Refactor daemomnize

include/daemonize.hpp

@@ -50,10 +50,7 @@ struct DaemonizeResult {
   // Daemonization function
   // cleanup_function is a callable invoked in the context of the intermediate,
   // short-lived process that will be killed by daemon process.
-  DaemonizeResult(std::function<void()> cleanup_function);
-
-  // Create an empty/error result
-  DaemonizeResult(bool _) { (void)_; };
+  bool daemonize(std::function<void()> cleanup_function);
 
 private:
   int pipe_read = -1;

src/daemonize.cc

@@ -7,9 +7,9 @@
 #include "logger.hpp"
 
 namespace ddprof {
-DaemonizeResult::DaemonizeResult(std::function<void()> cleanup_function) {
+bool DaemonizeResult::daemonize(std::function<void()> cleanup_function) {
   if (!openpipes()) {
-    return;
+    return false;
   }
   pid_t parent_pid = getpid();
   pid_t temp_pid = fork(); // "middle"/"child" (temporary) PID
@@ -38,20 +38,20 @@ DaemonizeResult::DaemonizeResult(std::function<void()> cleanup_function) {
       state = DaemonizeState::Daemon;
       invoker_pid = parent_pid;
       daemon_pid = grandchild_pid;
-      return;
+      return true;
     }
   } else if (temp_pid != -1) { // parent PID enter branch
     close(pipe_write);
     pipe_write = -1;
     if (read(pipe_read, &grandchild_pid, pid_sz) != pid_sz) {
-      return; // error
+      return false;
     }
 
     signal(SIGCHLD, SIG_IGN);
     state = DaemonizeState::Invoker;
     invoker_pid = parent_pid;
     daemon_pid = grandchild_pid;
-    return;
+    return true;
   }
 
   // Should only arrive here if the first-level fork failed, but add a sink
@@ -66,7 +66,6 @@ DaemonizeResult::DaemonizeResult(std::function<void()> cleanup_function) {
   close(pipe_write);
   pipe_read = -1;
   pipe_write = -1;
-  return;
+  return false;
 }
-
 } // namespace ddprof

src/exe/main.cc

@@ -221,7 +221,7 @@ static int start_profiler_internal(DDProfContext *ctx, bool &is_profiler) {
 
   const bool in_wrapper_mode = ctx->params.pid == 0;
   TempFileHolder dd_profiling_lib_holder, dd_loader_lib_holder;
-  ddprof::DaemonizeResult daemonize_res{false};
+  ddprof::DaemonizeResult daemonize_res;
 
   if (in_wrapper_mode) {
     // If no PID was specified earlier, we autodaemonize and target current pid
@@ -259,10 +259,10 @@ static int start_profiler_internal(DDProfContext *ctx, bool &is_profiler) {
     }
 
     ctx->params.pid = getpid();
-    daemonize_res = {[ctx] {
+    daemonize_res.daemonize({[ctx] {
       ctx->release();
       throw ddprof::exit();
-    }};
+    }});
 
     if (daemonize_res.is_failure()) {
       return -1;

src/lib/dd_profiling.cc

@@ -216,8 +216,8 @@ int ddprof_start_profiling_internal() {
     auto defer_parent_socket_close =
         make_defer([&sockfds]() { close(sockfds[kParentIdx]); });
 
-    ddprof::DaemonizeResult daemonize_res{nullptr};
-    if (daemonize_res.is_failure()) {
+    ddprof::DaemonizeResult daemonize_res;
+    if (!daemonize_res.daemonize(nullptr)) {
       return -1;
     }