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 /** Thread */
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 #ifndef TX_NO_TIMER
32 #include "tx_timer.h"
33 #endif
34
35
36 /**************************************************************************/
37 /* */
38 /* FUNCTION RELEASE */
39 /* */
40 /* _tx_thread_relinquish PORTABLE C */
41 /* 6.1 */
42 /* AUTHOR */
43 /* */
44 /* William E. Lamie, Microsoft Corporation */
45 /* */
46 /* DESCRIPTION */
47 /* */
48 /* This function moves the currently executing thread to the end of */
49 /* the list of threads ready at the same priority. If no other threads */
50 /* of the same or higher priority are ready, this function simply */
51 /* returns. */
52 /* */
53 /* INPUT */
54 /* */
55 /* None */
56 /* */
57 /* OUTPUT */
58 /* */
59 /* None */
60 /* */
61 /* CALLS */
62 /* */
63 /* _tx_thread_system_return Return to the system */
64 /* */
65 /* CALLED BY */
66 /* */
67 /* Application Code */
68 /* */
69 /* RELEASE HISTORY */
70 /* */
71 /* DATE NAME DESCRIPTION */
72 /* */
73 /* 05-19-2020 William E. Lamie Initial Version 6.0 */
74 /* 09-30-2020 Yuxin Zhou Modified comment(s), */
75 /* resulting in version 6.1 */
76 /* */
77 /**************************************************************************/
_tx_thread_relinquish(VOID)78 VOID _tx_thread_relinquish(VOID)
79 {
80
81 TX_INTERRUPT_SAVE_AREA
82
83 UINT priority;
84 TX_THREAD *thread_ptr;
85
86
87 /* Pickup thread pointer. */
88 TX_THREAD_GET_CURRENT(thread_ptr)
89
90 #ifdef TX_ENABLE_STACK_CHECKING
91
92 /* Check this thread's stack. */
93 TX_THREAD_STACK_CHECK(thread_ptr)
94 #endif
95
96 /* Disable interrupts. */
97 TX_DISABLE
98
99 #ifndef TX_NO_TIMER
100
101 /* Reset time slice for current thread. */
102 _tx_timer_time_slice = thread_ptr -> tx_thread_new_time_slice;
103 #endif
104
105 /* Pickup the thread's priority. */
106 priority = thread_ptr -> tx_thread_priority;
107
108 /* Determine if there is another thread at the same priority. */
109 if (thread_ptr -> tx_thread_ready_next != thread_ptr)
110 {
111
112 /* Yes, there is another thread at this priority, make it the highest at
113 this priority level. */
114 _tx_thread_priority_list[priority] = thread_ptr -> tx_thread_ready_next;
115
116 /* Mark the new thread as the one to execute. */
117 _tx_thread_execute_ptr = thread_ptr -> tx_thread_ready_next;
118 }
119
120 /* Determine if there is a higher-priority thread ready. */
121 if (_tx_thread_highest_priority < priority)
122 {
123
124 /* Yes, there is a higher priority thread ready to execute. Make
125 it visible to the thread scheduler. */
126 _tx_thread_execute_ptr = _tx_thread_priority_list[_tx_thread_highest_priority];
127
128 /* No need to clear the preempted bit in this case, since the currently running
129 thread must already have its preempted bit clear. */
130 }
131
132 /* If trace is enabled, insert this event into the trace buffer. */
133 TX_TRACE_IN_LINE_INSERT(TX_TRACE_THREAD_RELINQUISH, &thread_ptr, TX_POINTER_TO_ULONG_CONVERT(_tx_thread_execute_ptr), 0, 0, TX_TRACE_THREAD_EVENTS)
134
135 /* Log this kernel call. */
136 TX_EL_THREAD_RELINQUISH_INSERT
137
138 /* Restore previous interrupt posture. */
139 TX_RESTORE
140
141 /* Determine if this thread needs to return to the system. */
142 if (_tx_thread_execute_ptr != thread_ptr)
143 {
144
145 #ifdef TX_THREAD_ENABLE_PERFORMANCE_INFO
146
147 /* Increment the number of thread relinquishes. */
148 thread_ptr -> tx_thread_performance_relinquish_count++;
149
150 /* Increment the total number of thread relinquish operations. */
151 _tx_thread_performance_relinquish_count++;
152
153 /* Increment the non-idle return count. */
154 _tx_thread_performance_non_idle_return_count++;
155 #endif
156
157 #ifdef TX_ENABLE_STACK_CHECKING
158
159 /* Pickup the next execute pointer. */
160 thread_ptr = _tx_thread_execute_ptr;
161
162 /* Check this thread's stack. */
163 TX_THREAD_STACK_CHECK(thread_ptr)
164 #endif
165
166 /* Transfer control to the system so the scheduler can execute
167 the next thread. */
168 _tx_thread_system_return();
169 }
170 }
171
172
