From 36f1644d95e69ed7116d2eb8dcd991f85a022fc9 Mon Sep 17 00:00:00 2001
From: Kent Slaney <kent@slaney.org>
Date: Tue, 6 Feb 2024 15:21:53 -0800
Subject: [PATCH] fix double acquire attempt for m_pool_lock

---
 misc/aliases       | 4 +++-
 src/ClientPool.cpp | 5 +++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/misc/aliases b/misc/aliases
index 8887375f..c0161de7 100755
--- a/misc/aliases
+++ b/misc/aliases
@@ -49,7 +49,9 @@ case "$1" in
         source misc/git/pre-commit
         virtualize_libmc "`which python-dbg || which python3-dbg`"
         python setup.py build_ext --inplace
-        if [ -n "$2" ]; then
+        if [ "$2" == "bench" ]; then
+            cygdb . -- -ex start --args python misc/runbench.py
+        elif [ -n "$2" ]; then
             pattern="$2"
             shift 2
             cmds=(-ex start)
diff --git a/src/ClientPool.cpp b/src/ClientPool.cpp
index fa4ada8d..a7ff44c0 100644
--- a/src/ClientPool.cpp
+++ b/src/ClientPool.cpp
@@ -50,6 +50,7 @@ int ClientPool::init(const char* const * hosts, const uint32_t* ports,
                      const size_t n, const char* const * aliases) {
   updateServers(hosts, ports, n, aliases);
   std::unique_lock initializing(m_acquiring_growth);
+  std::lock_guard config_pool(m_pool_lock);
   return growPool(m_initial_clients);
 }
 
@@ -86,10 +87,9 @@ int ClientPool::setup(Client* c) {
   return c->init(m_hosts.data(), m_ports.data(), m_hosts.size(), m_aliases.data());
 }
 
-// if called outside acquire, needs to own m_acquiring_growth
+// needs to hold both m_acquiring_growth and m_pool_lock
 int ClientPool::growPool(size_t by) {
   assert(by > 0);
-  std::lock_guard growing_pool(m_pool_lock);
   size_t from = m_clients.size();
   m_clients.resize(from + by);
   std::atomic<int> rv = 0;
@@ -115,6 +115,7 @@ inline bool ClientPool::shouldGrowUnsafe() {
 int ClientPool::autoGrow() {
   std::unique_lock<std::shared_mutex> growing(m_acquiring_growth);
   if (shouldGrowUnsafe()) {
+    std::lock_guard growing_pool(m_pool_lock);
     return growPool(MIN(m_max_clients - m_clients.size(),
                     MIN(m_max_growth, m_clients.size())));
   }