[Lldb-commits] [lldb] [lldb] Unify/improve MainLoop signal handling (PR #115197)

[Jacob Lalonde via lldb-commits]

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@@ -17,29 +17,53 @@
 #include <cerrno>
 #include <csignal>
 #include <ctime>
+#include <fcntl.h>
 #include <vector>
 
 // Multiplexing is implemented using kqueue on systems that support it (BSD
-// variants including OSX). On linux we use ppoll, while android uses pselect
-// (ppoll is present but not implemented properly). On windows we use WSApoll
-// (which does not support signals).
+// variants including OSX). On linux we use ppoll.
 
 #if HAVE_SYS_EVENT_H
 #include <sys/event.h>
-#elif defined(__ANDROID__)
-#include <sys/syscall.h>
 #else
 #include <poll.h>
 #endif
 
 using namespace lldb;
 using namespace lldb_private;
 
-static sig_atomic_t g_signal_flags[NSIG];
+namespace {
+struct GlobalSignalInfo {
+  sig_atomic_t pipe_fd = -1;
+  static_assert(sizeof(sig_atomic_t) >= sizeof(int),
+                "Type too small for a file descriptor");
+  sig_atomic_t flag = 0;
+};
+} // namespace
+static GlobalSignalInfo g_signal_info[NSIG];
 
 static void SignalHandler(int signo, siginfo_t *info, void *) {
   assert(signo < NSIG);
-  g_signal_flags[signo] = 1;
+
+  // Set the flag before writing to the pipe!
+  g_signal_info[signo].flag = 1;
+
+  char c = '.';
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Jlalond wrote:

nit, I would like a slightly more descriptive variable name, mostly the intent of `.`

https://github.com/llvm/llvm-project/pull/115197