[4dc89814] | 1 | /* |
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| 2 | * NOTE: The structure of the routines is identical to that of POSIX |
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| 3 | * Message_queues to leave the option of having unnamed message |
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| 4 | * queues at a future date. They are currently not part of the |
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| 5 | * POSIX standard but unnamed message_queues are. This is also |
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| 6 | * the reason for the apparently unnecessary tracking of |
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| 7 | * the process_shared attribute. [In addition to the fact that |
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| 8 | * it would be trivial to add pshared to the mq_attr structure |
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| 9 | * and have process private message queues.] |
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| 10 | * |
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| 11 | * This code ignores the O_RDONLY/O_WRONLY/O_RDWR flag at open |
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| 12 | * time. |
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| 13 | * |
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| 14 | * $Id$ |
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| 15 | */ |
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| 16 | |
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| 17 | #include <stdarg.h> |
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| 18 | |
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| 19 | #include <pthread.h> |
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| 20 | #include <limits.h> |
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| 21 | #include <errno.h> |
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| 22 | #include <fcntl.h> |
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| 23 | #include <mqueue.h> |
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| 24 | |
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| 25 | #include <rtems/system.h> |
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| 26 | #include <rtems/score/watchdog.h> |
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| 27 | #include <rtems/posix/seterr.h> |
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| 28 | #include <rtems/posix/mqueue.h> |
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| 29 | #include <rtems/posix/time.h> |
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| 30 | |
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| 31 | /*PAGE |
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| 32 | * |
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| 33 | * 15.2.2 Open a Message Queue, P1003.1b-1993, p. 272 |
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| 34 | */ |
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| 35 | |
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| 36 | mqd_t mq_open( |
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| 37 | const char *name, |
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| 38 | int oflag, |
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| 39 | ... |
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| 40 | /* mode_t mode, */ |
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| 41 | /* struct mq_attr attr */ |
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| 42 | ) |
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| 43 | { |
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| 44 | va_list arg; |
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| 45 | mode_t mode; |
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| 46 | struct mq_attr *attr; |
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| 47 | int status; |
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| 48 | Objects_Id the_mq_id; |
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| 49 | POSIX_Message_queue_Control *the_mq; |
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[7fbef786] | 50 | Objects_Locations location; |
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[4dc89814] | 51 | |
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[7fbef786] | 52 | _Thread_Disable_dispatch(); |
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| 53 | |
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[4dc89814] | 54 | if ( oflag & O_CREAT ) { |
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| 55 | va_start(arg, oflag); |
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| 56 | mode = (mode_t) va_arg( arg, mode_t ); |
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| 57 | attr = (struct mq_attr *) va_arg( arg, struct mq_attr * ); |
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| 58 | va_end(arg); |
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| 59 | } |
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| 60 | |
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| 61 | status = _POSIX_Message_queue_Name_to_id( name, &the_mq_id ); |
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| 62 | |
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| 63 | /* |
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| 64 | * If the name to id translation worked, then the message queue exists |
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| 65 | * and we can just return a pointer to the id. Otherwise we may |
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| 66 | * need to check to see if this is a "message queue does not exist" |
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| 67 | * or some other miscellaneous error on the name. |
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| 68 | */ |
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| 69 | |
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| 70 | if ( status ) { |
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| 71 | |
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[7fbef786] | 72 | /* |
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| 73 | * Unless provided a valid name that did not already exist |
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| 74 | * and we are willing to create then it is an error. |
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| 75 | */ |
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| 76 | |
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| 77 | if ( !( status == ENOENT && (oflag & O_CREAT) ) ) { |
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| 78 | _Thread_Enable_dispatch(); |
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| 79 | set_errno_and_return_minus_one_cast( status, mqd_t ); |
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[4dc89814] | 80 | } |
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[7fbef786] | 81 | |
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[4dc89814] | 82 | } else { /* name -> ID translation succeeded */ |
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| 83 | |
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[7fbef786] | 84 | /* |
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| 85 | * Check for existence with creation. |
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| 86 | */ |
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| 87 | |
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[4dc89814] | 88 | if ( (oflag & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL) ) { |
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[7fbef786] | 89 | _Thread_Enable_dispatch(); |
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| 90 | set_errno_and_return_minus_one_cast( EEXIST, mqd_t ); |
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[4dc89814] | 91 | } |
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[7fbef786] | 92 | |
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[4dc89814] | 93 | /* |
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| 94 | * XXX In this case we need to do an ID->pointer conversion to |
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| 95 | * check the mode. This is probably a good place for a subroutine. |
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| 96 | */ |
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[7fbef786] | 97 | |
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| 98 | the_mq = _POSIX_Message_queue_Get( the_mq_id, &location ); |
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[4dc89814] | 99 | the_mq->open_count += 1; |
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[7fbef786] | 100 | _Thread_Enable_dispatch(); |
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| 101 | _Thread_Enable_dispatch(); |
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| 102 | return (mqd_t)the_mq->Object.id; |
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[4dc89814] | 103 | |
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| 104 | } |
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| 105 | |
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| 106 | /* XXX verify this comment... |
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| 107 | * |
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| 108 | * At this point, the message queue does not exist and everything has been |
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| 109 | * checked. We should go ahead and create a message queue. |
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| 110 | */ |
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| 111 | |
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| 112 | status = _POSIX_Message_queue_Create_support( |
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| 113 | name, |
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| 114 | TRUE, /* shared across processes */ |
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| 115 | oflag, |
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| 116 | attr, |
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| 117 | &the_mq |
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| 118 | ); |
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| 119 | |
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[7fbef786] | 120 | /* |
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| 121 | * errno was set by Create_support, so don't set it again. |
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| 122 | */ |
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| 123 | |
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| 124 | _Thread_Enable_dispatch(); |
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| 125 | |
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[4dc89814] | 126 | if ( status == -1 ) |
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| 127 | return (mqd_t) -1; |
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| 128 | |
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[7fbef786] | 129 | return (mqd_t) the_mq->Object.id; |
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[4dc89814] | 130 | } |
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| 131 | |
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