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_initialize.h"
30 #include "tx_thread.h"
31 #include "tx_timer.h"
32 #include "tx_semaphore.h"
33
34
35 /**************************************************************************/
36 /* */
37 /* FUNCTION RELEASE */
38 /* */
39 /* _txe_semaphore_create PORTABLE C */
40 /* 6.1 */
41 /* AUTHOR */
42 /* */
43 /* William E. Lamie, Microsoft Corporation */
44 /* */
45 /* DESCRIPTION */
46 /* */
47 /* This function checks for errors in the create semaphore function */
48 /* call. */
49 /* */
50 /* INPUT */
51 /* */
52 /* semaphore_ptr Pointer to semaphore control block*/
53 /* name_ptr Pointer to semaphore name */
54 /* initial_count Initial semaphore count */
55 /* semaphore_control_block_size Size of semaphore control block */
56 /* */
57 /* OUTPUT */
58 /* */
59 /* TX_SEMAPHORE_ERROR Invalid semaphore pointer */
60 /* TX_CALLER_ERROR Invalid caller of this function */
61 /* status Actual completion status */
62 /* */
63 /* CALLS */
64 /* */
65 /* _tx_semaphore_create Actual create semaphore function */
66 /* _tx_thread_system_preempt_check Check for preemption */
67 /* */
68 /* CALLED BY */
69 /* */
70 /* Application Code */
71 /* */
72 /* RELEASE HISTORY */
73 /* */
74 /* DATE NAME DESCRIPTION */
75 /* */
76 /* 05-19-2020 William E. Lamie Initial Version 6.0 */
77 /* 09-30-2020 Yuxin Zhou Modified comment(s), */
78 /* resulting in version 6.1 */
79 /* */
80 /**************************************************************************/
_txe_semaphore_create(TX_SEMAPHORE * semaphore_ptr,CHAR * name_ptr,ULONG initial_count,UINT semaphore_control_block_size)81 UINT _txe_semaphore_create(TX_SEMAPHORE *semaphore_ptr, CHAR *name_ptr, ULONG initial_count, UINT semaphore_control_block_size)
82 {
83
84 TX_INTERRUPT_SAVE_AREA
85
86 UINT status;
87 ULONG i;
88 TX_SEMAPHORE *next_semaphore;
89 #ifndef TX_TIMER_PROCESS_IN_ISR
90 TX_THREAD *thread_ptr;
91 #endif
92
93
94 /* Default status to success. */
95 status = TX_SUCCESS;
96
97 /* Check for an invalid semaphore pointer. */
98 if (semaphore_ptr == TX_NULL)
99 {
100
101 /* Semaphore pointer is invalid, return appropriate error code. */
102 status = TX_SEMAPHORE_ERROR;
103 }
104
105 /* Now check for a valid semaphore ID. */
106 else if (semaphore_control_block_size != (sizeof(TX_SEMAPHORE)))
107 {
108
109 /* Semaphore pointer is invalid, return appropriate error code. */
110 status = TX_SEMAPHORE_ERROR;
111 }
112 else
113 {
114
115 /* Disable interrupts. */
116 TX_DISABLE
117
118 /* Increment the preempt disable flag. */
119 _tx_thread_preempt_disable++;
120
121 /* Restore interrupts. */
122 TX_RESTORE
123
124 /* Next see if it is already in the created list. */
125 next_semaphore = _tx_semaphore_created_ptr;
126 for (i = ((ULONG) 0); i < _tx_semaphore_created_count; i++)
127 {
128
129 /* Determine if this semaphore matches the current semaphore in the list. */
130 if (semaphore_ptr == next_semaphore)
131 {
132
133 break;
134 }
135 else
136 {
137
138 /* Move to next semaphore. */
139 next_semaphore = next_semaphore -> tx_semaphore_created_next;
140 }
141 }
142
143 /* Disable interrupts. */
144 TX_DISABLE
145
146 /* Decrement the preempt disable flag. */
147 _tx_thread_preempt_disable--;
148
149 /* Restore interrupts. */
150 TX_RESTORE
151
152 /* Check for preemption. */
153 _tx_thread_system_preempt_check();
154
155 /* At this point, check to see if there is a duplicate semaphore. */
156 if (semaphore_ptr == next_semaphore)
157 {
158
159 /* Semaphore is already created, return appropriate error code. */
160 status = TX_SEMAPHORE_ERROR;
161 }
162
163 #ifndef TX_TIMER_PROCESS_IN_ISR
164 else
165 {
166
167 /* Pickup thread pointer. */
168 TX_THREAD_GET_CURRENT(thread_ptr)
169
170 /* Check for invalid caller of this function. First check for a calling thread. */
171 if (thread_ptr == &_tx_timer_thread)
172 {
173
174 /* Invalid caller of this function, return appropriate error code. */
175 status = TX_CALLER_ERROR;
176 }
177 }
178 #endif
179 }
180
181 /* Determine if everything is okay. */
182 if (status == TX_SUCCESS)
183 {
184
185 /* Check for interrupt call. */
186 if (TX_THREAD_GET_SYSTEM_STATE() != ((ULONG) 0))
187 {
188
189 /* Now, make sure the call is from an interrupt and not initialization. */
190 if (TX_THREAD_GET_SYSTEM_STATE() < TX_INITIALIZE_IN_PROGRESS)
191 {
192
193 /* Invalid caller of this function, return appropriate error code. */
194 status = TX_CALLER_ERROR;
195 }
196 }
197 }
198
199 /* Determine if everything is okay. */
200 if (status == TX_SUCCESS)
201 {
202
203 /* Call actual semaphore create function. */
204 status = _tx_semaphore_create(semaphore_ptr, name_ptr, initial_count);
205 }
206
207 /* Return completion status. */
208 return(status);
209 }
210
211
