From 84b2b8738a54d5f2d8fb170562711565b1fa2632 Mon Sep 17 00:00:00 2001
From: casey langen <casey.langen@gmail.com>
Date: Sat, 31 Oct 2020 11:48:25 -0700
Subject: [PATCH] Restructure RemoteLibrary and LocalLibrary queries that use
 kWaitIndefinite to avoid deadlock.

---
 src/musikcore/library/LocalLibrary.cpp  | 30 ++++++++++-----------
 src/musikcore/library/RemoteLibrary.cpp | 35 ++++++++++++++-----------
 2 files changed, 35 insertions(+), 30 deletions(-)

diff --git a/src/musikcore/library/LocalLibrary.cpp b/src/musikcore/library/LocalLibrary.cpp
index da1c0b8c5..fac621aec 100644
--- a/src/musikcore/library/LocalLibrary.cpp
+++ b/src/musikcore/library/LocalLibrary.cpp
@@ -196,27 +196,27 @@ int LocalLibrary::EnqueueAndWait(QueryPtr query, size_t timeoutMs, Callback call
             return -1;
         }
 
-        auto context = std::make_shared<QueryContext>();
-        context->query = localQuery;
-        context->callback = callback;
-
-        queryQueue.push_back(context);
-        queueCondition.notify_all();
-
         if (VERBOSE_LOGGING) {
             musik::debug::info(TAG, "query '" + localQuery->Name() + "' enqueued");
         }
 
-        if (timeoutMs > 0) {
-            while (!this->exit && (
+        auto context = std::make_shared<QueryContext>();
+        context->query = localQuery;
+        context->callback = callback;
+
+        if (timeoutMs == kWaitIndefinite) {
+            this->RunQuery(context);
+        }
+        else {
+            queryQueue.push_back(context);
+            queueCondition.notify_all();
+
+            if (timeoutMs > 0) {
+                while (!this->exit && (
                     context->query->GetStatus() == db::IQuery::Idle ||
                     context->query->GetStatus() == db::IQuery::Running)
-                )
-            {
-                if (timeoutMs == kWaitIndefinite) {
-                    this->queueCondition.wait(lock);
-                }
-                else {
+                    )
+                {
                     auto result = this->queueCondition.wait_for(lock, timeoutMs * milliseconds(1));
                     if (result == std::cv_status::timeout) {
                         break;
diff --git a/src/musikcore/library/RemoteLibrary.cpp b/src/musikcore/library/RemoteLibrary.cpp
index 66a8b23df..318951468 100644
--- a/src/musikcore/library/RemoteLibrary.cpp
+++ b/src/musikcore/library/RemoteLibrary.cpp
@@ -199,24 +199,29 @@ int RemoteLibrary::EnqueueAndWait(QueryPtr query, size_t timeoutMs, Callback cal
         context->query = serializableQuery;
         context->callback = callback;
 
-        queryQueue.push_back(context);
-        queueCondition.notify_all();
+        if (timeoutMs == kWaitIndefinite) {
+            this->RunQuery(context);
+        }
+        else {
+            queryQueue.push_back(context);
+            queueCondition.notify_all();
 
-        if (timeoutMs > 0) {
-            while (
-                !this->exit &&
-                this->IsQueryInFlight(context->query) &&
-                !isQueryDone(context->query))
-            {
-                if (timeoutMs == kWaitIndefinite) {
-                    this->syncQueryCondition.wait(lock);
-                    break;
-                }
-                else {
-                    auto result = this->syncQueryCondition.wait_for(lock, timeoutMs * milliseconds(1));
-                    if (result == std::cv_status::timeout) {
+            if (timeoutMs > 0) {
+                while (
+                    !this->exit &&
+                    this->IsQueryInFlight(context->query) &&
+                    !isQueryDone(context->query))
+                {
+                    if (timeoutMs == kWaitIndefinite) {
+                        this->syncQueryCondition.wait(lock);
                         break;
                     }
+                    else {
+                        auto result = this->syncQueryCondition.wait_for(lock, timeoutMs * milliseconds(1));
+                        if (result == std::cv_status::timeout) {
+                            break;
+                        }
+                    }
                 }
             }
         }