From 2139349468145af1c198ac7fb8afb78ca9ceb8be Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Fri, 21 Mar 2025 15:43:32 +0100
Subject: [PATCH] Use global FFT planner lock in GUI

This *should* not be needed since the GUI is single
threaded, but it doesn't hurt, just in case some
someday someone uses a background thread :)
---
 gtk2_ardour/fft.cc       | 4 ++++
 gtk2_ardour/fft_graph.cc | 2 ++
 2 files changed, 6 insertions(+)

diff --git a/gtk2_ardour/fft.cc b/gtk2_ardour/fft.cc
index b46e81a9b8..6d00698152 100644
--- a/gtk2_ardour/fft.cc
+++ b/gtk2_ardour/fft.cc
@@ -22,6 +22,8 @@
 #include <string.h>
 #include <math.h>
 
+#include "ardour/ardour.h"
+
 using namespace GTKArdour;
 
 FFT::FFT(uint32_t windowSize)
@@ -37,6 +39,7 @@ FFT::FFT(uint32_t windowSize)
 	_power_at_bin  = (float *) malloc(sizeof(float) * _data_size);
 	_phase_at_bin  = (float *) malloc(sizeof(float) * _data_size);
 
+	Glib::Threads::Mutex::Lock lk (ARDOUR::fft_planner_lock);
 	_plan = fftwf_plan_r2r_1d(_window_size, _fftInput, _fftOutput, FFTW_R2HC, FFTW_ESTIMATE);
 
 	reset();
@@ -138,6 +141,7 @@ FFT::~FFT()
 	if (_hann_window) {
 		free(_hann_window);
 	}
+	Glib::Threads::Mutex::Lock lk (ARDOUR::fft_planner_lock);
 	fftwf_destroy_plan(_plan);
 	free(_power_at_bin);
 	free(_phase_at_bin);
diff --git a/gtk2_ardour/fft_graph.cc b/gtk2_ardour/fft_graph.cc
index 30a7d6f219..529b36ec02 100644
--- a/gtk2_ardour/fft_graph.cc
+++ b/gtk2_ardour/fft_graph.cc
@@ -92,6 +92,7 @@ FFTGraph::setWindowSize_internal (int windowSize)
 	_windowSize = windowSize;
 	_dataSize = windowSize / 2;
 	if (_in != 0) {
+		Glib::Threads::Mutex::Lock lk (ARDOUR::fft_planner_lock);
 		fftwf_destroy_plan (_plan);
 		free (_in);
 		_in = 0;
@@ -143,6 +144,7 @@ FFTGraph::setWindowSize_internal (int windowSize)
 	for (unsigned int i = 0; i < _dataSize; i++) {
 		_logScale[i] = 0;
 	}
+	Glib::Threads::Mutex::Lock lk (ARDOUR::fft_planner_lock);
 	_plan = fftwf_plan_r2r_1d (_windowSize, _in, _out, FFTW_R2HC, FFTW_MEASURE);
 }