#include <sbuild-lock.h>
Inheritance diagram for sbuild::lock:
Public Types | |
enum | type { LOCK_SHARED = F_RDLCK, LOCK_EXCLUSIVE = F_WRLCK, LOCK_NONE = F_UNLCK } |
Lock type. More... | |
enum | error_code { TIMEOUT_HANDLER, TIMEOUT_SET, TIMEOUT_CANCEL, LOCK, LOCK_TIMEOUT, DEVICE_LOCK, DEVICE_LOCK_TIMEOUT, DEVICE_TEST, DEVICE_UNLOCK, DEVICE_UNLOCK_TIMEOUT } |
Error codes. More... | |
typedef custom_error< error_code > | error |
Exception type. | |
Public Member Functions | |
virtual void | set_lock (type lock_type, unsigned int timeout)=0 |
Acquire a lock. | |
virtual void | unset_lock ()=0 |
Release a lock. | |
Protected Member Functions | |
lock () | |
The constructor. | |
virtual | ~lock () |
The destructor. | |
void | set_alarm () |
Set the SIGALARM handler. | |
void | clear_alarm () |
Restore the state of SIGALRM prior to starting lock acquisition. | |
void | set_timer (struct itimerval const &timer) |
Set up an itimer for future expiry. | |
void | unset_timer () |
Remove any itimer currently set up. | |
Private Attributes | |
sigaction | saved_signals |
Signals saved during timeout. |
This class defines a simple interface for shared and exclusive locks.
Definition at line 38 of file sbuild-lock.h.
typedef custom_error<error_code> sbuild::lock::error |
enum sbuild::lock::type |
Lock type.
LOCK_SHARED | A shared (read) lock. |
LOCK_EXCLUSIVE | An exclusive (write) lock. |
LOCK_NONE | No lock. |
Definition at line 42 of file sbuild-lock.h.
Error codes.
Definition at line 50 of file sbuild-lock.h.
lock::lock | ( | ) | [protected] |
lock::~lock | ( | ) | [protected, virtual] |
virtual void sbuild::lock::set_lock | ( | type | lock_type, | |
unsigned int | timeout | |||
) | [pure virtual] |
Acquire a lock.
lock_type | the type of lock to acquire. | |
timeout | the time in seconds to wait on the lock. |
Implemented in sbuild::file_lock, and sbuild::device_lock.
virtual void sbuild::lock::unset_lock | ( | ) | [pure virtual] |
Release a lock.
This is equivalent to set_lock with a lock_type of LOCK_NONE and a timeout of 0.
Implemented in sbuild::file_lock, and sbuild::device_lock.
void lock::set_alarm | ( | ) | [protected] |
Set the SIGALARM handler.
An error will be thrown on failure.
Definition at line 102 of file sbuild-lock.cc.
References alarm_handler(), and TIMEOUT_HANDLER.
Referenced by set_timer().
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void lock::clear_alarm | ( | ) | [protected] |
Restore the state of SIGALRM prior to starting lock acquisition.
Definition at line 114 of file sbuild-lock.cc.
Referenced by set_timer(), and unset_timer().
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void lock::set_timer | ( | struct itimerval const & | timer | ) | [protected] |
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.
timer | the timeout to set. |
Definition at line 121 of file sbuild-lock.cc.
References clear_alarm(), set_alarm(), and TIMEOUT_SET.
Referenced by sbuild::device_lock::set_lock(), and sbuild::file_lock::set_lock().
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void lock::unset_timer | ( | ) | [protected] |
Remove any itimer currently set up.
This will clear any SIGALRM handler (using clear_alarm).
An error will be thrown on failure.
Definition at line 133 of file sbuild-lock.cc.
References clear_alarm(), and TIMEOUT_CANCEL.
Referenced by sbuild::device_lock::set_lock(), and sbuild::file_lock::set_lock().
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struct sigaction sbuild::lock::saved_signals [private] |