[PATCH] io.c: remove rb_ensure usage for rb_str_tmp_frozen_* calls

[Eric Wong <e@80x24.org>]

Using rb_ensure pessimizes the common case and makes the code
more difficult to read and follow.  If we hit an exceptions
during write, just let the GC handle cleanup as the exception
is already bad for garbage.

* io.c (io_fwrite): call rb_str_tmp_frozen{acquire,release} directly
  (rb_io_syswrite): ditto
  (fwrite_do, fwrite_end, swrite_do, swrite_end): remove
---
 io.c | 93 +++++++++++++++-----------------------------------------------------
 1 file changed, 20 insertions(+), 73 deletions(-)

diff --git a/io.c b/io.c
index 57ad592daf..9bb4570d26 100644
--- a/io.c
+++ b/io.c
@@ -1419,40 +1419,13 @@ do_writeconv(VALUE str, rb_io_t *fptr, int *converted)
     return str;
 }
 
-struct fwrite_arg {
-    VALUE orig;
-    VALUE tmp;
-    rb_io_t *fptr;
-    int nosync;
-};
-
-static VALUE
-fwrite_do(VALUE arg)
-{
-    struct fwrite_arg *fa = (struct fwrite_arg *)arg;
-    const char *ptr;
-    long len;
-
-    RSTRING_GETMEM(fa->tmp, ptr, len);
-
-    return (VALUE)io_binwrite(fa->tmp, ptr, len, fa->fptr, fa->nosync);
-}
-
-static VALUE
-fwrite_end(VALUE arg)
-{
-    struct fwrite_arg *fa = (struct fwrite_arg *)arg;
-
-    rb_str_tmp_frozen_release(fa->orig, fa->tmp);
-
-    return Qfalse;
-}
-
 static long
 io_fwrite(VALUE str, rb_io_t *fptr, int nosync)
 {
     int converted = 0;
-    struct fwrite_arg fa;
+    VALUE tmp;
+    long n, len;
+    const char *ptr;
 #ifdef _WIN32
     if (fptr->mode & FMODE_TTY) {
 	long len = rb_w32_write_console(str, fptr->fd);
@@ -1463,12 +1436,12 @@ io_fwrite(VALUE str, rb_io_t *fptr, int nosync)
     if (converted)
 	OBJ_FREEZE(str);
 
-    fa.orig = str;
-    fa.tmp = rb_str_tmp_frozen_acquire(str);
-    fa.fptr = fptr;
-    fa.nosync = nosync;
+    tmp = rb_str_tmp_frozen_acquire(str);
+    RSTRING_GETMEM(tmp, ptr, len);
+    n = io_binwrite(tmp, ptr, len, fptr, nosync);
+    rb_str_tmp_frozen_release(str, tmp);
 
-    return (long)rb_ensure(fwrite_do, (VALUE)&fa, fwrite_end, (VALUE)&fa);
+    return n;
 }
 
 ssize_t
@@ -4745,34 +4718,6 @@ rb_io_sysseek(int argc, VALUE *argv, VALUE io)
     return OFFT2NUM(pos);
 }
 
-struct swrite_arg {
-    VALUE orig;
-    VALUE tmp;
-    rb_io_t *fptr;
-};
-
-static VALUE
-swrite_do(VALUE arg)
-{
-    struct swrite_arg *sa = (struct swrite_arg *)arg;
-    const char *ptr;
-    long len;
-
-    RSTRING_GETMEM(sa->tmp, ptr, len);
-
-    return (VALUE)rb_write_internal(sa->fptr->fd, ptr, len);
-}
-
-static VALUE
-swrite_end(VALUE arg)
-{
-    struct swrite_arg *sa = (struct swrite_arg *)arg;
-
-    rb_str_tmp_frozen_release(sa->orig, sa->tmp);
-
-    return Qfalse;
-}
-
 /*
  *  call-seq:
  *     ios.syswrite(string)   -> integer
@@ -4789,25 +4734,27 @@ swrite_end(VALUE arg)
 static VALUE
 rb_io_syswrite(VALUE io, VALUE str)
 {
-    struct swrite_arg sa;
-    long n;
+    VALUE tmp;
+    rb_io_t *fptr;
+    long n, len;
+    const char *ptr;
 
     if (!RB_TYPE_P(str, T_STRING))
 	str = rb_obj_as_string(str);
 
     io = GetWriteIO(io);
-    GetOpenFile(io, sa.fptr);
-    rb_io_check_writable(sa.fptr);
+    GetOpenFile(io, fptr);
+    rb_io_check_writable(fptr);
 
-    if (sa.fptr->wbuf.len) {
+    if (fptr->wbuf.len) {
 	rb_warn("syswrite for buffered IO");
     }
 
-    sa.orig = str;
-    sa.tmp = rb_str_tmp_frozen_acquire(str);
-    n = (long)rb_ensure(swrite_do, (VALUE)&sa, swrite_end, (VALUE)&sa);
-
-    if (n == -1) rb_sys_fail_path(sa.fptr->pathv);
+    tmp = rb_str_tmp_frozen_acquire(str);
+    RSTRING_GETMEM(tmp, ptr, len);
+    n = rb_write_internal(fptr->fd, ptr, len);
+    if (n == -1) rb_sys_fail_path(fptr->pathv);
+    rb_str_tmp_frozen_release(str, tmp);
 
     return LONG2FIX(n);
 }
-- 
EW