A wrapper for mutexes that can be used across processes on the same host machine, as well as within a process, of course. More...
#include <Process_Mutex.h>
Public Member Functions | |
ACE_Process_Mutex (const char *name=0, void *arg=0, mode_t mode=ACE_DEFAULT_FILE_PERMS) | |
~ACE_Process_Mutex (void) | |
int | remove (void) |
int | acquire (void) |
int | acquire (ACE_Time_Value &tv) |
int | tryacquire (void) |
int | release (void) |
Release lock and unblock a thread at head of queue. | |
int | acquire_read (void) |
Acquire lock ownership (wait on queue if necessary). | |
int | acquire_write (void) |
Acquire lock ownership (wait on queue if necessary). | |
int | tryacquire_read (void) |
int | tryacquire_write (void) |
int | tryacquire_write_upgrade (void) |
const ACE_mutex_t & | lock (void) const |
Return the underlying mutex. | |
void | dump (void) const |
Dump the state of an object. | |
Public Attributes | |
ACE_ALLOC_HOOK_DECLARE | |
Declare the dynamic allocation hooks. | |
Private Member Functions | |
const ACE_TCHAR * | unique_name (void) |
Create and return the unique name. | |
Private Attributes | |
ACE_TCHAR | name_ [ACE_UNIQUE_NAME_LEN] |
ACE_Mutex | lock_ |
A wrapper for mutexes that can be used across processes on the same host machine, as well as within a process, of course.
ACE_Process_Mutex
is based can be configured at build time to be either ACE_SV_Semaphore_Complex
(on platforms that support it) or ACE_Mutex
. On platforms that offer System V IPC (the ACE_HAS_SYSV_IPC
config macro is defined) ACE_SV_Semaphore_Complex
is the default because it is more convenient and easy to use. ACE_Mutex
is the default on all other platforms. On platforms where ACE_SV_Semaphore_Complex is used by default, the mechanism can be changed to ACE_Mutex when ACE is built by adding #define ACE_USES_MUTEX_FOR_PROCESS_MUTEX
config.h
file. acquire()
, you must use ACE_Mutex as the underlying mechanism because timed acquire does not work with System V semaphores.ACE_Process_Mutex::ACE_Process_Mutex | ( | const char * | name = 0 , |
void * | arg = 0 , |
||
mode_t | mode = ACE_DEFAULT_FILE_PERMS |
||
) |
Create an ACE_Process_Mutex.
name | optional, null-terminated string containing the name of the object. Multiple users of the same ACE_Process_Mutex must use the same name to access the same object. If not specified, a name is generated. |
arg | optional, attributes to be used to initialize the mutex. If using ACE_SV_Semaphore_Complex as the underlying mechanism, this argument is ignored. |
mode | optional, the protection mode for either the backing store file (for ACE_Mutex use) or the ACE_SV_Semaphore_Complex that's created. |
ACE_Process_Mutex::~ACE_Process_Mutex | ( | void | ) |
Destructor.
int ACE_Process_Mutex::acquire | ( | void | ) |
Acquire lock ownership (wait on queue if necessary).
int ACE_Process_Mutex::acquire | ( | ACE_Time_Value & | tv ) |
Acquire lock ownership, but timeout if lock if hasn't been acquired by given time.
tv | the absolute time until which the caller is willing to wait to acquire the lock. |
int ACE_Process_Mutex::acquire_read | ( | void | ) |
Acquire lock ownership (wait on queue if necessary).
int ACE_Process_Mutex::acquire_write | ( | void | ) |
Acquire lock ownership (wait on queue if necessary).
void ACE_Process_Mutex::dump | ( | void | ) | const |
Dump the state of an object.
const ACE_mutex_t & ACE_Process_Mutex::lock | ( | void | ) | const |
Return the underlying mutex.
int ACE_Process_Mutex::release | ( | void | ) |
Release lock and unblock a thread at head of queue.
int ACE_Process_Mutex::remove | ( | void | ) |
Explicitly destroy the mutex. Note that only one thread should call this method since it doesn't protect against race conditions.
int ACE_Process_Mutex::tryacquire | ( | void | ) |
Conditionally acquire lock (i.e., don't wait on queue).
errno
is set to EBUSY
. int ACE_Process_Mutex::tryacquire_read | ( | void | ) |
Conditionally acquire a lock (i.e., won't block). Returns -1 on failure. If we "failed" because someone else already had the lock, errno
is set to EBUSY
.
int ACE_Process_Mutex::tryacquire_write | ( | void | ) |
Conditionally acquire a lock (i.e., won't block). Returns -1 on failure. If we "failed" because someone else already had the lock, errno
is set to EBUSY
.
int ACE_Process_Mutex::tryacquire_write_upgrade | ( | void | ) |
This is only here for consistency with the other synchronization APIs and usability with Lock adapters. Assumes the caller already has acquired the mutex and returns 0 in all cases.
const ACE_TCHAR * ACE_Process_Mutex::unique_name | ( | void | ) | [private] |
Create and return the unique name.
Declare the dynamic allocation hooks.
ACE_Mutex ACE_Process_Mutex::lock_ [private] |
ACE_TCHAR ACE_Process_Mutex::name_[ACE_UNIQUE_NAME_LEN] [private] |
If the user does not provide a name we generate a unique name in this buffer.