do not rely on os.WIFSIGNALED and os.WIFEXITED in popen.poll()

Author: tomasstupka

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/modules/MultiprocessingModuleBuiltins.java

@@ -225,11 +225,11 @@ PTuple waittid(long id, @SuppressWarnings("unused") int options) {
             // TODO implement for options - WNOHANG and 0
             Thread thread = lang.getChildContextThread(tid);
             if (thread != null && thread.isAlive()) {
-                return factory().createTuple(new Object[]{0, 0});
+                return factory().createTuple(new Object[]{0, 0, 0});
             }
 
             PythonContext.ChildContextData data = lang.getChildContextData(tid);
-            return factory().createTuple(new Object[]{id, data != null ? data.getExitCode() : 0});
+            return factory().createTuple(new Object[]{id, data.wasSignaled() ? data.getExitCode() : 0, data.getExitCode()});
         }
     }
 
@@ -248,7 +248,7 @@ Object terminate(long id, PInt sig) {
                     TruffleContext truffleCtx = data.getTruffleContext();
                     if (!truffleCtx.isCancelling() && data.compareAndSetExiting(false, true)) {
                         LOGGER.fine("terminating spawned thread");
-                        data.setExitCode(sig.intValue());
+                        data.setSignaled(sig.intValue());
                         truffleCtx.closeCancelled(this, "_terminate_spawned_thread");
                     }
                 } catch (InterruptedException ex) {

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/runtime/PythonContext.java

@@ -473,6 +473,7 @@ public Thread getOwner() {
 
     public static final class ChildContextData {
         private int exitCode = 0;
+        private boolean signaled;
         @CompilationFinal private TruffleContext ctx;
         @CompilationFinal private PythonContext parentCtx;
 
@@ -487,6 +488,15 @@ public int getExitCode() {
             return this.exitCode;
         }
 
+        public void setSignaled(int signaledCode) {
+            this.signaled = true;
+            this.exitCode = signaledCode;
+        }
+
+        public boolean wasSignaled() {
+            return this.signaled;
+        }
+
         private void setTruffleContext(TruffleContext ctx) {
             assert this.ctx == null;
             this.ctx = ctx;

graalpython/lib-python/3/multiprocessing/popen_truffleprocess.py

@@ -45,15 +45,17 @@ def duplicate_for_child(self, fd):
     def poll(self, flag=os.WNOHANG):
         if self.returncode is None:
             try:
-                tid, sts = _waittid(self._tid, flag)
+                # this is different than in popen_fork -> os.waitpid(self.pid, flag)
+                # we have no real proces pid and a process
+                # which could have been evenutally signaled
+                tid, sigcode, exitcode = _waittid(self._tid, flag)
             except OSError as e:
                 return None
-            if tid == self._tid:                
-                if os.WIFSIGNALED(sts):
-                    self.returncode = -os.WTERMSIG(sts)
+            if tid == self._tid:
+                if sigcode > 0:
+                    self.returncode = -sigcode
                 else:
-                    assert os.WIFEXITED(sts), "Status is {:n}".format(sts)
-                    self.returncode = os.WEXITSTATUS(sts)
+                    self.returncode = exitcode
         return self.returncode
 
     def wait(self, timeout=None):