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_trace.h"
30 #include "tx_semaphore.h"
31
32
33 /**************************************************************************/
34 /* */
35 /* FUNCTION RELEASE */
36 /* */
37 /* _tx_semaphore_create PORTABLE C */
38 /* 6.1 */
39 /* AUTHOR */
40 /* */
41 /* William E. Lamie, Microsoft Corporation */
42 /* */
43 /* DESCRIPTION */
44 /* */
45 /* This function creates a counting semaphore with the initial count */
46 /* specified in this call. */
47 /* */
48 /* INPUT */
49 /* */
50 /* semaphore_ptr Pointer to semaphore control block*/
51 /* name_ptr Pointer to semaphore name */
52 /* initial_count Initial semaphore count */
53 /* */
54 /* OUTPUT */
55 /* */
56 /* TX_SUCCESS Successful completion status */
57 /* */
58 /* CALLS */
59 /* */
60 /* None */
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_semaphore_create(TX_SEMAPHORE * semaphore_ptr,CHAR * name_ptr,ULONG initial_count)75 UINT _tx_semaphore_create(TX_SEMAPHORE *semaphore_ptr, CHAR *name_ptr, ULONG initial_count)
76 {
77
78 TX_INTERRUPT_SAVE_AREA
79
80 TX_SEMAPHORE *next_semaphore;
81 TX_SEMAPHORE *previous_semaphore;
82
83
84 /* Initialize semaphore control block to all zeros. */
85 TX_MEMSET(semaphore_ptr, 0, (sizeof(TX_SEMAPHORE)));
86
87 /* Setup the basic semaphore fields. */
88 semaphore_ptr -> tx_semaphore_name = name_ptr;
89 semaphore_ptr -> tx_semaphore_count = initial_count;
90
91 /* Disable interrupts to place the semaphore on the created list. */
92 TX_DISABLE
93
94 /* Setup the semaphore ID to make it valid. */
95 semaphore_ptr -> tx_semaphore_id = TX_SEMAPHORE_ID;
96
97 /* Place the semaphore on the list of created semaphores. First,
98 check for an empty list. */
99 if (_tx_semaphore_created_count == TX_EMPTY)
100 {
101
102 /* The created semaphore list is empty. Add semaphore to empty list. */
103 _tx_semaphore_created_ptr = semaphore_ptr;
104 semaphore_ptr -> tx_semaphore_created_next = semaphore_ptr;
105 semaphore_ptr -> tx_semaphore_created_previous = semaphore_ptr;
106 }
107 else
108 {
109
110 /* This list is not NULL, add to the end of the list. */
111 next_semaphore = _tx_semaphore_created_ptr;
112 previous_semaphore = next_semaphore -> tx_semaphore_created_previous;
113
114 /* Place the new semaphore in the list. */
115 next_semaphore -> tx_semaphore_created_previous = semaphore_ptr;
116 previous_semaphore -> tx_semaphore_created_next = semaphore_ptr;
117
118 /* Setup this semaphore's next and previous created links. */
119 semaphore_ptr -> tx_semaphore_created_previous = previous_semaphore;
120 semaphore_ptr -> tx_semaphore_created_next = next_semaphore;
121 }
122
123 /* Increment the created count. */
124 _tx_semaphore_created_count++;
125
126 /* Optional semaphore create extended processing. */
127 TX_SEMAPHORE_CREATE_EXTENSION(semaphore_ptr)
128
129 /* If trace is enabled, register this object. */
130 TX_TRACE_OBJECT_REGISTER(TX_TRACE_OBJECT_TYPE_SEMAPHORE, semaphore_ptr, name_ptr, initial_count, 0)
131
132 /* If trace is enabled, insert this event into the trace buffer. */
133 TX_TRACE_IN_LINE_INSERT(TX_TRACE_SEMAPHORE_CREATE, semaphore_ptr, initial_count, TX_POINTER_TO_ULONG_CONVERT(&next_semaphore), 0, TX_TRACE_SEMAPHORE_EVENTS)
134
135 /* Log this kernel call. */
136 TX_EL_SEMAPHORE_CREATE_INSERT
137
138 /* Restore interrupts. */
139 TX_RESTORE
140
141 /* Return TX_SUCCESS. */
142 return(TX_SUCCESS);
143 }
144
145
