In non-blocking recv functions in libmux and libdraw,
distinguish between "cannot receive without blocking"
and "EOF on connection".
In libmux, do not elect async guys muxers, so that
synchronous RPC calls run in the main event loop
(e.g., in eresized) do not get stuck.
Fixes problem reported by Lu Xuxiao, namely that
jpg etc. would spin at 100% cpu usage.
diff --git a/include/mux.h b/include/mux.h
index 53321fa..e9890fc 100644
--- a/include/mux.h
+++ b/include/mux.h
@@ -19,6 +19,7 @@
uint tag;
void *p;
int waiting;
+ int async;
};
struct Mux
@@ -27,7 +28,7 @@
uint maxtag;
int (*send)(Mux*, void*);
void *(*recv)(Mux*);
- void *(*nbrecv)(Mux*);
+ int (*nbrecv)(Mux*, void**);
int (*gettag)(Mux*, void*);
int (*settag)(Mux*, void*, uint);
void *aux; /* for private use by client */
@@ -52,18 +53,18 @@
void* muxrpc(Mux*, void*);
void muxprocs(Mux*);
Muxrpc* muxrpcstart(Mux*, void*);
-void* muxrpccanfinish(Muxrpc*);
+int muxrpccanfinish(Muxrpc*, void**);
/* private */
int _muxsend(Mux*, void*);
-void* _muxrecv(Mux*, int);
+int _muxrecv(Mux*, int, void**);
void _muxsendproc(void*);
void _muxrecvproc(void*);
Muxqueue *_muxqalloc(void);
int _muxqsend(Muxqueue*, void*);
void *_muxqrecv(Muxqueue*);
void _muxqhangup(Muxqueue*);
-void *_muxnbqrecv(Muxqueue*);
+int _muxnbqrecv(Muxqueue*, void**);
#if defined(__cplusplus)
}
diff --git a/src/cmd/devdraw/x11-init.c b/src/cmd/devdraw/x11-init.c
index bf1262a..9ad6054 100644
--- a/src/cmd/devdraw/x11-init.c
+++ b/src/cmd/devdraw/x11-init.c
@@ -47,7 +47,8 @@
xioerror(XDisplay *d)
{
/*print("X I/O error\n"); */
- sysfatal("X I/O error\n");
+ exit(0);
+ /*sysfatal("X I/O error\n");*/
abort();
return -1;
}
diff --git a/src/libdraw/drawclient.c b/src/libdraw/drawclient.c
index 6261594..93c5623 100644
--- a/src/libdraw/drawclient.c
+++ b/src/libdraw/drawclient.c
@@ -13,7 +13,7 @@
static int drawgettag(Mux *mux, void *vmsg);
static void* drawrecv(Mux *mux);
-static void* drawnbrecv(Mux *mux);
+static int drawnbrecv(Mux *mux, void**);
static int drawsend(Mux *mux, void *vmsg);
static int drawsettag(Mux *mux, void *vmsg, uint tag);
static int canreadfd(int);
@@ -83,40 +83,46 @@
return write(d->srvfd, msg, n);
}
-static void*
-_drawrecv(Mux *mux, int nb)
+static int
+_drawrecv(Mux *mux, int canblock, void **vp)
{
int n;
uchar buf[4], *p;
Display *d;
d = mux->aux;
- if(nb && !canreadfd(d->srvfd))
- return nil;
+ *vp = nil;
+ if(!canblock && !canreadfd(d->srvfd))
+ return 0;
if((n=readn(d->srvfd, buf, 4)) != 4)
- return nil;
+ return 1;
GET(buf, n);
p = malloc(n);
if(p == nil){
fprint(2, "out of memory allocating %d in drawrecv\n", n);
- return nil;
+ return 1;
}
memmove(p, buf, 4);
- if(readn(d->srvfd, p+4, n-4) != n-4)
- return nil;
- return p;
+ if(readn(d->srvfd, p+4, n-4) != n-4){
+ free(p);
+ return 1;
+ }
+ *vp = p;
+ return 1;
}
static void*
drawrecv(Mux *mux)
{
- return _drawrecv(mux, 0);
+ void *p;
+ _drawrecv(mux, 1, &p);
+ return p;
}
-static void*
-drawnbrecv(Mux *mux)
+static int
+drawnbrecv(Mux *mux, void **vp)
{
- return _drawrecv(mux, 1);
+ return _drawrecv(mux, 0, vp);
}
static int
diff --git a/src/libdraw/event.c b/src/libdraw/event.c
index 1da3fb3..101aa37 100644
--- a/src/libdraw/event.c
+++ b/src/libdraw/event.c
@@ -214,10 +214,14 @@
finishrpc(Muxrpc *r, Wsysmsg *w)
{
uchar *p;
+ void *v;
int n;
- if((p = muxrpccanfinish(r)) == nil)
+ if(!muxrpccanfinish(r, &v))
return 0;
+ p = v;
+ if(p == nil) /* eof on connection */
+ exit(0);
GET(p, n);
convM2W(p, n, w);
free(p);
@@ -269,6 +273,9 @@
if(eslave[i].rpc == nil)
eslave[i].rpc = startrpc(Trdmouse);
if(eslave[i].rpc){
+ /* if ready, don't block in select */
+ if(eslave[i].rpc->p)
+ canblock = 0;
FD_SET(display->srvfd, &rset);
FD_SET(display->srvfd, &xset);
if(display->srvfd > max)
@@ -278,6 +285,9 @@
if(eslave[i].rpc == nil)
eslave[i].rpc = startrpc(Trdkbd);
if(eslave[i].rpc){
+ /* if ready, don't block in select */
+ if(eslave[i].rpc->p)
+ canblock = 0;
FD_SET(display->srvfd, &rset);
FD_SET(display->srvfd, &xset);
if(display->srvfd > max)
diff --git a/src/libmux/io.c b/src/libmux/io.c
index 4a89ca2..d9d9d8a 100644
--- a/src/libmux/io.c
+++ b/src/libmux/io.c
@@ -34,7 +34,7 @@
qunlock(&mux->inlk);
qlock(&mux->lk);
_muxqhangup(q);
- while((p = _muxnbqrecv(q)) != nil)
+ while(_muxnbqrecv(q, &p))
free(p);
free(q);
mux->readq = nil;
@@ -64,7 +64,7 @@
qunlock(&mux->outlk);
qlock(&mux->lk);
_muxqhangup(q);
- while((p = _muxnbqrecv(q)) != nil)
+ while(_muxnbqrecv(q, &p))
free(p);
free(q);
mux->writeq = nil;
@@ -73,42 +73,39 @@
return;
}
-void*
-_muxrecv(Mux *mux, int canblock)
+int
+_muxrecv(Mux *mux, int canblock, void **vp)
{
void *p;
+ int ret;
qlock(&mux->lk);
-/*
- if(mux->state != VtStateConnected){
- werrstr("not connected");
- qunlock(&mux->lk);
- return nil;
- }
-*/
if(mux->readq){
qunlock(&mux->lk);
- if(canblock)
- return _muxqrecv(mux->readq);
- return _muxnbqrecv(mux->readq);
+ if(canblock){
+ *vp = _muxqrecv(mux->readq);
+ return 1;
+ }
+ return _muxnbqrecv(mux->readq, vp);
}
qlock(&mux->inlk);
qunlock(&mux->lk);
- if(canblock)
+ if(canblock){
p = mux->recv(mux);
- else{
+ ret = 1;
+ }else{
if(mux->nbrecv)
- p = mux->nbrecv(mux);
- else
+ ret = mux->nbrecv(mux, &p);
+ else{
+ /* send eof, not "no packet ready" */
p = nil;
+ ret = 1;
+ }
}
qunlock(&mux->inlk);
-/*
- if(!p && canblock)
- vthangup(mux);
-*/
- return p;
+ *vp = p;
+ return ret;
}
int
diff --git a/src/libmux/mux.c b/src/libmux/mux.c
index bfabb23..8257fb0 100644
--- a/src/libmux/mux.c
+++ b/src/libmux/mux.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 2003 Russ Cox, Massachusetts Institute of Technology */
+/* Copyright (C) 2003-2006 Russ Cox, Massachusetts Institute of Technology */
/* See COPYRIGHT */
/*
@@ -100,12 +100,17 @@
void
electmuxer(Mux *mux)
{
+ Muxrpc *rpc;
+
/* if there is anyone else sleeping, wake them to mux */
- if(mux->sleep.next != &mux->sleep){
- mux->muxer = mux->sleep.next;
- rwakeup(&mux->muxer->r);
- }else
- mux->muxer = nil;
+ for(rpc=mux->sleep.next; rpc != &mux->sleep; rpc = rpc->next){
+ if(!rpc->async){
+ mux->muxer = rpc;
+ rwakeup(&rpc->r);
+ return;
+ }
+ }
+ mux->muxer = nil;
}
void*
@@ -133,7 +138,7 @@
mux->muxer = r;
while(!r->p){
qunlock(&mux->lk);
- p = _muxrecv(mux, 1);
+ _muxrecv(mux, 1, &p);
if(p == nil){
/* eof -- just give up and pass the buck */
qlock(&mux->lk);
@@ -144,7 +149,6 @@
}
electmuxer(mux);
}
-/*print("finished %p\n", r); */
p = r->p;
puttag(mux, r);
qunlock(&mux->lk);
@@ -161,24 +165,29 @@
if((r = allocmuxrpc(mux)) == nil)
return nil;
+ r->async = 1;
if((tag = tagmuxrpc(r, tx)) < 0)
return nil;
return r;
}
-void*
-muxrpccanfinish(Muxrpc *r)
+int
+muxrpccanfinish(Muxrpc *r, void **vp)
{
- char *p;
+ void *p;
Mux *mux;
-
+ int ret;
+
mux = r->mux;
qlock(&mux->lk);
+ ret = 1;
if(!r->p && !mux->muxer){
mux->muxer = r;
while(!r->p){
qunlock(&mux->lk);
- p = _muxrecv(mux, 0);
+ p = nil;
+ if(!_muxrecv(mux, 0, &p))
+ ret = 0;
if(p == nil){
qlock(&mux->lk);
break;
@@ -191,7 +200,8 @@
if(p)
puttag(mux, r);
qunlock(&mux->lk);
- return p;
+ *vp = p;
+ return ret;
}
static void
diff --git a/src/libmux/queue.c b/src/libmux/queue.c
index 1cadbe6..2151c25 100644
--- a/src/libmux/queue.c
+++ b/src/libmux/queue.c
@@ -81,8 +81,8 @@
return p;
}
-void*
-_muxnbqrecv(Muxqueue *q)
+int
+_muxnbqrecv(Muxqueue *q, void **vp)
{
void *p;
Qel *e;
@@ -90,14 +90,16 @@
qlock(&q->lk);
if(q->head == nil){
qunlock(&q->lk);
- return nil;
+ *vp = nil;
+ return q->hungup;
}
e = q->head;
q->head = e->next;
qunlock(&q->lk);
p = e->p;
free(e);
- return p;
+ *vp = p;
+ return 1;
}
void
