[ruby-dev:17871] Re: non-blocking IO

なかだです。

At Wed, 31 Jul 2002 22:44:28 +0900,
Yukihiro Matsumoto wrote:
> ということで、現時点での私の気持ちは
> 
>   * getsなど行指向入力はEWOULDBLOCKを無視
>   * read系はEWOULDBLOCKがきたらすでに読み込んだぶんを文字列
>     で返す。

すでに読み込んだぶんが0だったら単に空文字列ということでしょうか?

ZnZさんのブロックを使うという案もどうかなと思うのですが…。
<http://znz.s1.xrea.com/t/?date=20020731#p02>

それと、1.6で末尾にゴミがつきます。


Index: io.c
===================================================================
RCS file: /cvs/ruby/src/ruby/io.c,v
retrieving revision 1.69.2.27
diff -u -2 -p -r1.69.2.27 io.c
--- io.c	20 May 2002 04:32:54 -0000	1.69.2.27
+++ io.c	31 Jul 2002 18:21:52 -0000
@@ -464,5 +464,5 @@ io_fread(ptr, len, f)
     int c;
 
-    while (n--) {
+    for (; n > 0; --n) {
 	if (!READ_DATA_PENDING(f)) {
 	    rb_thread_wait_fd(fileno(f));
@@ -474,7 +474,7 @@ io_fread(ptr, len, f)
 	    if (ferror(f)) {
 		if (errno == EINTR) continue;
-		if (errno == EAGAIN) return len - n;
+		if (errno == EAGAIN) break;
 #if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN
-		if (errno == EWOULDBLOCK) return len - n;
+		if (errno == EWOULDBLOCK) break;
 #endif
 		return 0;
@@ -486,5 +486,5 @@ io_fread(ptr, len, f)
     }
 
-    return len - n - 1;
+    return len - n;
 }
 

Index: io.c
===================================================================
RCS file: /cvs/ruby/src/ruby/io.c,v
retrieving revision 1.142
diff -u -2 -p -r1.142 io.c
--- io.c	28 Jun 2002 18:26:00 -0000	1.142
+++ io.c	31 Jul 2002 18:11:27 -0000
@@ -259,4 +259,24 @@ io_fflush(f, fptr)
 }
 
+void
+rb_io_wait_readable(f)
+    int f;
+{
+    fd_set rfds;
+    FD_ZERO(&rfds);
+    FD_SET(f, &rfds);
+    rb_thread_select(f + 1, &rfds, NULL, NULL, NULL);
+}
+
+void
+rb_io_wait_writable(f)
+    int f;
+{
+    fd_set wfds;
+    FD_ZERO(&wfds);
+    FD_SET(f, &wfds);
+    rb_thread_select(f + 1, NULL, &wfds, NULL, NULL);
+}
+
 /* writing functions */
 static VALUE
@@ -266,5 +286,6 @@ io_write(io, str)
     OpenFile *fptr;
     FILE *f;
-    long n;
+    long n, r;
+    register char *ptr;
 
     rb_secure(4);
@@ -282,21 +303,28 @@ io_write(io, str)
     f = GetWriteFile(fptr);
 
+    ptr = RSTRING(str)->ptr;
+    n = RSTRING(str)->len;
+    do {
 #ifdef __human68k__
-    {
-	register char *ptr = RSTRING(str)->ptr;
-	n = RSTRING(str)->len;
-	while (--n >= 0)
-	    if (fputc(*ptr++, f) == EOF)
-		break;
-	n = ptr - RSTRING(str)->ptr;
-    }
-    if (n != RSTRING(str)->len && ferror(f))
-	rb_sys_fail(fptr->path);
+	if (fputc(*ptr++, f) == EOF) {
+	    if (ferror(f)) rb_sys_fail(fptr->path);
+	    break;
+	}
+	--n;
 #else
-    n = fwrite(RSTRING(str)->ptr, 1, RSTRING(str)->len, f);
-    if (n != RSTRING(str)->len && ferror(f)) {
+	r = fwrite(ptr, 1, n, f);
+	if (r == n || !ferror(f)) break;
+#ifdef EWOULDBLOCK
+	if (errno == EWOULDBLOCK) {
+	    rb_io_wait_writable(fileno(f));
+	    ptr += r;
+	    n -= r;
+	    continue;
+	}
+#endif
 	rb_sys_fail(fptr->path);
-    }
 #endif
+    } while (n > 0);
+    n = ptr - RSTRING(str)->ptr;
     if (fptr->mode & FMODE_SYNC) {
 	io_fflush(f, fptr);
@@ -542,4 +570,24 @@ rb_io_to_io(io)
 
 /* reading functions */
+static void
+io_retryable(f, path)
+    FILE *f;
+    const char *path;
+{
+    switch (errno) {
+      case EAGAIN:
+#if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN
+      case EWOULDBLOCK:
+#endif
+	rb_io_wait_readable(fileno(f));
+	/* fall through */
+      case EINTR:
+	clearerr(f);
+	break;
+      default:
+	rb_sys_fail(path);
+	break;
+    }
+}
 
 static long
@@ -583,4 +631,5 @@ io_fread(ptr, len, f)
 		switch (errno) {
 		  case EINTR:
+		    clearerr(f);
 		    continue;
 		  case EAGAIN:
@@ -588,4 +637,5 @@ io_fread(ptr, len, f)
 		  case EWOULDBLOCK:
 #endif
+		    clearerr(f);
 #ifdef __BORLANDC__
 		  case EPIPE:
@@ -654,4 +704,5 @@ read_all(fptr, siz)
 	if (n == 0 && bytes == 0) {
 	    if (feof(fptr->f)) return Qnil;
+	    if (!ferror(fptr->f)) return rb_str_new(0, 0);
 	    rb_sys_fail(fptr->path);
 	}
@@ -753,6 +804,6 @@ appendline(fptr, delim, strp)
 	if (c == EOF) {
 	    if (ferror(f)) {
-		if (errno == EINTR) continue;
-		rb_sys_fail(fptr->path);
+		io_retryable(f, fptr->path);
+		continue;
 	    }
 	    return c;
@@ -1065,6 +1116,6 @@ rb_io_each_byte(io)
 	if (c == EOF) {
 	    if (ferror(f)) {
-		if (errno == EINTR) continue;
-		rb_sys_fail(fptr->path);
+		io_retryable(f, fptr->path);
+		continue;
 	    }
 	    break;
@@ -1096,6 +1147,6 @@ rb_io_getc(io)
     if (c == EOF) {
 	if (ferror(f)) {
-	    if (errno == EINTR) goto retry;
-	    rb_sys_fail(fptr->path);
+	    io_retryable(f, fptr->path);
+	    continue;
 	}
 	return Qnil;


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