53 lines
		
	
	
		
			810 B
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			53 lines
		
	
	
		
			810 B
		
	
	
	
		
			C
		
	
	
	
| /* Copyright 2002, Red Hat Inc. */
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| 
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| #include <mqueue.h>
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| #include <errno.h>
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| #include <sys/sem.h>
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| #include <string.h>
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| #define _LIBC 1
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| #include <sys/lock.h>
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| #undef _LIBC
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| 
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| #include "mqlocal.h"
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| 
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| int
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| mq_getattr (mqd_t msgid, struct mq_attr *mqstat)
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| {
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|   struct libc_mq *info;
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|   struct sembuf sb0 = {0, -1, 0};
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|   int num_msgs;
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|   int rc = 0;
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| 
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|   info = __find_mq (msgid);
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| 
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|   if (info == NULL)
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|     {
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|       errno = EBADF;
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|       return -1;
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|     }
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| 
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|   /* temporarily lock message queue */
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|   semop (info->semid, &sb0, 1);
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| 
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|   num_msgs = semctl (info->semid, 3, GETVAL);
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|   if (num_msgs >= 0)
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|     {
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|       memcpy (mqstat, info->attr, sizeof(struct mq_attr));
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|       mqstat->mq_curmsgs = num_msgs;
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|     }
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|   else
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|     rc = -1;
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| 
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|   /* release message queue */
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|   sb0.sem_op = 1;
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|   semop (info->semid, &sb0, 1);
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| 
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|   return rc;
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| }
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|       
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| 
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| 
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| 
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| 
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| 
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