From: nobu.nakada@...
Date: 2002-09-30T16:30:22+09:00
Subject: [ruby-dev:18420] Re: rubicon on EWS4800

なかだです。

At Mon, 30 Sep 2002 11:51:49 +0900,
WATANABE Tetsuya wrote:
> このパッチのよろしくないところは、fseek のエラー処理
> (エラーになるか確認したかったため)と「struct OpenFile 
> の mode」の bit を増やしているところです。

やってることはほぼ同じだと思います。ただ、[ruby-dev:18396]によ
るとfseek()の前にもfflush()が必要なように見えるんですが。

このパッチを当てたconfigureで、whether need to flushのテストの
結果はどうなるでしょうか。とくにbefore seek。


Index: configure.in
===================================================================
RCS file: /cvs/ruby/src/ruby/configure.in,v
retrieving revision 1.142
diff -u -2 -p -r1.142 configure.in
--- configure.in	25 Sep 2002 07:03:01 -0000	1.142
+++ configure.in	29 Sep 2002 23:07:32 -0000
@@ -251,5 +251,8 @@ beos*)		;;
 cygwin*)	rb_cv_have_daylight=no
 		ac_cv_var_tzname=no
-		ac_cv_func__setjmp=no;;
+		ac_cv_func__setjmp=no
+		rb_cv_need_io_flush_between_rw=no
+		rb_cv_need_io_flush_before_seek=no
+		;;
 mingw*)		LIBS="-lwsock32 -lmsvcrt $LIBS"
 		ac_cv_header_a_out_h=no
@@ -267,4 +270,6 @@ mingw*)		LIBS="-lwsock32 -lmsvcrt $LIBS"
 		ac_cv_func_telldir=yes
 		ac_cv_func_crypt=no
+		rb_cv_need_io_flush_between_rw=no
+		rb_cv_need_io_flush_before_seek=no
 		;;
 os2_emx*)	LIBS="-lm $LIBS"
@@ -568,4 +573,46 @@ else
 fi
 
+AC_DEFUN(RUBY_CHECK_IO_NEED_FLUSH,
+[AC_CACHE_CHECK(whether need to flush [$1], [$2],
+    [AC_TRY_RUN([
+#include <stdio.h>
+
+char *fn = "conftest.dat";
+char *wombat = "wombat\n";
+char *koara = "koara\n";
+
+int main()
+{
+    char buf[BUFSIZ];
+    FILE *f;
+    int r = 1;
+
+    if (!(f = fopen(fn, "w+"))) return 1;
+    fputs(wombat, f);
+    fflush(f);
+    fseek(f, 0, 0);
+    if (!fgets(buf, BUFSIZ, f) || strcmp(buf, wombat)) goto fail;
+    ]ifelse(index($2,between_rw),-1,fflush(f);)[
+    fputs(koara, f);
+    ]ifelse(index($2,before_seek),-1,fflush(f);)[
+    fseek(f, 0, 0);
+    ]ifelse(index($2,between_rw),-1,fflush(f);)[
+    if (!fgets(buf, BUFSIZ, f) || strcmp(buf, wombat)) goto fail;
+    if (!fgets(buf, BUFSIZ, f) || strcmp(buf, koara)) goto fail;
+    r = 0;
+  fail:
+    fclose(f);
+    unlink(fn);
+    return r;
+}
+], [$2]=no, [$2]=yes, [$2]=yes)])])
+
+RUBY_CHECK_IO_NEED_FLUSH(between R/W, rb_cv_need_io_flush_between_rw)
+RUBY_CHECK_IO_NEED_FLUSH(before seek, rb_cv_need_io_flush_before_seek)
+if test "$rb_cv_need_io_flush_between_rw" = yes -o \
+	"$rb_cv_need_io_flush_before_seek" = yes; then
+  AC_DEFINE(NEED_IO_FLUSH, 1)
+fi
+
 dnl default value for $KANJI
 DEFAULT_KCODE="KCODE_NONE"
Index: io.c
===================================================================
RCS file: /cvs/ruby/src/ruby/io.c,v
retrieving revision 1.160
diff -u -2 -p -r1.160 io.c
--- io.c	25 Sep 2002 07:03:01 -0000	1.160
+++ io.c	30 Sep 2002 06:18:36 -0000
@@ -183,4 +183,6 @@ rb_io_check_closed(fptr)
 }
 
+static void io_fflush _((FILE *, OpenFile *));
+
 void
 rb_io_check_readable(fptr)
@@ -190,4 +192,9 @@ rb_io_check_readable(fptr)
 	rb_raise(rb_eIOError, "not opened for reading");
     }
+#if NEED_IO_FLUSH
+    if ((fptr->mode & FMODE_WBUF) && !fptr->f2) {
+	io_fflush(fptr->f, fptr);
+    }
+#endif
 }
 
@@ -199,4 +206,9 @@ rb_io_check_writable(fptr)
 	rb_raise(rb_eIOError, "not opened for writing");
     }
+#if NEED_IO_FLUSH
+    if ((fptr->mode & FMODE_RBUF) && !fptr->f2) {
+	io_fflush(fptr->f, fptr);
+    }
+#endif
 }
 
@@ -248,5 +260,5 @@ io_fflush(f, fptr)
     TRAP_END;
     if (n == EOF) rb_sys_fail(fptr->path);
-    fptr->mode &= ~FMODE_WBUF;
+    fptr->mode &= ~(FMODE_WBUF|FMODE_RBUF);
 }
 
@@ -389,4 +401,21 @@ rb_io_tell(io)
 #endif
 
+#if NEED_IO_FLUSH
+static void
+flush_before_seek(fptr)
+    OpenFile *fptr;
+{
+    int mode = fptr->mode;
+    if (mode & FMODE_RBUF) {
+	io_fflush(fptr->f, fptr);
+    }
+    if (mode & FMODE_WBUF) {
+	io_fflush((fptr->f2 ? fptr->f2 : fptr->f), fptr);
+    }
+}
+#else
+#define flush_before_seek(fptr) ((void)(fptr))
+#endif
+
 static VALUE
 rb_io_seek(io, offset, whence)
@@ -398,4 +427,5 @@ rb_io_seek(io, offset, whence)
 
     GetOpenFile(io, fptr);
+    flush_before_seek(fptr);
     pos = fseeko(fptr->f, NUM2OFFT(offset), whence);
     if (pos != 0) rb_sys_fail(fptr->path);
@@ -429,4 +459,5 @@ rb_io_set_pos(io, offset)
 
     GetOpenFile(io, fptr);
+    flush_before_seek(fptr);
     pos = fseeko(fptr->f, NUM2OFFT(offset), SEEK_SET);
     if (pos != 0) rb_sys_fail(fptr->path);
@@ -443,4 +474,5 @@ rb_io_rewind(io)
 
     GetOpenFile(io, fptr);
+    flush_before_seek(fptr);
     if (fseeko(fptr->f, 0L, 0) != 0) rb_sys_fail(fptr->path);
     clearerr(fptr->f);
@@ -472,4 +504,5 @@ rb_io_eof(io)
     if (ch != EOF) {
 	ungetc(ch, fptr->f);
+	fptr->mode |= FMODE_RBUF;
 	return Qfalse;
     }
@@ -718,4 +751,5 @@ read_all(fptr, siz)
     if (bytes == 0) return rb_str_new(0,0);
     if (bytes != siz) rb_str_resize(str, bytes);
+    fptr->mode |= FMODE_RBUF;
 
     return str;
@@ -755,4 +789,5 @@ io_read(argc, argv, io)
 	rb_sys_fail(fptr->path);
     }
+    fptr->mode |= FMODE_RBUF;
     RSTRING(str)->len = n;
     RSTRING(str)->ptr[n] = '\0';
@@ -905,4 +940,5 @@ rb_io_getline_fast(fptr, delim)
 
     if (!NIL_P(str)) {
+	fptr->mode |= FMODE_RBUF;
 	fptr->lineno++;
 	lineno = INT2FIX(fptr->lineno);
@@ -960,4 +996,5 @@ rb_io_getline(rs, fptr)
 
     if (!NIL_P(str)) {
+	fptr->mode |= FMODE_RBUF;
 	fptr->lineno++;
 	lineno = INT2FIX(fptr->lineno);
@@ -2233,4 +2270,6 @@ io_reopen(io, nfile)
     }
     if ((orig->mode & FMODE_READABLE) && pos >= 0) {
+	flush_before_seek(fptr);
+	flush_before_seek(orig);
 	fseeko(fptr->f, pos, SEEK_SET);
 	fseeko(orig->f, pos, SEEK_SET);
Index: rubyio.h
===================================================================
RCS file: /cvs/ruby/src/ruby/rubyio.h,v
retrieving revision 1.18
diff -u -2 -p -r1.18 rubyio.h
--- rubyio.h	16 Aug 2002 02:52:25 -0000	1.18
+++ rubyio.h	21 Sep 2002 17:35:51 -0000
@@ -33,4 +33,5 @@ typedef struct OpenFile {
 #define FMODE_SYNC      8
 #define FMODE_WBUF     16
+#define FMODE_RBUF     32
 
 #define GetOpenFile(obj,fp) rb_io_check_closed((fp) = RFILE(rb_io_taint_check(obj))->fptr)


-- 
--- 僕の前にBugはない。
--- 僕の後ろにBugはできる。
    中田 伸悦