[mojo-edk] Avoid a recursive lock acquisition in data pipe.

BUG=None

Review URL: https://codereview.chromium.org/1763643002

Cr-Commit-Position: refs/heads/master@{#378968}

2 files changed, 7 insertions, 4 deletions

diff --git a/mojo/edk/system/data_pipe_consumer_dispatcher.cc b/mojo/edk/system/data_pipe_consumer_dispatcher.cc
index 269f8b2..2dfddbc 100644
--- a/mojo/edk/system/data_pipe_consumer_dispatcher.cc
+++ b/mojo/edk/system/data_pipe_consumer_dispatcher.cc
@@ -484,6 +484,10 @@ void DataPipeConsumerDispatcher::NotifyRead(uint32_t num_bytes) {
 }
 
 void DataPipeConsumerDispatcher::OnPortStatusChanged() {
+  // This has to be outside |lock_| because the watch callback can call data
+  // pipe functions which then try to acquire |lock_|.
+  RequestContext request_context;
+
   base::AutoLock lock(lock_);
 
   // We stop observing the control port as soon it's transferred, but this can
@@ -498,8 +502,6 @@ void DataPipeConsumerDispatcher::OnPortStatusChanged() {
 }
 
 void DataPipeConsumerDispatcher::UpdateSignalsStateNoLock() {
-  RequestContext request_context;
-
   lock_.AssertAcquired();
 
   bool was_peer_closed = peer_closed_;
diff --git a/mojo/edk/system/data_pipe_producer_dispatcher.cc b/mojo/edk/system/data_pipe_producer_dispatcher.cc
index 634fb68..0aa8f7e 100644
--- a/mojo/edk/system/data_pipe_producer_dispatcher.cc
+++ b/mojo/edk/system/data_pipe_producer_dispatcher.cc
@@ -462,6 +462,9 @@ void DataPipeProducerDispatcher::NotifyWrite(uint32_t num_bytes) {
 }
 
 void DataPipeProducerDispatcher::OnPortStatusChanged() {
+  // This has to be outside |lock_| because the watch callback can call data
+  // pipe functions which then try to acquire |lock_|.
+  RequestContext request_context;
   base::AutoLock lock(lock_);
 
   // We stop observing the control port as soon it's transferred, but this can
@@ -476,8 +479,6 @@ void DataPipeProducerDispatcher::OnPortStatusChanged() {
 }
 
 void DataPipeProducerDispatcher::UpdateSignalsStateNoLock() {
-  RequestContext request_context;
-
   lock_.AssertAcquired();
 
   bool was_peer_closed = peer_closed_;