MEDIUM: mux_h2: Implement the takeover() method.
Implement a takeover() method in the mux_h2, so that other threads may
take an idle connection over if they need it.
diff --git a/src/mux_h2.c b/src/mux_h2.c
index 0d42324..d10c525 100644
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -3517,17 +3517,58 @@
/* this is the tasklet referenced in h2c->wait_event.tasklet */
static struct task *h2_io_cb(struct task *t, void *ctx, unsigned short status)
{
- struct h2c *h2c = ctx;
+ struct connection *conn;
+ struct tasklet *tl = (struct tasklet *)t;
+ int conn_in_list;
+ struct h2c *h2c;
int ret = 0;
+
+ HA_SPIN_LOCK(OTHER_LOCK, &toremove_lock[tid]);
+ if (t->context == NULL) {
+ /* The connection has been taken over by another thread,
+ * we're no longer responsible for it, so just free the
+ * tasklet, and do nothing.
+ */
+ HA_SPIN_UNLOCK(OTHER_LOCK, &toremove_lock[tid]);
+ tasklet_free(tl);
+ return NULL;
+ }
+ h2c = ctx;
+ conn = h2c->conn;
+
+ TRACE_ENTER(H2_EV_H2C_WAKE, conn);
+
+ conn_in_list = conn->flags & CO_FL_LIST_MASK;
+
- TRACE_ENTER(H2_EV_H2C_WAKE, h2c->conn);
+ /* Remove the connection from the list, to be sure nobody attempts
+ * to use it while we handle the I/O events
+ */
+ if (conn_in_list)
+ MT_LIST_DEL(&conn->list);
+
+ HA_SPIN_UNLOCK(OTHER_LOCK, &toremove_lock[tid]);
if (!(h2c->wait_event.events & SUB_RETRY_SEND))
ret = h2_send(h2c);
if (!(h2c->wait_event.events & SUB_RETRY_RECV))
ret |= h2_recv(h2c);
if (ret || b_data(&h2c->dbuf))
- h2_process(h2c);
+ ret = h2_process(h2c);
+
+ /* If we were in an idle list, we want to add it back into it,
+ * unless h2_process() returned -1, which mean it has destroyed
+ * the connection (testing !ret is enough, if h2_process() wasn't
+ * called then ret will be 0 anyway.
+ */
+ if (!ret && conn_in_list) {
+ struct server *srv = objt_server(conn->target);
+
+ if (conn_in_list == CO_FL_SAFE_LIST)
+ MT_LIST_ADDQ(&srv->safe_conns[tid], &conn->list);
+ else
+ MT_LIST_ADDQ(&srv->idle_conns[tid], &conn->list);
+ }
TRACE_LEAVE(H2_EV_H2C_WAKE);
return NULL;
@@ -3676,6 +3717,22 @@
return t;
}
+ /* We're about to destroy the connection, so make sure nobody attempts
+ * to steal it from us.
+ */
+ HA_SPIN_LOCK(OTHER_LOCK, &toremove_lock[tid]);
+
+ if (h2c && h2c->conn->flags & CO_FL_LIST_MASK)
+ MT_LIST_DEL(&h2c->conn->list);
+
+ /* Somebody already stole the connection from us, so we should not
+ * free it, we just have to free the task.
+ */
+ if (!t->context)
+ h2c = NULL;
+
+ HA_SPIN_UNLOCK(OTHER_LOCK, &toremove_lock[tid]);
+
task_destroy(t);
if (!h2c) {
@@ -5979,6 +6036,50 @@
}
}
+/* Migrate the the connection to the current thread.
+ * Return 0 if successful, non-zero otherwise.
+ * Expected to be called with the old thread lock held.
+ */
+static int h2_takeover(struct connection *conn)
+{
+ struct h2c *h2c = conn->ctx;
+
+ if (fd_takeover(conn->handle.fd, conn) != 0)
+ return -1;
+ if (h2c->wait_event.events)
+ h2c->conn->xprt->unsubscribe(h2c->conn, h2c->conn->xprt_ctx,
+ h2c->wait_event.events, &h2c->wait_event);
+ /* To let the tasklet know it should free itself, and do nothing else,
+ * set its context to NULL.
+ */
+ h2c->wait_event.tasklet->context = NULL;
+ tasklet_wakeup(h2c->wait_event.tasklet);
+ if (h2c->task) {
+ h2c->task->context = NULL;
+ /* Wake the task, to let it free itself */
+ task_wakeup(h2c->task, TASK_WOKEN_OTHER);
+
+ h2c->task = task_new(tid_bit);
+ if (!h2c->task) {
+ h2_release(h2c);
+ return -1;
+ }
+ h2c->task->process = h2_timeout_task;
+ h2c->task->context = h2c;
+ }
+ h2c->wait_event.tasklet = tasklet_new();
+ if (!h2c->wait_event.tasklet) {
+ h2_release(h2c);
+ return -1;
+ }
+ h2c->wait_event.tasklet->process = h2_io_cb;
+ h2c->wait_event.tasklet->context = h2c;
+ h2c->conn->xprt->subscribe(h2c->conn, h2c->conn->xprt_ctx,
+ SUB_RETRY_RECV, &h2c->wait_event);
+
+ return 0;
+}
+
/*******************************************************/
/* functions below are dedicated to the config parsers */
/*******************************************************/
@@ -6070,6 +6171,7 @@
.shutw = h2_shutw,
.ctl = h2_ctl,
.show_fd = h2_show_fd,
+ .takeover = h2_takeover,
.flags = MX_FL_CLEAN_ABRT|MX_FL_HTX,
.name = "H2",
};