Merge branch 'selectivity' into ALL-the-things

src/core/lib/iomgr/combiner.c

@@ -59,6 +59,11 @@ struct grpc_combiner {
   grpc_closure_scheduler scheduler;
   grpc_closure_scheduler finally_scheduler;
   gpr_mpscq queue;
+  // either:
+  // a pointer to the initiating exec ctx if that is the only exec_ctx that has
+  // ever queued to this combiner, or NULL. If this is non-null, it's not
+  // dereferencable (since the initiating exec_ctx may have gone out of scope)
+  gpr_atm initiating_exec_ctx_or_null;
   // state is:
   // lower bit - zero if orphaned (STATE_UNORPHANED)
   // other bits - number of items queued on the lock (STATE_ELEM_COUNT_LOW_BIT)
@@ -168,15 +173,25 @@ static void combiner_exec(grpc_exec_ctx *exec_ctx, grpc_closure *cl,
   GRPC_COMBINER_TRACE(gpr_log(GPR_DEBUG,
                               "C:%p grpc_combiner_execute c=%p last=%" PRIdPTR,
                               lock, cl, last));
-  GPR_ASSERT(last & STATE_UNORPHANED);  // ensure lock has not been destroyed
-  assert(cl->cb);
-  cl->error_data.error = error;
-  gpr_mpscq_push(&lock->queue, &cl->next_data.atm_next);
   if (last == 1) {
+    gpr_atm_no_barrier_store(&lock->initiating_exec_ctx_or_null,
+                             (gpr_atm)exec_ctx);
     // first element on this list: add it to the list of combiner locks
     // executing within this exec_ctx
     push_last_on_exec_ctx(exec_ctx, lock);
+  } else {
+    // there may be a race with setting here: if that happens, we may delay
+    // offload for one or two actions, and that's fine
+    gpr_atm initiator =
+        gpr_atm_no_barrier_load(&lock->initiating_exec_ctx_or_null);
+    if (initiator != 0 && initiator != (gpr_atm)exec_ctx) {
+      gpr_atm_no_barrier_store(&lock->initiating_exec_ctx_or_null, 0);
+    }
   }
+  GPR_ASSERT(last & STATE_UNORPHANED);  // ensure lock has not been destroyed
+  assert(cl->cb);
+  cl->error_data.error = error;
+  gpr_mpscq_push(&lock->queue, &cl->next_data.atm_next);
   GPR_TIMER_END("combiner.execute", 0);
 }
 

tools/run_tests/python_utils/jobset.py

@@ -41,6 +41,7 @@ import subprocess
 import sys
 import tempfile
 import time
+import errno
 
 
 # cpu cost measurement
@@ -132,29 +133,44 @@ _TAG_COLOR = {
 _FORMAT = '%(asctime)-15s %(message)s'
 logging.basicConfig(level=logging.INFO, format=_FORMAT)
 
+
+def eintr_be_gone(fn):
+  """Run fn until it doesn't stop because of EINTR"""
+  while True:
+    try:
+      return fn()
+    except IOError, e:
+      if e.errno != errno.EINTR:
+        raise
+
+
+
 def message(tag, msg, explanatory_text=None, do_newline=False):
   if message.old_tag == tag and message.old_msg == msg and not explanatory_text:
     return
   message.old_tag = tag
   message.old_msg = msg
-  try:
-    if platform_string() == 'windows' or not sys.stdout.isatty():
-      if explanatory_text:
-        logging.info(explanatory_text)
-      logging.info('%s: %s', tag, msg)
-    else:
-      sys.stdout.write('%s%s%s\x1b[%d;%dm%s\x1b[0m: %s%s' % (
-          _BEGINNING_OF_LINE,
-          _CLEAR_LINE,
-          '\n%s' % explanatory_text if explanatory_text is not None else '',
-          _COLORS[_TAG_COLOR[tag]][1],
-          _COLORS[_TAG_COLOR[tag]][0],
-          tag,
-          msg,
-          '\n' if do_newline or explanatory_text is not None else ''))
-    sys.stdout.flush()
-  except:
-    pass
+  while True:
+    try:
+      if platform_string() == 'windows' or not sys.stdout.isatty():
+        if explanatory_text:
+          logging.info(explanatory_text)
+        logging.info('%s: %s', tag, msg)
+      else:
+        sys.stdout.write('%s%s%s\x1b[%d;%dm%s\x1b[0m: %s%s' % (
+            _BEGINNING_OF_LINE,
+            _CLEAR_LINE,
+            '\n%s' % explanatory_text if explanatory_text is not None else '',
+            _COLORS[_TAG_COLOR[tag]][1],
+            _COLORS[_TAG_COLOR[tag]][0],
+            tag,
+            msg,
+            '\n' if do_newline or explanatory_text is not None else ''))
+      sys.stdout.flush()
+      return
+    except IOError, e:
+      if e.errno != errno.EINTR:
+        raise
 
 message.old_tag = ''
 message.old_msg = ''
@@ -226,16 +242,6 @@ class JobResult(object):
     self.cpu_measured = 0
 
 
-def eintr_be_gone(fn):
-  """Run fn until it doesn't stop because of EINTR"""
-  while True:
-    try:
-      return fn()
-    except IOError, e:
-      if e.errno != errno.EINTR:
-        raise
-
-
 def read_from_start(f):
   f.seek(0)
   return f.read()