process.c (waitpid_wait): do not set ECHILD prematurely

It is possible to have both MJIT and normal child processes
alive, so we cannot set ECHILD based on such a guess.  We can
still elide waitpid(PID <= 0) calls if we have callers in
vm->waiting_pids, however.

For specs, ensure Process.waitall does not leak MJIT
PIDs to Rubyspace.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63764 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 14 insertions, 2 deletions

diff --git a/spec/ruby/core/process/wait2_spec.rb b/spec/ruby/core/process/wait2_spec.rb
index cb082541f9..d0163f80af 100644
--- a/spec/ruby/core/process/wait2_spec.rb
+++ b/spec/ruby/core/process/wait2_spec.rb
@@ -4,11 +4,19 @@ 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
diff --git a/spec/ruby/core/process/wait_spec.rb b/spec/ruby/core/process/wait_spec.rb
index f11b079c16..5130bb4391 100644
--- a/spec/ruby/core/process/wait_spec.rb
+++ b/spec/ruby/core/process/wait_spec.rb
@@ -8,6 +8,10 @@ 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