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#include <u.h>
#include <libc.h>
#include <thread.h>
#include "../eui.h"
#include "dat.h"
#include "fns.h"
static int infd = -1;
static int outfd = -1;
static int leader = 0;
static Channel *inc = nil;
static Channel *outc = nil;
typedef struct Msg Msg;
struct Msg {
u8int c;
u8int b;
u32int t;
};
enum{
Cex = 1,
Csync = 2,
Cgone = 0xFF,
};
static Msg mine = {Cgone};
static Msg theirs = {Cgone};
Event evse;
static void
writer(void *)
{
Msg m;
uchar buf[1+1+4];
while(recv(outc, &m) == 1){
buf[0] = m.c;
buf[1] = m.b;
buf[2] = m.t>>24;
buf[3] = m.t>>16;
buf[4] = m.t>>8;
buf[5] = m.t;
if(write(outfd, buf, sizeof buf) != sizeof buf)
break;
}
chanclose(outc);
threadexits(nil);
}
static void
reader(void *)
{
Msg m;
uchar buf[1+1+4];
while(readn(infd, buf, sizeof buf) == sizeof buf){
m.c = buf[0];
m.b = buf[1];
m.t = ((u32int)buf[2]<<24) | ((u32int)buf[3]<<16) | ((u32int)buf[4]<<8) | (u32int)buf[5];
send(inc, &m);
}
chanclose(inc);
threadexits(nil);
}
void
serialwrite(void)
{
if(outc == nil)
return;
mine = (Msg){Cex, reg[SB], clock};
}
void
serialtick(void *)
{
Msg m, t;
if(leader){
m = (Msg){mine.c == Cgone ? Csync : mine.c, mine.b, clock};
if(send(outc, &m) != 1)
return;
if(recv(inc, &t) != 1)
return;
theirs = t;
} else {
if(recv(inc, &t) != 1)
return;
theirs = t;
m = (Msg){theirs.c, reg[SB], clock};
if(send(outc, &m) != 1)
return;
}
addevent(&evse, FREQ / 64);
assert(theirs.c != Cgone);
if(theirs.c == Csync)
return;
reg[SB] = theirs.b;
reg[SC] &= ~0x80;
if(leader)
reg[SC] |= 0x1;
else
reg[SC] &= ~0x1;
reg[IF] |= 0x8;
}
void
serialinit(int dolis, char *addr)
{
int acfd, lcfd;
char adir[40], ldir[40];
evse.f = serialtick;
addevent(&evse, FREQ / 64);
if(dolis){
acfd = announce(addr, adir);
if(acfd < 0)
sysfatal("failed to announce: %r");
lcfd = listen(adir, ldir);
if(lcfd < 0)
sysfatal("failed to listen: %r");
infd = outfd = accept(lcfd, ldir);
leader = 1;
} else {
infd = outfd = dial(addr, nil, nil, nil);
}
if(infd < 0 || outfd < 0)
sysfatal("failed to establish link: %r");
inc = chancreate(sizeof(Msg), 0);
outc = chancreate(sizeof(Msg), 0);
proccreate(reader, nil, mainstacksize);
proccreate(writer, nil, mainstacksize);
}
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