diff options
Diffstat (limited to 'ext/io/nonblock/nonblock.c')
-rw-r--r-- | ext/io/nonblock/nonblock.c | 132 |
1 files changed, 99 insertions, 33 deletions
diff --git a/ext/io/nonblock/nonblock.c b/ext/io/nonblock/nonblock.c index 1c0bdc68e7..d90538f735 100644 --- a/ext/io/nonblock/nonblock.c +++ b/ext/io/nonblock/nonblock.c @@ -17,16 +17,27 @@ #endif #include <fcntl.h> +#ifndef HAVE_RB_IO_DESCRIPTOR +static int +io_descriptor_fallback(VALUE io) +{ + rb_io_t *fptr; + GetOpenFile(io, fptr); + return fptr->fd; +} +#define rb_io_descriptor io_descriptor_fallback +#endif + #ifdef F_GETFL static int -io_nonblock_mode(int fd) +get_fcntl_flags(int fd) { int f = fcntl(fd, F_GETFL); if (f == -1) rb_sys_fail(0); return f; } #else -#define io_nonblock_mode(fd) ((void)(fd), 0) +#define get_fcntl_flags(fd) ((void)(fd), 0) #endif #ifdef F_GETFL @@ -39,10 +50,8 @@ io_nonblock_mode(int fd) static VALUE rb_io_nonblock_p(VALUE io) { - rb_io_t *fptr; - GetOpenFile(io, fptr); - if (io_nonblock_mode(fptr->fd) & O_NONBLOCK) - return Qtrue; + if (get_fcntl_flags(rb_io_descriptor(io)) & O_NONBLOCK) + return Qtrue; return Qfalse; } #else @@ -50,6 +59,15 @@ rb_io_nonblock_p(VALUE io) #endif #ifdef F_SETFL +static void +set_fcntl_flags(int fd, int f) +{ + if (fcntl(fd, F_SETFL, f) == -1) + rb_sys_fail(0); +} + +#ifndef RUBY_IO_NONBLOCK_METHODS + static int io_nonblock_set(int fd, int f, int nb) { @@ -63,8 +81,7 @@ io_nonblock_set(int fd, int f, int nb) return 0; f &= ~O_NONBLOCK; } - if (fcntl(fd, F_SETFL, f) == -1) - rb_sys_fail(0); + set_fcntl_flags(fd, f); return 1; } @@ -74,32 +91,77 @@ io_nonblock_set(int fd, int f, int nb) * * Enables non-blocking mode on a stream when set to * +true+, and blocking mode when set to +false+. + * + * This method set or clear O_NONBLOCK flag for the file descriptor + * in <em>ios</em>. + * + * The behavior of most IO methods is not affected by this flag + * because they retry system calls to complete their task + * after EAGAIN and partial read/write. + * (An exception is IO#syswrite which doesn't retry.) + * + * This method can be used to clear non-blocking mode of standard I/O. + * Since nonblocking methods (read_nonblock, etc.) set non-blocking mode but + * they doesn't clear it, this method is usable as follows. + * + * END { STDOUT.nonblock = false } + * STDOUT.write_nonblock("foo") + * + * Since the flag is shared across processes and + * many non-Ruby commands doesn't expect standard I/O with non-blocking mode, + * it would be safe to clear the flag before Ruby program exits. + * + * For example following Ruby program leaves STDIN/STDOUT/STDER non-blocking mode. + * (STDIN, STDOUT and STDERR are connected to a terminal. + * So making one of them nonblocking-mode effects other two.) + * Thus cat command try to read from standard input and + * it causes "Resource temporarily unavailable" error (EAGAIN). + * + * % ruby -e ' + * STDOUT.write_nonblock("foo\n")'; cat + * foo + * cat: -: Resource temporarily unavailable + * + * Clearing the flag makes the behavior of cat command normal. + * (cat command waits input from standard input.) + * + * % ruby -rio/nonblock -e ' + * END { STDOUT.nonblock = false } + * STDOUT.write_nonblock("foo") + * '; cat + * foo + * */ static VALUE -rb_io_nonblock_set(VALUE io, VALUE nb) +rb_io_nonblock_set(VALUE self, VALUE value) { - rb_io_t *fptr; - GetOpenFile(io, fptr); - if (RTEST(nb)) - rb_io_set_nonblock(fptr); - else - io_nonblock_set(fptr->fd, io_nonblock_mode(fptr->fd), RTEST(nb)); - return io; + if (RTEST(value)) { + rb_io_t *fptr; + GetOpenFile(self, fptr); + rb_io_set_nonblock(fptr); + } + else { + int descriptor = rb_io_descriptor(self); + io_nonblock_set(descriptor, get_fcntl_flags(descriptor), RTEST(value)); + } + + return self; } +#endif /* RUBY_IO_NONBLOCK_METHODS */ + static VALUE io_nonblock_restore(VALUE arg) { int *restore = (int *)arg; - if (fcntl(restore[0], F_SETFL, restore[1]) == -1) - rb_sys_fail(0); + set_fcntl_flags(restore[0], restore[1]); return Qnil; } /* * call-seq: - * io.nonblock {|io| } -> io - * io.nonblock(boolean) {|io| } -> io + * io.nonblock {|io| } -> object + * io.nonblock(boolean) {|io| } -> object * * Yields +self+ in non-blocking mode. * @@ -107,24 +169,25 @@ io_nonblock_restore(VALUE arg) * The original mode is restored after the block is executed. */ static VALUE -rb_io_nonblock_block(int argc, VALUE *argv, VALUE io) +rb_io_nonblock_block(int argc, VALUE *argv, VALUE self) { int nb = 1; - rb_io_t *fptr; - int f, restore[2]; - GetOpenFile(io, fptr); + int descriptor = rb_io_descriptor(self); + if (argc > 0) { - VALUE v; - rb_scan_args(argc, argv, "01", &v); - nb = RTEST(v); + VALUE v; + rb_scan_args(argc, argv, "01", &v); + nb = RTEST(v); } - f = io_nonblock_mode(fptr->fd); - restore[0] = fptr->fd; - restore[1] = f; - if (!io_nonblock_set(fptr->fd, f, nb)) - return rb_yield(io); - return rb_ensure(rb_yield, io, io_nonblock_restore, (VALUE)restore); + + int current_flags = get_fcntl_flags(descriptor); + int restore[2] = {descriptor, current_flags}; + + if (!io_nonblock_set(descriptor, current_flags, nb)) + return rb_yield(self); + + return rb_ensure(rb_yield, self, io_nonblock_restore, (VALUE)restore); } #else #define rb_io_nonblock_set rb_f_notimplement @@ -134,7 +197,10 @@ rb_io_nonblock_block(int argc, VALUE *argv, VALUE io) void Init_nonblock(void) { +#ifndef RUBY_IO_NONBLOCK_METHODS rb_define_method(rb_cIO, "nonblock?", rb_io_nonblock_p, 0); rb_define_method(rb_cIO, "nonblock=", rb_io_nonblock_set, 1); +#endif + rb_define_method(rb_cIO, "nonblock", rb_io_nonblock_block, -1); } |