MpiFileMutex Class Reference

#include <xmipp_mpi.h>

Inheritance diagram for MpiFileMutex:

Collaboration diagram for MpiFileMutex:

Public Member Functions
	MpiFileMutex (const std::shared_ptr< MpiNode > &node)
	~MpiFileMutex ()
void	lock ()
void	unlock ()
Public Member Functions inherited from Mutex
	Mutex ()
virtual	~Mutex ()

Public Attributes
char	lockFilename [L_tmpnam]

Protected Attributes
std::shared_ptr< MpiNode >	node
int	lockFile
bool	fileCreator

Detailed Description

Mutex on files. This class extends threads mutex to also provide file locking.

Definition at line 118 of file xmipp_mpi.h.

Constructor & Destructor Documentation

MpiFileMutex()

MpiFileMutex::MpiFileMutex

(

const std::shared_ptr< MpiNode > &

node

)

Default constructor.

Definition at line 91 of file xmipp_mpi.cpp.

{
    fileCreator = false;

    if (node == nullptr || node->isMaster())
    {
        fileCreator = true;
        strcpy(lockFilename, "pijol_XXXXXX");
        if ((lockFile = mkstemp(lockFilename)) == -1)
        {
            perror("MpiFileMutex::Error generating tmp lock file");
            exit(1);
        }
        close(lockFile);
    }
    //if using mpi broadcast the filename from master to slaves
    if (node != nullptr)
        MPI_Bcast(lockFilename, L_tmpnam, MPI_CHAR, 0, MPI_COMM_WORLD);

    if ((lockFile = open(lockFilename, O_RDWR)) == -1)
    {
        perror("MpiFileMutex: Error opening lock file");
        exit(1);
    }
}

~MpiFileMutex()

MpiFileMutex::~MpiFileMutex

(

)

Destructor.

Definition at line 133 of file xmipp_mpi.cpp.

{
    close(lockFile);
    if (fileCreator && remove(lockFilename) == -1)
    {
        perror("~MpiFileMutex: error deleting lock file");
        exit(1);
    }
}

Member Function Documentation

lock()

void MpiFileMutex::lock ( )

virtual

Function to get the access to the mutex. If the some thread has the mutex and other ask to lock will be waiting until the first one release the mutex

Reimplemented from Mutex.

Definition at line 117 of file xmipp_mpi.cpp.

{
    Mutex::lock();
    lseek(lockFile, 0, SEEK_SET);
    if (lockf(lockFile, F_LOCK, 0)==-1)
        REPORT_ERROR(ERR_IO_NOPERM,"Cannot lock file");
}

unlock()

void MpiFileMutex::unlock ( )

virtual

Function to release the mutex. This allow the access to the mutex to other threads that are waiting for it.

Reimplemented from Mutex.

Definition at line 125 of file xmipp_mpi.cpp.

{
    lseek(lockFile, 0, SEEK_SET);
    if (lockf(lockFile, F_ULOCK, 0)==-1)
        REPORT_ERROR(ERR_IO_NOPERM,"Cannot unlock file");
    Mutex::unlock();
}

Member Data Documentation

fileCreator

bool MpiFileMutex::fileCreator

protected

Definition at line 123 of file xmipp_mpi.h.

lockFile

int MpiFileMutex::lockFile

protected

Definition at line 122 of file xmipp_mpi.h.

lockFilename

char MpiFileMutex::lockFilename[L_tmpnam]

Definition at line 144 of file xmipp_mpi.h.

node

std::shared_ptr<MpiNode> MpiFileMutex::node

protected

Definition at line 121 of file xmipp_mpi.h.

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The documentation for this class was generated from the following files:

• xmipp/libraries/parallel/xmipp_mpi.h
• xmipp/libraries/parallel/xmipp_mpi.cpp