Add non-blocking recv function to Socket class

renderdoc/os/os_specific.h

@@ -147,6 +147,7 @@ public:
 
   bool SendDataBlocking(const void *buf, uint32_t length);
   bool RecvDataBlocking(void *data, uint32_t length);
+  bool RecvDataNonBlocking(void *data, uint32_t &length);
 
 private:
   ptrdiff_t socket;

renderdoc/os/posix/posix_network.cpp

@@ -183,6 +183,38 @@ bool Socket::IsRecvDataWaiting()
   return ret > 0;
 }
 
+bool Socket::RecvDataNonBlocking(void *buf, uint32_t &length)
+{
+  if(length == 0)
+    return true;
+
+  // socket is already blocking, don't have to change anything
+  int ret = recv(socket, (char *)buf, length, 0);
+
+  if(ret > 0)
+  {
+    length = (uint32_t)ret;
+  }
+  else
+  {
+    length = 0;
+    int err = errno;
+
+    if(err == EWOULDBLOCK || err == EAGAIN)
+    {
+      return true;
+    }
+    else
+    {
+      RDCWARN("recv: %d", err);
+      Shutdown();
+      return false;
+    }
+  }
+
+  return true;
+}
+
 bool Socket::RecvDataBlocking(void *buf, uint32_t length)
 {
   if(length == 0)

renderdoc/os/win32/win32_network.cpp

@@ -184,6 +184,38 @@ bool Socket::IsRecvDataWaiting()
   return ret > 0;
 }
 
+bool Socket::RecvDataNonBlocking(void *buf, uint32_t &length)
+{
+  if(length == 0)
+    return true;
+
+  // socket is already blocking, don't have to change anything
+  int ret = recv(socket, (char *)buf, length, 0);
+
+  if(ret > 0)
+  {
+    length = (uint32_t)ret;
+  }
+  else
+  {
+    length = 0;
+    int err = WSAGetLastError();
+
+    if(err == WSAEWOULDBLOCK)
+    {
+      return true;
+    }
+    else
+    {
+      RDCWARN("recv: %d", err);
+      Shutdown();
+      return false;
+    }
+  }
+
+  return true;
+}
+
 bool Socket::RecvDataBlocking(void *buf, uint32_t length)
 {
   if(length == 0)