Introduce Fiber Scheduler blocking_region hook. (#11963)

Merged-By: ioquatix <samuel@codeotaku.com>

test/fiber/scheduler.rb

@@ -309,6 +309,10 @@ class Scheduler
       Addrinfo.getaddrinfo(hostname, nil).map(&:ip_address).uniq
     end.value
   end
+
+  def blocking_region(work)
+    Thread.new(&work).join
+  end
 end
 
 # This scheduler class implements `io_read` and `io_write` hooks which require
@@ -321,8 +325,7 @@ class IOBufferScheduler < Scheduler
     io.nonblock = true
 
     while true
-      maximum_size = buffer.size - offset
-      result = blocking{buffer.read(io, maximum_size, offset)}
+      result = blocking{buffer.read(io, 0, offset)}
 
       if result > 0
         total += result
@@ -349,8 +352,7 @@ class IOBufferScheduler < Scheduler
     io.nonblock = true
 
     while true
-      maximum_size = buffer.size - offset
-      result = blocking{buffer.write(io, maximum_size, offset)}
+      result = blocking{buffer.write(io, 0, offset)}
 
       if result > 0
         total += result
@@ -377,8 +379,7 @@ class IOBufferScheduler < Scheduler
     io.nonblock = true
 
     while true
-      maximum_size = buffer.size - offset
-      result = blocking{buffer.pread(io, from, maximum_size, offset)}
+      result = blocking{buffer.pread(io, from, 0, offset)}
 
       if result > 0
         total += result
@@ -406,8 +407,7 @@ class IOBufferScheduler < Scheduler
     io.nonblock = true
 
     while true
-      maximum_size = buffer.size - offset
-      result = blocking{buffer.pwrite(io, from, maximum_size, offset)}
+      result = blocking{buffer.pwrite(io, from, 0, offset)}
 
       if result > 0
         total += result

test/fiber/test_io.rb

@@ -153,12 +153,13 @@ class TestFiberIO < Test::Unit::TestCase
       Fiber.set_scheduler scheduler
 
       Fiber.schedule do
-        message = i.read(20)
+        # We add 1 here, to force the read to block (testing that specific code path).
+        message = i.read(MESSAGE.bytesize + 1)
         i.close
       end
 
       Fiber.schedule do
-        o.write("Hello World")
+        o.write(MESSAGE)
         o.close
       end
     end

test/fiber/test_io_buffer.rb

@@ -21,7 +21,8 @@ class TestFiberIOBuffer < Test::Unit::TestCase
       Fiber.set_scheduler scheduler
 
       Fiber.schedule do
-        message = i.read(20)
+        # We add 1 here, to force the read to block (testing that specific code path).
+        message = i.read(MESSAGE.bytesize + 1)
         i.close
       end
 

test/fiber/test_process.rb

@@ -59,12 +59,14 @@ class TestFiberProcess < Test::Unit::TestCase
 
   def test_fork
     omit 'fork not supported' unless Process.respond_to?(:fork)
+
+    pid = Process.fork{}
+
     Thread.new do
       scheduler = Scheduler.new
       Fiber.set_scheduler scheduler
 
       Fiber.schedule do
-        pid = Process.fork {}
         Process.wait(pid)
 
         assert_predicate $?, :success?