From 57d59b4c7a2cd25a21a0884fd771ed2d2c73c0de Mon Sep 17 00:00:00 2001
From: Chris Cannam <cannam@all-day-breakfast.com>
Date: Mon, 26 Sep 2022 10:11:16 +0100
Subject: [PATCH] Eliminate the mlock logic entirely. It's caused a couple of
 issues lately and it turns out it wasn't even used!

---
 src/common/RingBuffer.h | 23 +----------------------
 src/common/sysutils.h   | 10 ----------
 2 files changed, 1 insertion(+), 32 deletions(-)

diff --git a/src/common/RingBuffer.h b/src/common/RingBuffer.h
index 2fabd14..40d8ebb 100644
--- a/src/common/RingBuffer.h
+++ b/src/common/RingBuffer.h
@@ -77,12 +77,6 @@ public:
      */
     RingBuffer<T> *resized(int newSize) const;
 
-    /**
-     * Lock the ring buffer into physical memory.  Returns true
-     * for success.
-     */
-    bool mlock();
-
     /**
      * Reset read and write pointers, thus emptying the buffer.
      * Should be called from the write thread.
@@ -184,7 +178,6 @@ protected:
     std::atomic<int>  m_writer;
     std::atomic<int>  m_reader;
     const int         m_size;
-    bool              m_mlocked;
 
     int readSpaceFor(int w, int r) const {
         int space;
@@ -209,8 +202,7 @@ template <typename T>
 RingBuffer<T>::RingBuffer(int n) :
     m_buffer(allocate<T>(n + 1)),
     m_writer(0),
-    m_size(n + 1),
-    m_mlocked(false)
+    m_size(n + 1)
 {
 #ifdef DEBUG_RINGBUFFER
     std::cerr << "RingBuffer<T>[" << this << "]::RingBuffer(" << n << ")" << std::endl;
@@ -226,10 +218,6 @@ RingBuffer<T>::~RingBuffer()
     std::cerr << "RingBuffer<T>[" << this << "]::~RingBuffer" << std::endl;
 #endif
 
-    if (m_mlocked) {
-	MUNLOCK((void *)m_buffer, m_size * sizeof(T));
-    }
-
     deallocate(m_buffer);
 }
 
@@ -263,15 +251,6 @@ RingBuffer<T>::resized(int newSize) const
     return newBuffer;
 }
 
-template <typename T>
-bool
-RingBuffer<T>::mlock()
-{
-    if (MLOCK((void *)m_buffer, m_size * sizeof(T))) return false;
-    m_mlocked = true;
-    return true;
-}
-
 template <typename T>
 void
 RingBuffer<T>::reset()
diff --git a/src/common/sysutils.h b/src/common/sysutils.h
index f4ccebb..32d1440 100644
--- a/src/common/sysutils.h
+++ b/src/common/sysutils.h
@@ -108,10 +108,6 @@ void gettimeofday(struct timeval *p, void *tz);
 
 #ifdef _WIN32
 
-#define MLOCK(a,b)   (void)1
-#define MUNLOCK(a,b) (void)1
-#define MUNLOCK_SAMPLEBLOCK(a) (void)1
-
 namespace RubberBand {
 extern void system_memorybarrier();
 }
@@ -119,14 +115,8 @@ extern void system_memorybarrier();
 
 #else // !_WIN32
 
-#include <sys/mman.h>
-#include <dlfcn.h>
 #include <stdio.h>
 
-#define MLOCK(a,b)   mlock((char *)(a),(b))
-#define MUNLOCK(a,b) (munlock((char *)(a),(b)) ? (perror("munlock failed"), 0) : 0)
-#define MUNLOCK_SAMPLEBLOCK(a) do { if (!(a).empty()) { const float &b = *(a).begin(); MUNLOCK(&b, (a).capacity() * sizeof(float)); } } while(0);
-
 #ifdef __APPLE__
 #  if defined __MAC_10_12
 #    define MBARRIER() __sync_synchronize()