From 5f594bfbcb2d2bd132fb6eb006fe9dccc7ee5344 Mon Sep 17 00:00:00 2001
From: Christian Pointner <equinox@spreadspace.org>
Date: Thu, 17 Sep 2015 17:15:55 +0200
Subject: fixed race condition between killing processes

---
 src/sysexec.c | 23 +++++++++++++++++------
 src/sysexec.h |  4 +++-
 2 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/src/sysexec.c b/src/sysexec.c
index 782b10d..6f606ff 100644
--- a/src/sysexec.c
+++ b/src/sysexec.c
@@ -98,6 +98,10 @@ void child_list_clear(child_list_t* list)
     list->first_ = tmp->next_;
     if(tmp->script_)
       free(tmp->script_);
+    if(tmp->state_ == RUNNING) {
+      pid_t pgid = getpgid(tmp->pid_);
+      kill(pgid * -1, SIGKILL);
+    }
     free(tmp);
   }
 }
@@ -113,7 +117,7 @@ child_list_element_t* child_list_new(const char* script, char* const argv[], cha
   new_child->next_ = 0;
   new_child->pid_ = -1;
   new_child->err_fd_ = -1;
-  new_child->running_ = 0;
+  new_child->state_ = NEW;
   new_child->script_ = strdup(script);
   if(!new_child->script_) {
     free(new_child);
@@ -248,7 +252,7 @@ int child_list_num_running(child_list_t* list)
 
   child_list_element_t* tmp = list->first_;
   for(;tmp;tmp=tmp->next_)
-    if(tmp->running_) num++;
+    if(tmp->state_ == RUNNING) num++;
 
   return num;
 }
@@ -258,9 +262,16 @@ void child_list_kill_oldest(child_list_t* list)
   if(!list || !list->first_)
     return;
 
-  pid_t pgid = getpgid(list->first_->pid_);
-  log_printf(DEBUG, "sending KILL signal to child %d with process group id %d", list->first_->pid_, pgid);
-  kill(pgid * -1, SIGKILL);
+  child_list_element_t* tmp = list->first_;
+  for(;tmp;tmp=tmp->next_) {
+    if(tmp->state_ == RUNNING) {
+      pid_t pgid = getpgid(tmp->pid_);
+      log_printf(DEBUG, "sending KILL signal to child %d with process group id %d", list->first_->pid_, pgid);
+      kill(pgid * -1, SIGKILL);
+      tmp->state_ = KILLED;
+      break;
+    }
+  }
 }
 
 int rh_exec(const char* script, char* const argv[], char* const evp[], child_list_t* child_lst, options_t* opt)
@@ -337,7 +348,7 @@ int rh_exec_child(child_list_element_t* child)
 
   child->pid_ = pid;
   child->err_fd_ = pipefd[0];
-  child->running_ = 1;
+  child->state_ = RUNNING;
 
   log_printf(INFO, "called script '%s' with pid %d", child->script_, child->pid_);
 
diff --git a/src/sysexec.h b/src/sysexec.h
index 560a70f..4345a15 100644
--- a/src/sysexec.h
+++ b/src/sysexec.h
@@ -25,11 +25,13 @@
 #include <sys/types.h>
 #include "options.h"
 
+typedef enum { NEW, RUNNING, KILLED } child_state_t;
+
 struct child_list_element_struct {
   pid_t pid_;
   char* script_;
   int err_fd_;
-  int running_;
+  child_state_t state_;
   char** argv_;
   char** evp_;
   struct child_list_element_struct* next_;
-- 
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