From 06fb5c7c6955fc323ba55203ca6afda26112b6d2 Mon Sep 17 00:00:00 2001
From: gabime <gmelman1@gmail.com>
Date: Wed, 19 Jun 2019 18:30:50 +0300
Subject: [PATCH] Close issue #1113

---
 include/spdlog/details/thread_pool-inl.h | 15 +++++++++++++--
 include/spdlog/details/thread_pool.h     |  3 +++
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/include/spdlog/details/thread_pool-inl.h b/include/spdlog/details/thread_pool-inl.h
index 46c9cc44..bfb4908d 100644
--- a/include/spdlog/details/thread_pool-inl.h
+++ b/include/spdlog/details/thread_pool-inl.h
@@ -11,7 +11,8 @@
 
 namespace spdlog {
 namespace details {
-SPDLOG_INLINE thread_pool::thread_pool(size_t q_max_items, size_t threads_n)
+
+SPDLOG_INLINE thread_pool::thread_pool(size_t q_max_items, size_t threads_n, std::function<void()> on_thread_start)
     : q_(q_max_items)
 {
     if (threads_n == 0 || threads_n > 1000)
@@ -21,10 +22,20 @@ SPDLOG_INLINE thread_pool::thread_pool(size_t q_max_items, size_t threads_n)
     }
     for (size_t i = 0; i < threads_n; i++)
     {
-        threads_.emplace_back(&thread_pool::worker_loop_, this);
+        threads_.emplace_back([this, on_thread_start]
+        {
+            on_thread_start();
+            this->thread_pool::worker_loop_();
+        });
     }
 }
 
+SPDLOG_INLINE thread_pool::thread_pool(size_t q_max_items, size_t threads_n):
+    thread_pool(q_max_items, threads_n, []{})
+{
+
+}
+
 // message all threads to terminate gracefully join them
 SPDLOG_INLINE thread_pool::~thread_pool()
 {
diff --git a/include/spdlog/details/thread_pool.h b/include/spdlog/details/thread_pool.h
index d8e821aa..f7904cf1 100644
--- a/include/spdlog/details/thread_pool.h
+++ b/include/spdlog/details/thread_pool.h
@@ -11,6 +11,7 @@
 #include <memory>
 #include <thread>
 #include <vector>
+#include <functional>
 
 namespace spdlog {
 class async_logger;
@@ -118,7 +119,9 @@ public:
     using item_type = async_msg;
     using q_type = details::mpmc_blocking_queue<item_type>;
 
+    thread_pool(size_t q_max_items, size_t threads_n, std::function<void()> on_thread_start);
     thread_pool(size_t q_max_items, size_t threads_n);
+
     // message all threads to terminate gracefully join them
     ~thread_pool();