Add UringMachine.kernel_version, skip read_each tests on early kernel

Author: noteflakes

ext/um/extconf.rb

@@ -22,15 +22,16 @@ def get_config
   raise "UringMachine requires kernel version 6.4 or newer!" if combined_version < 604
 
   {
-    kernel_version:     combined_version,
-    submit_all_flag:    combined_version >= 518,
-    coop_taskrun_flag:  combined_version >= 519,
-    single_issuer_flag: combined_version >= 600,
-    prep_bind:          combined_version >= 611,
-    prep_listen:        combined_version >= 611,
-    prep_cmd_sock:      combined_version >= 607,
-    prep_futex:         combined_version >= 607,
-    prep_waitid:        combined_version >= 607
+    kernel_version:       combined_version,
+    submit_all_flag:      combined_version >= 518,
+    coop_taskrun_flag:    combined_version >= 519,
+    single_issuer_flag:   combined_version >= 600,
+    prep_bind:            combined_version >= 611,
+    prep_listen:          combined_version >= 611,
+    prep_cmd_sock:        combined_version >= 607,
+    prep_futex:           combined_version >= 607,
+    prep_waitid:          combined_version >= 607,
+    prep_read_multishot:  combined_version >= 607
   }
 end
 
@@ -55,13 +56,15 @@ def get_config
   raise "Couldn't find liburing.a"
 end
 
-$defs << '-DHAVE_IORING_SETUP_SUBMIT_ALL'   if config[:submit_all_flag]
-$defs << '-DHAVE_IORING_SETUP_COOP_TASKRUN' if config[:coop_taskrun_flag]
-$defs << '-DHAVE_IO_URING_PREP_BIND'        if config[:prep_bind]
-$defs << '-DHAVE_IO_URING_PREP_LISTEN'      if config[:prep_listen]
-$defs << '-DHAVE_IO_URING_PREP_CMD_SOCK'    if config[:prep_cmd_sock]
-$defs << '-DHAVE_IO_URING_PREP_FUTEX'       if config[:prep_futex]
-$defs << '-DHAVE_IO_URING_PREP_WAITID'      if config[:prep_waitid]
+$defs << "-DUM_KERNEL_VERSION=#{config[:kernel_version]}"
+$defs << '-DHAVE_IORING_SETUP_SUBMIT_ALL'       if config[:submit_all_flag]
+$defs << '-DHAVE_IORING_SETUP_COOP_TASKRUN'     if config[:coop_taskrun_flag]
+$defs << '-DHAVE_IO_URING_PREP_BIND'            if config[:prep_bind]
+$defs << '-DHAVE_IO_URING_PREP_LISTEN'          if config[:prep_listen]
+$defs << '-DHAVE_IO_URING_PREP_CMD_SOCK'        if config[:prep_cmd_sock]
+$defs << '-DHAVE_IO_URING_PREP_FUTEX'           if config[:prep_futex]
+$defs << '-DHAVE_IO_URING_PREP_WAITID'          if config[:prep_waitid]
+$defs << '-DHAVE_IO_URING_PREP_READ_MULTISHOT'  if config[:prep_read_multishot]
 $CFLAGS << ' -Wno-pointer-arith'
 
 CONFIG['optflags'] << ' -fno-strict-aliasing'

ext/um/um_class.c

@@ -107,8 +107,12 @@ VALUE UM_read(int argc, VALUE *argv, VALUE self) {
 }
 
 VALUE UM_read_each(VALUE self, VALUE fd, VALUE bgid) {
+#ifdef HAVE_IO_URING_PREP_READ_MULTISHOT
   struct um *machine = get_machine(self);
   return um_read_each(machine, NUM2INT(fd), NUM2INT(bgid));
+#else
+  rb_raise(rb_eRuntimeError, "Not supported by kernel");
+#endif
 }
 
 VALUE UM_write(int argc, VALUE *argv, VALUE self) {
@@ -254,6 +258,10 @@ VALUE UM_queue_shift(VALUE self, VALUE queue) {
 
 #endif
 
+VALUE UM_kernel_version(VALUE self) {
+  return INT2NUM(UM_KERNEL_VERSION);
+}
+
 void Init_UM(void) {
   rb_ext_ractor_safe(true);
 
@@ -295,5 +303,7 @@ void Init_UM(void) {
   rb_define_method(cUM, "shift", UM_queue_shift, 1);
   #endif
 
+  rb_define_singleton_method(cUM, "kernel_version", UM_kernel_version, 0);
+
   um_define_net_constants(cUM);
 }

test/test_um.rb

@@ -3,6 +3,14 @@
 require_relative 'helper'
 require 'socket'
 
+class UringMachineTest < Minitest::Test
+  def test_kernel_version
+    v = UringMachine.kernel_version
+    assert_kind_of Integer, v
+    assert_in_range 600..700, v
+  end
+end
+
 class SchedulingTest < UMBaseTest
   def test_schedule_and_yield
     buf = []
@@ -254,9 +262,10 @@ def test_read_with_negative_buffer_offset
 
 class ReadEachTest < UMBaseTest
   def test_read_each
+    skip if UringMachine.kernel_version < 607
+
     r, w = IO.pipe
     bufs = []
-
     bgid = machine.setup_buffer_ring(4096, 1024)
     assert_equal 0, bgid
 
@@ -283,8 +292,9 @@ def test_read_each
 
   # send once and close write fd
   def test_read_each_raising_1
-    r, w = IO.pipe
+    skip if UringMachine.kernel_version < 607
 
+    r, w = IO.pipe
     bgid = machine.setup_buffer_ring(4096, 1024)
     assert_equal 0, bgid
 
@@ -306,8 +316,9 @@ def test_read_each_raising_1
 
   # send once and leave write fd open
   def test_read_each_raising_2
-    r, w = IO.pipe
+    skip if UringMachine.kernel_version < 607
 
+    r, w = IO.pipe
     bgid = machine.setup_buffer_ring(4096, 1024)
     assert_equal 0, bgid
 
@@ -330,8 +341,9 @@ def test_read_each_raising_2
 
   # send twice
   def test_read_each_raising_3
-    r, w = IO.pipe
+    skip if UringMachine.kernel_version < 607
 
+    r, w = IO.pipe
     bgid = machine.setup_buffer_ring(4096, 1024)
     assert_equal 0, bgid
 
@@ -354,8 +366,9 @@ def test_read_each_raising_3
   end
 
   def test_read_each_break
-    r, w = IO.pipe
+    skip if UringMachine.kernel_version < 607
 
+    r, w = IO.pipe
     bgid = machine.setup_buffer_ring(4096, 1024)
 
     t = Thread.new do
@@ -379,6 +392,8 @@ def test_read_each_break
   end
 
   def test_read_each_bad_file
+    skip if UringMachine.kernel_version < 607
+
     _r, w = IO.pipe
     bgid = machine.setup_buffer_ring(4096, 1024)