138 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			138 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| 
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| #define _MINIX 1
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| #define _SYSTEM 1
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| 
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| #include <minix/config.h>
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| #include <ansi.h> 
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| #include <assert.h> 
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| #include <sys/types.h>
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| #include <minix/const.h>
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| #include <minix/type.h>
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| 
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| #include <fcntl.h>
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| #include <unistd.h>
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| #include <minix/syslib.h>
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| #include <minix/sysutil.h>
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| 
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| #include <limits.h>
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| #include <errno.h>
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| 
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| #define ASYN_NR	100
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| PRIVATE asynmsg_t msgtable[ASYN_NR];
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| PRIVATE int first_slot= 0, next_slot= 0;
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| 
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| PUBLIC int asynsend(dst, mp)
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| endpoint_t dst;
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| message *mp;
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| {
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| 	int r, src_ind, dst_ind;
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| 	unsigned flags;
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| 	static int first = 1;
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| 	static int inside = 0;
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| 	int len;
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| 
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| 	/* printf() causes asynsend? */
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| 	if(inside) {
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| 		exit(1);
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| 	}
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| 
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| 	inside = 1;
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| 
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| 	if(first) {
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| 		int i;
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| 		for(i = 0; i < ASYN_NR; i++) {
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| 			msgtable[i].flags = AMF_EMPTY;
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| 		}
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| 		first = 0;
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| 	}
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| 
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| 	/* Update first_slot */
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| 	for (; first_slot < next_slot; first_slot++)
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| 	{
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| 		flags= msgtable[first_slot].flags;
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| 		if ((flags & (AMF_VALID|AMF_DONE)) == (AMF_VALID|AMF_DONE))
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| 		{
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| 			if (msgtable[first_slot].result != OK)
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| 			{
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| #if 0
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| 				printf(
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| 			"asynsend: found completed entry %d with error %d\n",
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| 					first_slot,
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| 					msgtable[first_slot].result);
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| #endif
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| 			}
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| 			continue;
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| 		}
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| 		if (flags != AMF_EMPTY)
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| 			break;
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| 	}
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| 
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| 	if (first_slot >= next_slot)
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| 	{
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| 		/* Reset first_slot and next_slot */
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| 		next_slot= first_slot= 0;
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| 	}
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| 
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| 	if (next_slot >= ASYN_NR)
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| 	{
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| 		/* Tell the kernel to stop processing */
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| 		r= senda(NULL, 0);
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| 		if (r != OK)
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| 			panic(__FILE__, "asynsend: senda failed", r);
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| 
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| 		dst_ind= 0;
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| 		for (src_ind= first_slot; src_ind<next_slot; src_ind++)
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| 		{
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| 			flags= msgtable[src_ind].flags;
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| 			if ((flags & (AMF_VALID|AMF_DONE)) ==
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| 				(AMF_VALID|AMF_DONE))
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| 			{
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| 				if (msgtable[src_ind].result != OK)
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| 				{
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| #if 0
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| 					printf(
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| 			"asynsend: found completed entry %d with error %d\n",
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| 						src_ind,
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| 						msgtable[src_ind].result);
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| #endif
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| 				}
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| 				continue;
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| 			}
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| 			if (flags == AMF_EMPTY)
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| 				continue;
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| #if 0
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| 			printf("asynsend: copying entry %d to %d\n",
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| 				src_ind, dst_ind);
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| #endif
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| 			if (src_ind != dst_ind)
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| 				msgtable[dst_ind]= msgtable[src_ind];
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| 			dst_ind++;
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| 		}
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| 		first_slot= 0;
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| 		next_slot= dst_ind;
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| 		if (next_slot >= ASYN_NR)
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| 			panic(__FILE__, "asynsend: msgtable full", NO_NUM);
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| 	}
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| 
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| 	msgtable[next_slot].dst= dst;
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| 	msgtable[next_slot].msg= *mp;
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| 	msgtable[next_slot].flags= AMF_VALID;	/* Has to be last. The kernel 
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| 					 	 * scans this table while we
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| 						 * are sleeping.
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| 					 	 */
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| 	next_slot++;
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| 
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| 	assert(first_slot < ASYN_NR);
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| 	assert(next_slot >= first_slot);
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| 	len = next_slot-first_slot;
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| 	assert(first_slot + len <= ASYN_NR);
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| 
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| 	/* Tell the kernel to rescan the table */
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| 	r = senda(msgtable+first_slot, len);
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| 
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| 	inside = 0;
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| 
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| 	return r;
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| }
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| 
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