Merge branch 'develop' into rlva/base

1 files changed, 102 insertions, 0 deletions

diff --git a/indra/llcommon/lualistener.cpp b/indra/llcommon/lualistener.cpp
new file mode 100644
index 0000000000..94085c6798
--- /dev/null
+++ b/indra/llcommon/lualistener.cpp
@@ -0,0 +1,102 @@
+/**
+ * @file   lualistener.cpp
+ * @author Nat Goodspeed
+ * @date   2024-02-06
+ * @brief  Implementation for lualistener.
+ *
+ * $LicenseInfo:firstyear=2024&license=viewerlgpl$
+ * Copyright (c) 2024, Linden Research, Inc.
+ * $/LicenseInfo$
+ */
+
+// Precompiled header
+#include "linden_common.h"
+// associated header
+#include "lualistener.h"
+// STL headers
+// std headers
+#include <iomanip>                  // std::quoted()
+// external library headers
+#include "luau/lua.h"
+// other Linden headers
+#include "llerror.h"
+#include "llleaplistener.h"
+#include "lua_function.h"
+
+const int MAX_QSIZE = 1000;
+
+std::ostream& operator<<(std::ostream& out, const LuaListener& self)
+{
+    return out << "LuaListener(" << std::quoted(self.mCoroName) << ", "
+               << self.getReplyName() << ", " << self.getCommandName() << ")";
+}
+
+LuaListener::LuaListener(lua_State* L):
+    mCoroName(LLCoros::getName()),
+    mListener(new LLLeapListener(
+        "LuaListener",
+        [this](const std::string& pump, const LLSD& data)
+        { return queueEvent(pump, data); })),
+    // Listen for shutdown events.
+    mShutdownConnection(
+        LLCoros::getStopListener(
+            "LuaState",
+            mCoroName,
+            [this](const LLSD&)
+            {
+                // If a Lua script is still blocked in getNext() during
+                // viewer shutdown, close the queue to wake up getNext().
+                mQueue.close();
+            }))
+{
+    LL_DEBUGS("Lua") << "LuaListener(" << std::quoted(mCoroName) << ")" << LL_ENDL;
+}
+
+LuaListener::~LuaListener()
+{
+    LL_DEBUGS("Lua") << "~LuaListener(" << std::quoted(mCoroName) << ")" << LL_ENDL;
+}
+
+std::string LuaListener::getReplyName() const
+{
+    return mListener->getReplyPump().getName();
+}
+
+std::string LuaListener::getCommandName() const
+{
+    return mListener->getPumpName();
+}
+
+bool LuaListener::queueEvent(const std::string& pump, const LLSD& data)
+{
+    // Our Lua script might be stalled, or just fail to retrieve events. Don't
+    // grow this queue indefinitely. But don't set MAX_QSIZE as the queue
+    // capacity or we'd block the post() call trying to propagate this event!
+    if (auto size = mQueue.size(); size > MAX_QSIZE)
+    {
+        LL_WARNS("Lua") << "LuaListener queue for " << mCoroName
+                        << " exceeds " << MAX_QSIZE << ": " << size
+                        << " -- discarding event" << LL_ENDL;
+    }
+    else
+    {
+        mQueue.push(decltype(mQueue)::value_type(pump, data));
+    }
+    return false;
+}
+
+LuaListener::PumpData LuaListener::getNext()
+{
+    try
+    {
+        LLCoros::TempStatus status("get_event_next()");
+        return mQueue.pop();
+    }
+    catch (const LLThreadSafeQueueInterrupt&)
+    {
+        // mQueue has been closed. The only way that happens is when we detect
+        // viewer shutdown. Terminate the calling Lua coroutine.
+        LLCoros::checkStop();
+        return {};
+    }
+}