lib: Added support for blocking on multiple file descriptors.

[ashd.git] / lib / mtio-select.c

diff --git a/lib/mtio-select.c b/lib/mtio-select.c
index 26e6785..6e9a767 100644 (file)
--- a/lib/mtio-select.c
+++ b/lib/mtio-select.c
@@ -37,39 +37,73 @@ static int exitstatus;
 struct blocker {
     struct blocker *n, *p;
     int fd;
-    int ev;
+    int ev, rev, id;
     time_t to;
     struct muth *th;
 };
 
-int block(int fd, int ev, time_t to)
+static void addblock(struct blocker *bl)
 {
-    struct blocker *bl;
-    int rv;
-    
-    if(fd >= FD_SETSIZE) {
-       flog(LOG_ERR, "tried to use more file descriptors than select() can handle: fd %i", fd);
-       errno = EMFILE;
-       return(-1);
-    }
-    omalloc(bl);
-    bl->fd = fd;
-    bl->ev = ev;
-    if(to > 0)
-       bl->to = time(NULL) + to;
-    bl->th = current;
     bl->n = blockers;
     if(blockers)
        blockers->p = bl;
     blockers = bl;
-    rv = yield();
+}
+
+static void remblock(struct blocker *bl)
+{
     if(bl->n)
        bl->n->p = bl->p;
     if(bl->p)
        bl->p->n = bl->n;
     if(bl == blockers)
        blockers = bl->n;
-    free(bl);
+}
+
+struct selected mblock(time_t to, int n, struct selected *spec)
+{
+    int i, id;
+    struct blocker bls[n];
+    
+    to = (to > 0)?(time(NULL) + to):0;
+    for(i = 0; i < n; i++) {
+       bls[i] = (struct blocker){
+           .fd = spec[i].fd,
+           .ev = spec[i].ev,
+           .id = i,
+           .to = to,
+           .th = current,
+       };
+       addblock(&bls[i]);
+    }
+    id = yield();
+    for(i = 0; i < n; i++)
+       remblock(&bls[i]);
+    if(id < 0)
+       return((struct selected){.fd = -1, .ev = -1});
+    return((struct selected){.fd = bls[id].fd, .ev = bls[id].rev});
+}
+
+int block(int fd, int ev, time_t to)
+{
+    struct blocker bl;
+    int rv;
+    
+    if(fd >= FD_SETSIZE) {
+       flog(LOG_ERR, "tried to use more file descriptors than select() can handle: fd %i", fd);
+       errno = EMFILE;
+       return(-1);
+    }
+    bl = (struct blocker) {
+       .fd = fd,
+       .ev = ev,
+       .id = -1,
+       .to = (to > 0)?(time(NULL) + to):0,
+       .th = current,
+    };
+    addblock(&bl);
+    rv = yield();
+    remblock(&bl);
     return(rv);
 }
 
@@ -125,10 +159,21 @@ int ioloop(void)
                    ev |= EV_WRITE;
                if(FD_ISSET(bl->fd, &efds))
                    ev = -1;
-               if((ev < 0) || (ev & bl->ev))
-                   resume(bl->th, ev);
-               else if((bl->to != 0) && (bl->to <= now))
-                   resume(bl->th, 0);
+               if((ev < 0) || (ev & bl->ev)) {
+                   if(bl->id < 0) {
+                       resume(bl->th, ev);
+                   } else {
+                       bl->rev = ev;
+                       resume(bl->th, bl->id);
+                   }
+               } else if((bl->to != 0) && (bl->to <= now)) {
+                   if(bl->id < 0) {
+                       resume(bl->th, 0);
+                   } else {
+                       bl->rev = 0;
+                       resume(bl->th, bl->id);
+                   }
+               }
            }
        }
     }