From 1b1e355046866ab4d19dac603967e422907169b0 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Fri, 21 Oct 2011 15:49:17 +1100 Subject: [PATCH] lsusd - a Linux SUSpend Daemon Initial commit. Signed-off-by: NeilBrown --- COPYING | 339 ++++++++++++++++++++++++++++++++++++++++++++++ Makefile | 47 +++++++ README | 104 ++++++++++++++ alarm_test.c | 57 ++++++++ block.sh | 29 ++++ block_test.c | 45 ++++++ dnotify.py | 127 +++++++++++++++++ event_test.c | 69 ++++++++++ libsus.h | 39 ++++++ lsusd.c | 196 +++++++++++++++++++++++++++ lsused.c | 264 ++++++++++++++++++++++++++++++++++++ request_suspend.c | 72 ++++++++++ suspend.py | 88 ++++++++++++ suspend_block.c | 52 +++++++ test_block.sh | 26 ++++ wakealarm.c | 103 ++++++++++++++ wakealarmd.c | 225 ++++++++++++++++++++++++++++++ wakeevent.c | 148 ++++++++++++++++++++ watch_test.c | 51 +++++++ watcher.c | 143 +++++++++++++++++++ 20 files changed, 2224 insertions(+) create mode 100644 COPYING create mode 100644 Makefile create mode 100644 README create mode 100644 alarm_test.c create mode 100644 block.sh create mode 100644 block_test.c create mode 100644 dnotify.py create mode 100644 event_test.c create mode 100644 libsus.h create mode 100644 lsusd.c create mode 100644 lsused.c create mode 100644 request_suspend.c create mode 100644 suspend.py create mode 100644 suspend_block.c create mode 100644 test_block.sh create mode 100644 wakealarm.c create mode 100644 wakealarmd.c create mode 100644 wakeevent.c create mode 100644 watch_test.c create mode 100644 watcher.c diff --git a/COPYING b/COPYING new file mode 100644 index 0000000..d159169 --- /dev/null +++ b/COPYING @@ -0,0 +1,339 @@ + GNU GENERAL PUBLIC LICENSE + Version 2, June 1991 + + Copyright (C) 1989, 1991 Free Software Foundation, Inc., + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + Preamble + + The licenses for most software are designed to take away your +freedom to share and change it. By contrast, the GNU General Public +License is intended to guarantee your freedom to share and change free +software--to make sure the software is free for all its users. This +General Public License applies to most of the Free Software +Foundation's software and to any other program whose authors commit to +using it. (Some other Free Software Foundation software is covered by +the GNU Lesser General Public License instead.) You can apply it to +your programs, too. + + When we speak of free software, we are referring to freedom, not +price. Our General Public Licenses are designed to make sure that you +have the freedom to distribute copies of free software (and charge for +this service if you wish), that you receive source code or can get it +if you want it, that you can change the software or use pieces of it +in new free programs; and that you know you can do these things. + + To protect your rights, we need to make restrictions that forbid +anyone to deny you these rights or to ask you to surrender the rights. +These restrictions translate to certain responsibilities for you if you +distribute copies of the software, or if you modify it. + + For example, if you distribute copies of such a program, whether +gratis or for a fee, you must give the recipients all the rights that +you have. You must make sure that they, too, receive or can get the +source code. And you must show them these terms so they know their +rights. + + We protect your rights with two steps: (1) copyright the software, and +(2) offer you this license which gives you legal permission to copy, +distribute and/or modify the software. + + Also, for each author's protection and ours, we want to make certain +that everyone understands that there is no warranty for this free +software. If the software is modified by someone else and passed on, we +want its recipients to know that what they have is not the original, so +that any problems introduced by others will not reflect on the original +authors' reputations. + + Finally, any free program is threatened constantly by software +patents. We wish to avoid the danger that redistributors of a free +program will individually obtain patent licenses, in effect making the +program proprietary. To prevent this, we have made it clear that any +patent must be licensed for everyone's free use or not licensed at all. + + The precise terms and conditions for copying, distribution and +modification follow. + + GNU GENERAL PUBLIC LICENSE + TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION + + 0. This License applies to any program or other work which contains +a notice placed by the copyright holder saying it may be distributed +under the terms of this General Public License. The "Program", below, +refers to any such program or work, and a "work based on the Program" +means either the Program or any derivative work under copyright law: +that is to say, a work containing the Program or a portion of it, +either verbatim or with modifications and/or translated into another +language. (Hereinafter, translation is included without limitation in +the term "modification".) Each licensee is addressed as "you". + +Activities other than copying, distribution and modification are not +covered by this License; they are outside its scope. The act of +running the Program is not restricted, and the output from the Program +is covered only if its contents constitute a work based on the +Program (independent of having been made by running the Program). +Whether that is true depends on what the Program does. + + 1. You may copy and distribute verbatim copies of the Program's +source code as you receive it, in any medium, provided that you +conspicuously and appropriately publish on each copy an appropriate +copyright notice and disclaimer of warranty; keep intact all the +notices that refer to this License and to the absence of any warranty; +and give any other recipients of the Program a copy of this License +along with the Program. + +You may charge a fee for the physical act of transferring a copy, and +you may at your option offer warranty protection in exchange for a fee. + + 2. You may modify your copy or copies of the Program or any portion +of it, thus forming a work based on the Program, and copy and +distribute such modifications or work under the terms of Section 1 +above, provided that you also meet all of these conditions: + + a) You must cause the modified files to carry prominent notices + stating that you changed the files and the date of any change. + + b) You must cause any work that you distribute or publish, that in + whole or in part contains or is derived from the Program or any + part thereof, to be licensed as a whole at no charge to all third + parties under the terms of this License. + + c) If the modified program normally reads commands interactively + when run, you must cause it, when started running for such + interactive use in the most ordinary way, to print or display an + announcement including an appropriate copyright notice and a + notice that there is no warranty (or else, saying that you provide + a warranty) and that users may redistribute the program under + these conditions, and telling the user how to view a copy of this + License. (Exception: if the Program itself is interactive but + does not normally print such an announcement, your work based on + the Program is not required to print an announcement.) + +These requirements apply to the modified work as a whole. If +identifiable sections of that work are not derived from the Program, +and can be reasonably considered independent and separate works in +themselves, then this License, and its terms, do not apply to those +sections when you distribute them as separate works. But when you +distribute the same sections as part of a whole which is a work based +on the Program, the distribution of the whole must be on the terms of +this License, whose permissions for other licensees extend to the +entire whole, and thus to each and every part regardless of who wrote it. + +Thus, it is not the intent of this section to claim rights or contest +your rights to work written entirely by you; rather, the intent is to +exercise the right to control the distribution of derivative or +collective works based on the Program. + +In addition, mere aggregation of another work not based on the Program +with the Program (or with a work based on the Program) on a volume of +a storage or distribution medium does not bring the other work under +the scope of this License. + + 3. You may copy and distribute the Program (or a work based on it, +under Section 2) in object code or executable form under the terms of +Sections 1 and 2 above provided that you also do one of the following: + + a) Accompany it with the complete corresponding machine-readable + source code, which must be distributed under the terms of Sections + 1 and 2 above on a medium customarily used for software interchange; or, + + b) Accompany it with a written offer, valid for at least three + years, to give any third party, for a charge no more than your + cost of physically performing source distribution, a complete + machine-readable copy of the corresponding source code, to be + distributed under the terms of Sections 1 and 2 above on a medium + customarily used for software interchange; or, + + c) Accompany it with the information you received as to the offer + to distribute corresponding source code. (This alternative is + allowed only for noncommercial distribution and only if you + received the program in object code or executable form with such + an offer, in accord with Subsection b above.) + +The source code for a work means the preferred form of the work for +making modifications to it. For an executable work, complete source +code means all the source code for all modules it contains, plus any +associated interface definition files, plus the scripts used to +control compilation and installation of the executable. However, as a +special exception, the source code distributed need not include +anything that is normally distributed (in either source or binary +form) with the major components (compiler, kernel, and so on) of the +operating system on which the executable runs, unless that component +itself accompanies the executable. + +If distribution of executable or object code is made by offering +access to copy from a designated place, then offering equivalent +access to copy the source code from the same place counts as +distribution of the source code, even though third parties are not +compelled to copy the source along with the object code. + + 4. You may not copy, modify, sublicense, or distribute the Program +except as expressly provided under this License. Any attempt +otherwise to copy, modify, sublicense or distribute the Program is +void, and will automatically terminate your rights under this License. +However, parties who have received copies, or rights, from you under +this License will not have their licenses terminated so long as such +parties remain in full compliance. + + 5. You are not required to accept this License, since you have not +signed it. However, nothing else grants you permission to modify or +distribute the Program or its derivative works. These actions are +prohibited by law if you do not accept this License. Therefore, by +modifying or distributing the Program (or any work based on the +Program), you indicate your acceptance of this License to do so, and +all its terms and conditions for copying, distributing or modifying +the Program or works based on it. + + 6. Each time you redistribute the Program (or any work based on the +Program), the recipient automatically receives a license from the +original licensor to copy, distribute or modify the Program subject to +these terms and conditions. You may not impose any further +restrictions on the recipients' exercise of the rights granted herein. +You are not responsible for enforcing compliance by third parties to +this License. + + 7. If, as a consequence of a court judgment or allegation of patent +infringement or for any other reason (not limited to patent issues), +conditions are imposed on you (whether by court order, agreement or +otherwise) that contradict the conditions of this License, they do not +excuse you from the conditions of this License. If you cannot +distribute so as to satisfy simultaneously your obligations under this +License and any other pertinent obligations, then as a consequence you +may not distribute the Program at all. For example, if a patent +license would not permit royalty-free redistribution of the Program by +all those who receive copies directly or indirectly through you, then +the only way you could satisfy both it and this License would be to +refrain entirely from distribution of the Program. + +If any portion of this section is held invalid or unenforceable under +any particular circumstance, the balance of the section is intended to +apply and the section as a whole is intended to apply in other +circumstances. + +It is not the purpose of this section to induce you to infringe any +patents or other property right claims or to contest validity of any +such claims; this section has the sole purpose of protecting the +integrity of the free software distribution system, which is +implemented by public license practices. Many people have made +generous contributions to the wide range of software distributed +through that system in reliance on consistent application of that +system; it is up to the author/donor to decide if he or she is willing +to distribute software through any other system and a licensee cannot +impose that choice. + +This section is intended to make thoroughly clear what is believed to +be a consequence of the rest of this License. + + 8. If the distribution and/or use of the Program is restricted in +certain countries either by patents or by copyrighted interfaces, the +original copyright holder who places the Program under this License +may add an explicit geographical distribution limitation excluding +those countries, so that distribution is permitted only in or among +countries not thus excluded. In such case, this License incorporates +the limitation as if written in the body of this License. + + 9. The Free Software Foundation may publish revised and/or new versions +of the General Public License from time to time. Such new versions will +be similar in spirit to the present version, but may differ in detail to +address new problems or concerns. + +Each version is given a distinguishing version number. If the Program +specifies a version number of this License which applies to it and "any +later version", you have the option of following the terms and conditions +either of that version or of any later version published by the Free +Software Foundation. If the Program does not specify a version number of +this License, you may choose any version ever published by the Free Software +Foundation. + + 10. If you wish to incorporate parts of the Program into other free +programs whose distribution conditions are different, write to the author +to ask for permission. For software which is copyrighted by the Free +Software Foundation, write to the Free Software Foundation; we sometimes +make exceptions for this. Our decision will be guided by the two goals +of preserving the free status of all derivatives of our free software and +of promoting the sharing and reuse of software generally. + + NO WARRANTY + + 11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY +FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN +OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES +PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED +OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF +MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS +TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE +PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, +REPAIR OR CORRECTION. + + 12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING +WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR +REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, +INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING +OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED +TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY +YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER +PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE +POSSIBILITY OF SUCH DAMAGES. + + END OF TERMS AND CONDITIONS + + How to Apply These Terms to Your New Programs + + If you develop a new program, and you want it to be of the greatest +possible use to the public, the best way to achieve this is to make it +free software which everyone can redistribute and change under these terms. + + To do so, attach the following notices to the program. It is safest +to attach them to the start of each source file to most effectively +convey the exclusion of warranty; and each file should have at least +the "copyright" line and a pointer to where the full notice is found. + + + Copyright (C) + + This program 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 2 of the License, or + (at your option) any later version. + + This program 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, write to the Free Software Foundation, Inc., + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + +Also add information on how to contact you by electronic and paper mail. + +If the program is interactive, make it output a short notice like this +when it starts in an interactive mode: + + Gnomovision version 69, Copyright (C) year name of author + Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. + This is free software, and you are welcome to redistribute it + under certain conditions; type `show c' for details. + +The hypothetical commands `show w' and `show c' should show the appropriate +parts of the General Public License. Of course, the commands you use may +be called something other than `show w' and `show c'; they could even be +mouse-clicks or menu items--whatever suits your program. + +You should also get your employer (if you work as a programmer) or your +school, if any, to sign a "copyright disclaimer" for the program, if +necessary. Here is a sample; alter the names: + + Yoyodyne, Inc., hereby disclaims all copyright interest in the program + `Gnomovision' (which makes passes at compilers) written by James Hacker. + + , 1 April 1989 + Ty Coon, President of Vice + +This General Public License does not permit incorporating your program into +proprietary programs. If your program is a subroutine library, you may +consider it more useful to permit linking proprietary applications with the +library. If this is what you want to do, use the GNU Lesser General +Public License instead of this License. diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..6371a81 --- /dev/null +++ b/Makefile @@ -0,0 +1,47 @@ +# Copyright (C) 2011 Neil Brown +# +# This program 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 2 of the License, or +# (at your option) any later version. +# +# This program 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, write to the Free Software Foundation, Inc., +# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + +PROGS = lsusd lsused request_suspend wakealarmd +TESTS = block_test watch_test event_test alarm_test +LIBS = suspend_block.o watcher.o wakeevent.o wakealarm.o + +all: $(PROGS) $(TESTS) + +lsusd: lsusd.o + +lsused: lsused.o libsus.a + $(CC) -o lsused lsused.o libsus.a -levent + +wakealarmd: wakealarmd.o libsus.a + $(CC) -o wakealarmd wakealarmd.o libsus.a -levent + +request_suspend: request_suspend.o + +block_test: block_test.o libsus.a + $(CC) -o block_test block_test.o libsus.a +watch_test: watch_test.o libsus.a + $(CC) -o watch_test watch_test.o libsus.a -levent +event_test: event_test.o libsus.a + $(CC) -o event_test event_test.o libsus.a -levent +alarm_test: alarm_test.o libsus.a + $(CC) -o alarm_test alarm_test.o libsus.a -levent + +libsus.a: $(LIBS) + ar cr libsus.a $(LIBS) + +clean: + rm -f *.o *.a *.pyc $(PROGS) $(TESTS) + diff --git a/README b/README new file mode 100644 index 0000000..89b1c1e --- /dev/null +++ b/README @@ -0,0 +1,104 @@ + +This directory contains a prototype proof-of-concept system +for managing suspend in Linux. +Thus the Linux SUSpend Daemon. + +It contains: + + lsusd: + The main daemon. It is written to run a tight loop and blocks as + required. It obeys the wakeup_count protocol to get race-free + suspend and allows clients to register to find out about + suspend and to block it either briefly or longer term. + It uses files in /var/run/suspend for all communication. + + File are: + + disabled: This file always exists. If any process holds a + shared flock(), suspend will not happen. + immediate: If this file exists, lsusd will try to suspend whenever + possible. + request: If this is created, then lsusd will try to suspend + once, and will remove the file when suspend completes or aborts. + watching: This is normally empty. Any process wanting to know + about suspend should take a shared flock and check the file is + still empty, and should watch for modification. + When suspend is imminent, lsusd creates 'watching-next', writes + a byte to 'watching' and waits for an exclusive lock on 'watching'. + Clients should move their lock to 'watching-next' when ready for + suspend. + When suspend completes, another byte (or 2) is written to + 'watching', and 'watching-next' is renamed over it. Clients can + use either of these to know that resume has happened. + + watching-next: The file that will be 'watching' in the next awake cycle. + + lsusd does not try to be event-loop based because: + - /sys/power/wakeup_count is not pollable. This could probably be + 'fixed' but I want code to work with today's kernel. It will probably + only block 100msec at most, but that might be too long??? + - I cannot get an event notification when a lock is removed from a + file. :-( And I think locks are an excellent light-weight + mechanism for blocking suspend. + + lsused: + This is an event-loop based daemon that can therefore easily handle + socket connections and client protocols which need prompt + response. It communicates with lsusd and provides extra + services to client. + + lsused (which needs a better name) listens on the socket + /var/run/suspend/registration + A client may connect and send a list of file descriptors. + When a suspend is immanent, if any file descriptor is readable, + lsused will send a 'S' message to the client and await an 'R' reply + (S == suspend, R == ready). When all replies are in, lsused will + allow the suspend to complete. When it does (or aborts), it will send + 'A' (awake) to those clients to which it sent 'S'. + + This allows a client to get a chance to handle any wakeup events, + but not to be woken unnecessarily on every suspend. + + wakealarmd: + This allows clients to register on the socket. + /var/run/suspend/wakealarm + They write a timestamp in seconds since epoch, and will receive + a 'Now' message when that time arrives. + Between the time the connection is made and the time a "seconds" + number is written, suspend will be blocked. + Also between the time that "Now" is sent and when the socket is + closed, suspend is also blocked. + + request_suspend: + A simple tool to create the 'request' file and then wait for it + to be removed. + + libsus.a: A library of client-side interfaces. + suspend_open, suspend_block, suspend_allow, suspend_close: + easy interface to blocking suspend + suspend_watch, suspend_unwatch: + For use in libevent program to get notifications of + suspend and resume via the 'watching' file. + wake_set, wake_destory: + create a libevent event for an fd which is protected from + suspend. Whenever it is readable, suspend will not be entered. + wakealarm_set, wakealarm_destroy: + create a libevent event for a particular time which will + trigger even if system is suspend, and will protect against + suspend while event is happening. + + + block_test watch_test event_test alarm_test + simple test programs for the above interfaces. + + + suspend.py dnotify.py: + Sample code for detecting suspend/resume from python + block.sh test_block.sh: + Sample code for disabling suspend from shell. + +All code is available under GPLv2+. However if you ask for a different +license I am unlikely to refuse (at least with the early prototype). + +Patches and comment are welcome, but please also feel free to include +any of this in some more complete framework. diff --git a/alarm_test.c b/alarm_test.c new file mode 100644 index 0000000..37c30fa --- /dev/null +++ b/alarm_test.c @@ -0,0 +1,57 @@ + + +/* Test wakealarm. + * argv is a number of seconds to wait for. + * + * Copyright (C) 2011 Neil Brown + * + * This program 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 2 of the License, or + * (at your option) any later version. + * + * This program 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, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include +#include +#include "libsus.h" + +void callback(int fd, short ev, void *data) +{ + printf("Ping - got the event\n"); + suspend_block(-1); + event_loopbreak(); +} + +int main(int argc, char *argv[]) +{ + time_t now; + time_t then; + int diff; + struct event *ev; + + if (argc != 2) { + fprintf(stderr, "Usage: alarm_test seconds\n"); + exit(1); + } + diff = atoi(argv[1]); + time(&now); + then = now + diff; + event_init(); + + ev = wakealarm_set(then, callback, NULL); + + event_loop(0); + printf("Hold off suspend for a while...\n"); + sleep(4); + printf("OK - done\n"); + exit(0); +} diff --git a/block.sh b/block.sh new file mode 100644 index 0000000..50767d0 --- /dev/null +++ b/block.sh @@ -0,0 +1,29 @@ + +# shell functions to allow suspend to be blocked. +# +# Copyright (C) 2011 Neil Brown +# +# This program 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 2 of the License, or +# (at your option) any later version. +# +# This program 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, write to the Free Software Foundation, Inc., +# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + +block_suspend() { + exec 9< /var/run/suspend/disabled + flock --shared 9 +} + +enable_suspend() { + flock --unlock 9 + exec 9<&- +} + diff --git a/block_test.c b/block_test.c new file mode 100644 index 0000000..ea5430b --- /dev/null +++ b/block_test.c @@ -0,0 +1,45 @@ +/* + * block_test - test program for blocking suspend + * + * Copyright (C) 2011 Neil Brown + * + * This program 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 2 of the License, or + * (at your option) any later version. + * + * This program 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, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ +#include +#include +#include + +#include "libsus.h" + +main(int argc, char *argv[]) +{ + int sleep_time = 5; + int handle; + if (argc == 2) + sleep_time = atoi(argv[1]); + + handle = suspend_block(-1); + printf("Have the block - waiting\n"); + sleep(sleep_time); + printf("Releasing...\n"); + suspend_allow(handle); + sleep(1); + handle = suspend_block(handle); + printf("Blocked again\n"); + sleep(sleep_time); + suspend_close(handle); + printf("OK all done\n"); + exit(1); +} diff --git a/dnotify.py b/dnotify.py new file mode 100644 index 0000000..2746f9a --- /dev/null +++ b/dnotify.py @@ -0,0 +1,127 @@ +#!/usr/bin/env python + +# class to allow watching multiple files and +# calling a callback when any change (size or mtime) +# +# We take exclusive use of SIGIO and maintain a global list of +# watched files. +# As we cannot get siginfo in python, we check every file +# every time we get a signal. +# we report change is size, mtime, or ino of the file (given by name) + +# Copyright (C) 2011 Neil Brown +# +# This program 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 2 of the License, or +# (at your option) any later version. +# +# This program 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, write to the Free Software Foundation, Inc., +# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + + +import os, fcntl, signal + + +dirlist = [] +def notified(sig, stack): + for d in dirlist: + fcntl.fcntl(d.fd, fcntl.F_NOTIFY, (fcntl.DN_MODIFY|fcntl.DN_RENAME| + fcntl.DN_CREATE|fcntl.DN_DELETE)) + d.check() + +class dir(): + def __init__(self, dname): + self.dname = dname + self.fd = os.open(dname, 0) + self.files = [] + self.callbacks = [] + fcntl.fcntl(self.fd, fcntl.F_NOTIFY, (fcntl.DN_MODIFY|fcntl.DN_RENAME| + fcntl.DN_CREATE|fcntl.DN_DELETE)) + if not dirlist: + signal.signal(signal.SIGIO, notified) + dirlist.append(self) + + def watch(self, fname, callback): + f = file(os.path.join(self.dname, fname), callback) + self.files.append(f) + return f + + def watchall(self, callback): + self.callbacks.append(callback) + + def check(self): + newlist = [] + for c in self.callbacks: + if c(): + newlist.append(c) + self.callbacks = newlist + + for f in self.files: + f.check() + + def cancel(self, victim): + if victim in self.files: + self.files.remove(victim) + +class file(): + def __init__(self, fname, callback): + self.name = fname + try: + stat = os.stat(self.name) + except OSError: + self.ino = 0 + self.size = 0 + self.mtime = 0 + else: + self.ino = stat.st_ino + self.size = stat.st_size + self.mtime = stat.st_mtime + self.callback = callback + + def check(self): + try: + stat = os.stat(self.name) + except OSError: + if self.ino == 0: + return False + self.size = 0 + self.mtime = 0 + self.ino = 0 + else: + if stat.st_size == self.size and stat.st_mtime == self.mtime \ + and stat.st_ino == self.ino: + return False + self.size = stat.st_size + self.mtime = stat.st_mtime + self.ino = stat.st_ino + + self.callback(self) + return True + + def cancel(self): + global dirlist + for d in dirlist: + d.cancel(self) + + +if __name__ == "__main__" : + import signal + + + ## + def ping(f): print "got ", f.name + + d = dir("/tmp/n") + a = d.watch("a", ping) + b = d.watch("b", ping) + c = d.watch("c", ping) + + while True: + signal.pause() diff --git a/event_test.c b/event_test.c new file mode 100644 index 0000000..3039cd7 --- /dev/null +++ b/event_test.c @@ -0,0 +1,69 @@ + +/* + * test handling wakeup events on fd. + * You will need to strace things and watch to get any real + * feedback as this only does anything interesting when there + * is a race. + * + * Copyright (C) 2011 Neil Brown + * + * This program 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 2 of the License, or + * (at your option) any later version. + * + * This program 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, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include +#include +#include +#include +#include "libsus.h" + +void read_event(int fd, short ev, void *data) +{ + char buf[80]; + int n; + int i; + + printf("Can read now .. give it a moment though\n"); + sleep(5); + n = read(fd, buf, 80); + if (n < 0) + exit(1); + + for (i = 0; i < n ; i++) + printf(" %02x", buf[i] & 0xff); + printf("\n"); +} + +main(int argc, char *argv[]) +{ + int fd; + struct event *ev; + + if (argc != 2) { + fprintf(stderr, "Usage: event_test devicename\n"); + exit(1); + } + fd = open(argv[1], O_RDONLY); + if (fd < 0) { + perror(argv[1]); + exit(1); + } + + event_init(); + event_priority_init(3); + ev = wake_set(fd, read_event, NULL, 1); + + event_loop(0); + exit(0); +} diff --git a/libsus.h b/libsus.h new file mode 100644 index 0000000..56e4432 --- /dev/null +++ b/libsus.h @@ -0,0 +1,39 @@ +/* headers for libsus - supporting suspend management. + * + * Copyright (C) 2011 Neil Brown + * + * This program 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 2 of the License, or + * (at your option) any later version. + * + * This program 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, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ +int suspend_open(); +int suspend_block(int handle); +void suspend_allow(int handle); +int suspend_close(int handle); + + +void *suspend_watch(int (*will_suspend)(void *data), + void (*did_resume)(void *data), + void *data); +void suspend_ok(void *han); +void suspend_unwatch(void *v); + +struct event *wake_set(int fd, void(*fn)(int,short,void*), + void *data, int prio); +void wake_destroy(struct event *ev); + +struct event *wakealarm_set(time_t when, void(*fn)(int, short, void*), + void *data); +void wakealarm_destroy(struct event *ev); + + diff --git a/lsusd.c b/lsusd.c new file mode 100644 index 0000000..91b0512 --- /dev/null +++ b/lsusd.c @@ -0,0 +1,196 @@ +/* + * lsusd - Linus SUSpend daemon. + * This daemon enters suspend when required and allows clients + * to block suspend, request suspend, or be notified of suspend. + * + * Copyright (C) 2011 Neil Brown + * + * This program 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 2 of the License, or + * (at your option) any later version. + * + * This program 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, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ +#define _GNU_SOURCE + +#include +#include +#include +#include +#include +#include +#include + +static void alert_watchers(void) +{ + int fd; + char zero = 0; + + fd = open("/var/run/suspend/watching-next", + O_RDWR|O_CREAT|O_TRUNC, 0640); + if (fd < 0) + return; + close(fd); + fd = open("/var/run/suspend/watching", + O_RDWR|O_CREAT|O_TRUNC, 0640); + if (fd < 0) + return; + if (write(fd, &zero, 1) != 1) + return; + flock(fd, LOCK_EX); + /* all watches must have moved to next file */ + close(fd); +} + +static void cycle_watchers(void) +{ + int fd; + char zero[2]; + + fd = open("/var/run/suspend/watching", O_RDWR|O_CREAT, 0640); + if (fd < 0) + return; + zero[0] = zero[1] = 0; + if (write(fd, zero, 2) != 2) { + close(fd); + return; + } + close(fd); + rename("/var/run/suspend/watching-next", + "/var/run/suspend/watching"); +} + +static int read_wakeup_count() +{ + int fd; + int n; + char buf[20]; + + fd = open("/sys/power/wakeup_count", O_RDONLY); + if (fd < 0) + return -1; + n = read(fd, buf, sizeof(buf)-1); + close(fd); + if (n < 0) + return -1; + buf[n] = 0; + return atoi(buf); +} + +static int set_wakeup_count(int count) +{ + int fd; + char buf[20]; + int n; + + if (count < 0) + return 1; /* Something wrong - just suspend */ + + fd = open("/sys/power/wakeup_count", O_RDWR); + if (fd < 0) + return 1; + + snprintf(buf, sizeof(buf), "%d", count); + n = write(fd, buf, strlen(buf)); + close(fd); + if (n < 0) + return 0; + return 1; +} + +static void catch(int sig) +{ + return; +} + +static void wait_request(int dirfd) +{ + int found_immediate = 0; + int found_request = 0; + + do { + DIR *dir; + struct dirent *de; + sigset_t set, oldset; + sigemptyset(&set); + sigaddset(&set, SIGIO); + + sigprocmask(SIG_BLOCK, &set, &oldset); + signal(SIGIO, catch); + + fcntl(dirfd, F_NOTIFY, DN_CREATE); + + lseek(dirfd, 0L, 0); + dir = fdopendir(dup(dirfd)); + while ((de = readdir(dir)) != NULL) { + if (strcmp(de->d_name, "immediate") == 0) + found_immediate = 1; + if (strcmp(de->d_name, "request") == 0) + found_request = 1; + } + + if (!found_request && !found_immediate) + sigsuspend(&oldset); + closedir(dir); + signal(SIGIO, SIG_DFL); + sigprocmask(SIG_UNBLOCK, &set, &oldset); + } while (!found_immediate && !found_request); +} + +static void do_suspend(void) +{ + int fd = open("/sys/power/state", O_RDWR); + if (fd >= 0) { + write(fd, "mem\n", 4); + close(fd); + } else + sleep(5); +} + +main(int argc, char *argv) +{ + int dir; + int disable; + + mkdir("/var/run/suspend", 0770); + + dir = open("/var/run/suspend", O_RDONLY); + disable = open("/var/run/suspend/disabled", O_RDWR|O_CREAT, 0640); + + if (dir < 0 || disable < 0) + exit(1); + + while (1) { + int count; + + /* Don't accept an old request */ + unlink("/var/run/suspend/request"); + wait_request(dir); + if (flock(disable, LOCK_EX|LOCK_NB) != 0) { + flock(disable, LOCK_EX); + flock(disable, LOCK_UN); + unlink("/var/run/suspend/request"); + /* blocked - so need to ensure request still valid */ + continue; + } + /* we got that without blocking but are not holding it */ + + /* Next two might block, but that doesn't abort suspend */ + count = read_wakeup_count(); + alert_watchers(); + + if (flock(disable, LOCK_EX|LOCK_NB) == 0 + && set_wakeup_count(count)) + do_suspend(); + flock(disable, LOCK_UN); + cycle_watchers(); + } +} diff --git a/lsused.c b/lsused.c new file mode 100644 index 0000000..99179a8 --- /dev/null +++ b/lsused.c @@ -0,0 +1,264 @@ + +/* + * lsused - Linux SUSpend Event monitoring Daemon + * + * apps and services can send fds to this daemon. + * We will not allow suspend to happen if any fd is readable. + * A client should also notice that it is readable, take a + * shared lock on the suspend/disabled file and then read the event. + * + * The client opens connects on a unix domain socket to + * /var/run/suspend/registration + * It sets 'W' with some fds attached to be watched. + * On notification if any fds are readable we send by 'S' to say + * Suspend Soon and wait for 'R' to say 'Ready'. + * We don't bother checking the fds again until the next suspend + * attempt. + * + * + * Copyright (C) 2011 Neil Brown + * + * This program 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 2 of the License, or + * (at your option) any later version. + * + * This program 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, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include "libsus.h" + + +struct handle { + struct event ev; + int sent; /* 'S' has been sent */ + int suspending; /* ... 'R' hasn't been received yet */ + struct handle *next; + struct state *state; +}; + +struct state { + int waiting; /* Number of replies waiting for */ + struct handle *handles; /* linked list of handles */ + struct pollfd *fds; /* for 'poll' */ + struct handle **hans; /* aligned with fds */ + int nfds; /* number of active 'fds' */ + int fdsize; /* allocated size of fds array */ + void *sus; /* handle from suspend_watch */ +}; + +static void del_fd(struct state *state, int i) +{ + state->fds[i] = state->fds[state->nfds - 1]; + state->hans[i] = state->hans[state->nfds - 1]; + state->nfds--; +} + +static void add_fd(struct state *state, struct handle *han, + int fd, short events) +{ + int n = state->nfds; + if (state->nfds >= state->fdsize) { + /*need to make bigger */ + int need = 16; + while (need < n+1) + need *= 2; + state->fds = realloc(state->fds, + need * sizeof(struct pollfd)); + state->hans = realloc(state->hans, + need * sizeof(struct handle *)); + } + state->hans[n] = han; + state->fds[n].fd = fd; + state->fds[n].events = events; + state->nfds++; +} + +static void add_han(struct handle *han, struct state *state) +{ + + han->next = state->handles; + state->handles = han; +} + +static void del_han(struct handle *han) +{ + struct state *state = han->state; + struct handle **hanp = &state->handles; + struct handle *h; + int i; + + /* First remove the fds; */ + for (i = 0; i < state->nfds ; i++) + if (state->hans[i] == han) { + del_fd(state, i); + i--; + } + + /* Then remove the han */ + for (h = *hanp; h; hanp = &h->next, h = *hanp) { + if (h == han) { + *hanp = h->next; + break; + } + } +} + +static void do_read(int fd, short ev, void *data) +{ + struct handle *han = data; + char buf; + struct msghdr msg; + struct cmsghdr *cm; + struct iovec iov; + char mbuf[100]; + + buf = 0; + msg.msg_name = NULL; + msg.msg_namelen = 0; + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + iov.iov_base = &buf; + iov.iov_len = 1; + msg.msg_control = mbuf; + msg.msg_controllen = sizeof(mbuf); + msg.msg_flags = 0; + + if (recvmsg(fd, &msg, MSG_CMSG_CLOEXEC|MSG_DONTWAIT) < 0 + && errno == EAGAIN) + return; + + switch (buf) { + case 'W': + for (cm = CMSG_FIRSTHDR(&msg); + cm != NULL; + cm = CMSG_NXTHDR(&msg, cm)) + if (cm->cmsg_level == SOL_SOCKET && + cm->cmsg_type == SCM_RIGHTS) { + int *fdptr = (int*)CMSG_DATA(cm); + int n = (cm->cmsg_len - + CMSG_ALIGN(sizeof(struct cmsghdr))) + / sizeof(int); + int i; + for (i = 0; i < n; i++) + add_fd(han->state, han, fdptr[i], + POLLIN|POLLPRI); + } + write(fd, "A", 1); + break; + + case 'R': + if (han->suspending) { + han->suspending = 0; + han->state->waiting--; + if (han->state->waiting == 0) + suspend_ok(han->state->sus); + } + break; + + default: + event_del(&han->ev); + del_han(han); + close(fd); + } +} + +static void do_accept(int fd, short ev, void *data) +{ + struct state *state = data; + struct handle *han; + int newfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC); + if (newfd < 0) + return; + + han = malloc(sizeof(*han)); + if (!han) { + close(newfd); + return; + } + han->sent = 0; + han->suspending = 0; + han->state = state; + add_han(han, state); + event_set(&han->ev, newfd, EV_READ | EV_PERSIST, do_read, han); + event_add(&han->ev, NULL); + write(newfd, "A", 1); +} + +static int do_suspend(void *data) +{ + struct state *state = data; + struct handle *han; + int n; + int i; + + n = poll(state->fds, state->nfds, 0); + if (n == 0) + /* nothing happening */ + return 1; + for (han = state->handles ; han ; han = han->next) + han->sent = 0; + state->waiting = 1; + for (i = 0; i < state->nfds; i++) + if (state->fds[i].revents) { + han = state->hans[i]; + if (!han->sent) { + han->sent = 1; + han->suspending = 1; + write(EVENT_FD(&han->ev), "S", 1); + state->waiting++; + } + } + state->waiting--; + return (state->waiting == 0); +} + +static void did_resume(void *data) +{ + struct state *state = data; + struct handle *han; + + for (han = state->handles ; han ; han = han->next) + if (han->sent) + write(EVENT_FD(&han->ev), "A", 1); +} + +main(int argc, char *argv[]) +{ + struct sockaddr_un addr; + struct state state; + struct event ev; + int s; + + memset(&state, 0, sizeof(state)); + + s = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK|SOCK_CLOEXEC, 0); + addr.sun_family = AF_UNIX; + strcpy(addr.sun_path, "/var/run/suspend/registration"); + unlink("/var/run/suspend/registration"); + bind(s, (struct sockaddr *)&addr, sizeof(addr)); + listen(s, 20); + + event_init(); + + state.sus = suspend_watch(do_suspend, did_resume, &state); + event_set(&ev, s, EV_READ | EV_PERSIST, do_accept, &state); + event_add(&ev, NULL); + + event_loop(0); + exit(0); +} diff --git a/request_suspend.c b/request_suspend.c new file mode 100644 index 0000000..3a60341 --- /dev/null +++ b/request_suspend.c @@ -0,0 +1,72 @@ +/* Request suspend + * Create the suspend-request file, then wait for it to be deleted. + * + * Copyright (C) 2011 Neil Brown + * + * This program 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 2 of the License, or + * (at your option) any later version. + * + * This program 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, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ +#define _GNU_SOURCE + +#include +#include +#include +#include + +static void catch(int sig) +{ + return; +} + +main(int argc, char *argv[]) +{ + int dirfd = open("/var/run/suspend", O_RDONLY); + int fd_request = open("/var/run/suspend/request", + O_RDWR|O_CREAT, 0640); + if (fd_request < 0) + exit(1); + + + if (dirfd < 0) + exit(1); + /* Wait for unlink */ + while (1) { + int fd; + struct stat stat; + sigset_t set, oldset; + sigemptyset(&set); + sigaddset(&set, SIGIO); + + sigprocmask(SIG_BLOCK, &set, &oldset); + signal(SIGIO, catch); + + fcntl(dirfd, F_NOTIFY, DN_DELETE); + + if (fstat(fd_request, &stat) != 0 + || stat.st_nlink == 0) + exit(0); + fd = open("/var/run/suspend/disabled", O_RDONLY); + if (fd >= 0) { + if (flock(fd, LOCK_EX|LOCK_NB) != 0) { + /* Someone is blocking suspend */ + unlink("/var/run/suspend/request"); + exit(1); + } + close(fd); + } + + sigsuspend(&oldset); + sigprocmask(SIG_UNBLOCK, &set, &oldset); + } +} diff --git a/suspend.py b/suspend.py new file mode 100644 index 0000000..2de18b4 --- /dev/null +++ b/suspend.py @@ -0,0 +1,88 @@ + +# +# interact with lsusd to provide suspend notification +# +# Copyright (C) 2011 Neil Brown +# +# This program 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 2 of the License, or +# (at your option) any later version. +# +# This program 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, write to the Free Software Foundation, Inc., +# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + +import dnotify, fcntl, os + +lock_watcher = None + +class monitor: + def __init__(self, suspend_callback, resume_callback): + """ + Arrange that suspend_callback is called before we suspend, and + resume_callback is called when we resume. + If suspend_callback returns False, it must have arranged for + 'release' to be called soon to allow suspend to continue. + """ + global lock_watcher + if not lock_watcher: + lock_watcher = dnotify.dir('/var/run/suspend') + + self.f = open('/var/run/suspend/watching', 'r') + self.getlock() + while os.fstat(self.f.fileno()).st_nlink == 0: + self.f.close() + self.f = open('/var/run/suspend/watching', 'r') + self.getlock() + + self.suspended = False + self.suspend = suspend_callback + self.resume = resume_callback + self.watch = lock_watcher.watch("watching", self.change) + + def getlock(self): + # lock file, protecting againt getting IOError when we get signalled. + locked = False + while not locked: + try: + fcntl.flock(self.f, fcntl.LOCK_SH) + locked = True + except IOError: + pass + + def change(self, watched): + if os.fstat(self.f.fileno()).st_size == 0: + if self.suspended and os.stat('/var/run/suspend/watching').st_size == 0: + self.suspended = False + if self.resume: + self.resume() + return + if not self.suspended and (not self.suspend or self.suspend()): + # ready for suspend + self.release() + + def release(self): + # ready for suspend + old = self.f + self.f = open('/var/run/suspend/watching-next', 'r') + self.getlock() + self.suspended = True + fcntl.flock(old, fcntl.LOCK_UN) + old.close() + + + +if __name__ == '__main__': + import signal + def sus(): print "Suspending"; return True + def res(): print "Resuming" + monitor(sus, res) + print "ready" + while True: + signal.pause() diff --git a/suspend_block.c b/suspend_block.c new file mode 100644 index 0000000..e50c1f3 --- /dev/null +++ b/suspend_block.c @@ -0,0 +1,52 @@ +/* + * Library routine to block and re-enable suspend. + * + * Copyright (C) 2011 Neil Brown + * + * This program 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 2 of the License, or + * (at your option) any later version. + * + * This program 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, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ +#define _GNU_SOURCE +#include +#include +#include +#include "libsus.h" + +int suspend_open() +{ + return open("/var/run/suspend/disabled", O_RDONLY|O_CLOEXEC); +} + +int suspend_block(int handle) +{ + if (handle < 0) + handle = suspend_open(); + if (handle < 0) + return handle; + + flock(handle, LOCK_SH); + return handle; +} + +void suspend_allow(int handle) +{ + flock(handle, LOCK_UN); +} + +int suspend_close(int handle) +{ + if (handle >= 0) + close(handle); +} + diff --git a/test_block.sh b/test_block.sh new file mode 100644 index 0000000..19d306c --- /dev/null +++ b/test_block.sh @@ -0,0 +1,26 @@ +#!/bin/sh +# Copyright (C) 2011 Neil Brown +# +# This program 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 2 of the License, or +# (at your option) any later version. +# +# This program 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, write to the Free Software Foundation, Inc., +# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + +source ./block.sh + +block_suspend + +echo now blocked. +sleep 10 +echo allowing now. + +enable_suspend diff --git a/wakealarm.c b/wakealarm.c new file mode 100644 index 0000000..65f83f7 --- /dev/null +++ b/wakealarm.c @@ -0,0 +1,103 @@ + +/* + * Library code to allow libevent app to register for a wake alarm + * and register with wakealarmd to keep suspend at bay for the time. + * + * Copyright (C) 2011 Neil Brown + * + * This program 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 2 of the License, or + * (at your option) any later version. + * + * This program 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, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include +#include +#include +#include +#include +#include +#include +#include "libsus.h" + +struct han { + struct event ev; + int sock; + int disable; + void (*fn)(int,short,void*); + void *data; +}; + +static void alarm_clock(int fd, short ev, void *data) +{ + char buf[20]; + int n; + struct han *h = data; + + n = read(fd, buf, sizeof(buf)-1); + if (n < 0 && errno == EAGAIN) + return; + if (n <= 0 || + strncmp(buf, "Now", 3) == 0) { + h->fn(-1, ev, h->data); + wakealarm_destroy(&h->ev); + } + /* Some other message, keep waiting */ +} + +struct event *wakealarm_set(time_t when, void(*fn)(int, short, void*), + void *data) +{ + struct sockaddr_un addr; + struct han *h = malloc(sizeof(*h)); + char buf[20]; + + if (!h) + return NULL; + + h->fn = fn; + h->data = data; + h->disable = suspend_open(); + h->sock = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0); + if (h->sock < 0 || h->disable < 0) + goto abort; + + addr.sun_family = AF_UNIX; + strcpy(addr.sun_path, "/var/run/suspend/wakealarm"); + if (connect(h->sock, (struct sockaddr*)&addr, sizeof(addr)) != 0) + goto abort; + + fcntl(h->sock, F_SETFL, fcntl(h->sock, F_GETFL, 0) | O_NONBLOCK); + sprintf(buf, "%lld\n", (long long)when); + write(h->sock, buf, strlen(buf)); + + event_set(&h->ev, h->sock, EV_READ|EV_PERSIST, alarm_clock, h); + event_add(&h->ev, NULL); + + return &h->ev; + +abort: + suspend_close(h->disable); + if (h->sock >= 0) + close(h->sock); + free(h); + return NULL; +} + +void wakealarm_destroy(struct event *ev) +{ + struct han *h = (struct han *)ev; + event_del(&h->ev); + close(h->sock); + suspend_close(h->disable); + free(h); +} diff --git a/wakealarmd.c b/wakealarmd.c new file mode 100644 index 0000000..494e96e --- /dev/null +++ b/wakealarmd.c @@ -0,0 +1,225 @@ + +/* wake alarm service. + * We provide a wakeup service to use the rtc wakealarm + * to ensure the system is running at given times and to + * alert clients. + * + * Client can connect and register a time as seconds since epoch + * We echo back the time and then when the time comes we echo "Now". + * We keep system awake until another time is written, or until + * connection is closed. + * + * Copyright (C) 2011 Neil Brown + * + * This program 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 2 of the License, or + * (at your option) any later version. + * + * This program 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, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include "libsus.h" + +struct conn { + struct event ev; + struct event tev; + time_t stamp; /* When to wake */ + int active; /* stamp has passed */ + struct conn *next; /* sorted by 'stamp' */ + struct state *state; +}; + +struct state { + struct event ev; + int disablefd; + int disabled; + void *watcher; + struct conn *conns; + int active_count; +}; + +static void add_han(struct conn *han) +{ + struct state *state = han->state; + struct conn **hanp = &state->conns; + struct timeval tv; + time_t now; + + while (*hanp && + (*hanp)->stamp < han->stamp) + hanp = &(*hanp)->next; + han->next = *hanp; + *hanp = han; + + time(&now); + if (now < han->stamp) { + tv.tv_sec = han->stamp - now; + tv.tv_usec = 0; + evtimer_add(&han->tev, &tv); + han->active = 0; + } else { + if (!han->active) { + han->active = 1; + state->active_count++; + } + } +} + +static void del_han(struct conn *han) +{ + struct state *state = han->state; + struct conn **hanp = &state->conns; + + while (*hanp && + *hanp != han) + hanp = &(*hanp)->next; + if (*hanp == han) { + *hanp = han->next; + if (han->active) { + state->active_count--; + if (state->active_count == 0 + && state->disabled) { + suspend_allow(state->disablefd); + state->disabled = 0; + } + } + } +} + +static void destroy_han(struct conn *han) +{ + event_del(&han->ev); + event_del(&han->tev); + free(han); +} + +static void do_read(int fd, short ev, void *data) +{ + struct conn *han = data; + char buf[20]; + int n; + + n = read(fd, buf, sizeof(buf)-1); + if (n < 0 && errno == EAGAIN) + return; + if (n <= 0) { + del_han(han); + destroy_han(han); + return; + } + del_han(han); + han->stamp = atol(buf); + add_han(han); + sprintf(buf, "%lld\n", (long long)han->stamp); + write(fd, buf, strlen(buf)); +} + +static void do_timeout(int fd, short ev, void *data) +{ + struct conn *han = data; + + if (!han->active) { + han->active = 1; + han->state->active_count++; + } + write(EVENT_FD(&han->ev), "Now\n", 4); +} + +static void do_accept(int fd, short ev, void *data) +{ + struct state *state = data; + struct conn *han; + int newfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC); + + if (newfd < 0) + return; + han = malloc(sizeof(*han)); + if (!han) { + close(newfd); + return; + } + han->state = state; + han->stamp = 0; + han->active = 1; + state->active_count++; + han->next = state->conns; + state->conns = han; + + evtimer_set(&han->tev, do_timeout, han); + event_set(&han->ev, newfd, EV_READ | EV_PERSIST, do_read, han); + event_add(&han->ev, NULL); + write(newfd, "0\n", 2); +} + +static int do_suspend(void *data) +{ + struct state *state = data; + time_t now; + + time(&now); + + /* active_count must be zero */ + if (state->conns == NULL) + return 1; + + if (state->conns->stamp > now + 4) { + int fd = open("/sys/class/rtc/rtc0/wakealarm", O_WRONLY); + if (fd >= 0) { + char buf[20]; + sprintf(buf, "%lld\n", + (long long)state->conns->stamp - 2); + write(fd, buf, strlen(buf)); + close(fd); + } + return 1; + } + /* too close to next wakeup */ + if (state->disabled) { + suspend_block(state->disablefd); + state->disabled = 1; + } + return 1; +} + +int main(int argc, char *argv[]) +{ + struct state st; + struct sockaddr_un addr; + int s; + + st.disablefd = suspend_open(); + st.disabled = 0; + st.conns = NULL; + st.active_count = 0; + + s = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK|SOCK_CLOEXEC, 0); + addr.sun_family = AF_UNIX; + strcpy(addr.sun_path, "/var/run/suspend/wakealarm"); + unlink("/var/run/suspend/wakealarm"); + bind(s, (struct sockaddr *)&addr, sizeof(addr)); + listen(s, 20); + + event_init(); + st.watcher = suspend_watch(do_suspend, NULL, &st); + event_set(&st.ev, s, EV_READ | EV_PERSIST, do_accept, &st); + event_add(&st.ev, NULL); + + event_loop(0); + exit(0); +} diff --git a/wakeevent.c b/wakeevent.c new file mode 100644 index 0000000..3640e28 --- /dev/null +++ b/wakeevent.c @@ -0,0 +1,148 @@ + +/* Register an fd which produces wake events with + * eventlib. + * Whenever the fd is readable, we block suspend, + * call the handler, then allow suspend. + * Meanwhile we open a socket to the event daemon passing + * it the same fd. + * At a lower priority, when we read 'S' from the daemon we reply + * with 'R'. + * + * Copyright (C) 2011 Neil Brown + * + * This program 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 2 of the License, or + * (at your option) any later version. + * + * This program 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, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include +#include +#include +#include +#include +#include +#include "libsus.h" + +struct han { + struct event ev; + struct event sev; + int sock; + int disable; + void (*fn)(int,short,void*); + void *data; +}; + +static void wakeup_call(int fd, short ev, void *data) +{ + /* A (potential) wakeup event can be read from this fd. + * We won't go to sleep because we haven't replied to + * 'S' yet as that is handle with a lower priority. + */ + struct han *han = data; + han->fn(fd, ev, han->data); +} + +static void wakeup_sock(int fd, short ev, void *data) +{ + char buf; + struct han *han = data; + int n = read(fd, &buf, 1); + + if (n < 0 && errno == EAGAIN) + return; + if (n != 1) { + /* How do I signal an error ?*/ + event_del(&han->sev); + return; + } + if (buf == 'S') + /* As we are at a lower priority (higher number) + * than the main event, we must have handled everything + */ + write(fd, "R", 1); +} + +static void send_fd(int sock, int fd) +{ + struct msghdr msg = {0}; + struct iovec iov; + struct cmsghdr *cmsg; + int myfds[1]; + char buf[CMSG_SPACE(sizeof myfds)]; + int *fdptr; + + msg.msg_control = buf; + msg.msg_controllen = sizeof buf; + cmsg = CMSG_FIRSTHDR(&msg); + cmsg->cmsg_level = SOL_SOCKET; + cmsg->cmsg_type = SCM_RIGHTS; + cmsg->cmsg_len = CMSG_LEN(sizeof(int)); + fdptr = (int*)CMSG_DATA(cmsg); + fdptr[0] = fd; + msg.msg_controllen = cmsg->cmsg_len; + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + iov.iov_base = "W"; + iov.iov_len = 1; + sendmsg(sock, &msg, 0); +} + +struct event *wake_set(int fd, void(*fn)(int,short,void*), void *data, int prio) +{ + struct sockaddr_un addr; + struct han *h = malloc(sizeof(*h)); + + if (!h) + return NULL; + + h->fn = fn; + h->data = data; + h->disable = suspend_open(); + h->sock = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0); + if (h->sock < 0 || h->disable < 0) + goto abort; + addr.sun_family = AF_UNIX; + strcpy(addr.sun_path, "/var/run/suspend/registration"); + if (connect(h->sock, (struct sockaddr*)&addr, sizeof(addr)) != 0) + goto abort; + + fcntl(h->sock, F_SETFL, fcntl(h->sock, F_GETFL, 0) | O_NONBLOCK); + + send_fd(h->sock, fd); + + event_set(&h->ev, fd, EV_READ|EV_PERSIST, wakeup_call, h); + event_set(&h->sev, h->sock, EV_READ|EV_PERSIST, wakeup_sock, h); + event_priority_set(&h->ev, prio); + event_priority_set(&h->sev, prio+1); + event_add(&h->ev, NULL); + event_add(&h->sev, NULL); + + return &h->ev; + +abort: + suspend_close(h->disable); + if (h->sock >= 0) + close(h->sock); + free(h); + return NULL; +} + +void wake_destroy(struct event *ev) +{ + struct han *h = (struct han *)ev; + event_del(&h->ev); + event_del(&h->sev); + close(h->sock); + suspend_close(h->disable); + free(h); +} diff --git a/watch_test.c b/watch_test.c new file mode 100644 index 0000000..cbd2352 --- /dev/null +++ b/watch_test.c @@ -0,0 +1,51 @@ + +/* Test watching for suspend notifications + * + * Copyright (C) 2011 Neil Brown + * + * This program 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 2 of the License, or + * (at your option) any later version. + * + * This program 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, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ +#include +#include +#include +#include "libsus.h" + +static int suspend(void *m) +{ + char *msg = m; + printf("Suspend: %s\n", msg); + printf("Hang on while I tie my shoe laces...\n"); + sleep(3); + printf("... OK, Done\n"); + return 1; +} + +static void resume(void *m) +{ + char *msg = m; + printf("Resume: %s\n", msg); +} + + +main(int argc, char *argv[]) +{ + + event_init(); + + suspend_watch(suspend, resume, "I saw that"); + + event_loop(0); + exit(0); +} diff --git a/watcher.c b/watcher.c new file mode 100644 index 0000000..1049e8c --- /dev/null +++ b/watcher.c @@ -0,0 +1,143 @@ + +/* + * Use libevent to watch for suspends and take action. + * The calling program must already have a libevent loop running. + * One or two callbacks are registered with suspend_watch. + * The first is required and gets called just before suspend. + * It must return promptly but may call suspend_block first. + * The second is options and will get called after resume. + * + * + * Copyright (C) 2011 Neil Brown + * + * This program 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 2 of the License, or + * (at your option) any later version. + * + * This program 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, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include + +struct cb { + int (*will_suspend)(void *data); + void (*did_resume)(void *data); + void *data; + int dirfd; + int fd, nextfd; + struct event ev; +}; + +static void checkdir(int efd, short ev, void *vp) +{ + struct cb *han = vp; + struct stat stb; + int fd; + int rv; + + if (han->fd < 0) + /* too early */ + return; + + if (han->nextfd >= 0) { + /*suspended - maybe not any more */ + fstat(han->fd, &stb); + if (stb.st_size <= 0) + /*false alarm */ + return; + /* back from resume */ + close(han->fd); + han->fd = han->nextfd; + han->nextfd = -1; + if (han->did_resume) + han->did_resume(han->data); + /* Fall through incase suspend has started again */ + } + + /* not suspended yet */ + if (fstat(han->fd, &stb) == 0 + && stb.st_size == 0) + /* false alarm */ + return; + + /* We need to move on now. */ + fd = open("/var/run/suspend/watching-next", O_RDONLY|O_CLOEXEC); + flock(fd, LOCK_SH); + han->nextfd = fd; + rv = han->will_suspend(han->data); + if (rv) + suspend_ok(han); +} + +int suspend_ok(void *v) +{ + struct cb *han = v; + flock(han->fd, LOCK_UN); + return 1; +} + +void *suspend_watch(int (*will_suspend)(void *data), + void (*did_resume)(void *data), + void *data) +{ + struct cb *han = malloc(sizeof(*han)); + struct stat stb; + int fd = -1; + if (!han) + return NULL; + + han->data = data; + han->will_suspend = will_suspend; + han->did_resume = did_resume; + han->fd = -1; + han->nextfd = -1; + signal_set(&han->ev, SIGIO, checkdir, han); + signal_add(&han->ev, NULL); + han->dirfd = open("/var/run/suspend", O_RDONLY|O_CLOEXEC); + if (han->dirfd < 0) + goto abort; + fcntl(han->dirfd, F_NOTIFY, DN_MODIFY | DN_MULTISHOT); +again: + fd = open("/var/run/suspend/watching", O_RDONLY|O_CLOEXEC); + flock(fd, LOCK_SH); + han->fd = fd; + checkdir(0, 0, han); + /* OK, he won't suspend until I say OK. */ + + return han; +abort: + signal_del(&han->ev); + if (fd >= 0) + close(fd); + if (han->dirfd >= 0) + close(han->dirfd); + free(han); +} + +void suspend_unwatch(void *v) +{ + struct cb *han = v; + if (han->dirfd >= 0) + close(han->dirfd); + signal_del(&han->ev); + if (han->fd >= 0) + close(han->fd); + if (han->nextfd >= 0) + close(han->nextfd); + free(han); +} + -- 2.39.5