unrevert r63852 but keep SIGCHLD path disabled for win32

Reading win32/win32.c waitpid implementation, maybe waitpid(-1, ...)
on that platform will never conflict with mjit use of waitpid.

In any case, I've added WAITPID_USE_SIGCHLD macro to vm_core.h
so it can be easy for Linux/BSD users to test (hopefully!)
win32-compatible code.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63855 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 118 insertions, 112 deletions

diff --git a/spec/ruby/core/process/wait2_spec.rb b/spec/ruby/core/process/wait2_spec.rb
index 3f5aa3c7e2..d0163f80af 100644
--- a/spec/ruby/core/process/wait2_spec.rb
+++ b/spec/ruby/core/process/wait2_spec.rb
@@ -4,31 +4,37 @@ describe "Process.wait2" do
   before :all do
     # HACK: this kludge is temporarily necessary because some
     # misbehaving spec somewhere else does not clear processes
+    # Note: background processes are unavoidable with MJIT,
+    # but we shouldn't reap them from Ruby-space
     begin
       Process.wait(-1, Process::WNOHANG)
-      $stderr.puts "Leaked process before wait2 specs! Waiting for it"
+      without_feature :mjit do
+        $stderr.puts "Leaked process before wait2 specs! Waiting for it"
+      end
       leaked = Process.waitall
-      $stderr.puts "leaked before wait2 specs: #{leaked}"
+      $stderr.puts "leaked before wait2 specs: #{leaked}" unless leaked.empty?
+      with_feature :mjit do
+        # Ruby-space should not see PIDs used by mjit
+        leaked.should be_empty
+      end
     rescue Errno::ECHILD # No child processes
     rescue NotImplementedError
     end
   end
 
-  without_feature :mjit do # [Bug #14867]
-    platform_is_not :windows do
-      it "returns the pid and status of child process" do
-        pidf = Process.fork { Process.exit! 99 }
-        results = Process.wait2
-        results.size.should == 2
-        pidw, status = results
-        pidf.should == pidw
-        status.exitstatus.should == 99
-      end
+  platform_is_not :windows do
+    it "returns the pid and status of child process" do
+      pidf = Process.fork { Process.exit! 99 }
+      results = Process.wait2
+      results.size.should == 2
+      pidw, status = results
+      pidf.should == pidw
+      status.exitstatus.should == 99
     end
+  end
 
-    it "raises a StandardError if no child processes exist" do
-      lambda { Process.wait2 }.should raise_error(Errno::ECHILD)
-      lambda { Process.wait2 }.should raise_error(StandardError)
-    end
+  it "raises a StandardError if no child processes exist" do
+    lambda { Process.wait2 }.should raise_error(Errno::ECHILD)
+    lambda { Process.wait2 }.should raise_error(StandardError)
   end
 end
diff --git a/spec/ruby/core/process/wait_spec.rb b/spec/ruby/core/process/wait_spec.rb
index 447c62f42a..5130bb4391 100644
--- a/spec/ruby/core/process/wait_spec.rb
+++ b/spec/ruby/core/process/wait_spec.rb
@@ -8,85 +8,87 @@ describe "Process.wait" do
     begin
       leaked = Process.waitall
       puts "leaked before wait specs: #{leaked}" unless leaked.empty?
+      with_feature :mjit do
+        # Ruby-space should not see PIDs used by mjit
+        leaked.should be_empty
+      end
     rescue NotImplementedError
     end
   end
 
-  without_feature :mjit do # [Bug #14867]
-    it "raises an Errno::ECHILD if there are no child processes" do
-      lambda { Process.wait }.should raise_error(Errno::ECHILD)
+  it "raises an Errno::ECHILD if there are no child processes" do
+    lambda { Process.wait }.should raise_error(Errno::ECHILD)
+  end
+
+  platform_is_not :windows do
+    it "returns its childs pid" do
+      pid = Process.spawn(ruby_cmd('exit'))
+      Process.wait.should == pid
     end
 
-    platform_is_not :windows do
-      it "returns its childs pid" do
-        pid = Process.spawn(ruby_cmd('exit'))
-        Process.wait.should == pid
-      end
+    it "sets $? to a Process::Status" do
+      pid = Process.spawn(ruby_cmd('exit'))
+      Process.wait
+      $?.should be_kind_of(Process::Status)
+      $?.pid.should == pid
+    end
 
-      it "sets $? to a Process::Status" do
-        pid = Process.spawn(ruby_cmd('exit'))
-        Process.wait
-        $?.should be_kind_of(Process::Status)
-        $?.pid.should == pid
-      end
+    it "waits for any child process if no pid is given" do
+      pid = Process.spawn(ruby_cmd('exit'))
+      Process.wait.should == pid
+      lambda { Process.kill(0, pid) }.should raise_error(Errno::ESRCH)
+    end
 
-      it "waits for any child process if no pid is given" do
-        pid = Process.spawn(ruby_cmd('exit'))
-        Process.wait.should == pid
-        lambda { Process.kill(0, pid) }.should raise_error(Errno::ESRCH)
-      end
+    it "waits for a specific child if a pid is given" do
+      pid1 = Process.spawn(ruby_cmd('exit'))
+      pid2 = Process.spawn(ruby_cmd('exit'))
+      Process.wait(pid2).should == pid2
+      Process.wait(pid1).should == pid1
+      lambda { Process.kill(0, pid1) }.should raise_error(Errno::ESRCH)
+      lambda { Process.kill(0, pid2) }.should raise_error(Errno::ESRCH)
+    end
 
-      it "waits for a specific child if a pid is given" do
-        pid1 = Process.spawn(ruby_cmd('exit'))
-        pid2 = Process.spawn(ruby_cmd('exit'))
-        Process.wait(pid2).should == pid2
-        Process.wait(pid1).should == pid1
-        lambda { Process.kill(0, pid1) }.should raise_error(Errno::ESRCH)
-        lambda { Process.kill(0, pid2) }.should raise_error(Errno::ESRCH)
-      end
+    it "coerces the pid to an Integer" do
+      pid1 = Process.spawn(ruby_cmd('exit'))
+      Process.wait(mock_int(pid1)).should == pid1
+      lambda { Process.kill(0, pid1) }.should raise_error(Errno::ESRCH)
+    end
 
-      it "coerces the pid to an Integer" do
-        pid1 = Process.spawn(ruby_cmd('exit'))
-        Process.wait(mock_int(pid1)).should == pid1
-        lambda { Process.kill(0, pid1) }.should raise_error(Errno::ESRCH)
-      end
+    # This spec is probably system-dependent.
+    it "waits for a child whose process group ID is that of the calling process" do
+      pid1 = Process.spawn(ruby_cmd('exit'), pgroup: true)
+      pid2 = Process.spawn(ruby_cmd('exit'))
 
-      # This spec is probably system-dependent.
-      it "waits for a child whose process group ID is that of the calling process" do
-        pid1 = Process.spawn(ruby_cmd('exit'), pgroup: true)
-        pid2 = Process.spawn(ruby_cmd('exit'))
+      Process.wait(0).should == pid2
+      Process.wait.should == pid1
+    end
 
-        Process.wait(0).should == pid2
-        Process.wait.should == pid1
+    # This spec is probably system-dependent.
+    it "doesn't block if no child is available when WNOHANG is used" do
+      read, write = IO.pipe
+      pid = Process.fork do
+        read.close
+        Signal.trap("TERM") { Process.exit! }
+        write << 1
+        write.close
+        sleep
       end
 
-      # This spec is probably system-dependent.
-      it "doesn't block if no child is available when WNOHANG is used" do
-        read, write = IO.pipe
-        pid = Process.fork do
-          read.close
-          Signal.trap("TERM") { Process.exit! }
-          write << 1
-          write.close
-          sleep
-        end
-
-        Process.wait(pid, Process::WNOHANG).should be_nil
+      Process.wait(pid, Process::WNOHANG).should be_nil
 
-        # wait for the child to setup its TERM handler
-        write.close
-        read.read(1)
-        read.close
+      # wait for the child to setup its TERM handler
+      write.close
+      read.read(1)
+      read.close
 
-        Process.kill("TERM", pid)
-        Process.wait.should == pid
-      end
+      Process.kill("TERM", pid)
+      Process.wait.should == pid
+    end
 
-      it "always accepts flags=0" do
-        pid = Process.spawn(ruby_cmd('exit'))
-        Process.wait(-1, 0).should == pid
-        lambda { Process.kill(0, pid) }.should raise_error(Errno::ESRCH)
-      end
+    it "always accepts flags=0" do
+      pid = Process.spawn(ruby_cmd('exit'))
+      Process.wait(-1, 0).should == pid
+      lambda { Process.kill(0, pid) }.should raise_error(Errno::ESRCH)
     end
   end
 end
diff --git a/spec/ruby/core/process/waitall_spec.rb b/spec/ruby/core/process/waitall_spec.rb
index ff06ae21f9..bdc1ea7490 100644
--- a/spec/ruby/core/process/waitall_spec.rb
+++ b/spec/ruby/core/process/waitall_spec.rb
@@ -8,43 +8,41 @@ describe "Process.waitall" do
     end
   end
 
-  without_feature :mjit do # [Bug #14867]
-    it "returns an empty array when there are no children" do
-      Process.waitall.should == []
-    end
+  it "returns an empty array when there are no children" do
+    Process.waitall.should == []
+  end
 
-    it "takes no arguments" do
-      lambda { Process.waitall(0) }.should raise_error(ArgumentError)
-    end
+  it "takes no arguments" do
+    lambda { Process.waitall(0) }.should raise_error(ArgumentError)
+  end
 
-    platform_is_not :windows do
-      it "waits for all children" do
-        pids = []
-        pids << Process.fork { Process.exit! 2 }
-        pids << Process.fork { Process.exit! 1 }
-        pids << Process.fork { Process.exit! 0 }
-        Process.waitall
-        pids.each { |pid|
-          lambda { Process.kill(0, pid) }.should raise_error(Errno::ESRCH)
-        }
-      end
+  platform_is_not :windows do
+    it "waits for all children" do
+      pids = []
+      pids << Process.fork { Process.exit! 2 }
+      pids << Process.fork { Process.exit! 1 }
+      pids << Process.fork { Process.exit! 0 }
+      Process.waitall
+      pids.each { |pid|
+        lambda { Process.kill(0, pid) }.should raise_error(Errno::ESRCH)
+      }
+    end
 
-      it "returns an array of pid/status pairs" do
-        pids = []
-        pids << Process.fork { Process.exit! 2 }
-        pids << Process.fork { Process.exit! 1 }
-        pids << Process.fork { Process.exit! 0 }
-        a = Process.waitall
-        a.should be_kind_of(Array)
-        a.size.should == 3
-        pids.each { |pid|
-          pid_status = a.assoc(pid)
-          pid_status.should be_kind_of(Array)
-          pid_status.size.should == 2
-          pid_status.first.should == pid
-          pid_status.last.should be_kind_of(Process::Status)
-        }
-      end
+    it "returns an array of pid/status pairs" do
+      pids = []
+      pids << Process.fork { Process.exit! 2 }
+      pids << Process.fork { Process.exit! 1 }
+      pids << Process.fork { Process.exit! 0 }
+      a = Process.waitall
+      a.should be_kind_of(Array)
+      a.size.should == 3
+      pids.each { |pid|
+        pid_status = a.assoc(pid)
+        pid_status.should be_kind_of(Array)
+        pid_status.size.should == 2
+        pid_status.first.should == pid
+        pid_status.last.should be_kind_of(Process::Status)
+      }
     end
   end
 end