1 | /* |
---|
2 | * @file |
---|
3 | * |
---|
4 | * @brief Get Object |
---|
5 | * @ingroup Score |
---|
6 | */ |
---|
7 | |
---|
8 | /* |
---|
9 | * COPYRIGHT (c) 1989-1999. |
---|
10 | * On-Line Applications Research Corporation (OAR). |
---|
11 | * |
---|
12 | * The license and distribution terms for this file may be |
---|
13 | * found in the file LICENSE in this distribution or at |
---|
14 | * http://www.rtems.org/license/LICENSE. |
---|
15 | */ |
---|
16 | |
---|
17 | #if HAVE_CONFIG_H |
---|
18 | #include "config.h" |
---|
19 | #endif |
---|
20 | |
---|
21 | #include <rtems/score/objectimpl.h> |
---|
22 | |
---|
23 | Objects_Control *_Objects_Get( |
---|
24 | Objects_Information *information, |
---|
25 | Objects_Id id, |
---|
26 | Objects_Locations *location |
---|
27 | ) |
---|
28 | { |
---|
29 | Objects_Control *the_object; |
---|
30 | uint32_t index; |
---|
31 | |
---|
32 | /* |
---|
33 | * Extract the index portion of an Id in a way that produces a valid |
---|
34 | * index for objects within this class and an invalid value for objects |
---|
35 | * outside this class. |
---|
36 | * |
---|
37 | * If the Id matches the api, class, and node but index portion is 0, |
---|
38 | * then the subtraction will underflow and the addition of 1 will |
---|
39 | * result in a 0 index. The zeroth element in the local_table is |
---|
40 | * always NULL. |
---|
41 | * |
---|
42 | * If the Id is valid but the object has not been created yet, then |
---|
43 | * the local_table entry will be NULL. |
---|
44 | */ |
---|
45 | index = id - information->minimum_id + 1; |
---|
46 | |
---|
47 | /* |
---|
48 | * If the index is less than maximum, then it is OK to use it to |
---|
49 | * index into the local_table array. |
---|
50 | */ |
---|
51 | if ( index <= information->maximum ) { |
---|
52 | _Thread_Disable_dispatch(); |
---|
53 | if ( (the_object = information->local_table[ index ]) != NULL ) { |
---|
54 | *location = OBJECTS_LOCAL; |
---|
55 | return the_object; |
---|
56 | } |
---|
57 | |
---|
58 | /* |
---|
59 | * Valid Id for this API, Class and Node but the object has not |
---|
60 | * been allocated yet. |
---|
61 | */ |
---|
62 | _Thread_Enable_dispatch(); |
---|
63 | *location = OBJECTS_ERROR; |
---|
64 | return NULL; |
---|
65 | } |
---|
66 | |
---|
67 | /* |
---|
68 | * Object Id is not within this API and Class on this node. So |
---|
69 | * it may be global in a multiprocessing system. But it is clearly |
---|
70 | * invalid on a single processor system. |
---|
71 | */ |
---|
72 | *location = OBJECTS_ERROR; |
---|
73 | |
---|
74 | #if defined(RTEMS_MULTIPROCESSING) |
---|
75 | _Objects_MP_Is_remote( information, id, location, &the_object ); |
---|
76 | return the_object; |
---|
77 | #else |
---|
78 | return NULL; |
---|
79 | #endif |
---|
80 | } |
---|