1 # The atomic_ops library (`libatomic_ops`)
3 IN NEW CODE, PLEASE USE C11 OR C++14 STANDARD ATOMICS INSTEAD OF THIS PACKAGE.
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13 This is version 7.7.0 (next release development) of libatomic_ops.
18 You might find a more recent/stable version on the
19 [Download](https://github.com/ivmai/libatomic_ops/wiki/Download) page, or
20 [BDWGC site](http://www.hboehm.info/gc/).
22 Also, the latest bug fixes and new features are available in the
23 [development repository](https://github.com/ivmai/libatomic_ops).
28 This package provides semi-portable access to hardware-provided
29 atomic memory update operations on a number of architectures. These might
30 allow you to write code:
32 * That does more interesting things in signal handlers.
34 * Makes more effective use of multiprocessors by allowing you to write
35 clever lock-free code. Note that such code is very difficult to get
36 right, and will unavoidably be less portable than lock-based code. It
37 is also not always faster than lock-based code. But it may occasionally
38 be a large performance win.
40 * To experiment with new and much better thread programming paradigms, etc.
42 For details and licensing restrictions see the files in the "doc"
46 ## Installation and Usage
48 The configuration and build scripts for this package were generated by
49 Automake/Autoconf. `./configure; make; sudo make install` in this
50 directory should work. For a more customized build, see the output of
51 `./configure --help`. To build it from the development repository,
52 `./autogen.sh` should be executed first.
54 Note that much of the content of this library is in the header files.
55 However, two small libraries are built and installed:
57 * `libatomic_ops.a` is a support library, which is not needed on some
58 platforms. This is intended to be usable, under some mild restrictions,
59 in free or proprietary code, as are all the header files.
60 See doc/LICENSING.txt.
62 * `libatomic_ops_gpl.a` contains some higher level facilities. This code is
63 currently covered by the GPL. The contents currently correspond to
64 the headers `atomic_ops_stack.h` and `atomic_ops_malloc.h`.
67 ## Platform Specific Notes
69 Win32/64: src/Makefile.msft contains a very simple Makefile for building
70 and running tests and building the gpl library. The core `libatomic_ops`
71 implementation is entirely in header files.
73 HP-UX/PA-RISC: `aCC -Ae` won't work as a C compiler, since it doesn't support
74 inline assembly code. Use cc.
77 ## Feedback, Contribution, Questions and Notifications
79 Please address bug reports and new feature ideas to
80 [GitHub issues](https://github.com/ivmai/libatomic_ops/issues). Before the
81 submission please check that it has not been done yet by someone else.
83 If you want to contribute, submit
84 a [pull request](https://github.com/ivmai/libatomic_ops/pulls) to GitHub.
87 [Stack Overflow](https://stackoverflow.com/questions/tagged/atomic-ops).
88 Older questions on the site can be found by
89 [this query](https://stackoverflow.com/search?q=atomic_ops).
90 Older technical discussions are also available in `bdwgc` mailing list
91 archive - it can be downloaded as a
92 [compressed file](https://github.com/ivmai/bdwgc/files/1038163/bdwgc-mailing-list-archive-2017_04.tar.gz)
93 or browsed at [Narkive](http://bdwgc.opendylan.narkive.com) (please search
94 for _atomic_ keyword).
96 To get new release announcements, subscribe to
97 [RSS feed](https://github.com/ivmai/libatomic_ops/releases.atom).
98 (To receive the notifications by email, a 3rd-party free service like
99 [IFTTT RSS Feed](https://ifttt.com/feed) can be setup.)
100 To be notified on all issues, please
101 [watch](https://github.com/ivmai/libatomic_ops/watchers) the project on
105 ## Copyright & Warranty
107 * Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved.
108 * Copyright (c) 1996-1999 by Silicon Graphics. All rights reserved.
109 * Copyright (c) 1999-2011 Hewlett-Packard Development Company, L.P.
110 * Copyright (c) 2008-2019 Ivan Maidanski
112 The file armcc/arm_v6.h is also
114 * Copyright (c) 2007 by NEC LE-IT. All rights reserved.
116 The file gcc/avr32.h is
118 * Copyright (c) 2009 Bradley Smith <brad@brad-smith.co.uk>
120 The file gcc/mips.h is
122 * Copyright (c) 2005, 2007 Thiemo Seufer <ths@networkno.de>
126 * Copyright (c) 2009 by Takashi YOSHII. All rights reserved.
128 See doc/LICENSING.txt for the details.