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 /** Block Pool */
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_block_pool.h"
32
33
34 /**************************************************************************/
35 /* */
36 /* FUNCTION RELEASE */
37 /* */
38 /* _tx_block_release PORTABLE C */
39 /* 6.1 */
40 /* AUTHOR */
41 /* */
42 /* William E. Lamie, Microsoft Corporation */
43 /* */
44 /* DESCRIPTION */
45 /* */
46 /* This function returns a previously allocated block to its */
47 /* associated memory block pool. */
48 /* */
49 /* INPUT */
50 /* */
51 /* block_ptr Pointer to memory block */
52 /* */
53 /* OUTPUT */
54 /* */
55 /* TX_SUCCESS Successful completion status */
56 /* */
57 /* CALLS */
58 /* */
59 /* _tx_thread_system_resume Resume thread service */
60 /* _tx_thread_system_ni_resume Non-interruptable resume thread */
61 /* */
62 /* CALLED BY */
63 /* */
64 /* Application Code */
65 /* */
66 /* RELEASE HISTORY */
67 /* */
68 /* DATE NAME DESCRIPTION */
69 /* */
70 /* 05-19-2020 William E. Lamie Initial Version 6.0 */
71 /* 09-30-2020 Yuxin Zhou Modified comment(s), */
72 /* resulting in version 6.1 */
73 /* */
74 /**************************************************************************/
_tx_block_release(VOID * block_ptr)75 UINT _tx_block_release(VOID *block_ptr)
76 {
77
78 TX_INTERRUPT_SAVE_AREA
79
80 TX_BLOCK_POOL *pool_ptr;
81 TX_THREAD *thread_ptr;
82 UCHAR *work_ptr;
83 UCHAR **return_block_ptr;
84 UCHAR **next_block_ptr;
85 UINT suspended_count;
86 TX_THREAD *next_thread;
87 TX_THREAD *previous_thread;
88
89
90 /* Disable interrupts to put this block back in the pool. */
91 TX_DISABLE
92
93 /* Pickup the pool pointer which is just previous to the starting
94 address of the block that the caller sees. */
95 work_ptr = TX_VOID_TO_UCHAR_POINTER_CONVERT(block_ptr);
96 work_ptr = TX_UCHAR_POINTER_SUB(work_ptr, (sizeof(UCHAR *)));
97 next_block_ptr = TX_UCHAR_TO_INDIRECT_UCHAR_POINTER_CONVERT(work_ptr);
98 pool_ptr = TX_UCHAR_TO_BLOCK_POOL_POINTER_CONVERT((*next_block_ptr));
99
100 #ifdef TX_BLOCK_POOL_ENABLE_PERFORMANCE_INFO
101
102 /* Increment the total releases counter. */
103 _tx_block_pool_performance_release_count++;
104
105 /* Increment the number of releases on this pool. */
106 pool_ptr -> tx_block_pool_performance_release_count++;
107 #endif
108
109 /* If trace is enabled, insert this event into the trace buffer. */
110 TX_TRACE_IN_LINE_INSERT(TX_TRACE_BLOCK_RELEASE, pool_ptr, TX_POINTER_TO_ULONG_CONVERT(block_ptr), pool_ptr -> tx_block_pool_suspended_count, TX_POINTER_TO_ULONG_CONVERT(&work_ptr), TX_TRACE_BLOCK_POOL_EVENTS)
111
112 /* Log this kernel call. */
113 TX_EL_BLOCK_RELEASE_INSERT
114
115 /* Determine if there are any threads suspended on the block pool. */
116 thread_ptr = pool_ptr -> tx_block_pool_suspension_list;
117 if (thread_ptr != TX_NULL)
118 {
119
120 /* Remove the suspended thread from the list. */
121
122 /* Decrement the number of threads suspended. */
123 (pool_ptr -> tx_block_pool_suspended_count)--;
124
125 /* Pickup the suspended count. */
126 suspended_count = (pool_ptr -> tx_block_pool_suspended_count);
127
128 /* See if this is the only suspended thread on the list. */
129 if (suspended_count == TX_NO_SUSPENSIONS)
130 {
131
132 /* Yes, the only suspended thread. */
133
134 /* Update the head pointer. */
135 pool_ptr -> tx_block_pool_suspension_list = TX_NULL;
136 }
137 else
138 {
139
140 /* At least one more thread is on the same expiration list. */
141
142 /* Update the list head pointer. */
143 next_thread = thread_ptr -> tx_thread_suspended_next;
144 pool_ptr -> tx_block_pool_suspension_list = next_thread;
145
146 /* Update the links of the adjacent threads. */
147 previous_thread = thread_ptr -> tx_thread_suspended_previous;
148 next_thread -> tx_thread_suspended_previous = previous_thread;
149 previous_thread -> tx_thread_suspended_next = next_thread;
150 }
151
152 /* Prepare for resumption of the first thread. */
153
154 /* Clear cleanup routine to avoid timeout. */
155 thread_ptr -> tx_thread_suspend_cleanup = TX_NULL;
156
157 /* Return this block pointer to the suspended thread waiting for
158 a block. */
159 return_block_ptr = TX_VOID_TO_INDIRECT_UCHAR_POINTER_CONVERT(thread_ptr -> tx_thread_additional_suspend_info);
160 work_ptr = TX_VOID_TO_UCHAR_POINTER_CONVERT(block_ptr);
161 *return_block_ptr = work_ptr;
162
163 /* Put return status into the thread control block. */
164 thread_ptr -> tx_thread_suspend_status = TX_SUCCESS;
165
166 #ifdef TX_NOT_INTERRUPTABLE
167
168 /* Resume the thread! */
169 _tx_thread_system_ni_resume(thread_ptr);
170
171 /* Restore interrupts. */
172 TX_RESTORE
173 #else
174
175 /* Temporarily disable preemption. */
176 _tx_thread_preempt_disable++;
177
178 /* Restore interrupts. */
179 TX_RESTORE
180
181 /* Resume thread. */
182 _tx_thread_system_resume(thread_ptr);
183 #endif
184 }
185 else
186 {
187
188 /* No thread is suspended for a memory block. */
189
190 /* Put the block back in the available list. */
191 *next_block_ptr = pool_ptr -> tx_block_pool_available_list;
192
193 /* Adjust the head pointer. */
194 pool_ptr -> tx_block_pool_available_list = work_ptr;
195
196 /* Increment the count of available blocks. */
197 pool_ptr -> tx_block_pool_available++;
198
199 /* Restore interrupts. */
200 TX_RESTORE
201 }
202
203 /* Return successful completion status. */
204 return(TX_SUCCESS);
205 }
206
207
