Ensure that shutdown commands end the server process before completion

This change ensures that the server process is terminated before the
client process terminates, when evaluating a command that shuts down
the server.

When completing such a command, the server communicates to the client
that the server will terminate itself by setting a termination_expected
bit in the final RunResponse message. The client then waits up to 60s
for the server process to actually terminate. If it does not, then the
client SIGKILLs the server.

Also makes the gRPC server stop accepting new commands before the
shutdown command completes.

Drive-by fix to comments on Search{Un,Null}aryOption.

RELNOTES: Commands that shut down the server (like "shutdown") now ensure that the server process has terminated before the client process terminates.
PiperOrigin-RevId: 161537480

1 files changed, 5 insertions, 10 deletions

diff --git a/src/main/cpp/blaze_util_darwin.cc b/src/main/cpp/blaze_util_darwin.cc
index 075b48a1e0..008b721e0a 100644
--- a/src/main/cpp/blaze_util_darwin.cc
+++ b/src/main/cpp/blaze_util_darwin.cc
@@ -196,16 +196,11 @@ void WriteSystemSpecificProcessIdentifier(
     const string& server_dir, pid_t server_pid) {
 }
 
-bool VerifyServerProcess(
-    int pid, const string& output_base, const string& install_base) {
-  // TODO(lberki): This might accidentally kill an unrelated process if the
-  // server died and the PID got reused.
-  return true;
-}
-
-bool KillServerProcess(int pid) {
-  killpg(pid, SIGKILL);
-  return true;
+bool VerifyServerProcess(int pid, const string &output_base) {
+  // TODO(lberki): This only checks for the process's existence, not whether
+  // its start time matches. Therefore this might accidentally kill an
+  // unrelated process if the server died and the PID got reused.
+  return killpg(pid, 0) == 0;
 }
 
 // Sets a flag on path to exclude the path from Apple's automatic backup service