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 /** Queue */
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_trace.h"
30 #include "tx_thread.h"
31 #include "tx_queue.h"
32
33
34 /**************************************************************************/
35 /* */
36 /* FUNCTION RELEASE */
37 /* */
38 /* _tx_queue_flush PORTABLE C */
39 /* 6.1 */
40 /* AUTHOR */
41 /* */
42 /* William E. Lamie, Microsoft Corporation */
43 /* */
44 /* DESCRIPTION */
45 /* */
46 /* This function resets the specified queue, if there are any messages */
47 /* in it. Messages waiting to be placed on the queue are also thrown */
48 /* out. */
49 /* */
50 /* INPUT */
51 /* */
52 /* queue_ptr Pointer to queue control block */
53 /* */
54 /* OUTPUT */
55 /* */
56 /* TX_SUCCESS Successful completion status */
57 /* */
58 /* CALLS */
59 /* */
60 /* _tx_thread_system_preempt_check Check for preemption */
61 /* _tx_thread_system_resume Resume thread service */
62 /* _tx_thread_system_ni_resume Non-interruptable resume thread */
63 /* */
64 /* CALLED BY */
65 /* */
66 /* Application Code */
67 /* */
68 /* RELEASE HISTORY */
69 /* */
70 /* DATE NAME DESCRIPTION */
71 /* */
72 /* 05-19-2020 William E. Lamie Initial Version 6.0 */
73 /* 09-30-2020 Yuxin Zhou Modified comment(s), */
74 /* resulting in version 6.1 */
75 /* */
76 /**************************************************************************/
_tx_queue_flush(TX_QUEUE * queue_ptr)77 UINT _tx_queue_flush(TX_QUEUE *queue_ptr)
78 {
79
80 TX_INTERRUPT_SAVE_AREA
81
82 TX_THREAD *suspension_list;
83 UINT suspended_count;
84 TX_THREAD *thread_ptr;
85
86
87 /* Initialize the suspended count and list. */
88 suspended_count = TX_NO_SUSPENSIONS;
89 suspension_list = TX_NULL;
90
91 /* Disable interrupts to reset various queue parameters. */
92 TX_DISABLE
93
94 /* If trace is enabled, insert this event into the trace buffer. */
95 TX_TRACE_IN_LINE_INSERT(TX_TRACE_QUEUE_FLUSH, queue_ptr, TX_POINTER_TO_ULONG_CONVERT(&thread_ptr), 0, 0, TX_TRACE_QUEUE_EVENTS)
96
97 /* Log this kernel call. */
98 TX_EL_QUEUE_FLUSH_INSERT
99
100 /* Determine if there is something on the queue. */
101 if (queue_ptr -> tx_queue_enqueued != TX_NO_MESSAGES)
102 {
103
104 /* Yes, there is something in the queue. */
105
106 /* Reset the queue parameters to erase all of the queued messages. */
107 queue_ptr -> tx_queue_enqueued = TX_NO_MESSAGES;
108 queue_ptr -> tx_queue_available_storage = queue_ptr -> tx_queue_capacity;
109 queue_ptr -> tx_queue_read = queue_ptr -> tx_queue_start;
110 queue_ptr -> tx_queue_write = queue_ptr -> tx_queue_start;
111
112 /* Now determine if there are any threads suspended on a full queue. */
113 if (queue_ptr -> tx_queue_suspended_count != TX_NO_SUSPENSIONS)
114 {
115
116 /* Yes, there are threads suspended on this queue, they must be
117 resumed! */
118
119 /* Copy the information into temporary variables. */
120 suspension_list = queue_ptr -> tx_queue_suspension_list;
121 suspended_count = queue_ptr -> tx_queue_suspended_count;
122
123 /* Clear the queue variables. */
124 queue_ptr -> tx_queue_suspension_list = TX_NULL;
125 queue_ptr -> tx_queue_suspended_count = TX_NO_SUSPENSIONS;
126
127 /* Temporarily disable preemption. */
128 _tx_thread_preempt_disable++;
129 }
130 }
131
132 /* Restore interrupts. */
133 TX_RESTORE
134
135 /* Walk through the queue list to resume any and all threads suspended
136 on this queue. */
137 if (suspended_count != TX_NO_SUSPENSIONS)
138 {
139
140 /* Pickup the thread to resume. */
141 thread_ptr = suspension_list;
142 while (suspended_count != ((ULONG) 0))
143 {
144
145 /* Decrement the suspension count. */
146 suspended_count--;
147
148 /* Check for a NULL thread pointer. */
149 if (thread_ptr == TX_NULL)
150 {
151
152 /* Get out of the loop. */
153 break;
154 }
155
156 /* Resume the next suspended thread. */
157
158 /* Lockout interrupts. */
159 TX_DISABLE
160
161 /* Clear the cleanup pointer, this prevents the timeout from doing
162 anything. */
163 thread_ptr -> tx_thread_suspend_cleanup = TX_NULL;
164
165 /* Set the return status in the thread to TX_SUCCESS. */
166 thread_ptr -> tx_thread_suspend_status = TX_SUCCESS;
167
168 /* Move the thread pointer ahead. */
169 thread_ptr = thread_ptr -> tx_thread_suspended_next;
170
171 #ifdef TX_NOT_INTERRUPTABLE
172
173 /* Resume the thread! */
174 _tx_thread_system_ni_resume(thread_ptr -> tx_thread_suspended_previous);
175
176 /* Restore interrupts. */
177 TX_RESTORE
178 #else
179
180 /* Temporarily disable preemption again. */
181 _tx_thread_preempt_disable++;
182
183 /* Restore interrupts. */
184 TX_RESTORE
185
186 /* Resume the thread. */
187 _tx_thread_system_resume(thread_ptr -> tx_thread_suspended_previous);
188 #endif
189 }
190
191 /* Disable interrupts. */
192 TX_DISABLE
193
194 /* Restore previous preempt posture. */
195 _tx_thread_preempt_disable--;
196
197 /* Restore interrupts. */
198 TX_RESTORE
199
200 /* Check for preemption. */
201 _tx_thread_system_preempt_check();
202 }
203
204 /* Return TX_SUCCESS. */
205 return(TX_SUCCESS);
206 }
207
208
