[Qemu-devel] [PATCH 3/4] slirp: set mainloop timeout with more precise value

[Jan Kiszka]

From: Liu Ping Fan <qemul...@gmail.com>

If slirp needs to emulate tcp timeout, then the timeout value
for mainloop should be more precise, which is determined by
slirp's fasttimo or slowtimo. Achieve this by swap the logic
sequence of slirp_pollfds_fill and slirp_update_timeout.

Signed-off-by: Liu Ping Fan <pingf...@linux.vnet.ibm.com>
Signed-off-by: Jan Kiszka <jan.kis...@siemens.com>
---
 main-loop.c      |  3 +--
 slirp/libslirp.h |  3 +--
 slirp/slirp.c    | 28 ++++++++++++++++++++++++----
 stubs/slirp.c    |  6 +-----
 4 files changed, 27 insertions(+), 13 deletions(-)

diff --git a/main-loop.c b/main-loop.c
index 1c38ea2..c3c9c28 100644
--- a/main-loop.c
+++ b/main-loop.c
@@ -466,8 +466,7 @@ int main_loop_wait(int nonblocking)
     g_array_set_size(gpollfds, 0); /* reset for new iteration */
     /* XXX: separate device handlers from system ones */
 #ifdef CONFIG_SLIRP
-    slirp_update_timeout(&timeout);
-    slirp_pollfds_fill(gpollfds);
+    slirp_pollfds_fill(gpollfds, &timeout);
 #endif
     qemu_iohandler_fill(gpollfds);
 
diff --git a/slirp/libslirp.h b/slirp/libslirp.h
index ceabff8..5bdcbd5 100644
--- a/slirp/libslirp.h
+++ b/slirp/libslirp.h
@@ -16,8 +16,7 @@ Slirp *slirp_init(int restricted, struct in_addr vnetwork,
                   void *opaque);
 void slirp_cleanup(Slirp *slirp);
 
-void slirp_update_timeout(uint32_t *timeout);
-void slirp_pollfds_fill(GArray *pollfds);
+void slirp_pollfds_fill(GArray *pollfds, uint32_t *timeout);
 
 void slirp_pollfds_poll(GArray *pollfds, int select_error);
 
diff --git a/slirp/slirp.c b/slirp/slirp.c
index 23e60a0..fe16367 100644
--- a/slirp/slirp.c
+++ b/slirp/slirp.c
@@ -262,14 +262,33 @@ void slirp_cleanup(Slirp *slirp)
 #define CONN_CANFSEND(so) (((so)->so_state & 
(SS_FCANTSENDMORE|SS_ISFCONNECTED)) == SS_ISFCONNECTED)
 #define CONN_CANFRCV(so) (((so)->so_state & (SS_FCANTRCVMORE|SS_ISFCONNECTED)) 
== SS_ISFCONNECTED)
 
-void slirp_update_timeout(uint32_t *timeout)
+static void slirp_update_timeout(uint32_t *timeout)
 {
-    if (!QTAILQ_EMPTY(&slirp_instances)) {
-        *timeout = MIN(TIMEOUT_DEFAULT, *timeout);
+    Slirp *slirp;
+    uint32_t t;
+
+    if (*timeout <= TIMEOUT_FAST) {
+        return;
+    }
+    *timeout = MIN(1000, *timeout);
+    t = *timeout;
+
+    /* If we have tcp timeout with slirp, then we will fill @timeout with
+     * more precise value.
+     */
+    QTAILQ_FOREACH(slirp, &slirp_instances, entry) {
+        if (slirp->time_fasttimo) {
+            *timeout = TIMEOUT_FAST;
+            return;
+        }
+        if (slirp->do_slowtimo) {
+            t = MIN(TIMEOUT_SLOW, t);
+        }
     }
+    *timeout = t;
 }
 
-void slirp_pollfds_fill(GArray *pollfds)
+void slirp_pollfds_fill(GArray *pollfds, uint32_t *timeout)
 {
     Slirp *slirp;
     struct socket *so, *so_next;
@@ -439,6 +458,7 @@ void slirp_pollfds_fill(GArray *pollfds)
             }
         }
     }
+    slirp_update_timeout(timeout);
 }
 
 void slirp_pollfds_poll(GArray *pollfds, int select_error)
diff --git a/stubs/slirp.c b/stubs/slirp.c
index f1fc833..bd0ac7f 100644
--- a/stubs/slirp.c
+++ b/stubs/slirp.c
@@ -1,11 +1,7 @@
 #include "qemu-common.h"
 #include "slirp/slirp.h"
 
-void slirp_update_timeout(uint32_t *timeout)
-{
-}
-
-void slirp_pollfds_fill(GArray *pollfds)
+void slirp_pollfds_fill(GArray *pollfds, uint32_t *timeout)
 {
 }
 
-- 
1.8.1.1.298.ge7eed54