From ca4f0e5239c38ac3329f2359f6e66d410a4d73c2 Mon Sep 17 00:00:00 2001
From: Hombre <natureh.510@gmail.com>
Date: Sat, 14 Jul 2018 15:52:43 +0200
Subject: [PATCH] Add mutex to the Lensfun library access.

(try to fix #4580)
---
 rtengine/rtlensfun.cc | 15 +++++++++++++--
 rtengine/rtlensfun.h  |  2 ++
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/rtengine/rtlensfun.cc b/rtengine/rtlensfun.cc
index 8216f0b83..792a86b61 100644
--- a/rtengine/rtlensfun.cc
+++ b/rtengine/rtlensfun.cc
@@ -33,6 +33,7 @@ extern const Settings *settings;
 LFModifier::~LFModifier()
 {
     if (data_) {
+        MyMutex::MyLock lock(*lfModifierMutex);
         data_->Destroy();
     }
 }
@@ -56,7 +57,7 @@ void LFModifier::correctDistortion(double &x, double &y, int cx, int cy, double
     if (swap_xy_) {
         std::swap(xx, yy);
     }
-    if (data_->ApplyGeometryDistortion(xx, yy, 1, 1, pos)) {
+    if (data_->ApplyGeometryDistortion(xx, yy, 1, 1, pos)) {  // This is thread-safe
         x = pos[0];
         y = pos[1];
         if (swap_xy_) {
@@ -95,7 +96,7 @@ void LFModifier::correctCA(double &x, double &y, int cx, int cy, int channel) co
     if (swap_xy_) {
         std::swap(x, y);
     }
-    data_->ApplySubpixelDistortion(x, y, 1, 1, pos);
+    data_->ApplySubpixelDistortion(x, y, 1, 1, pos);  // This is thread-safe
     x = pos[2*channel];
     y = pos[2*channel+1];
     if (swap_xy_) {
@@ -112,12 +113,14 @@ void LFModifier::correctCA(double &x, double &y, int cx, int cy, int channel) co
 
 void LFModifier::processVignetteLine(int width, int y, float *line) const
 {
+    MyMutex::MyLock lock(*lfModifierMutex);
     data_->ApplyColorModification(line, 0, y, width, 1, LF_CR_1(INTENSITY), 0);
 }
 
 
 void LFModifier::processVignetteLine3Channels(int width, int y, float *line) const
 {
+    MyMutex::MyLock lock(*lfModifierMutex);
     data_->ApplyColorModification(line, 0, y, width, 1, LF_CR_3(RED, GREEN, BLUE), 0);
 }
 
@@ -157,6 +160,7 @@ LFModifier::LFModifier(lfModifier *m, bool swap_xy, int flags):
     swap_xy_(swap_xy),
     flags_(flags)
 {
+    lfModifierMutex = new MyMutex;
 }
 
 
@@ -374,12 +378,14 @@ bool LFDatabase::LoadDirectory(const char *dirname)
 LFDatabase::LFDatabase():
     data_(nullptr)
 {
+    lfDBMutex = new MyMutex;
 }
 
 
 LFDatabase::~LFDatabase()
 {
     if (data_) {
+        MyMutex::MyLock lock(*lfDBMutex);
         data_->Destroy();
     }
 }
@@ -395,6 +401,7 @@ std::vector<LFCamera> LFDatabase::getCameras() const
 {
     std::vector<LFCamera> ret;
     if (data_) {
+        MyMutex::MyLock lock(*lfDBMutex);
         auto cams = data_->GetCameras();
         while (*cams) {
             ret.emplace_back();
@@ -410,6 +417,7 @@ std::vector<LFLens> LFDatabase::getLenses() const
 {
     std::vector<LFLens> ret;
     if (data_) {
+        MyMutex::MyLock lock(*lfDBMutex);
         auto lenses = data_->GetLenses();
         while (*lenses) {
             ret.emplace_back();
@@ -425,6 +433,7 @@ LFCamera LFDatabase::findCamera(const Glib::ustring &make, const Glib::ustring &
 {
     LFCamera ret;
     if (data_) {
+        MyMutex::MyLock lock(*lfDBMutex);
         auto found = data_->FindCamerasExt(make.c_str(), model.c_str());
         if (found) {
             ret.data_ = found[0];
@@ -439,6 +448,7 @@ LFLens LFDatabase::findLens(const LFCamera &camera, const Glib::ustring &name) c
 {
     LFLens ret;
     if (data_) {
+        MyMutex::MyLock lock(*lfDBMutex);
         auto found = data_->FindLenses(camera.data_, nullptr, name.c_str());
         for (size_t pos = 0; !found && pos < name.size(); ) {
             // try to split the maker from the model of the lens -- we have to
@@ -476,6 +486,7 @@ std::unique_ptr<LFModifier> LFDatabase::getModifier(const LFCamera &camera, cons
 {
     std::unique_ptr<LFModifier> ret;
     if (data_) {
+        MyMutex::MyLock lock(*lfDBMutex);
         if (camera && lens) {
             lfModifier *mod = lfModifier::Create(lens.data_, camera.getCropFactor(), width, height);
             int flags = LF_MODIFY_DISTORTION | LF_MODIFY_SCALE | LF_MODIFY_TCA;
diff --git a/rtengine/rtlensfun.h b/rtengine/rtlensfun.h
index 7690ef544..f75f25d4f 100644
--- a/rtengine/rtlensfun.h
+++ b/rtengine/rtlensfun.h
@@ -57,6 +57,7 @@ private:
     lfModifier *data_;
     bool swap_xy_;
     int flags_;
+    MyMutex *lfModifierMutex;
 };
 
 class LFCamera final
@@ -121,6 +122,7 @@ private:
     LFDatabase();
     bool LoadDirectory(const char *dirname);
 
+    MyMutex *lfDBMutex;
     static LFDatabase instance_;
     lfDatabase *data_;
 };