make/os.h

/* Declarations for operating system interfaces for GNU Make.
Copyright (C) 2016 Free Software Foundation, Inc.
This file is part of GNU Make.

GNU Make is free software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
Foundation; either version 3 of the License, or (at your option) any later
version.

GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with
this program.  If not, see <http://www.gnu.org/licenses/>.  */


/* This section provides OS-specific functions to support the jobserver.  */

#ifdef MAKE_JOBSERVER

/* Returns 1 if the jobserver is enabled, else 0.  */
unsigned int jobserver_enabled ();

/* Called in the master instance to set up the jobserver initially.  */
void jobserver_setup (int job_slots);

/* Called in a child instance to connect to the jobserver.  */
void jobserver_parse_arg (const char* arg);

/* Returns an allocated buffer used to pass to child instances.  */
char *jobserver_get_arg ();

/* Clear this instance's jobserver configuration.  */
void jobserver_clear ();

/* Recover all the jobserver tokens and return the number we got.  */
unsigned int jobserver_acquire_all ();

/* Release a jobserver token.  If it fails and is_fatal is 1, fatal.  */
void jobserver_release (int is_fatal);

/* Notify the jobserver that a child exited.  */
void jobserver_signal ();

/* Get ready to start a non-recursive child.  */
void jobserver_pre_child ();

/* Complete starting a non-recursive child.  */
void jobserver_post_child ();

/* Set up to acquire a new token.  */
void jobserver_pre_acquire ();

/* Wait until we can acquire a jobserver token.
   TIMEOUT is 1 if we have other jobs waiting for the load to go down;
   in this case we won't wait forever, so we can check the load.
   Returns 1 if we got a token, or 0 if we stopped waiting due to a child
   exiting or a timeout.    */
int jobserver_acquire (int timeout);

#else

#define jobserver_enabled()       (0)
#define jobserver_setup(_slots)   (void)(0)
#define jobserver_parse_arg(_arg) (void)(0)
#define jobserver_get_arg()       (NULL)
#define jobserver_clear()         (void)(0)
#define jobserver_release(_fatal) (void)(0)
#define jobserver_acquire_all()   (0)
#define jobserver_signal()        (void)(0)
#define jobserver_pre_child(_r)   (void)(0)
#define jobserver_post_child(_r)  (void)(0)
#define jobserver_pre_acquire()   (void)(0)
#define jobserver_acquire(_tmout) (0)

#endif

/* Create a "bad" file descriptor for stdin when parallel jobs are run.  */
#if !defined(VMD) && !defined(WINDOWS32) && !defined(_AMIGA) && !defined(__MSDOS__)
int get_bad_stdin ();
#else
# define get_bad_stdin() (-1)
#endif