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 /** POSIX wrapper for THREADX */
17 /** */
18 /** */
19 /** */
20 /**************************************************************************/
21 /**************************************************************************/
22
23 /* Include necessary system files. */
24
25 #include "tx_api.h" /* Threadx API */
26 #include "pthread.h" /* Posix API */
27 #include "px_int.h" /* Posix helper functions */
28
29
30 /**************************************************************************/
31 /* */
32 /* FUNCTION RELEASE */
33 /* */
34 /* posix_get_new_queue PORTABLE C */
35 /* 6.1.7 */
36 /* AUTHOR */
37 /* */
38 /* William E. Lamie, Microsoft Corporation */
39 /* */
40 /* DESCRIPTION */
41 /* */
42 /* This function attempts to build a ThreadX message queue */
43 /* for variable length message queues */
44 /* */
45 /* INPUT */
46 /* */
47 /* maxnum Number of queue entries */
48 /* */
49 /* OUTPUT */
50 /* */
51 /* q_ptr Pointer to posix queue */
52 /* */
53 /* CALLS */
54 /* */
55 /* posix_memory_allocate Memory allocate */
56 /* posix_memory_release Memory free */
57 /* */
58 /* CALLED BY */
59 /* */
60 /* POSIX internal Code */
61 /* */
62 /* RELEASE HISTORY */
63 /* */
64 /* DATE NAME DESCRIPTION */
65 /* */
66 /* 06-02-2021 William E. Lamie Initial Version 6.1.7 */
67 /* */
68 /**************************************************************************/
posix_get_new_queue(ULONG maxnum)69 POSIX_MSG_QUEUE * posix_get_new_queue(ULONG maxnum)
70 {
71
72 ULONG i;
73 POSIX_MSG_QUEUE *q_ptr;
74 VOID *bp;
75 INT retval;
76 ULONG size;
77
78
79 /* Determine how much memory we need for the queue.
80 The queue holds "maxnum" entries; each entry is 2 ULONG. */
81 size = (maxnum * (TX_4_ULONG * sizeof(ULONG)));
82
83 /* Now attempt to allocate memory for the queue. */
84 retval = posix_memory_allocate(size, &bp);
85
86 /* Make sure we obtained the memory we requested. */
87 if (retval)
88 {
89 return((POSIX_MSG_QUEUE *)NULL);
90 }
91 /* Loop through the list of queues - */
92 /* try to find one that is not "in use". */
93 /* Search the queue pool for an available queue. */
94 for (i = 0, q_ptr = &(posix_queue_pool[0]);
95 i < POSIX_MAX_QUEUES;
96 i++, q_ptr++)
97 {
98 /* Make sure the queue is not "in use". */
99 if (q_ptr->in_use == TX_FALSE)
100 {
101 /* This queue is now in use. */
102 q_ptr->in_use = TX_TRUE;
103
104 /* Point to allocated memory. */
105 q_ptr->storage = bp;
106
107 q_ptr->px_queue_id = PX_QUEUE_ID;
108
109 /* Stop searching. */
110 break;
111 }
112 }
113 /* If we didn't find a free queue, free the allocated memory. */
114 if ( i >= POSIX_MAX_QUEUES)
115 {
116 posix_memory_release(bp);
117 return((POSIX_MSG_QUEUE *)0);
118 }
119 /* Return home. */
120 return(q_ptr);
121 }
122
