intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 35 insertions, 0 deletions

diff --git a/util/system/mincore.cpp b/util/system/mincore.cpp
new file mode 100644
index 0000000000..8cbae72586
--- /dev/null
+++ b/util/system/mincore.cpp
@@ -0,0 +1,35 @@
+#include "align.h"
+#include "compiler.h"
+#include "info.h"
+#include "mincore.h"
+
+#include <util/generic/yexception.h>
+
+#include <cstring>
+
+#if defined(_unix_)
+    #include <sys/unistd.h>
+    #include <sys/mman.h>
+    #if defined(_android_)
+        #include <sys/syscall.h>
+    #endif
+#endif
+
+void InCoreMemory(const void* addr, size_t len, unsigned char* vec, size_t vecLen) {
+#if defined(_linux_)
+    const size_t pageSize = NSystemInfo::GetPageSize();
+    void* maddr = const_cast<void*>(AlignDown(addr, pageSize));
+    len = AlignUp(len, pageSize);
+    if (vecLen * pageSize < len) {
+        ythrow yexception() << "vector argument for mincore is too small: " << vecLen * pageSize << " < " << len;
+    }
+    if (::mincore(maddr, len, vec)) {
+        ythrow yexception() << LastSystemErrorText();
+    }
+#else
+    // pessimistic assumption: nothing is in core
+    Y_UNUSED(addr);
+    Y_UNUSED(len);
+    ::memset(vec, 0, vecLen);
+#endif
+}