svm: queue sub: Add conditional timed wait

On reviece side svm queue only permits blocking and
non-blocking calls. This patch adds timed wait blocking
functionality which returns either on signal/event or
on given time out.

It also preserves the original behavior, so it will not
hurt client applications which are using svm queue.

Change-Id: Ic10632170330a80afb8bc781d4ccddfe4da2c69a
Signed-off-by: Mohsin Kazmi <sykazmi@cisco.com>

3 files changed, 14 insertions, 6 deletions

diff --git a/src/vpp-api/vapi/vapi.c b/src/vpp-api/vapi/vapi.c
index 7aa346bf083..754c89cf561 100644
--- a/src/vpp-api/vapi/vapi.c
+++ b/src/vpp-api/vapi/vapi.c
@@ -502,7 +502,8 @@ out:
 }
 
 vapi_error_e
-vapi_recv (vapi_ctx_t ctx, void **msg, size_t * msg_size)
+vapi_recv (vapi_ctx_t ctx, void **msg, size_t * msg_size,
+	   svm_q_conditional_wait_t cond, u32 time)
 {
   if (!ctx || !ctx->connected || !msg || !msg_size)
     {
@@ -519,7 +520,9 @@ vapi_recv (vapi_ctx_t ctx, void **msg, size_t * msg_size)
 
   svm_queue_t *q = am->vl_input_queue;
   VAPI_DBG ("doing shm queue sub");
-  int tmp = svm_queue_sub (q, (u8 *) & data, 0);
+
+  int tmp = svm_queue_sub (q, (u8 *) & data, cond, time);
+
   if (tmp == 0)
     {
 #if VAPI_DEBUG_ALLOC
@@ -700,7 +703,7 @@ vapi_dispatch_one (vapi_ctx_t ctx)
   VAPI_DBG ("vapi_dispatch_one()");
   void *msg;
   size_t size;
-  vapi_error_e rv = vapi_recv (ctx, &msg, &size);
+  vapi_error_e rv = vapi_recv (ctx, &msg, &size, SVM_Q_WAIT, 0);
   if (VAPI_OK != rv)
     {
       VAPI_DBG ("vapi_recv failed with rv=%d", rv);
diff --git a/src/vpp-api/vapi/vapi.h b/src/vpp-api/vapi/vapi.h
index 245bf654e8a..fc48e7d402c 100644
--- a/src/vpp-api/vapi/vapi.h
+++ b/src/vpp-api/vapi/vapi.h
@@ -22,6 +22,7 @@
 #include <stdbool.h>
 #include <vppinfra/types.h>
 #include <vapi/vapi_common.h>
+#include <svm/queue.h>
 
 #ifdef __cplusplus
 extern "C"
@@ -162,10 +163,13 @@ extern "C"
  * @param ctx opaque vapi context
  * @param[out] msg pointer to result variable containing message
  * @param[out] msg_size pointer to result variable containing message size
+ * @param cond enum type for blocking, non-blocking or timed wait call
+ * @param time in sec for timed wait
  *
  * @return VAPI_OK on success, other error code on error
  */
-  vapi_error_e vapi_recv (vapi_ctx_t ctx, void **msg, size_t * msg_size);
+  vapi_error_e vapi_recv (vapi_ctx_t ctx, void **msg, size_t * msg_size,
+			  svm_q_conditional_wait_t cond, u32 time);
 
 /**
  * @brief wait for connection to become readable or writable
diff --git a/src/vpp-api/vapi/vapi.hpp b/src/vpp-api/vapi/vapi.hpp
index 893851a0dbb..28357db420c 100644
--- a/src/vpp-api/vapi/vapi.hpp
+++ b/src/vpp-api/vapi/vapi.hpp
@@ -245,7 +245,7 @@ public:
    *
    * @return VAPI_OK on success, other error code on error
    */
-  vapi_error_e dispatch (const Common_req *limit = nullptr)
+  vapi_error_e dispatch (const Common_req *limit = nullptr, u32 time = 5)
   {
     std::lock_guard<std::mutex> lock (dispatch_mutex);
     vapi_error_e rv = VAPI_OK;
@@ -254,7 +254,8 @@ public:
       {
         void *shm_data;
         size_t shm_data_size;
-        rv = vapi_recv (vapi_ctx, &shm_data, &shm_data_size);
+        rv = vapi_recv (vapi_ctx, &shm_data, &shm_data_size, SVM_Q_TIMEDWAIT,
+                        time);
         if (VAPI_OK != rv)
           {
             return rv;