From: nobuyoshi nakada <nobuyoshi.nakada@...>
Date: 2005-12-22T14:38:33+09:00
Subject: Re: getpasswd

Hi,

At Thu, 22 Dec 2005 09:00:56 +0900,
Bertram Scharpf wrote in [ruby-core:06973]:
> The reason is easy to find: the `static struct passwd' that
> is used internally by both the `Etc::passwd' method and
> `expand_path' substitute-~ mechanism. `Etc' even seems to
> protect itself from using the struct twice using a static
> variable named `passwd_blocking'.

Hmmm, get{pw,gr}*_r() family aren't actually reentrant at all.

Just a dirty hack.  Otherwise, iterative methods in etc.c
would have to read all items at first.


Index: file.c
===================================================================
RCS file: /cvs/ruby/src/ruby/file.c,v
retrieving revision 1.233
diff -U2 -p -r1.233 file.c
--- file.c	21 Dec 2005 09:20:00 -0000	1.233
+++ file.c	22 Dec 2005 05:32:09 -0000
@@ -92,4 +92,29 @@ be_fchown(int fd, uid_t owner, gid_t gro
 #endif /* __BEOS__ */
 
+#ifdef HAVE_PWD_H
+int rb_passwd_blocking;
+
+struct passwd *
+rb_getpwnam(const char *name)
+{
+    if (rb_passwd_blocking) {
+	rb_raise(rb_eRuntimeError, "parallel passwd iteration");
+    }
+    return getpwnam(name);
+}
+
+struct passwd *
+rb_getpwuid(rb_uid_t uid)
+{
+    if (rb_passwd_blocking) {
+	rb_raise(rb_eRuntimeError, "parallel passwd iteration");
+    }
+    return getpwuid(uid);
+}
+
+#define getpwnam rb_getpwnam
+#define getpwuid rb_getpwuid
+#endif
+
 VALUE rb_cFile;
 VALUE rb_mFileTest;
Index: process.c
===================================================================
RCS file: /cvs/ruby/src/ruby/process.c,v
retrieving revision 1.142
diff -U2 -p -r1.142 process.c
--- process.c	20 Nov 2005 03:30:43 -0000	1.142
+++ process.c	22 Dec 2005 05:32:05 -0000
@@ -117,4 +117,28 @@ static VALUE S_Tms;
 	do {int saved_errno = errno; stmts; errno = saved_errno;} while (0)
 
+#ifdef HAVE_GRP_H
+int rb_group_blocking;
+
+struct group *
+rb_getgrnam(const char *name)
+{
+    if (rb_group_blocking) {
+	rb_raise(rb_eRuntimeError, "parallel group iteration");
+    }
+    return getgrnam(name);
+}
+
+struct group *
+rb_getgrgid(rb_gid_t gid)
+{
+    if (rb_group_blocking) {
+	rb_raise(rb_eRuntimeError, "parallel group iteration");
+    }
+    return getgrgid(gid);
+}
+
+#define getgrnam rb_getgrnam
+#define getgrgid rb_getgrgid
+#endif
 
 /*
Index: ext/etc/etc.c
===================================================================
RCS file: /cvs/ruby/src/ruby/ext/etc/etc.c,v
retrieving revision 1.20
diff -U2 -p -r1.20 etc.c
--- ext/etc/etc.c	12 Dec 2005 00:35:07 -0000	1.20
+++ ext/etc/etc.c	22 Dec 2005 05:08:56 -0000
@@ -108,4 +108,7 @@ setup_passwd(pwd)
 	);
 }
+
+RUBY_EXTERN int rb_passwd_blocking;
+#define passwd_blocking rb_passwd_blocking
 #endif
 
@@ -170,5 +173,4 @@ etc_getpwnam(obj, nam)
 
 #ifdef HAVE_GETPWENT
-static int passwd_blocking = 0;
 static VALUE
 passwd_ensure()
@@ -317,4 +319,7 @@ setup_group(grp)
 			 mem);
 }
+
+RUBY_EXTERN int rb_group_blocking;
+#define group_blocking rb_group_blocking
 #endif
 
@@ -375,5 +380,4 @@ etc_getgrnam(obj, nam)
 
 #ifdef HAVE_GETGRENT
-static int group_blocking = 0;
 static VALUE
 group_ensure()


-- 
Nobu Nakada