Remove usage of IO internals

TODO.md

@@ -1,4 +1,3 @@
-- issue #102 - test and see what this is about
 - Look at RPC benchmark more closely: is there a way to reduce the overhead of
   the `backend_base_switch_fiber` function?
 

docs/cheat-sheet.md

@@ -71,7 +71,7 @@ def calculate_some_stuff(n)
     acc += big_calc(acc, i)
     snooze if (i % 1000) == 0
   end
-end 
+end
 ```
 
 ### Suspend fiber

examples/core/rpc_benchmark.rb

@@ -94,11 +94,11 @@ def bm_fiber_raw
   $server_raw.transfer 3
 end
 
-p bm_raw
-p bm_send
-p bm_fiber
-p bm_fiber_optimized
-p bm_fiber_single
+# p bm_raw
+# p bm_send
+# p bm_fiber
+# p bm_fiber_optimized
+# p bm_fiber_single
 p bm_fiber_raw
 p bm_fiber_schedule
 
@@ -116,17 +116,17 @@ def warmup_jit
 
 puts "warming up JIT..."
 
-3.times do
-  warmup_jit
-  sleep 1
-end
+# 3.times do
+#   warmup_jit
+#   sleep 1
+# end
 
 Benchmark.ips do |x|
-  x.report("raw") { bm_raw }
-  x.report("send") { bm_send }
-  x.report("fiber") { bm_fiber }
-  x.report("fiber_optimized") { bm_fiber_optimized }
-  x.report("fiber_single") { bm_fiber_single }
+  # x.report("raw") { bm_raw }
+  # x.report("send") { bm_send }
+  # x.report("fiber") { bm_fiber }
+  # x.report("fiber_optimized") { bm_fiber_optimized }
+  # x.report("fiber_single") { bm_fiber_single }
   x.report("fiber_raw") { bm_fiber_raw }
   x.report("fiber_schedule") { bm_fiber_schedule }
   x.compare!

examples/core/stream_mockup.rb

@@ -0,0 +1,68 @@
+# frozen_string_literal: true
+
+require 'bundler/setup'
+require 'polyphony'
+
+class Stream
+  def initialize(io)
+    @io = io
+    @buffer = +''
+    @length = 0
+    @pos = 0
+  end
+
+  def getbyte
+    if @pos == @length
+      return nil if !fill_buffer
+    end
+    byte = @buffer[@pos].getbyte(0)
+    @pos += 1
+    byte
+  end
+
+  def getc
+    if @pos == @length
+      return nil if !fill_buffer
+    end
+    char = @buffer[@pos]
+    @pos += 1
+    char
+  end
+
+  def ungetc(c)
+    @buffer.insert(@pos, c)
+    @length += 1
+    c
+  end
+
+  def gets
+  end
+
+  def read
+  end
+
+  def readpartial
+  end
+
+  private
+
+  def fill_buffer
+    Polyphony.backend_read(@io, @buffer, 8192, false, -1)
+    @length = @buffer.size
+  end
+end
+
+i, o = IO.pipe
+s = Stream.new(i)
+
+f = spin do
+  loop do
+    b = s.getbyte
+    p getbyte: b
+    s.ungetc(b.to_s) if rand > 0.5
+  end
+end
+
+o << 'hello'
+sleep 0.1
+

ext/polyphony/backend_common.c

@@ -389,12 +389,12 @@ inline void set_fd_blocking_mode(int fd, int blocking) {
 #endif
 }
 
-inline void io_verify_blocking_mode(rb_io_t *fptr, VALUE io, VALUE blocking) {
+inline void io_verify_blocking_mode(VALUE io, int fd, VALUE blocking) {
   VALUE blocking_mode = rb_ivar_get(io, ID_ivar_blocking_mode);
   if (blocking == blocking_mode) return;
 
   rb_ivar_set(io, ID_ivar_blocking_mode, blocking);
-  set_fd_blocking_mode(fptr->fd, blocking == Qtrue);
+  set_fd_blocking_mode(fd, blocking == Qtrue);
 }
 
 inline void backend_run_idle_tasks(struct Backend_base *base) {
@@ -455,9 +455,7 @@ VALUE Backend_stats(VALUE self) {
 }
 
 VALUE Backend_verify_blocking_mode(VALUE self, VALUE io, VALUE blocking) {
-  rb_io_t *fptr;
-  GetOpenFile(io, fptr);
-  io_verify_blocking_mode(fptr, io, blocking);
+  io_verify_blocking_mode(io, rb_io_descriptor(io), blocking);
   return self;
 }
 

ext/polyphony/backend_common.h

@@ -10,6 +10,15 @@
 #include "ruby/io.h"
 #include "runqueue.h"
 
+#ifndef HAVE_RB_IO_DESCRIPTOR
+static int rb_io_descriptor_fallback(VALUE io) {
+  rb_io_t *fptr;
+  GetOpenFile(io, fptr);
+  return fptr->fd;
+}
+#define rb_io_descriptor rb_io_descriptor_fallback
+#endif
+
 struct backend_stats {
   unsigned int runqueue_size;
   unsigned int runqueue_length;
@@ -145,7 +154,7 @@ VALUE Backend_stats(VALUE self);
 VALUE Backend_verify_blocking_mode(VALUE self, VALUE io, VALUE blocking);
 void backend_run_idle_tasks(struct Backend_base *base);
 void set_fd_blocking_mode(int fd, int blocking);
-void io_verify_blocking_mode(rb_io_t *fptr, VALUE io, VALUE blocking);
+void io_verify_blocking_mode(VALUE io, int fd, VALUE blocking);
 void backend_setup_stats_symbols();
 int backend_getaddrinfo(VALUE host, VALUE port, struct sockaddr **ai_addr);
 VALUE name_to_addrinfo(void *name, socklen_t len);

ext/polyphony/backend_io_uring.c

@@ -28,9 +28,9 @@ VALUE SYM_write;
 VALUE eArgumentError;
 
 #ifdef POLYPHONY_UNSET_NONBLOCK
-#define io_unset_nonblock(fptr, io) io_verify_blocking_mode(fptr, io, Qtrue)
+#define io_unset_nonblock(io, fd) io_verify_blocking_mode(io, fd, Qtrue)
 #else
-#define io_unset_nonblock(fptr, io)
+#define io_unset_nonblock(io, fd)
 #endif
 
 typedef struct Backend_t {
@@ -389,10 +389,10 @@ static inline int fd_from_io(VALUE io, rb_io_t **fptr, int write_mode, int recti
     if (underlying_io != Qnil) io = underlying_io;
 
     GetOpenFile(io, *fptr);
-    io_unset_nonblock(*fptr, io);
+    int fd = rb_io_descriptor(io);
+    io_unset_nonblock(io, fd);
     if (rectify_file_pos) rectify_io_file_pos(*fptr);
-
-    return (*fptr)->fd;
+    return fd;
   }
 }
 
@@ -1376,7 +1376,7 @@ VALUE Backend_wait_io(VALUE self, VALUE io, VALUE write) {
 
 //   if (fd < 0) return Qnil;
 
-//   io_unset_nonblock(fptr, io);
+//   io_unset_nonblock(io, fd);
 
 //   ctx = context_store_acquire(&backend->store, OP_CLOSE);
 //   sqe = io_uring_backend_get_sqe(backend);

ext/polyphony/backend_libev.c

@@ -277,10 +277,10 @@ static inline int fd_from_io(VALUE io, rb_io_t **fptr, int write_mode, int recti
     if (underlying_io != Qnil) io = underlying_io;
 
     GetOpenFile(io, *fptr);
-    io_verify_blocking_mode(*fptr, io, Qfalse);
+    int fd = rb_io_descriptor(io);
+    io_verify_blocking_mode(io, fd, Qfalse);
     if (rectify_file_pos) rectify_io_file_pos(*fptr);
-
-    return (*fptr)->fd;
+    return rb_io_descriptor(io);
   }
 }
 
@@ -681,7 +681,7 @@ VALUE Backend_accept(VALUE self, VALUE server_socket, VALUE socket_class) {
       fp->fd = fd;
       fp->mode = FMODE_READWRITE | FMODE_DUPLEX;
       rb_io_ascii8bit_binmode(socket);
-      io_verify_blocking_mode(fp, socket, Qfalse);
+      io_verify_blocking_mode(socket, fd, Qfalse);
       rb_io_synchronized(fp);
 
       // if (rsock_do_not_reverse_lookup) {
@@ -736,7 +736,7 @@ VALUE Backend_accept_loop(VALUE self, VALUE server_socket, VALUE socket_class) {
       fp->fd = fd;
       fp->mode = FMODE_READWRITE | FMODE_DUPLEX;
       rb_io_ascii8bit_binmode(socket);
-      io_verify_blocking_mode(fp, socket, Qfalse);
+      io_verify_blocking_mode(socket, fd, Qfalse);
       rb_io_synchronized(fp);
 
       rb_yield(socket);

ext/polyphony/extconf.rb

@@ -98,4 +98,10 @@ def define_bool(name, value)
 
 have_header('ruby/io/buffer.h')
 
+have_func('rb_io_path')
+have_func('rb_io_descriptor')
+have_func('rb_io_get_write_io')
+have_func('rb_io_closed_p')
+have_func('rb_io_open_descriptor')
+
 create_makefile 'polyphony_ext'