1 files changed, 97 insertions, 0 deletions
diff --git a/util/alevt/fdset.c b/util/alevt/fdset.c
new file mode 100644
index 0000000..99edac4
--- /dev/null
+++ b/util/alevt/fdset.c
@@ -0,0 +1,97 @@
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/time.h>
+#include "dllist.h"
+#include "misc.h"
+#include "fdset.h"
+
+struct fdset fds[1];		/* global fd list */
+
+
+int fdset_init(struct fdset *fds)
+{
+    dl_init(fds->list);
+    fds->del_count = 0;
+    return 0;
+}
+
+
+int fdset_add_fd(struct fdset *fds, int fd, void *handler, void *data)
+{
+    struct fdset_node *fn;
+
+    if (fd < 0)
+	return -1;
+    if (handler == 0)
+	return -1;
+
+    for (fn = PTR fds->list->first; fn->node->next; fn = PTR fn->node->next)
+	if (fn->fd == fd)
+	    return -1;
+
+    if (not(fn = malloc(sizeof(*fn))))
+	return -1;
+    fn->fd = fd;
+    fn->handler = handler;
+    fn->data = data;
+    dl_insert_last(fds->list, fn->node);
+    return 0;
+}
+
+
+int fdset_del_fd(struct fdset *fds, int fd)
+{
+    struct fdset_node *fn;
+
+    for (fn = PTR fds->list->first; fn->node->next; fn = PTR fn->node->next)
+	if (fn->fd == fd)
+	{
+	    dl_remove(fn->node);
+	    free(fn);
+	    fds->del_count++;
+	    return 0;
+	}
+    return -1;
+}
+
+
+int fdset_select(struct fdset *fds, int timeout)
+{
+    struct fdset_node *fn;
+    fd_set rfds[1];
+    struct timeval tv[1], *tvp = 0;
+    int max_fd, x, del_count;
+
+    FD_ZERO(rfds);
+    max_fd = 0;
+    for (fn = PTR fds->list->first; fn->node->next; fn = PTR fn->node->next)
+    {
+	FD_SET(fn->fd, rfds);
+	if (fn->fd >= max_fd)
+	    max_fd = fn->fd + 1;
+    }
+
+    if (timeout >= 0)
+    {
+	tv->tv_sec = timeout/1000;
+	tv->tv_usec = timeout%1000*1000;
+	tvp = tv;
+    }
+
+    x = select(max_fd, rfds, 0, 0, tvp);
+    if (x <= 0)
+	return x;
+
+    /* A little bit complicated. A called handler may modify the fdset... */
+restart:
+    del_count = fds->del_count;
+    for (fn = PTR fds->list->first; fn->node->next; fn = PTR fn->node->next)
+	if (FD_ISSET(fn->fd, rfds))
+	{
+	    FD_CLR(fn->fd, rfds);
+	    fn->handler(fn->data, fn->fd);
+	    if (fds->del_count != del_count)
+		goto restart;
+	}
+    return 1;
+}