From 9b22fd38b8259f33928c7b3ff7868e0bc4b60d1e Mon Sep 17 00:00:00 2001
From: Ruslan Migirov <trapi78@gmail.com>
Date: Tue, 28 Nov 2023 13:25:36 +0200
Subject: [PATCH] Remove 'friend' from 'read_wavein' callback function (#6971)

Resolves build issue in MSYS2 MinGW64 environment

Signed-off-by: Ruslan Migirov <trapi78@gmail.com>
---
 gr-audio/lib/windows/windows_source.cc | 21 +++++++++++++--------
 gr-audio/lib/windows/windows_source.h  | 20 ++++++++++++++------
 2 files changed, 27 insertions(+), 14 deletions(-)

diff --git a/gr-audio/lib/windows/windows_source.cc b/gr-audio/lib/windows/windows_source.cc
index ad494417eb5..21999fb1177 100644
--- a/gr-audio/lib/windows/windows_source.cc
+++ b/gr-audio/lib/windows/windows_source.cc
@@ -321,25 +321,30 @@ int windows_source::open_wavein_device(void)
     return 0;
 }
 
-static void CALLBACK read_wavein(
+void CALLBACK windows_source::read_wavein(
     HWAVEIN hwi, UINT uMsg, DWORD_PTR dwInstance, DWORD_PTR dwParam1, DWORD_PTR dwParam2)
 {
-    // Ignore WIM_OPEN and WIM_CLOSE messages
     if (uMsg == WIM_DATA) {
-        if (!dwInstance) {
+        windows_source* source = reinterpret_cast<windows_source*>(dwInstance);
+        if (!source) {
             gr::logger_ptr logger;
             logger->error("callback function missing buffer queue: {:s}",
                           strerror(errno));
+            return;
         }
-        LPWAVEHDR lp_wave_hdr = (LPWAVEHDR)dwParam1; // The new audio data
-        windows_source* source = (windows_source*)dwInstance;
+
+        LPWAVEHDR lp_wave_hdr =
+            reinterpret_cast<LPWAVEHDR>(dwParam1); // The new audio data
+
         {
-            std::lock_guard<std::mutex> lock(source->buffer_queue_mutex);
-            if (source->buffer_queue.size() < MAX_QUEUE_SIZE) {
-                source->buffer_queue.push(lp_wave_hdr); // Add the buffer to the queue
+            std::lock_guard<std::mutex> lock(source->get_buffer_queue_mutex());
+            auto& buffer_queue = source->get_buffer_queue();
+            if (buffer_queue.size() < MAX_QUEUE_SIZE) {
+                buffer_queue.push(lp_wave_hdr); // Add the buffer to the queue
             }
         }
     }
 }
+
 } /* namespace audio */
 } /* namespace gr */
diff --git a/gr-audio/lib/windows/windows_source.h b/gr-audio/lib/windows/windows_source.h
index fa206f1b5e4..444c69ea6d1 100644
--- a/gr-audio/lib/windows/windows_source.h
+++ b/gr-audio/lib/windows/windows_source.h
@@ -11,8 +11,12 @@
 #ifndef INCLUDED_AUDIO_WINDOWS_SOURCE_H
 #define INCLUDED_AUDIO_WINDOWS_SOURCE_H
 
+#ifndef WIN32_LEAN_AND_MEAN
 #define WIN32_LEAN_AND_MEAN
+#endif
+#ifndef NOMINMAX
 #define NOMINMAX // stops windef.h defining max/min under cygwin
+#endif
 
 #include <mmsystem.h>
 #include <windows.h>
@@ -51,11 +55,11 @@ class windows_source : public source
     UINT find_device(std::string szDeviceName);
     std::queue<LPWAVEHDR> buffer_queue;
     std::mutex buffer_queue_mutex;
-    friend static void CALLBACK read_wavein(HWAVEIN hwi,
-                                            UINT uMsg,
-                                            DWORD_PTR dwInstance,
-                                            DWORD_PTR dwParam1,
-                                            DWORD_PTR dwParam2);
+    static void CALLBACK read_wavein(HWAVEIN hwi,
+                                     UINT uMsg,
+                                     DWORD_PTR dwInstance,
+                                     DWORD_PTR dwParam1,
+                                     DWORD_PTR dwParam2);
 
 public:
     windows_source(int sampling_freq, const std::string device_name = "");
@@ -64,9 +68,13 @@ class windows_source : public source
     int work(int noutput_items,
              gr_vector_const_void_star& input_items,
              gr_vector_void_star& output_items);
+
+    std::mutex& get_buffer_queue_mutex() { return buffer_queue_mutex; }
+
+    std::queue<LPWAVEHDR>& get_buffer_queue() { return buffer_queue; }
 };
 
-static void CALLBACK read_wavein(
+void CALLBACK read_wavein(
     HWAVEIN hwi, UINT uMsg, DWORD_PTR dwInstance, DWORD_PTR dwParam1, DWORD_PTR dwParam2);
 
 } /* namespace audio */