Add merge-subtree back

diff --git a/run-command.h b/run-command.h
index 7958eb1e0b7a927019460e06d7a01622eddf81df..1fc781d7668468f9e74bd430b7569dc040440ba8 100644 (file)
--- a/run-command.h
+++ b/run-command.h
@@ -16,12 +16,14 @@ struct child_process {
        pid_t pid;
        int in;
        int out;
+       int err;
        const char *dir;
        const char *const *env;
        unsigned close_in:1;
        unsigned close_out:1;
        unsigned no_stdin:1;
        unsigned no_stdout:1;
+       unsigned no_stderr:1;
        unsigned git_cmd:1; /* if this is to be git sub-command */
        unsigned stdout_to_stderr:1;
 };
@@ -42,4 +44,26 @@ int run_command_v_opt_cd(const char **argv, int opt, const char *dir);
  */
 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env);
 
+/*
+ * The purpose of the following functions is to feed a pipe by running
+ * a function asynchronously and providing output that the caller reads.
+ *
+ * It is expected that no synchronization and mutual exclusion between
+ * the caller and the feed function is necessary so that the function
+ * can run in a thread without interfering with the caller.
+ */
+struct async {
+       /*
+        * proc writes to fd and closes it;
+        * returns 0 on success, non-zero on failure
+        */
+       int (*proc)(int fd, void *data);
+       void *data;
+       int out;        /* caller reads from here and closes it */
+       pid_t pid;
+};
+
+int start_async(struct async *async);
+int finish_async(struct async *async);
+
 #endif