/usr/include/sbuild/sbuild-lock.h is in libsbuild-dev 1.6.8-1ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 | /* Copyright © 2005-2007 Roger Leigh <rleigh@debian.org>
*
* schroot 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.
*
* schroot 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/>.
*
*********************************************************************/
#ifndef SBUILD_LOCK_H
#define SBUILD_LOCK_H
#include <sbuild/sbuild-lock.h>
#include <sbuild/sbuild-custom-error.h>
#include <string>
#include <sys/time.h>
#include <fcntl.h>
#include <signal.h>
namespace sbuild
{
/**
* Advisory locking. This class defines a simple interface for
* shared and exclusive locks.
*/
class lock
{
public:
/// Lock type.
enum type
{
LOCK_SHARED = F_RDLCK, ///< A shared (read) lock.
LOCK_EXCLUSIVE = F_WRLCK, ///< An exclusive (write) lock.
LOCK_NONE = F_UNLCK ///< No lock.
};
/// Error codes.
enum error_code
{
TIMEOUT_HANDLER, ///< Failed to set timeout handler.
TIMEOUT_SET, ///< Failed to set timeout.
TIMEOUT_CANCEL, ///< Failed to cancel timeout.
LOCK, ///< Failed to lock file.
UNLOCK, ///< Failed to unlock file.
LOCK_TIMEOUT, ///< Failed to lock file (timed out).
UNLOCK_TIMEOUT, ///< Failed to unlock file (timed out).
DEVICE_LOCK, ///< Failed to lock device.
DEVICE_LOCK_TIMEOUT, ///< Failed to lock device (timed out).
DEVICE_TEST, ///< Failed to test device lock.
DEVICE_UNLOCK, ///< Failed to unlock device.
DEVICE_UNLOCK_TIMEOUT ///< Failed to unlock device (timed out)
};
/// Exception type.
typedef custom_error<error_code> error;
/**
* Acquire a lock.
*
* @param lock_type the type of lock to acquire.
* @param timeout the time in seconds to wait on the lock.
*/
virtual void
set_lock (type lock_type,
unsigned int timeout) = 0;
/**
* Release a lock. This is equivalent to set_lock with a
* lock_type of LOCK_NONE and a timeout of 0.
*/
virtual void
unset_lock () = 0;
protected:
/// The constructor.
lock ();
/// The destructor.
virtual ~lock ();
/**
* Set the SIGALARM handler.
*
* An error will be thrown on failure.
*/
void
set_alarm ();
/**
* Restore the state of SIGALRM prior to starting lock
* acquisition.
*/
void
clear_alarm ();
/**
* Set up an itimer for future expiry. This is used to interrupt
* system calls. This will set a handler for SIGALRM as a side
* effect (using set_alarm).
*
* An error will be thrown on failure.
*
* @param timer the timeout to set.
*/
void
set_timer (struct itimerval const& timer);
/**
* Remove any itimer currently set up. This will clear any
* SIGALRM handler (using clear_alarm).
*
* An error will be thrown on failure.
*/
void
unset_timer ();
private:
/// Signals saved during timeout.
struct sigaction saved_signals;
};
/**
* File lock. Simple whole-file shared and exclusive advisory
* locking based upon POSIX fcntl byte region locks.
*/
class file_lock : public lock
{
public:
/**
* The constructor.
*
* @param fd the file descriptor to lock.
*/
file_lock (int fd);
/// The destructor.
virtual ~file_lock ();
virtual void
set_lock (lock::type lock_type,
unsigned int timeout);
virtual void
unset_lock ();
private:
/// The file descriptor to lock.
int fd;
/// Is the file locked?
bool locked;
};
}
#endif /* SBUILD_LOCK_H */
/*
* Local Variables:
* mode:C++
* End:
*/
|