contrib/chg/hgclient.h

debugcommands: introduce actions to perform deterministic reads

"readavailable" is useful as a debugging device to see what data is
available on a pipe. But the mechanism isn't deterministic because
what's available on a pipe is highly conditional on timing, system
load, OS behavior, etc. This makes it not suitable for tests.

We introduce "ereadline," "read," and "eread" for performing
deterministic I/O operations (at least on blocking file descriptors).

We stop short of converting existing consumers of "readavailable"
in tests because we're working out race conditions and deadlocks
on Windows. But the goal is to eventually move tests away from
"readavailable" to these new APIs.

Differential Revision: https://phab.mercurial-scm.org/D2720

/*
 * A command server client that uses Unix domain socket
 *
 * Copyright (c) 2011 Yuya Nishihara <[e-mail]>
 *
 * This software may be used and distributed according to the terms of the
 * GNU General Public License version 2 or any later version.
 */

#ifndef HGCLIENT_H_
#define HGCLIENT_H_

#include <sys/types.h>

struct hgclient_tag_;
typedef struct hgclient_tag_ hgclient_t;

hgclient_t *hgc_open(const char *sockname);
void hgc_close(hgclient_t *hgc);

pid_t hgc_peerpgid(const hgclient_t *hgc);
pid_t hgc_peerpid(const hgclient_t *hgc);

const char **hgc_validate(hgclient_t *hgc, const char *const args[],
                          size_t argsize);
int hgc_runcommand(hgclient_t *hgc, const char *const args[], size_t argsize);
void hgc_attachio(hgclient_t *hgc);
void hgc_setenv(hgclient_t *hgc, const char *const envp[]);

#endif /* HGCLIENT_H_ */