From 40caf8dbdb9d82c13af800341b2dac4ccbc39fe2 Mon Sep 17 00:00:00 2001
From: Volker Birk <vb@pep.foundation>
Date: Mon, 22 Oct 2018 20:00:00 +0200
Subject: [PATCH] lazy unmarshalling for COM interface on sync thread

---
 CpEpEngine.cpp | 20 ++++++++++++++------
 CpEpEngine.h   | 17 ++++++++++-------
 2 files changed, 24 insertions(+), 13 deletions(-)

diff --git a/CpEpEngine.cpp b/CpEpEngine.cpp
index 859a613..448eb3f 100644
--- a/CpEpEngine.cpp
+++ b/CpEpEngine.cpp
@@ -12,7 +12,7 @@ using namespace pEp::Adapter;
 
 // CpEpEngine
 
-pEp::pc_container< CpEpEngine::MarshaledCallbacks, IpEpEngineCallbacks > CpEpEngine::sync_callbacks;
+CpEpEngine::callback_container CpEpEngine::sync_callbacks;
 
 // the init_mutex protects our initialization and destruction
 // against a running keysync thread, and it ensures that the
@@ -736,6 +736,18 @@ int CpEpEngine::examine_identity(pEp_identity *ident, void *management)
     return _ident;
 }
 
+static IpEpEngineCallbacks * _unmarshaled_consumer(CpEpEngine::callback_container::Container::const_iterator p)
+{
+    if (!p->cdata && p->pdata->marshaled) {
+        HRESULT r = CoGetInterfaceAndReleaseStream(p->pdata->marshaled, IID_IpEpEngineCallbacks, (LPVOID*) &p->cdata);
+        if (!SUCCEEDED(r))
+            throw runtime_error("_unmarshaled_consumer(): CoGetInterfaceAndReleaseStream() failed");
+        p->pdata->marshaled = nullptr;
+    }
+
+    return p->cdata;
+}
+
 PEP_STATUS CpEpEngine::messageToSend(message *msg)
 {
     assert(msg);
@@ -745,11 +757,7 @@ PEP_STATUS CpEpEngine::messageToSend(message *msg)
     bool in_sync = on_sync_thread();
 
     for (auto p = sync_callbacks.begin(); p != sync_callbacks.end(); ++p) {
-        IpEpEngineCallbacks *cb;
-        if (in_sync)
-            cb = p->cdata;
-        else
-            cb = p->pdata->unmarshaled;
+        IpEpEngineCallbacks *cb = in_sync ? _unmarshaled_consumer(p) : p->pdata->unmarshaled;
 
         if (cb) {
             TextMessage _msg;
diff --git a/CpEpEngine.h b/CpEpEngine.h
index 828071b..da9fa29 100644
--- a/CpEpEngine.h
+++ b/CpEpEngine.h
@@ -84,11 +84,11 @@ public:
             return res;
         }
 
+        startup<CpEpEngine>(messageToSend, notifyHandshake, this, &CpEpEngine::Startup_sync);
+
         ::register_examine_function(session(), CpEpEngine::examine_identity, (void *)this);
         ::log_event(session(), "Startup", "pEp COM Adapter", NULL, NULL);
 
-        startup<CpEpEngine>(messageToSend, notifyHandshake, this, &CpEpEngine::Startup_sync);
-
         return S_OK;
     }
 
@@ -96,6 +96,13 @@ public:
     {
     }
 
+    struct MarshaledCallbacks {
+        IpEpEngineCallbacks *unmarshaled;
+        LPSTREAM marshaled;
+    };
+
+    typedef pEp::pc_container< MarshaledCallbacks, IpEpEngineCallbacks > callback_container;
+
 protected:
     typedef locked_queue<pEp_identity_cpp> identity_queue_t;
     static ::pEp_identity * retrieve_next_identity(void *management);
@@ -117,12 +124,8 @@ protected:
 
 private:
     // callbacks for sync
-    struct MarshaledCallbacks {
-        IpEpEngineCallbacks *unmarshaled;
-        LPSTREAM marshaled;
-    };
 
-    static pEp::pc_container< MarshaledCallbacks, IpEpEngineCallbacks > sync_callbacks;
+    static callback_container sync_callbacks;
 
     void Startup_sync()
     {