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-rw-r--r--glougloud/imsgev.c160
1 files changed, 160 insertions, 0 deletions
diff --git a/glougloud/imsgev.c b/glougloud/imsgev.c
new file mode 100644
index 0000000..ba577aa
--- /dev/null
+++ b/glougloud/imsgev.c
@@ -0,0 +1,160 @@
+/*
+ * Copyright (c) 2009 Eric Faurot <eric@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/param.h>
+#include <sys/queue.h>
+#include <sys/socket.h>
+#include <sys/uio.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "imsgev.h"
+
+void imsgev_add(struct imsgev *);
+void imsgev_dispatch(int, short, void *);
+void imsgev_disconnect(struct imsgev *, int);
+
+void
+imsgev_init(struct imsgev *iev, int fd, void *data,
+ void (*callback)(struct imsgev *, int, struct imsg *))
+{
+ imsg_init(&iev->ibuf, fd);
+ iev->terminate = 0;
+
+ iev->data = data;
+ iev->handler = imsgev_dispatch;
+ iev->callback = callback;
+
+ iev->events = EV_READ;
+ event_set(&iev->ev, iev->ibuf.fd, iev->events, iev->handler, iev);
+ event_add(&iev->ev, NULL);
+}
+
+int
+imsgev_compose(struct imsgev *iev, u_int16_t type, u_int32_t peerid,
+ uint32_t pid, int fd, void *data, u_int16_t datalen)
+{
+ int r;
+
+ r = imsg_compose(&iev->ibuf, type, peerid, pid, fd, data, datalen);
+ if (r != -1)
+ imsgev_add(iev);
+
+ return (r);
+}
+
+void
+imsgev_close(struct imsgev *iev)
+{
+ iev->terminate = 1;
+ imsgev_add(iev);
+}
+
+void
+imsgev_clear(struct imsgev *iev)
+{
+ event_del(&iev->ev);
+ msgbuf_clear(&iev->ibuf.w);
+ close(iev->ibuf.fd);
+}
+
+void
+imsgev_add(struct imsgev *iev)
+{
+ short events = 0;
+
+ if (!iev->terminate)
+ events = EV_READ;
+ if (iev->ibuf.w.queued || iev->terminate)
+ events |= EV_WRITE;
+
+ /* optimization: skip event_{del/set/add} if already set */
+ if (events == iev->events)
+ return;
+
+ iev->events = events;
+ event_del(&iev->ev);
+ event_set(&iev->ev, iev->ibuf.fd, iev->events, iev->handler, iev);
+ event_add(&iev->ev, NULL);
+}
+
+void
+imsgev_dispatch(int fd, short ev, void *humppa)
+{
+ struct imsgev *iev = humppa;
+ struct imsgbuf *ibuf = &iev->ibuf;
+ struct imsg imsg;
+ ssize_t n;
+
+ iev->events = 0;
+
+ if (ev & EV_READ) {
+ if ((n = imsg_read(ibuf)) == -1) {
+ imsgev_disconnect(iev, IMSGEV_EREAD);
+ return;
+ }
+ if (n == 0) {
+ /*
+ * Connection is closed for reading, and we assume
+ * it is also closed for writing, so we error out
+ * if write data is pending.
+ */
+ imsgev_disconnect(iev,
+ (iev->ibuf.w.queued) ? IMSGEV_EWRITE : IMSGEV_DONE);
+ return;
+ }
+ }
+
+ if (ev & EV_WRITE) {
+ /*
+ * We wanted to write data out but the connection is either
+ * closed, or some error occured. Both case are not recoverable
+ * from the imsg perspective, so we treat it as a WRITE error.
+ */
+ if ((n = msgbuf_write(&ibuf->w)) != 0) {
+ imsgev_disconnect(iev, IMSGEV_EWRITE);
+ return;
+ }
+ }
+
+ while (iev->terminate == 0) {
+ if ((n = imsg_get(ibuf, &imsg)) == -1) {
+ imsgev_disconnect(iev, IMSGEV_EIMSG);
+ return;
+ }
+ if (n == 0)
+ break;
+ iev->callback(iev, IMSGEV_IMSG, &imsg);
+ imsg_free(&imsg);
+ }
+
+ if (iev->terminate && iev->ibuf.w.queued == 0) {
+ imsgev_disconnect(iev, IMSGEV_DONE);
+ return;
+ }
+
+ imsgev_add(iev);
+}
+
+void
+imsgev_disconnect(struct imsgev *iev, int code)
+{
+ iev->callback(iev, code, NULL);
+}