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/*****************************************************************************
* *
* PrimeSense PSCommon Library *
* Copyright (C) 2012 PrimeSense Ltd. *
* *
* This file is part of PSCommon. *
* *
* Licensed under the Apache License, Version 2.0 (the "License"); *
* you may not use this file except in compliance with the License. *
* You may obtain a copy of the License at *
* *
* http://www.apache.org/licenses/LICENSE-2.0 *
* *
* Unless required by applicable law or agreed to in writing, software *
* distributed under the License is distributed on an "AS IS" BASIS, *
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. *
* See the License for the specific language governing permissions and *
* limitations under the License. *
* *
*****************************************************************************/
//---------------------------------------------------------------------------
// Includes
//---------------------------------------------------------------------------
#include "XnLinuxSysVNamedEvents.h"
#ifndef XN_PLATFORM_LINUX_NO_SYSV
//---------------------------------------------------------------------------
// Defines
//---------------------------------------------------------------------------
enum _XN_EVENT_SEM_TYPE
{
XN_EVENT_SEM_REF_COUNT = 0,
XN_EVENT_SEM_SIGNALED,
XN_EVENT_SEM_MANUAL_RESET,
XN_EVENT_NUM_OF_SEMS
};
//---------------------------------------------------------------------------
// Types
//---------------------------------------------------------------------------
#ifndef XN_PLATFORM_HAS_BUILTIN_SEMUN
union semun {
int val; /* Value for SETVAL */
struct semid_ds *buf; /* Buffer for IPC_STAT, IPC_SET */
unsigned short *array; /* Array for GETALL, SETALL */
struct seminfo *__buf; /* Buffer for IPC_INFO
(Linux-specific) */
};
#endif
//---------------------------------------------------------------------------
// Code
//---------------------------------------------------------------------------
XnLinuxSysVNamedEvent::XnLinuxSysVNamedEvent(XnBool bManualReset, const XnChar* strName, XnBool bCreate) : XnLinuxNamedEvent(bManualReset, strName, bCreate)
{
}
XnStatus XnLinuxSysVNamedEvent::CreateNamed(const XnChar* strName)
{
// translate event name to key file name
XnUInt32 nBytesWritten;
xnOSStrFormat(m_csSemFileName, XN_FILE_MAX_PATH, &nBytesWritten, "/tmp/XnCore.Event.%s.key", strName);
// create the file (must exist for ftok)
m_hSemFile = open(m_csSemFileName, O_CREAT | O_RDONLY, S_IRWXU | S_IRWXG | S_IRWXO);
if (-1 == m_hSemFile)
{
XN_LOG_WARNING_RETURN(XN_STATUS_OS_EVENT_CREATION_FAILED, XN_MASK_OS, "Create named event: failed to create key file (%d)", errno);
}
// create the key
key_t key = ftok(m_csSemFileName, 1);
// Try to create the semaphore
// Creating two semaphores. First semaphore will be used as reference count, and second for the signaled state
m_hSem = semget(key, XN_EVENT_NUM_OF_SEMS, IPC_CREAT | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
if (-1 == m_hSem)
{
XN_LOG_WARNING_RETURN(XN_STATUS_OS_EVENT_CREATION_FAILED, XN_MASK_OS, "Create named event: failed to create semaphore (%d)", errno);
}
// if no one is using it so far (this is a newly created event), reset it
if (0 == semctl(m_hSem, XN_EVENT_SEM_REF_COUNT, GETVAL))
{
// set it to the non-signaled state
semun val;
val.val = 0;
if (0 != semctl(m_hSem, XN_EVENT_SEM_SIGNALED, SETVAL, val))
{
xnLogWarning(XN_MASK_OS, "Create named event: semctl for signaled failed (%d)", errno);
semctl(m_hSem, 0, IPC_RMID);
return XN_STATUS_OS_EVENT_CREATION_FAILED;
}
// set its manual reset value
val.val = m_bManualReset;
if (0 != semctl(m_hSem, XN_EVENT_SEM_MANUAL_RESET, SETVAL, val))
{
xnLogWarning(XN_MASK_OS, "Create named event: semctl for manual reset failed (%d)", errno);
semctl(m_hSem, 0, IPC_RMID);
return XN_STATUS_OS_EVENT_CREATION_FAILED;
}
}
// adding 1 to reference count
struct sembuf op;
op.sem_op = 1;
op.sem_num = XN_EVENT_SEM_REF_COUNT;
op.sem_flg = SEM_UNDO;
semop(m_hSem, &op, 1);
m_bManualReset = semctl(m_hSem, XN_EVENT_SEM_MANUAL_RESET, GETVAL);
return (XN_STATUS_OK);
}
XnStatus XnLinuxSysVNamedEvent::OpenNamed(const XnChar* strName)
{
// translate event name to key file name
XnUInt32 nBytesWritten;
xnOSStrFormat(m_csSemFileName, XN_FILE_MAX_PATH, &nBytesWritten, "/tmp/XnCore.Event.%s.key", strName);
// create the key
key_t key = ftok(m_csSemFileName, 1);
if (-1 == key)
{
// event does not exist
XN_LOG_WARNING_RETURN(XN_STATUS_OS_EVENT_OPEN_FAILED, XN_MASK_OS, "Open named event: failed to open key file (%d) - event might not exist...", errno);
}
// Try to open the semaphore
m_hSem = semget(key, XN_EVENT_NUM_OF_SEMS, 0);
if (-1 == m_hSem)
{
XN_LOG_WARNING_RETURN(XN_STATUS_OS_EVENT_OPEN_FAILED, XN_MASK_OS, "Open named event: failed to get semaphore (%d)", errno);
}
// if ref count is 0, the event does not really exist
if (0 == semctl(m_hSem, XN_EVENT_SEM_REF_COUNT, GETVAL))
{
XN_LOG_WARNING_RETURN(XN_STATUS_OS_EVENT_OPEN_FAILED, XN_MASK_OS, "Open named event: ref count is zero - event does not exist!", errno);
}
// adding 1 to reference count
struct sembuf op;
op.sem_op = 1;
op.sem_num = XN_EVENT_SEM_REF_COUNT;
op.sem_flg = SEM_UNDO;
semop(m_hSem, &op, 1);
m_bManualReset = semctl(m_hSem, XN_EVENT_SEM_MANUAL_RESET, GETVAL);
return XN_STATUS_OK;
}
XnStatus XnLinuxSysVNamedEvent::Destroy()
{
// dec ref count
struct sembuf op;
op.sem_num = XN_EVENT_SEM_REF_COUNT;
op.sem_op = -1;
op.sem_flg = IPC_NOWAIT | SEM_UNDO;
semop(m_hSem, &op, 1);
// check current ref count. If 0, destroy it
int val = semctl(m_hSem, 0, GETVAL);
if (0 == val)
{
// destroy the semaphore
semctl(m_hSem, 0, IPC_RMID);
// and remove file
xnOSDeleteFile(m_csSemFileName);
}
return (XN_STATUS_OK);
}
XnStatus XnLinuxSysVNamedEvent::Set()
{
struct sembuf op[2];
// check if it's not signaled (by waiting for 0, with IPC_NOWAIT)
op[0].sem_num = XN_EVENT_SEM_SIGNALED;
op[0].sem_op = 0;
op[0].sem_flg = IPC_NOWAIT;
// signal (if zero)
op[1].sem_num = XN_EVENT_SEM_SIGNALED;
op[1].sem_op = 1;
op[1].sem_flg = SEM_UNDO;
semop(m_hSem, op, 2);
// no need to check error code. either it succeeded, or the event is already signaled
return (XN_STATUS_OK);
}
XnStatus XnLinuxSysVNamedEvent::Reset()
{
// unsignal it, with NOWAIT (that way, if it's not signaled, nothing will happen)
struct sembuf op;
op.sem_num = XN_EVENT_SEM_SIGNALED;
op.sem_op = -1;
op.sem_flg = IPC_NOWAIT;
semop(m_hSem, &op, 1);
return XN_STATUS_OK;
}
XnStatus XnLinuxSysVNamedEvent::Wait(XnUInt32 nMilliseconds)
{
XnStatus nRetVal = XN_STATUS_OK;
struct timespec time = {0};
if (nMilliseconds != XN_WAIT_INFINITE)
{
nRetVal = xnOSGetTimeout(&time, nMilliseconds);
if (nRetVal != XN_STATUS_OK)
{
return XN_STATUS_OS_EVENT_WAIT_FAILED;
}
}
struct sembuf op[2];
// wait for it to be 1
op[0].sem_num = XN_EVENT_SEM_SIGNALED;
op[0].sem_op = -1;
op[0].sem_flg = 0;
// re set it (if manual reset)
op[1].sem_num = XN_EVENT_SEM_SIGNALED;
op[1].sem_op = 1;
op[1].sem_flg = 0;
XnInt32 nOpsCount = m_bManualReset ? 2 : 1;
if (XN_WAIT_INFINITE != nMilliseconds)
{
#if _GNU_SOURCE
if (0 != semtimedop(m_hSem, op, nOpsCount, &time))
#else
if (0 != semop(m_hSem, op, nOpsCount))
#endif
{
if(EAGAIN == errno)
{
return XN_STATUS_OS_EVENT_TIMEOUT;
}
return XN_STATUS_OS_EVENT_WAIT_FAILED;
}
}
else
{
if (0 != semop(m_hSem, op, nOpsCount))
{
return XN_STATUS_OS_EVENT_WAIT_FAILED;
}
}
return (XN_STATUS_OK);
}
#endif // if we have SysV
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