Always ref writable streams

We suffered a bug whereby doing a follow-up write to another write could
resurrect a deleted stream, causing all sorts of crash.

Fix: when a stream becomes writable (vs when we start writing) take a
ref on the stream, and only relinquish it once we're done writing.

2 files changed, 21 insertions, 1 deletions

diff --git a/src/core/iomgr/iomgr.c b/src/core/iomgr/iomgr.c
index 04580150f3..9c89c2c08a 100644
--- a/src/core/iomgr/iomgr.c
+++ b/src/core/iomgr/iomgr.c
@@ -41,9 +41,11 @@
 #include <grpc/support/string_util.h>
 #include <grpc/support/sync.h>
 #include <grpc/support/thd.h>
+#include <grpc/support/useful.h>
 
 #include "src/core/iomgr/iomgr_internal.h"
 #include "src/core/iomgr/timer.h"
+#include "src/core/support/env.h"
 #include "src/core/support/string.h"
 
 static gpr_mu g_mu;
@@ -116,6 +118,9 @@ void grpc_iomgr_shutdown(void) {
                     "memory leaks are likely",
                     count_objects());
             dump_objects("LEAKED");
+            if (grpc_iomgr_abort_on_leaks()) {
+              abort();
+            }
           }
           break;
         }
@@ -154,3 +159,14 @@ void grpc_iomgr_unregister_object(grpc_iomgr_object *obj) {
   gpr_mu_unlock(&g_mu);
   gpr_free(obj->name);
 }
+
+bool grpc_iomgr_abort_on_leaks(void) {
+  char *env = gpr_getenv("GRPC_ABORT_ON_LEAKS");
+  if (env == NULL) return false;
+  static const char *truthy[] = {"yes",  "Yes",  "YES", "true",
+                                 "True", "TRUE", "1"};
+  for (size_t i = 0; i < GPR_ARRAY_SIZE(truthy); i++) {
+    if (0 == strcmp(env, truthy[i])) return true;
+  }
+  return false;
+}
diff --git a/src/core/iomgr/iomgr_internal.h b/src/core/iomgr/iomgr_internal.h
index e372c18e8a..ac2c46ebe6 100644
--- a/src/core/iomgr/iomgr_internal.h
+++ b/src/core/iomgr/iomgr_internal.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -34,6 +34,8 @@
 #ifndef GRPC_INTERNAL_CORE_IOMGR_IOMGR_INTERNAL_H
 #define GRPC_INTERNAL_CORE_IOMGR_IOMGR_INTERNAL_H
 
+#include <stdbool.h>
+
 #include "src/core/iomgr/iomgr.h"
 #include <grpc/support/sync.h>
 
@@ -55,4 +57,6 @@ void grpc_iomgr_platform_flush(void);
 /** tear down all platform specific global iomgr structures */
 void grpc_iomgr_platform_shutdown(void);
 
+bool grpc_iomgr_abort_on_leaks(void);
+
 #endif /* GRPC_INTERNAL_CORE_IOMGR_IOMGR_INTERNAL_H */