Method checkProcessMode

Core/MMKV_Android.cpp:322–375

#ifndef MMKV_OHOS

bool MMKV::checkProcessMode() {
    // avoid exception on open() error
    if (!m_file->isFileValid()) {
        return true;
    }
    // avoid invalid status
    if (!g_enableProcessModeCheck || !m_fileModeLock || !m_sharedProcessModeLock) {
        return true;
    }

    if (isMultiProcess()) {
        if (!m_exclusiveProcessModeLock) {
            m_exclusiveProcessModeLock = new InterProcessLock(m_fileModeLock, ExclusiveLockType);
        }
        // avoid multiple processes get shared lock at the same time, https://github.com/Tencent/MMKV/issues/523
        auto tryAgain = false;
        auto exclusiveLocked = m_exclusiveProcessModeLock->try_lock(&tryAgain);
        if (exclusiveLocked) {
            return true;
        }
        auto shareLocked = m_sharedProcessModeLock->try_lock();
        if (!shareLocked) {
            // this call will fail on most case, just do it to make sure
            m_exclusiveProcessModeLock->try_lock();
            return true;
        } else {
            if (!tryAgain) {
                // something wrong with the OS/filesystem, let's try again
                exclusiveLocked = m_exclusiveProcessModeLock->try_lock(&tryAgain);
                if (!exclusiveLocked && !tryAgain) {
                    // still something wrong, we have to give up and assume it passed the test
                    MMKVWarning("Got a shared lock, but fail to exclusive lock [%s], assume it's ok", m_mmapID.c_str());
                    exclusiveLocked = true;
                }
            }
            if (!exclusiveLocked) {
                MMKVError("Got a shared lock, but fail to exclusive lock [%s]", m_mmapID.c_str());
            }
            return exclusiveLocked;
        }
    } else {
        auto tryAgain = false;
        auto shareLocked = m_sharedProcessModeLock->try_lock(&tryAgain);
        if (!shareLocked && !tryAgain) {
            // something wrong with the OS/filesystem, we have to give up and assume it passed the test
            MMKVWarning("Fail to shared lock [%s], assume it's ok", m_mmapID.c_str());
            shareLocked = true;
        }
        if (!shareLocked) {
            MMKVError("Fail to share lock [%s]", m_mmapID.c_str());
        }
        return shareLocked;
    }
}

void MMKV::enableDisableProcessMode(bool enable) {
    MMKVInfo("process mode check enable/disable: %d", enable);