SubProcess: allow CLOSE/PIPE/KEEP parent std fd

Signed-off-by: Yunchuan Wen <yunchuan.wen@kylin-cloud.com>

diff --git a/src/common/SubProcess.h b/src/common/SubProcess.h
index 8b8ffc7cc8d7dfdf9c4c1e4edcd2f0a756c606bf..42c1dad5853d8fc76fb815f991fad4e5d6f7396d 100644 (file)
--- a/src/common/SubProcess.h
+++ b/src/common/SubProcess.h
@@ -40,7 +40,7 @@
  *
  * Example:
  *
- *   SubProcess cat("cat", true, true);
+ *   SubProcess cat("cat", SubProcess::PIPE, SubProcess::PIPE);
  *   if (cat.spawn() != 0) {
  *     std::cerr << "cat failed: " << cat.err() << std::endl;
  *     return false;
@@ -56,8 +56,16 @@
 
 class SubProcess {
 public:
-  SubProcess(const char *cmd, bool pipe_stdin = false, bool pipe_stdout = false,
-            bool pipe_stderr = false);
+  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, ...);
@@ -90,9 +98,9 @@ private:
 protected:
   std::string cmd;
   std::vector<std::string> cmd_args;
-  bool pipe_stdin;
-  bool pipe_stdout;
-  bool pipe_stderr;
+  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;
@@ -102,8 +110,8 @@ protected:
 
 class SubProcessTimed : public SubProcess {
 public:
-  SubProcessTimed(const char *cmd, bool pipe_stdin = false,
-                 bool pipe_stdout = false, bool pipe_stderr = false,
+  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:
@@ -114,12 +122,12 @@ private:
   int sigkill;
 };
 
-SubProcess::SubProcess(const char *cmd_, bool use_stdin, bool use_stdout, bool use_stderr) :
+SubProcess::SubProcess(const char *cmd_, std_fd_op stdin_op_, std_fd_op stdout_op_, std_fd_op stderr_op_) :
   cmd(cmd_),
   cmd_args(),
-  pipe_stdin(use_stdin),
-  pipe_stdout(use_stdout),
-  pipe_stderr(use_stderr),
+  stdin_op(stdin_op_),
+  stdout_op(stdout_op_),
+  stderr_op(stderr_op_),
   stdin_pipe_out_fd(-1),
   stdout_pipe_in_fd(-1),
   stderr_pipe_in_fd(-1),
@@ -155,21 +163,21 @@ void SubProcess::add_cmd_arg(const char *arg) {
 
 int SubProcess::get_stdin() const {
   assert(is_spawned());
-  assert(pipe_stdin);
+  assert(stdin_op == PIPE);
 
   return stdin_pipe_out_fd;
 }
 
 int SubProcess::get_stdout() const {
   assert(is_spawned());
-  assert(pipe_stdout);
+  assert(stdout_op == PIPE);
 
   return stdout_pipe_in_fd;
 }
 
 int SubProcess::get_stderr() const {
   assert(is_spawned());
-  assert(pipe_stderr);
+  assert(stderr_op == PIPE);
 
   return stderr_pipe_in_fd;
 }
@@ -184,21 +192,21 @@ void SubProcess::close(int &fd) {
 
 void SubProcess::close_stdin() {
   assert(is_spawned());
-  assert(pipe_stdin);
+  assert(stdin_op == PIPE);
 
   close(stdin_pipe_out_fd);
 }
 
 void SubProcess::close_stdout() {
   assert(is_spawned());
-  assert(pipe_stdout);
+  assert(stdout_op == PIPE);
 
   close(stdout_pipe_in_fd);
 }
 
 void SubProcess::close_stderr() {
   assert(is_spawned());
-  assert(pipe_stderr);
+  assert(stderr_op == PIPE);
 
   close(stderr_pipe_in_fd);
 }
@@ -247,9 +255,9 @@ int SubProcess::spawn() {
 
   int ret = 0;
 
-  if ((pipe_stdin  && ::pipe(ipipe) == -1) ||
-      (pipe_stdout && ::pipe(opipe) == -1) ||
-      (pipe_stderr && ::pipe(epipe) == -1)) {
+  if ((stdin_op == PIPE  && ::pipe(ipipe) == -1) ||
+      (stdout_op == PIPE && ::pipe(opipe) == -1) ||
+      (stderr_op == PIPE && ::pipe(epipe) == -1)) {
     ret = -errno;
     errstr << "pipe failed: " << cpp_strerror(errno);
     goto fail;
@@ -290,11 +298,11 @@ int SubProcess::spawn() {
     if (maxfd == -1)
       maxfd = 16384;
     for (int fd = 0; fd <= maxfd; fd++) {
-      if (fd == STDIN_FILENO && pipe_stdin)
+      if (fd == STDIN_FILENO && stdin_op != CLOSE)
        continue;
-      if (fd == STDOUT_FILENO && pipe_stdout)
+      if (fd == STDOUT_FILENO && stdout_op != CLOSE)
        continue;
-      if (fd == STDERR_FILENO && pipe_stderr)
+      if (fd == STDERR_FILENO && stderr_op != CLOSE)
        continue;
       ::close(fd);
     }
@@ -363,10 +371,10 @@ int SubProcess::join() {
   return EXIT_FAILURE;
 }
 
-SubProcessTimed::SubProcessTimed(const char *cmd, bool pipe_stdin,
-                                bool pipe_stdout, bool pipe_stderr,
+SubProcessTimed::SubProcessTimed(const char *cmd, std_fd_op stdin_op,
+                                std_fd_op stdout_op, std_fd_op stderr_op,
                                 int timeout_, int sigkill_) :
-  SubProcess(cmd, pipe_stdin, pipe_stdout, pipe_stderr),
+  SubProcess(cmd, stdin_op, stdout_op, stderr_op),
   timeout(timeout_),
   sigkill(sigkill_) {
 }