1 files changed, 118 insertions, 0 deletions
diff --git a/src/common/SubProcess.h b/src/common/SubProcess.h
new file mode 100644
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--- /dev/null
+++ b/src/common/SubProcess.h
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+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph distributed storage system
+ *
+ * Copyright (C) 2015 Mirantis Inc
+ *
+ * Author: Mykola Golub <mgolub@mirantis.com>
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ */
+
+#ifndef SUB_PROCESS_H
+#define SUB_PROCESS_H
+
+#if defined(__FreeBSD__) || defined(__APPLE__)
+#include <signal.h>
+#endif
+
+#include <sys/wait.h>
+#include <sstream>
+#include <vector>
+
+/**
+ * SubProcess:
+ * A helper class to spawn a subprocess.
+ *
+ * Example:
+ *
+ *   SubProcess cat("cat", SubProcess::PIPE, SubProcess::PIPE);
+ *   if (cat.spawn() != 0) {
+ *     std::cerr << "cat failed: " << cat.err() << std::endl;
+ *     return false;
+ *   }
+ *   write_to_fd(cat.get_stdout(), "hello world!\n");
+ *   cat.close_stdout();
+ *   read_from_fd(cat.get_stdin(), buf);
+ *   if (cat.join() != 0) {
+ *     std::cerr << cat.err() << std::endl;
+ *     return false;
+ *   }
+ */
+
+class SubProcess {
+public:
+  enum std_fd_op{
+    KEEP,
+    CLOSE,
+    PIPE
+  };
+public:
+  SubProcess(const char *cmd,
+             std_fd_op stdin_op = CLOSE,
+             std_fd_op stdout_op = CLOSE,
+             std_fd_op stderr_op = CLOSE);
+  virtual ~SubProcess();
+
+  void add_cmd_args(const char *arg, ...);
+  void add_cmd_arg(const char *arg);
+
+  virtual int spawn(); // Returns 0 on success or -errno on failure.
+  virtual int join();  // Returns exit code (0 on success).
+
+  bool is_spawned() const { return pid > 0; }
+
+  int get_stdin() const;
+  int get_stdout() const;
+  int get_stderr() const;
+
+  void close_stdin();
+  void close_stdout();
+  void close_stderr();
+
+  void kill(int signo = SIGTERM) const;
+
+  const std::string err() const;
+
+protected:
+  bool is_child() const { return pid == 0; }
+  virtual void exec();
+
+private:
+  void close(int &fd);
+
+protected:
+  std::string cmd;
+  std::vector<std::string> cmd_args;
+  std_fd_op stdin_op;
+  std_fd_op stdout_op;
+  std_fd_op stderr_op;
+  int stdin_pipe_out_fd;
+  int stdout_pipe_in_fd;
+  int stderr_pipe_in_fd;
+  int pid;
+  std::ostringstream errstr;
+};
+
+class SubProcessTimed : public SubProcess {
+public:
+  SubProcessTimed(const char *cmd, std_fd_op stdin_op = CLOSE,
+		  std_fd_op stdout_op = CLOSE, std_fd_op stderr_op = CLOSE,
+		  int timeout = 0, int sigkill = SIGKILL);
+
+protected:
+  void exec() override;
+
+private:
+  int timeout;
+  int sigkill;
+};
+
+void timeout_sighandler(int sig);
+
+#endif