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add experimental prefetching support

master
Felix von Leitner 18 years ago
parent
commit
126e947ac2
  1. 29
      io/iob_prefetch.c
  2. 3
      io/iob_send.c
  3. 1
      iob.h
  4. 2
      test/dnsip.c

29
io/iob_prefetch.c

@ -0,0 +1,29 @@
#include "iob_internal.h"
#include <stdio.h>
#include <sys/mman.h>
void iob_prefetch(io_batch* b,uint64 bytes) {
iob_entry* e,* last;
if (b->bytesleft==0) return;
last=(iob_entry*)(((char*)array_start(&b->b))+array_bytes(&b->b));
e=(iob_entry*)array_start(&b->b);
if (!e) return;
for (; e<last; ++e) {
if (e->type==FROMFILE) {
char* c,* d;
if (e->n>=1000000) {
d=c=mmap(0,bytes,PROT_READ,MAP_SHARED,e->fd,(e->offset|4095)+1);
if (c!=MAP_FAILED) {
while (bytes>4096) {
volatile char x=*d;
bytes-=4096;
d+=4096;
(void)x;
}
}
munmap(c,bytes);
}
return;
}
}
}

3
io/iob_send.c

@ -20,7 +20,7 @@ int64 iob_send(int64 s,io_batch* b) {
#endif
if (b->bytesleft==0) return 0;
last=((char*)array_start(&b->b))+array_bytes(&b->b);
last=(iob_entry*)(((char*)array_start(&b->b))+array_bytes(&b->b));
v=alloca(b->bufs*sizeof(struct iovec));
total=0;
for (;;) {
@ -114,6 +114,7 @@ eagain:
if (!rest) break;
} else {
e[i].offset+=rest;
e[i].n-=rest;
goto abort;
}
}

1
iob.h

@ -29,5 +29,6 @@ int iob_adds_free(io_batch* b,const char* s);
int iob_addfile(io_batch* b,int64 fd,uint64 off,uint64 n);
int64 iob_send(int64 s,io_batch* b);
void iob_reset(io_batch* b);
void iob_prefetch(io_batch* b,uint64 bytes);
#endif

2
test/dnsip.c

@ -22,7 +22,7 @@ int main(int argc,char* argv[]) {
buffer_puts(buffer_2,"unable to find IP address for ");
buffer_puts(buffer_2,*argv);
buffer_puts(buffer_2,": ");
buffer_puts(buffer_2,strerror(errno));
buffer_puterror(buffer_2);
buffer_putnlflush(buffer_2);
return 111;
}

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