From 4a1bcc63cd2919f74f29b41c7b000f80da7449f4 Mon Sep 17 00:00:00 2001
From: Christian Mollekopf <chrigi_1@fastmail.fm>
Date: Thu, 31 Aug 2017 13:57:25 -0600
Subject: Avoid non threadsafe initialization.

local static initialization is only threadsafe if initialized on
construction. The other codepath is not threadsafe, but is only used in
testcode.
---
 common/definitions.cpp | 18 +++++++++++++-----
 common/definitions.h   |  8 +++++++-
 2 files changed, 20 insertions(+), 6 deletions(-)

(limited to 'common')

diff --git a/common/definitions.cpp b/common/definitions.cpp
index 17977bc..ee18d52 100644
--- a/common/definitions.cpp
+++ b/common/definitions.cpp
@@ -39,11 +39,17 @@ QString Sink::storageLocation()
     return dataLocation() + "/storage";
 }
 
+static QString sinkLocation(QStandardPaths::StandardLocation location)
+{
+    return QStandardPaths::writableLocation(location) + "/sink";
+}
+
 QString Sink::dataLocation()
 {
-    static QString location;
+    static QString location = sinkLocation(QStandardPaths::GenericDataLocation);
+    //Warning: This is not threadsafe, but clearLocationCache is only ever used in testcode. The initialization above is required to make at least the initialization threadsafe (relies on C++11 threadsafe initialization).
     if (rereadDataLocation) {
-        location = QStandardPaths::writableLocation(QStandardPaths::GenericDataLocation) + "/sink";
+        location = sinkLocation(QStandardPaths::GenericDataLocation);
         rereadDataLocation = false;
     }
     return location;
@@ -51,9 +57,10 @@ QString Sink::dataLocation()
 
 QString Sink::configLocation()
 {
-    static QString location;
+    static QString location = sinkLocation(QStandardPaths::GenericConfigLocation);
+    //Warning: This is not threadsafe, but clearLocationCache is only ever used in testcode. The initialization above is required to make at least the initialization threadsafe (relies on C++11 threadsafe initialization).
     if (rereadConfigLocation) {
-        location = QStandardPaths::writableLocation(QStandardPaths::GenericConfigLocation) + "/sink";
+        location = sinkLocation(QStandardPaths::GenericConfigLocation);
         rereadConfigLocation = false;
     }
     return location;
@@ -61,8 +68,9 @@ QString Sink::configLocation()
 
 QString Sink::temporaryFileLocation()
 {
-    static QString location;
+    static QString location = dataLocation() + "/temporaryFiles";
     static bool dirCreated = false;
+    //Warning: This is not threadsafe, but clearLocationCache is only ever used in testcode. The initialization above is required to make at least the initialization threadsafe (relies on C++11 threadsafe initialization).
     if (rereadTemporaryFileLocation) {
         location = dataLocation() + "/temporaryFiles";
         dirCreated = QDir{}.mkpath(location);
diff --git a/common/definitions.h b/common/definitions.h
index ce9e794..7ef215b 100644
--- a/common/definitions.h
+++ b/common/definitions.h
@@ -25,10 +25,16 @@
 #include <QByteArray>
 
 namespace Sink {
-void SINK_EXPORT clearLocationCache();
 QString SINK_EXPORT storageLocation();
 QString SINK_EXPORT dataLocation();
 QString SINK_EXPORT configLocation();
 QString SINK_EXPORT temporaryFileLocation();
 QString SINK_EXPORT resourceStorageLocation(const QByteArray &resourceInstanceIdentifier);
+
+/**
+ * Clear the location cache and lookup locations again.
+ *
+ * Warning: Calling this results in non-threadsafe initialization, only use it in test-code.
+ */
+void SINK_EXPORT clearLocationCache();
 }
-- 
cgit v1.2.3