1 files changed, 75 insertions, 0 deletions
diff --git a/indra/llcommon/threadpool.cpp b/indra/llcommon/threadpool.cpp
new file mode 100644
index 0000000000..aa7d4179a2
--- /dev/null
+++ b/indra/llcommon/threadpool.cpp
@@ -0,0 +1,75 @@
+/**
+ * @file   threadpool.cpp
+ * @author Nat Goodspeed
+ * @date   2021-10-21
+ * @brief  Implementation for threadpool.
+ * 
+ * $LicenseInfo:firstyear=2021&license=viewerlgpl$
+ * Copyright (c) 2021, Linden Research, Inc.
+ * $/LicenseInfo$
+ */
+
+// Precompiled header
+#include "linden_common.h"
+// associated header
+#include "threadpool.h"
+// STL headers
+// std headers
+// external library headers
+// other Linden headers
+#include "llerror.h"
+#include "llevents.h"
+#include "stringize.h"
+
+LL::ThreadPool::ThreadPool(const std::string& name, size_t threads):
+    mQueue(name),
+    mName("ThreadPool:" + name)
+{
+    for (size_t i = 0; i < threads; ++i)
+    {
+        std::string tname{ STRINGIZE(mName << ':' << (i+i) << '/' << threads) };
+        mThreads.emplace_back(tname, [this, tname](){ run(tname); });
+    }
+    // Listen on "LLApp", and when the app is shutting down, close the queue
+    // and join the workers.
+    LLEventPumps::instance().obtain("LLApp").listen(
+        mName,
+        [this](const LLSD& stat)
+        {
+            std::string status(stat["status"]);
+            if (status != "running")
+            {
+                // viewer is starting shutdown -- proclaim the end is nigh!
+                LL_DEBUGS("ThreadPool") << mName << " saw " << status << LL_ENDL;
+                close();
+            }
+            return false;
+        });
+}
+
+LL::ThreadPool::~ThreadPool()
+{
+    close();
+}
+
+void LL::ThreadPool::close()
+{
+    if (! mQueue.isClosed())
+    {
+        LL_DEBUGS("ThreadPool") << mName << " closing queue and joining threads" << LL_ENDL;
+        mQueue.close();
+        for (auto& pair: mThreads)
+        {
+            LL_DEBUGS("ThreadPool") << mName << " waiting on thread " << pair.first << LL_ENDL;
+            pair.second.join();
+        }
+        LL_DEBUGS("ThreadPool") << mName << " shutdown complete" << LL_ENDL;
+    }
+}
+
+void LL::ThreadPool::run(const std::string& name)
+{
+    LL_DEBUGS("ThreadPool") << name << " starting" << LL_ENDL;
+    mQueue.runUntilClose();
+    LL_DEBUGS("ThreadPool") << name << " stopping" << LL_ENDL;
+}