Merge branch 'cb/maint-kill-subprocess-upon-signal' into maint

* cb/maint-kill-subprocess-upon-signal:
dashed externals: kill children on exit
run-command: optionally kill children on exit

diff --git a/git.c b/git.c
index fb9029cbf17bdad1d52ea6eae0c8f4ddf6a13979..380561663061f011189de883a865fbd59a922190 100644 (file)
--- a/git.c
+++ b/git.c
@@ -495,7 +495,7 @@ static void execv_dashed_external(const char **argv)
         * if we fail because the command is not found, it is
         * OK to return. Otherwise, we just pass along the status code.
         */
-       status = run_command_v_opt(argv, RUN_SILENT_EXEC_FAILURE);
+       status = run_command_v_opt(argv, RUN_SILENT_EXEC_FAILURE | RUN_CLEAN_ON_EXIT);
        if (status >= 0 || errno != ENOENT)
                exit(status);
 

diff --git a/run-command.c b/run-command.c
index 1c5104388429e50722769358d5d89948c55bb3aa..1db8abf9843516576f30f8105bbfdd66487db6e1 100644 (file)
--- a/run-command.c
+++ b/run-command.c
@@ -1,8 +1,66 @@
 #include "cache.h"
 #include "run-command.h"
 #include "exec_cmd.h"
+#include "sigchain.h"
 #include "argv-array.h"
 
+struct child_to_clean {
+       pid_t pid;
+       struct child_to_clean *next;
+};
+static struct child_to_clean *children_to_clean;
+static int installed_child_cleanup_handler;
+
+static void cleanup_children(int sig)
+{
+       while (children_to_clean) {
+               struct child_to_clean *p = children_to_clean;
+               children_to_clean = p->next;
+               kill(p->pid, sig);
+               free(p);
+       }
+}
+
+static void cleanup_children_on_signal(int sig)
+{
+       cleanup_children(sig);
+       sigchain_pop(sig);
+       raise(sig);
+}
+
+static void cleanup_children_on_exit(void)
+{
+       cleanup_children(SIGTERM);
+}
+
+static void mark_child_for_cleanup(pid_t pid)
+{
+       struct child_to_clean *p = xmalloc(sizeof(*p));
+       p->pid = pid;
+       p->next = children_to_clean;
+       children_to_clean = p;
+
+       if (!installed_child_cleanup_handler) {
+               atexit(cleanup_children_on_exit);
+               sigchain_push_common(cleanup_children_on_signal);
+               installed_child_cleanup_handler = 1;
+       }
+}
+
+static void clear_child_for_cleanup(pid_t pid)
+{
+       struct child_to_clean **last, *p;
+
+       last = &children_to_clean;
+       for (p = children_to_clean; p; p = p->next) {
+               if (p->pid == pid) {
+                       *last = p->next;
+                       free(p);
+                       return;
+               }
+       }
+}
+
 static inline void close_pair(int fd[2])
 {
        close(fd[0]);
@@ -130,6 +188,9 @@ static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
        } else {
                error("waitpid is confused (%s)", argv0);
        }
+
+       clear_child_for_cleanup(pid);
+
        errno = failed_errno;
        return code;
 }
@@ -292,6 +353,8 @@ int start_command(struct child_process *cmd)
        if (cmd->pid < 0)
                error("cannot fork() for %s: %s", cmd->argv[0],
                        strerror(failed_errno = errno));
+       else if (cmd->clean_on_exit)
+               mark_child_for_cleanup(cmd->pid);
 
        /*
         * Wait for child's execvp. If the execvp succeeds (or if fork()
@@ -312,6 +375,7 @@ int start_command(struct child_process *cmd)
                cmd->pid = -1;
        }
        close(notify_pipe[0]);
+
 }
 #else
 {
@@ -356,6 +420,8 @@ int start_command(struct child_process *cmd)
        failed_errno = errno;
        if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
                error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
+       if (cmd->clean_on_exit && cmd->pid >= 0)
+               mark_child_for_cleanup(cmd->pid);
 
        if (cmd->env)
                free_environ(env);
@@ -431,6 +497,7 @@ static void prepare_run_command_v_opt(struct child_process *cmd,
        cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
        cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
        cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
+       cmd->clean_on_exit = opt & RUN_CLEAN_ON_EXIT ? 1 : 0;
 }
 
 int run_command_v_opt(const char **argv, int opt)
@@ -540,6 +607,8 @@ int start_async(struct async *async)
                exit(!!async->proc(proc_in, proc_out, async->data));
        }
 
+       mark_child_for_cleanup(async->pid);
+
        if (need_in)
                close(fdin[0]);
        else if (async->in)

diff --git a/run-command.h b/run-command.h
index 56491b9f2344541c02bd0da2928a535f11193bd8..44f7d2bd42ddcf2d65722b7e54bea69645d167a2 100644 (file)
--- a/run-command.h
+++ b/run-command.h
@@ -38,6 +38,7 @@ struct child_process {
        unsigned silent_exec_failure:1;
        unsigned stdout_to_stderr:1;
        unsigned use_shell:1;
+       unsigned clean_on_exit:1;
        void (*preexec_cb)(void);
 };
 
@@ -52,6 +53,7 @@ extern int run_hook(const char *index_file, const char *name, ...);
 #define RUN_COMMAND_STDOUT_TO_STDERR 4
 #define RUN_SILENT_EXEC_FAILURE 8
 #define RUN_USING_SHELL 16
+#define RUN_CLEAN_ON_EXIT 32
 int run_command_v_opt(const char **argv, int opt);
 
 /*