[Yunq] Delete client capability in destructor.

Add a method to the server class to create an unowned capability. This
makes it simpler to create a capability for passing to other processes.

Duplicate the init yellowstone cap when using it temporarily.

yunq/client.cpp.jinja

@@ -3,9 +3,17 @@
 
 #include <glacier/buffer/byte_buffer.h>
 #include <glacier/buffer/cap_buffer.h>
+#include <mammoth/util/debug.h>
 #include <zcall.h>
 
 {% for interface in interfaces %}
+
+{{interface.name}}Client::~{{interface.name}}Client() {
+  if (endpoint_ != 0) {
+    check(ZCapRelease(endpoint_));
+    }
+}
+
 {% for method in interface.methods %}
 
 {% if method.request == None %}

yunq/client.h.jinja

@@ -14,6 +14,7 @@ class {{interface.name}}Client {
   {{interface.name}}Client(z_cap_t {{interface.name}}_cap) : endpoint_({{interface.name}}_cap) {}
   {{interface.name}}Client(const {{interface.name}}Client&) = delete;
   {{interface.name}}Client({{interface.name}}Client&& other) : endpoint_(other.endpoint_) {other.endpoint_ = 0;};
+  ~{{interface.name}}Client();
 
   z_cap_t Capability() { return endpoint_; }
 

yunq/server.cpp.jinja

@@ -35,6 +35,12 @@ void {{interface.name}}ServerBaseThreadBootstrap(void* server_base) {
   }
 }
 
+glcr::ErrorOr<z_cap_t> {{interface.name}}ServerBase::CreateClientCap() {
+  uint64_t client_cap;
+  RET_ERR(ZCapDuplicate(endpoint_, ~(kZionPerm_Read), &client_cap));
+  return client_cap;
+}
+
 glcr::ErrorOr<{{interface.name}}Client> {{interface.name}}ServerBase::CreateClient() {
   uint64_t client_cap;
   RET_ERR(ZCapDuplicate(endpoint_, ~(kZionPerm_Read), &client_cap));

yunq/server.h.jinja

@@ -17,6 +17,7 @@ class {{interface.name}}ServerBase {
   {{interface.name}}ServerBase({{interface.name}}ServerBase&&) = delete;
   virtual ~{{interface.name}}ServerBase();
 
+  glcr::ErrorOr<z_cap_t> CreateClientCap();
   glcr::ErrorOr<{{interface.name}}Client> CreateClient();
 
   [[nodiscard]] Thread RunServer();