68de328ac1
this is a fix for e.g. the situation where lots of processes die instantly, and PM has to send an asyn msg for each one to VFS, and panics if there are too many. there are likely more situations in which this table should be dependent on the no. of processes. reported by pikpik on #minix3.
141 lines
2.6 KiB
C
141 lines
2.6 KiB
C
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#define _MINIX 1
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#define _SYSTEM 1
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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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#include <stdlib.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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#include <minix/sys_config.h>
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#include <limits.h>
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#include <errno.h>
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#define ASYN_NR (2*_NR_PROCS)
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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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PUBLIC int asynsend3(dst, mp, fl)
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endpoint_t dst;
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message *mp;
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int fl;
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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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/* printf() causes asynsend? */
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if(inside) {
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exit(1);
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}
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inside = 1;
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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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/* 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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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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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("asynsend: senda failed: %d", r);
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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("asynsend: msgtable full");
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}
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fl |= AMF_VALID;
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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= fl; /* 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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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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/* Tell the kernel to rescan the table */
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r = senda(msgtable+first_slot, len);
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inside = 0;
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return r;
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}
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