rework server-worker communication

OK, this is a major rework.

* tcp_server: connection threads are not detached anymore, the caller has
  to clean them up. This was done so that the server can clean up the
  threads cleanly.
* run_queue: simple refactoring, run_queue_entry is called just run now.
* server: worker threads are now killed when a run is assigned to a
  worker.
* worker: the connection to server is no longer persistent. A worker
  sends "new-worker", waits for a task, closes the connection, and when
  it's done, sends the "complete" message and waits for a new task.

This is supposed to improve resilience, since the worker-server
connections don't have to be maintained while the worker is doing a CI
run.

1 files changed, 8 insertions, 3 deletions

diff --git a/src/command.h b/src/command.h
index 0ab44c1..90facbb 100644
--- a/src/command.h
+++ b/src/command.h
@@ -12,8 +12,7 @@
 
 #include <stddef.h>
 
-typedef int (*cmd_handler)(int conn_fd, const struct msg *request, struct msg **response,
-                           void *ctx);
+typedef int (*cmd_handler)(const struct msg *request, struct msg **response, void *ctx);
 
 struct cmd_desc {
 	char *name;
@@ -26,7 +25,13 @@ int cmd_dispatcher_create(struct cmd_dispatcher **, struct cmd_desc *, size_t nu
                           void *ctx);
 void cmd_dispatcher_destroy(struct cmd_dispatcher *);
 
-int cmd_dispatcher_handle_msg(const struct cmd_dispatcher *, int conn_fd, const struct msg *);
+int cmd_dispatcher_handle(const struct cmd_dispatcher *, const struct msg *command,
+                          struct msg **response);
+
+struct cmd_conn_ctx {
+	int fd;
+	void *arg;
+};
 
 /* This is supposed to be used as an argument to tcp_server_accept. */
 int cmd_dispatcher_handle_conn(int conn_fd, void *dispatcher);