* process.c (redirect_dup2): when the new FD of dup2() coflicts

  with one of the timer thread FDs, the internal FD is diverted.
  [Bug #11336] [ruby-core:69886] [Bug #11350] [ruby-core:69961]
    
* process.c (dup2_with_divert): new function for the above purpose.
   
* thread_pthread.c (rb_divert_reserved_fd): new function for
  diverting reserved FD. If the given FD is the same as one of the
  reserved FDs, the reserved FD number is internally changed.
  It returns -1 when error. Otherwise, returns 0. It also returns
  0 if there is no need to change reserved FD number.

* thread_win32.c (rb_divert_reserved_fd): always returns 0 because
  of no reserved FDs.

* internal.h (rb_divert_reserved_fd): prototype declaration.
  It is Ruby internal use only.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51268 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 12 insertions, 2 deletions

diff --git a/process.c b/process.c
index 7d3b1f580a..daf2eabf1e 100644
--- a/process.c
+++ b/process.c
@@ -305,6 +305,16 @@ close_unless_reserved(int fd)
     return close(fd); /* async-signal-safe */
 }
 
+static inline int
+dup2_with_divert(int oldfd, int newfd)
+{
+    if (rb_divert_reserved_fd(newfd) == -1) { /* async-signal-safe if no error occurred */
+        return -1;
+    } else {
+        return dup2(oldfd, newfd); /* async-signal-safe */
+    }
+}
+
 /*#define DEBUG_REDIRECT*/
 #if defined(DEBUG_REDIRECT)
 
@@ -344,7 +354,7 @@ static int
 redirect_dup2(int oldfd, int newfd)
 {
     int ret;
-    ret = dup2(oldfd, newfd);
+    ret = dup2_with_divert(oldfd, newfd);
     ttyprintf("dup2(%d, %d) => %d\n", oldfd, newfd, ret);
     return ret;
 }
@@ -378,7 +388,7 @@ parent_redirect_close(int fd)
 
 #else
 #define redirect_dup(oldfd) dup(oldfd)
-#define redirect_dup2(oldfd, newfd) dup2((oldfd), (newfd))
+#define redirect_dup2(oldfd, newfd) dup2_with_divert((oldfd), (newfd))
 #define redirect_close(fd) close_unless_reserved(fd)
 #define parent_redirect_open(pathname, flags, perm) rb_cloexec_open((pathname), (flags), (perm))
 #define parent_redirect_close(fd) close_unless_reserved(fd)