Add C++ wrappers of common posix functionality

posix.hh

@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) 2014 Cloudius Systems, Ltd.
+ */
+
+#ifndef FILE_DESC_HH_
+#define FILE_DESC_HH_
+
+#include "reactor.hh"
+#include "sstring.hh"
+#include <unistd.h>
+#include <assert.h>
+#include <utility>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+
+class file_desc {
+    int _fd;
+public:
+    file_desc() = delete;
+    file_desc(const file_desc&) = delete;
+    file_desc(file_desc&& x) : _fd(x._fd) { x._fd = -1; }
+    ~file_desc() { if (_fd != -1) { ::close(_fd); } }
+    void operator=(const file_desc&) = delete;
+    file_desc& operator=(file_desc&& x) {
+        if (this != &x) {
+            std::swap(_fd, x._fd);
+            if (x._fd != -1) {
+                x.close();
+            }
+        }
+        return *this;
+    }
+    void close() {
+        assert(_fd != -1);
+        auto r = ::close(_fd);
+        throw_system_error_on(r == -1);
+        _fd = -1;
+    }
+    int get() { return _fd; }
+    static file_desc open(sstring name, int flags, mode_t mode = 0) {
+        int fd = ::open(name.c_str(), flags, mode);
+        throw_system_error_on(fd == -1);
+        return file_desc(fd);
+    }
+    static file_desc socket(int family, int type, int protocol = 0) {
+        int fd = ::socket(family, type, protocol);
+        throw_system_error_on(fd == -1);
+        return file_desc(fd);
+    }
+    int ioctl(int request) {
+        return ioctl(request, 0);
+    }
+    int ioctl(int request, int value) {
+        int r = ::ioctl(_fd, request, value);
+        throw_system_error_on(r == -1);
+        return r;
+    }
+    template <class X>
+    int ioctl(int request, X& data) {
+        int r = ::ioctl(_fd, request, &data);
+        throw_system_error_on(r == -1);
+        return r;
+    }
+    template <class X>
+    int ioctl(int request, X&& data) {
+        int r = ::ioctl(_fd, request, &data);
+        throw_system_error_on(r == -1);
+        return r;
+    }
+    template <class X>
+    int setsockopt(int level, int optname, X& data) {
+        int r = ::setsockopt(_fd, level, optname, &data, sizeof(data));
+        throw_system_error_on(r == -1);
+        return r;
+    }
+    int setsockopt(int level, int optname, const char* data) {
+        int r = ::setsockopt(_fd, level, optname, data, strlen(data) + 1);
+        throw_system_error_on(r == -1);
+        return r;
+    }
+private:
+    file_desc(int fd) : _fd(fd) {}
+ };
+
+
+
+#endif /* FILE_DESC_HH_ */