[Lldb-commits] [lldb] Send an explicit interrupt to cancel an attach waitfor. (PR #72565)

[Jonas Devlieghere via lldb-commits]

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@@ -799,7 +799,33 @@ DNBProcessAttachWait(RNBContext *ctx, const char *waitfor_process_name,
         break;
       }
 
-      ::usleep(waitfor_interval); // Sleep for WAITFOR_INTERVAL, then poll again
+      // Now we're going to wait a while before polling again.  But we also
+      // need to check whether we've gotten an event from the debugger  
+      // telling us to interrupt the wait.  So we'll use the wait for a possible
+      // next event to also be our short pause...
+      struct timespec short_timeout;
+      DNBTimer::OffsetTimeOfDay(&short_timeout, 0, waitfor_interval);
+      uint32_t event_mask = RNBContext::event_read_packet_available 
+          | RNBContext::event_read_thread_exiting;
+      nub_event_t set_events = ctx->Events().WaitForSetEvents(event_mask, 
+          &short_timeout);
+      if (set_events & RNBContext::event_read_packet_available) {
+        // If we get any packet from the debugger while waiting on the async,
+        // it has to be telling us to interrupt.  So always exit here.
+        // Over here in DNB land we can see that there was a packet, but all
+        // the methods to actually handle it are protected.  It's not worth
+        // rearranging all that just to get which packet we were sent...
+        DNBLogError("Interrupted by packet while waiting for '%s' to appear.\n",
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JDevlieghere wrote:

Can we check the packet and assert/log when it's not an interrupt? I know that's technically not allowed by the GDB remote protocol, but that would make it easy to catch such a mistake. 

https://github.com/llvm/llvm-project/pull/72565