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aan: handle case when reader closes netfd

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when netfd is closed and set to -1 by the fromnet()
reader proc, handle it like network failure and try
reconnecting.
This commit is contained in:
cinap_lenrek 2016-03-10 18:50:29 +01:00
parent 897da507f4
commit 51115b9214
1 changed files with 35 additions and 26 deletions
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61
sys/src/cmd/aan.c
View file

@ -21,21 +21,13 @@ enum {
Hdrsz = 3*4,
};
typedef struct Endpoints Endpoints;
struct Endpoints {
char *lsys;
char *lserv;
char *rsys;
char *rserv;
};
typedef struct {
uchar nb[4]; // Number of data bytes in this message
uchar msg[4]; // Message number
uchar acked[4]; // Number of messages acked
} Hdr;
typedef struct t_Buf {
typedef struct {
Hdr hdr;
uchar buf[Bufsize];
} Buf;
@ -52,6 +44,8 @@ static char *dialstring;
static int maxto = Maxto;
static char *Logname = "aan";
static int client;
static int reader = -1;
static int lostsync;
static Alt a[] = {
/* c v op */
@ -62,7 +56,7 @@ static Alt a[] = {
static void fromnet(void*);
static void fromclient(void*);
static void reconnect(int);
static int reconnect(int);
static void synchronize(void);
static int sendcommand(ulong, ulong);
static void showmsg(int, char *, Buf *);
@ -77,6 +71,7 @@ usage(void)
exits("usage");
}
static int
catch(void *, char *s)
{
@ -107,6 +102,7 @@ threadmain(int argc, char **argv)
vlong synctime;
int i, n, failed;
Channel *timer;
Hdr hdr;
Buf *b;
ARGBEGIN {
@ -151,8 +147,7 @@ threadmain(int argc, char **argv)
* long if there is some general connection problem
* (like NAT).
*/
netfd = -1;
reconnect(60);
netfd = reconnect(60);
unsent = chancreate(sizeof(Buf *), Nbuf);
unacked = chancreate(sizeof(Buf *), Nbuf);
@ -164,7 +159,8 @@ threadmain(int argc, char **argv)
for (i = 0; i < Nbuf; i++)
sendp(empty, emalloc(sizeof(Buf)));
if (proccreate(fromnet, nil, Stacksize) < 0)
reader = proccreate(fromnet, nil, Stacksize);
if (reader < 0)
sysfatal("Cannot start fromnet; %r");
if (proccreate(fromclient, nil, Stacksize) < 0)
@ -177,24 +173,29 @@ threadmain(int argc, char **argv)
a[Unsent].c = unsent;
a[Unsent].v = &b;
Restart:
synctime = nsec() + Synctime;
failed = 0;
lostsync = 0;
while (!done) {
if (failed) {
if (netfd < 0 || failed) {
// Wait for the netreader to die.
while (netfd >= 0) {
dmessage(1, "main; waiting for netreader to die\n");
threadint(reader);
sleep(1000);
}
// the reader died; reestablish the world.
reconnect(maxto);
netfd = reconnect(maxto);
synchronize();
failed = 0;
goto Restart;
}
if (nsec() >= synctime) {
Hdr hdr;
switch (alt(a)) {
case Timer:
if (netfd < 0 || nsec() < synctime)
break;
PBIT32(hdr.nb, 0);
PBIT32(hdr.acked, inmsg);
@ -205,16 +206,21 @@ threadmain(int argc, char **argv)
failed = 1;
continue;
}
synctime = nsec() + Synctime;
}
switch (alt(a)) {
case Timer:
if(++lostsync > 2){
syslog(0, Logname, "connection seems hung up...");
failed = 1;
continue;
}
synctime = nsec() + Synctime;
break;
case Unsent:
sendp(unacked, b);
if (netfd < 0)
break;
PBIT32(b->hdr.acked, inmsg);
if (writen(netfd, (uchar *)&b->hdr, Hdrsz) < 0) {
@ -268,10 +274,13 @@ fromclient(void*)
static void
fromnet(void*)
{
extern void _threadnote(void *, char *);
static int lastacked;
int n, m, len, acked;
Buf *b;
notify(_threadnote);
threadsetname("fromnet");
b = emalloc(sizeof(Buf));
@ -294,6 +303,7 @@ fromnet(void*)
netfd = -1;
continue;
}
lostsync = 0; // reset timeout
n = GBIT32(b->hdr.nb);
m = GBIT32(b->hdr.msg);
acked = GBIT32(b->hdr.acked);
@ -353,7 +363,7 @@ fromnet(void*)
done = 1;
}
static void
static int
reconnect(int secs)
{
NetConnInfo *nci;
@ -395,9 +405,8 @@ reconnect(int secs)
freenetconninfo(nci);
} else
syslog(0, Logname, "connected");
// Wakes up the netreader.
netfd = fd;
return fd;
}
static void