[refactor] reorganize platform and wire sources

apps/desktop/src/platform/common/posix_daemon_backend.cpp

@@ -0,0 +1,56 @@
+#include "platform/daemon_backend.h"
+
+#include <errno.h>
+#include <signal.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include <chrono>
+#include <thread>
+
+namespace crossdesk::platform {
+
+volatile std::sig_atomic_t g_daemon_stop_requested = 0;
+
+void ResetDaemonStop() { g_daemon_stop_requested = 0; }
+
+void RequestDaemonStop() { g_daemon_stop_requested = 1; }
+
+bool DaemonStopRequested() { return g_daemon_stop_requested != 0; }
+
+DaemonChildResult RunDaemonChild(const std::string& executable_path,
+                                 const std::function<bool()>& keep_running) {
+  DaemonChildResult result;
+  const pid_t child = fork();
+  if (child == 0) {
+    execl(executable_path.c_str(), executable_path.c_str(), "--child",
+          nullptr);
+    _exit(1);
+  }
+  if (child < 0) return result;
+
+  result.started = true;
+  int status = 0;
+  pid_t waited = -1;
+  while (keep_running()) {
+    waited = waitpid(child, &status, WNOHANG);
+    if (waited == child || (waited < 0 && errno != EINTR)) break;
+    std::this_thread::sleep_for(std::chrono::milliseconds(200));
+  }
+  if (!keep_running() && waited != child) {
+    kill(child, SIGTERM);
+    waited = waitpid(child, &status, 0);
+  }
+  if (waited < 0) return result;
+
+  if (WIFEXITED(status)) {
+    result.exit_code = WEXITSTATUS(status);
+    result.normal_exit = result.exit_code == 0;
+  } else if (WIFSIGNALED(status)) {
+    result.terminated_by_signal = true;
+    result.exit_code = WTERMSIG(status);
+  }
+  return result;
+}
+
+}  // namespace crossdesk::platform