From b78c842cf962120c5d346cbc76dc5a44f6e15652 Mon Sep 17 00:00:00 2001
From: David Anderson <davea@ssl.berkeley.edu>
Date: Mon, 29 Jun 2015 22:05:48 -0700
Subject: [PATCH] client: always show task_debug message if kill_program()
 fails

... but change kill_program() so it's not a failure if the process doesn't exit.
This is to help debug a possible "zombie process" bug
---
 client/app_control.cpp | 29 +++++++++++++++--------------
 lib/util.cpp           |  5 ++++-
 2 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/client/app_control.cpp b/client/app_control.cpp
index 57442dd89b..d0f2c4388a 100644
--- a/client/app_control.cpp
+++ b/client/app_control.cpp
@@ -225,33 +225,34 @@ int ACTIVE_TASK::request_abort() {
 }
 
 #ifdef _WIN32
-static void kill_app_process(int pid, bool will_restart, bool show_errors) {
+static void kill_app_process(int pid, bool will_restart) {
     int retval = 0;
     retval = kill_program(pid, will_restart?0:EXIT_ABORTED_BY_CLIENT);
-    if (retval && log_flags.task_debug && show_errors) {
+    if (retval && log_flags.task_debug) {
         msg_printf(0, MSG_INFO,
-            "[task] kill_app_process() failed: %s",
-            strerror(retval)
+            "[task] kill_program(%d) failed: %s",
+            pid, boincerror(retval)
         );
     }
 }
 #else
-static void kill_app_process(int pid, bool, bool show_errors) {
+static void kill_app_process(int pid, bool) {
     int retval = 0;
     if (g_use_sandbox) {
         retval = kill_via_switcher(pid);
-        if (retval && log_flags.task_debug && show_errors) {
+        if (retval && log_flags.task_debug) {
             msg_printf(0, MSG_INFO,
-                "[task] kill_via_switcher() failed: %s (%d)",
+                "[task] kill_via_switcher(%d) failed: %s (%d)",
+                pid,
                 (retval>=0) ? strerror(errno) : boincerror(retval), retval
             );
         }
     } else {
-        retval = kill(pid, SIGKILL);
-        if (retval && log_flags.task_debug && show_errors) {
+        retval = kill_program(pid);
+        if (retval && log_flags.task_debug) {
             msg_printf(0, MSG_INFO,
-                "[task] kill() failed: %s",
-                strerror(errno)
+                "[task] kill_program(%d) failed: %s",
+                pid, strerror(errno)
             );
         }
     }
@@ -263,7 +264,7 @@ static void kill_app_process(int pid, bool, bool show_errors) {
 // will be cleaned up after it exits, by cleanup_task();
 //
 int ACTIVE_TASK::kill_running_task(bool will_restart) {
-    kill_app_process(pid, will_restart, true);
+    kill_app_process(pid, will_restart);
     return 0;
 }
 
@@ -277,10 +278,10 @@ int ACTIVE_TASK::kill_running_task(bool will_restart) {
 int ACTIVE_TASK::kill_subsidiary_processes() {
     unsigned int i;
     for (i=0; i<other_pids.size(); i++) {
-        kill_app_process(other_pids[i], false, false);
+        kill_app_process(other_pids[i], false);
     }
     for (i=0; i<descendants.size(); i++) {
-        kill_app_process(descendants[i], false, false);
+        kill_app_process(descendants[i], false);
     }
     return 0;
 }
diff --git a/lib/util.cpp b/lib/util.cpp
index 6ee94fb745..2ac4deef01 100644
--- a/lib/util.cpp
+++ b/lib/util.cpp
@@ -468,7 +468,9 @@ int kill_program(int pid, int exit_code) {
     int retval;
 
     HANDLE h = OpenProcess(PROCESS_TERMINATE, false, pid);
-    if (h == NULL) return ERR_NOT_FOUND;
+    if (h == NULL) return 0;
+        // process isn't there, so no error
+
     if (TerminateProcess(h, exit_code)) {
         retval = 0;
     } else {
@@ -486,6 +488,7 @@ int kill_program(HANDLE pid) {
 #else
 int kill_program(int pid) {
     if (kill(pid, SIGKILL)) {
+        if (errno == ESRCH) return 0;
         return ERR_KILL;
     }
     return 0;