[Lldb-commits] [lldb] [lldb-dap] Implement a MemoryMonitor for macOS & Linux (PR #129332)

[John Harrison via lldb-commits]

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@@ -0,0 +1,114 @@
+//===-- MemoryMonitor.cpp -------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "MemoryMonitor.h"
+#include "llvm/ADT/ScopeExit.h"
+#include <atomic>
+#include <cstdio>
+#include <cstring>
+#include <thread>
+
+#if defined(__APPLE__)
+#include <dispatch/dispatch.h>
+#endif
+
+#if defined(__linux__)
+#include <fcntl.h>
+#include <poll.h>
+#include <unistd.h>
+#endif
+
+using namespace lldb_dap;
+
+#if defined(__APPLE__)
+class MemoryMonitorDarwin : public MemoryMonitor {
+  using MemoryMonitor::MemoryMonitor;
+  void Start() override {
+    m_memory_pressure_source = dispatch_source_create(
+        DISPATCH_SOURCE_TYPE_MEMORYPRESSURE,
+        0, // system-wide monitoring
+        DISPATCH_MEMORYPRESSURE_WARN | DISPATCH_MEMORYPRESSURE_CRITICAL,
+        dispatch_get_main_queue());
+
+    dispatch_source_set_event_handler(m_memory_pressure_source, ^{
+      dispatch_source_memorypressure_flags_t pressureLevel =
+          dispatch_source_get_data(m_memory_pressure_source);
+      if (pressureLevel &
+          (DISPATCH_MEMORYPRESSURE_WARN | DISPATCH_MEMORYPRESSURE_CRITICAL)) {
+        m_callback();
+      }
+    });
+  }
+
+  void Stop() override { dispatch_source_cancel(m_memory_pressure_source); }
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ashgti wrote:

Do we also need to release this? I don't think we have ARC enabled in this target.

https://github.com/llvm/llvm-project/pull/129332