From 73d3af591adb14c60114f1057aa8f1b427daa3c8 Mon Sep 17 00:00:00 2001
From: Hongyi Jia <jiayisuse@fb.com>
Date: Tue, 24 Mar 2020 00:10:37 -0700
Subject: [PATCH] Catch exception from shm connection start()

Summary:
util::ringbuffer::shm::create(kDefaultSize) could throw system exception and
cause connection destruction before initilization completes. If not catch the
exception on connection level, destruction will clean up unregistered
resources to cause unrelated errors.

Differential Revision: D20616906

fbshipit-source-id: 3b91458e26cca2e6bd393264ad1ca6dea4fb7b29
---
 tensorpipe/transport/shm/connection.cc | 14 ++++++++++++--
 tensorpipe/transport/shm/connection.h  |  1 +
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/tensorpipe/transport/shm/connection.cc b/tensorpipe/transport/shm/connection.cc
index 8e6b23afd..b619cb7db 100644
--- a/tensorpipe/transport/shm/connection.cc
+++ b/tensorpipe/transport/shm/connection.cc
@@ -50,8 +50,15 @@ Connection::~Connection() {
 void Connection::start() {
   // Create ringbuffer for inbox.
   std::shared_ptr<util::ringbuffer::RingBuffer> inboxRingBuffer;
-  std::tie(inboxHeaderFd_, inboxDataFd_, inboxRingBuffer) =
-      util::ringbuffer::shm::create(kDefaultSize);
+  try {
+    std::tie(inboxHeaderFd_, inboxDataFd_, inboxRingBuffer) =
+        util::ringbuffer::shm::create(kDefaultSize);
+  } catch (std::system_error& e) {
+    state_ = INITIALIZING_ERROR;
+    // Triggers destructor.
+    TP_THROW_SYSTEM(errno) << "Error while creating shm with " << kDefaultSize
+                           << " bytes";
+  }
   inbox_.emplace(std::move(inboxRingBuffer));
 
   // Register method to be called when our peer writes to our inbox.
@@ -429,6 +436,9 @@ void Connection::close() {
   // can't extend its lifetime by capturing a shared_ptr and increasing its
   // refcount.
   std::unique_lock<std::mutex> guard(mutex_);
+  if (state_ == INITIALIZING_ERROR) {
+    return;
+  }
   closeHoldingMutex();
 }
 
diff --git a/tensorpipe/transport/shm/connection.h b/tensorpipe/transport/shm/connection.h
index d012b276f..c06d43318 100644
--- a/tensorpipe/transport/shm/connection.h
+++ b/tensorpipe/transport/shm/connection.h
@@ -36,6 +36,7 @@ class Connection final : public transport::Connection,
 
   enum State {
     INITIALIZING = 1,
+    INITIALIZING_ERROR,
     SEND_FDS,
     RECV_FDS,
     ESTABLISHED,