diff options
| -rw-r--r-- | include/mts/MTS_IO_LockFile.h | 6 | ||||
| -rw-r--r-- | src/MTS_IO_LockFile.cpp | 92 |
2 files changed, 26 insertions, 72 deletions
diff --git a/include/mts/MTS_IO_LockFile.h b/include/mts/MTS_IO_LockFile.h index 730cf3c..22e641b 100644 --- a/include/mts/MTS_IO_LockFile.h +++ b/include/mts/MTS_IO_LockFile.h @@ -34,11 +34,8 @@ namespace MTS { namespace IO { - class LockFile : MTS::NonCopyable { - public: - LockFile(const std::string& sFilePath); virtual ~LockFile(); @@ -46,11 +43,10 @@ namespace MTS { void unlock(); bool isLocked(); - protected: - private: std::string m_sFile; int m_iLockFd; + int m_iLockErr; }; } diff --git a/src/MTS_IO_LockFile.cpp b/src/MTS_IO_LockFile.cpp index b74ba73..4312ce4 100644 --- a/src/MTS_IO_LockFile.cpp +++ b/src/MTS_IO_LockFile.cpp @@ -18,9 +18,9 @@ * */ -/*! +/*! \file MTS_IO_LockFile.cpp - \brief A brief description + \brief A brief description \date Oct 8, 2014 \author sgodinez @@ -29,13 +29,7 @@ #include <mts/MTS_IO_LockFile.h> #include <mts/MTS_Timer.h> -#include <mts/MTS_Logger.h> -#include <mts/MTS_System.h> -#include <mts/MTS_Text.h> #include <sys/file.h> -#include <sys/stat.h> -#include <errno.h> -#include <string.h> #include <unistd.h> using namespace MTS::IO; @@ -43,79 +37,43 @@ using namespace MTS::IO; LockFile::LockFile(const std::string& sFile) : m_sFile(sFile) , m_iLockFd(-1) +, m_iLockErr(-1) { - } -LockFile::~LockFile() { +LockFile::~LockFile() +{ unlock(); } -bool LockFile::lock(uint32_t attemptMillis) { - if(isLocked()) { +bool LockFile::lock(uint32_t attemptMillis) +{ + if (isLocked()) return true; - } MTS::Timer timer; - timer.start(); - while(timer.getMillis() < attemptMillis) { - m_iLockFd =::open(m_sFile.c_str(), O_CREAT | O_WRONLY | O_TRUNC | O_EXCL, 0644); - if (m_iLockFd < 0) { - // device already locked -> bail out - printWarning("LockFile| Failed to Lock [%s] [%d][%s]", m_sFile.c_str(), errno, strerror(errno)); - - //Check if lock file's process still exists - std::string sResult; - if(MTS::System::readFile(m_sFile, sResult) == 0 && sResult.size() > 0) { - struct stat sts; - std::string sProc = "/proc/" + MTS::Text::trim(sResult); - if (stat(sProc.c_str(), &sts) == -1 && errno == ENOENT) { - printWarning("LockFile| Current Lock's Process [%s] does not exist. Removing lock.", sResult.c_str()); - // process doesn't exist -> remove file - ::unlink(m_sFile.c_str()); - } - } - - } else { - //TODO: Investigate using flock in addition to minicom-style lock : flock(m_iLockFd, LOCK_EX | LOCK_NB); - - // %4d to make concurrent mgetty (if any) happy. - // Mgetty treats 4-bytes lock files as binary, - // not text, PID. Making 5+ char file. Brrr... - char buf[256] = {0}; - size_t written = 0; - - sprintf(buf, "%4d\n", getpid()); - size_t wsize = strlen(buf); - - written = write(m_iLockFd, buf, wsize); - - if (wsize != written) { - printError("LockFile| Error writing to lock file [%s] [%d][%s]", m_sFile.c_str(), errno, strerror(errno)); - close(m_iLockFd); - return false; - } - else { - close(m_iLockFd); - return true; - } - } - uint32_t randomSleepTime = ((rand() % 10) + 1) * 100000; //Sleep from 100ms to 1 Second - ::usleep(randomSleepTime); + m_iLockFd = ::open(m_sFile.c_str(), O_CREAT | O_RDWR, 0666); + while (timer.getMillis() < attemptMillis) { + m_iLockErr = ::flock(m_iLockFd, LOCK_EX | LOCK_NB); + if (m_iLockErr == 0) + return true; + ::usleep(((rand() % 10) + 1) * 100000); //Sleep from 100ms to 1 Second } + ::close(m_iLockFd); + m_iLockFd = -1; return false; } -void LockFile::unlock() { - if(isLocked()) { - ::unlink(m_sFile.c_str()); - //TODO: flock cleanup : flock(m_iLockFd, LOCK_UN); - m_iLockFd = -1; - } +void LockFile::unlock() +{ + ::flock(m_iLockFd, LOCK_UN); + ::close(m_iLockFd); + m_iLockFd = -1; + m_iLockErr = -1; } -bool LockFile::isLocked() { - return m_iLockFd >= 0; +bool LockFile::isLocked() +{ + return m_iLockErr == 0; } - |