALLED BY */ 64 /* */ 65 /* Application Code */ 66 /* */ 67 /* RELEASE HISTORY */ 68 /* */ 69 /* DATE NAME DESCRIPTION */ 70 /* */ 71 /* 05-19-2020 William E. Lamie Initial Version 6.0 */ 72 /* 09-30-2020 Yuxin Zhou Modified comment(s), */ 73 /* resulting in version 6.1 */ 74 /* */ 75 /**************************************************************************/ _txe_semaphore_get(TX_SEMAPHORE * semaphore_ptr,ULONG wait_option)76UINT _txe_semaphore_get(TX_SEMAPHORE *semaphore_ptr, ULONG wait_option) 77 { 78 79 UINT status; 80 81 #ifndef TX_TIMER_PROCESS_IN_ISR 82 TX_THREAD *current_thread; 83 #endif 84 85 86 /* Default status to success. */ 87 status = TX_SUCCESS; 88 89 /* Check for an invalid semaphore pointer. */ 90 if (semaphore_ptr == TX_NULL) 91 { 92 93 /* Semaphore pointer is invalid, return appropriate error code. */ 94 status = TX_SEMAPHORE_ERROR; 95 } 96 97 /* Now check for invalid semaphore ID. */ 98 else if (semaphore_ptr -> tx_semaphore_id != TX_SEMAPHORE_ID) 99 { 100 101 /* Semaphore pointer is invalid, return appropriate error code. */ 102 status = TX_SEMAPHORE_ERROR; 103 } 104 else 105 { 106 107 /* Check for a wait option error. Only threads are allowed any form of 108 suspension. */ 109 if (wait_option != TX_NO_WAIT) 110 { 111 112 /* Is the call from an ISR or Initialization? */ 113 if (TX_THREAD_GET_SYSTEM_STATE() != ((ULONG) 0)) 114 { 115 116 /* A non-thread is trying to suspend, return appropriate error code. */ 117 status = TX_WAIT_ERROR; 118 } 119 120 #ifndef TX_TIMER_PROCESS_IN_ISR 121 else 122 { 123 124 /* Pickup thread pointer. */ 125 TX_THREAD_GET_CURRENT(current_thread) 126 127 /* Is the current thread the timer thread? */ 128 if (current_thread == &_tx_timer_thread) 129 { 130 131 /* A non-thread is trying to suspend, return appropriate error code. */ 132 status = TX_WAIT_ERROR; 133 } 134 } 135 #endif 136 } 137 } 138 139 /* Determine if everything is okay. */ 140 if (status == TX_SUCCESS) 141 { 142 143 /* Call actual get semaphore function. */ 144 status = _tx_semaphore_get(semaphore_ptr, wait_option); 145 } 146 147 /* Return completion status. */ 148 return(status); 149 } 150 151
