make/os.h
Paul Smith 5bd7ad2b22 Preserve the real value of -jN in MAKEFLAGS using jobserver.
Previously if the jobserver was active, MAKEFLAGS would contain only
the -j option but not the number (not -j5 or whatever) so users
could not discover that value.  Allow that value to be provided in
MAKEFLAGS without error but still give warnings if -jN is provided
on the command line if the jobserver is already activated.

* NEWS: Discuss the new behavior.
* os.h, posixos.c, w32/w32os.c: Return success/failure from
jobserver_setup() and jobserver_parse_auth().
* main.c (main): Separate the command line storage of job slots (now
in arg_job_slots) from the control storage (in job_slots).  Make a
distinction between -jN flags read from MAKEFLAGS and those seen
on the command line: for the latter if the jobserver is enabled then
warn and disable it, as before.
* tests/scripts/features/jobserver: Add new testing.
2016-04-04 01:38:37 -04:00

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C

/* 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. */
unsigned int jobserver_setup (int job_slots);
/* Called in a child instance to connect to the jobserver. */
unsigned int jobserver_parse_auth (const char* auth);
/* Returns an allocated buffer used to pass to child instances. */
char *jobserver_get_auth ();
/* 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. */
unsigned int jobserver_acquire (int timeout);
#else
#define jobserver_enabled() (0)
#define jobserver_setup(_slots) (0)
#define jobserver_parse_auth(_auth) (0)
#define jobserver_get_auth() (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