nghttpx: Use std::atomic for Config::cached_time

src/shrpx.cc

@@ -569,7 +569,8 @@ void fill_default_config()
     (mod_config()->http2_option, 1);
 
   mod_config()->tls_proto_mask = 0;
-  mod_config()->cached_time = cache_time(time_cache_buf_idx);
+  mod_config()->cached_time.store(cache_time(time_cache_buf_idx),
+                                  std::memory_order_release);
 }
 } // namespace
 

src/shrpx_config.h

@@ -35,6 +35,7 @@
 #include <cstdio>
 #include <vector>
 #include <memory>
+#include <atomic>
 
 #include <event.h>
 #include <openssl/ssl.h>
@@ -199,7 +200,7 @@ struct Config {
   FILE *http2_upstream_dump_request_header;
   FILE *http2_upstream_dump_response_header;
   nghttp2_option *http2_option;
-  volatile const char *cached_time;
+  std::atomic<const char*> cached_time;
   size_t downstream_addrlen;
   size_t num_worker;
   size_t http2_max_concurrent_streams;

src/shrpx_log.cc

@@ -119,7 +119,7 @@ Log::~Log()
 
   rv = snprintf(buf, sizeof(buf),
                 "%s PID%d [%s%s%s] %s\n    %s(%s:%d)%s\n",
-                get_config()->cached_time,
+                get_config()->cached_time.load(std::memory_order_acquire),
                 getpid(),
                 tty ? SEVERITY_COLOR[severity_] : "",
                 SEVERITY_STR[severity_],
@@ -183,7 +183,7 @@ void upstream_accesslog(const std::string& client_ip, unsigned int status_code,
 
   rv = snprintf(buf, sizeof(buf), fmt,
                 client_ip.c_str(),
-                get_config()->cached_time,
+                get_config()->cached_time.load(std::memory_order_acquire),
                 method,
                 path,
                 major,