/*
  ==============================================================================

   This file is part of the juce_core module of the JUCE library.
   Copyright (c) 2013 - Raw Material Software Ltd.

   Permission to use, copy, modify, and/or distribute this software for any purpose with
   or without fee is hereby granted, provided that the above copyright notice and this
   permission notice appear in all copies.

   THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
   TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN
   NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
   DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
   IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
   CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

   ------------------------------------------------------------------------------

   NOTE! This permissive ISC license applies ONLY to files within the juce_core module!
   All other JUCE modules are covered by a dual GPL/commercial license, so if you are
   using any other modules, be sure to check that you also comply with their license.

   For more details, visit www.juce.com

  ==============================================================================
*/

CriticalSection::CriticalSection() noexcept
{
    pthread_mutexattr_t atts;
    pthread_mutexattr_init (&atts);
    pthread_mutexattr_settype (&atts, PTHREAD_MUTEX_RECURSIVE);
   #if ! JUCE_ANDROID
    pthread_mutexattr_setprotocol (&atts, PTHREAD_PRIO_INHERIT);
   #endif
    pthread_mutex_init (&internal, &atts);
}

CriticalSection::~CriticalSection() noexcept
{
    pthread_mutex_destroy (&internal);
}

void CriticalSection::enter() const noexcept
{
    pthread_mutex_lock (&internal);
}

bool CriticalSection::tryEnter() const noexcept
{
    return pthread_mutex_trylock (&internal) == 0;
}

void CriticalSection::exit() const noexcept
{
    pthread_mutex_unlock (&internal);
}


//==============================================================================
WaitableEvent::WaitableEvent (const bool useManualReset) noexcept
    : triggered (false), manualReset (useManualReset)
{
    pthread_cond_init (&condition, 0);

    pthread_mutexattr_t atts;
    pthread_mutexattr_init (&atts);
   #if ! JUCE_ANDROID
    pthread_mutexattr_setprotocol (&atts, PTHREAD_PRIO_INHERIT);
   #endif
    pthread_mutex_init (&mutex, &atts);
}

WaitableEvent::~WaitableEvent() noexcept
{
    pthread_cond_destroy (&condition);
    pthread_mutex_destroy (&mutex);
}

bool WaitableEvent::wait (const int timeOutMillisecs) const noexcept
{
    pthread_mutex_lock (&mutex);

    if (! triggered)
    {
        if (timeOutMillisecs < 0)
        {
            do
            {
                pthread_cond_wait (&condition, &mutex);
            }
            while (! triggered);
        }
        else
        {
            struct timeval now;
            gettimeofday (&now, 0);

            struct timespec time;
            time.tv_sec  = now.tv_sec  + (timeOutMillisecs / 1000);
            time.tv_nsec = (now.tv_usec + ((timeOutMillisecs % 1000) * 1000)) * 1000;

            if (time.tv_nsec >= 1000000000)
            {
                time.tv_nsec -= 1000000000;
                time.tv_sec++;
            }

            do
            {
                if (pthread_cond_timedwait (&condition, &mutex, &time) == ETIMEDOUT)
                {
                    pthread_mutex_unlock (&mutex);
                    return false;
                }
            }
            while (! triggered);
        }
    }

    if (! manualReset)
        triggered = false;

    pthread_mutex_unlock (&mutex);
    return true;
}

void WaitableEvent::signal() const noexcept
{
    pthread_mutex_lock (&mutex);
    triggered = true;
    pthread_cond_broadcast (&condition);
    pthread_mutex_unlock (&mutex);
}

void WaitableEvent::reset() const noexcept
{
    pthread_mutex_lock (&mutex);
    triggered = false;
    pthread_mutex_unlock (&mutex);
}

//==============================================================================
void JUCE_CALLTYPE Thread::sleep (int millisecs)
{
    struct timespec time;
    time.tv_sec = millisecs / 1000;
    time.tv_nsec = (millisecs % 1000) * 1000000;
    nanosleep (&time, nullptr);
}


//==============================================================================
const juce_wchar File::separator = '/';
const String File::separatorString ("/");

//==============================================================================
File File::getCurrentWorkingDirectory()
{
    HeapBlock<char> heapBuffer;

    char localBuffer [1024];
    char* cwd = getcwd (localBuffer, sizeof (localBuffer) - 1);
    size_t bufferSize = 4096;

    while (cwd == nullptr && errno == ERANGE)
    {
        heapBuffer.malloc (bufferSize);
        cwd = getcwd (heapBuffer, bufferSize - 1);
        bufferSize += 1024;
    }

    return File (CharPointer_UTF8 (cwd));
}

bool File::setAsCurrentWorkingDirectory() const
{
    return chdir (getFullPathName().toUTF8()) == 0;
}

//==============================================================================
namespace
{
   #if JUCE_LINUX || (JUCE_IOS && ! __DARWIN_ONLY_64_BIT_INO_T) // (this iOS stuff is to avoid a simulator bug)
    typedef struct stat64 juce_statStruct;
    #define JUCE_STAT     stat64
   #else
    typedef struct stat   juce_statStruct;
    #define JUCE_STAT     stat
   #endif

    bool juce_stat (const String& fileName, juce_statStruct& info)
    {
        return fileName.isNotEmpty()
                 && JUCE_STAT (fileName.toUTF8(), &info) == 0;
    }

    // if this file doesn't exist, find a parent of it that does..
    bool juce_doStatFS (File f, struct statfs& result)
    {
        for (int i = 5; --i >= 0;)
        {
            if (f.exists())
                break;

            f = f.getParentDirectory();
        }

        return statfs (f.getFullPathName().toUTF8(), &result) == 0;
    }

    void updateStatInfoForFile (const String& path, bool* const isDir, int64* const fileSize,
                                Time* const modTime, Time* const creationTime, bool* const isReadOnly)
    {
        if (isDir != nullptr || fileSize != nullptr || modTime != nullptr || creationTime != nullptr)
        {
            juce_statStruct info;
            const bool statOk = juce_stat (path, info);

            if (isDir != nullptr)         *isDir        = statOk && ((info.st_mode & S_IFDIR) != 0);
            if (fileSize != nullptr)      *fileSize     = statOk ? info.st_size : 0;
            if (modTime != nullptr)       *modTime      = Time (statOk ? (int64) info.st_mtime * 1000 : 0);
            if (creationTime != nullptr)  *creationTime = Time (statOk ? (int64) info.st_ctime * 1000 : 0);
        }

        if (isReadOnly != nullptr)
            *isReadOnly = access (path.toUTF8(), W_OK) != 0;
    }

    Result getResultForErrno()
    {
        return Result::fail (String (strerror (errno)));
    }

    Result getResultForReturnValue (int value)
    {
        return value == -1 ? getResultForErrno() : Result::ok();
    }

    int getFD (void* handle) noexcept        { return (int) (pointer_sized_int) handle; }
    void* fdToVoidPointer (int fd) noexcept  { return (void*) (pointer_sized_int) fd; }
}

bool File::isDirectory() const
{
    juce_statStruct info;

    return fullPath.isEmpty()
            || (juce_stat (fullPath, info) && ((info.st_mode & S_IFDIR) != 0));
}

bool File::exists() const
{
    return fullPath.isNotEmpty()
             && access (fullPath.toUTF8(), F_OK) == 0;
}

bool File::existsAsFile() const
{
    return exists() && ! isDirectory();
}

int64 File::getSize() const
{
    juce_statStruct info;
    return juce_stat (fullPath, info) ? info.st_size : 0;
}

//==============================================================================
bool File::hasWriteAccess() const
{
    if (exists())
        return access (fullPath.toUTF8(), W_OK) == 0;

    if ((! isDirectory()) && fullPath.containsChar (separator))
        return getParentDirectory().hasWriteAccess();

    return false;
}

bool File::setFileReadOnlyInternal (const bool shouldBeReadOnly) const
{
    juce_statStruct info;
    if (! juce_stat (fullPath, info))
        return false;

    info.st_mode &= 0777;   // Just permissions

    if (shouldBeReadOnly)
        info.st_mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
    else
        // Give everybody write permission?
        info.st_mode |= S_IWUSR | S_IWGRP | S_IWOTH;

    return chmod (fullPath.toUTF8(), info.st_mode) == 0;
}

void File::getFileTimesInternal (int64& modificationTime, int64& accessTime, int64& creationTime) const
{
    modificationTime = 0;
    accessTime = 0;
    creationTime = 0;

    juce_statStruct info;
    if (juce_stat (fullPath, info))
    {
        modificationTime = (int64) info.st_mtime * 1000;
        accessTime = (int64) info.st_atime * 1000;
        creationTime = (int64) info.st_ctime * 1000;
    }
}

bool File::setFileTimesInternal (int64 modificationTime, int64 accessTime, int64 /*creationTime*/) const
{
    juce_statStruct info;

    if ((modificationTime != 0 || accessTime != 0) && juce_stat (fullPath, info))
    {
        struct utimbuf times;
        times.actime  = accessTime != 0       ? (time_t) (accessTime / 1000)       : info.st_atime;
        times.modtime = modificationTime != 0 ? (time_t) (modificationTime / 1000) : info.st_mtime;

        return utime (fullPath.toUTF8(), &times) == 0;
    }

    return false;
}

bool File::deleteFile() const
{
    if (! exists())
        return true;

    if (isDirectory())
        return rmdir (fullPath.toUTF8()) == 0;

    return remove (fullPath.toUTF8()) == 0;
}

bool File::moveInternal (const File& dest) const
{
    if (rename (fullPath.toUTF8(), dest.getFullPathName().toUTF8()) == 0)
        return true;

    if (hasWriteAccess() && copyInternal (dest))
    {
        if (deleteFile())
            return true;

        dest.deleteFile();
    }

    return false;
}

Result File::createDirectoryInternal (const String& fileName) const
{
    return getResultForReturnValue (mkdir (fileName.toUTF8(), 0777));
}

//=====================================================================
int64 juce_fileSetPosition (void* handle, int64 pos)
{
    if (handle != 0 && lseek (getFD (handle), pos, SEEK_SET) == pos)
        return pos;

    return -1;
}

void FileInputStream::openHandle()
{
    const int f = open (file.getFullPathName().toUTF8(), O_RDONLY, 00644);

    if (f != -1)
        fileHandle = fdToVoidPointer (f);
    else
        status = getResultForErrno();
}

void FileInputStream::closeHandle()
{
    if (fileHandle != 0)
    {
        close (getFD (fileHandle));
        fileHandle = 0;
    }
}

size_t FileInputStream::readInternal (void* const buffer, const size_t numBytes)
{
    ssize_t result = 0;

    if (fileHandle != 0)
    {
        result = ::read (getFD (fileHandle), buffer, numBytes);

        if (result < 0)
        {
            status = getResultForErrno();
            result = 0;
        }
    }

    return (size_t) result;
}

//==============================================================================
void FileOutputStream::openHandle()
{
    if (file.exists())
    {
        const int f = open (file.getFullPathName().toUTF8(), O_RDWR, 00644);

        if (f != -1)
        {
            currentPosition = lseek (f, 0, SEEK_END);

            if (currentPosition >= 0)
            {
                fileHandle = fdToVoidPointer (f);
            }
            else
            {
                status = getResultForErrno();
                close (f);
            }
        }
        else
        {
            status = getResultForErrno();
        }
    }
    else
    {
        const int f = open (file.getFullPathName().toUTF8(), O_RDWR + O_CREAT, 00644);

        if (f != -1)
            fileHandle = fdToVoidPointer (f);
        else
            status = getResultForErrno();
    }
}

void FileOutputStream::closeHandle()
{
    if (fileHandle != 0)
    {
        close (getFD (fileHandle));
        fileHandle = 0;
    }
}

ssize_t FileOutputStream::writeInternal (const void* const data, const size_t numBytes)
{
    ssize_t result = 0;

    if (fileHandle != 0)
    {
        result = ::write (getFD (fileHandle), data, numBytes);

        if (result == -1)
            status = getResultForErrno();
    }

    return result;
}

void FileOutputStream::flushInternal()
{
    if (fileHandle != 0)
    {
        if (fsync (getFD (fileHandle)) == -1)
            status = getResultForErrno();

       #if JUCE_ANDROID
        // This stuff tells the OS to asynchronously update the metadata
        // that the OS has cached aboud the file - this metadata is used
        // when the device is acting as a USB drive, and unless it's explicitly
        // refreshed, it'll get out of step with the real file.
        const LocalRef<jstring> t (javaString (file.getFullPathName()));
        android.activity.callVoidMethod (JuceAppActivity.scanFile, t.get());
       #endif
    }
}

Result FileOutputStream::truncate()
{
    if (fileHandle == 0)
        return status;

    flush();
    return getResultForReturnValue (ftruncate (getFD (fileHandle), (off_t) currentPosition));
}

//==============================================================================
String SystemStats::getEnvironmentVariable (const String& name, const String& defaultValue)
{
    if (const char* s = ::getenv (name.toUTF8()))
        return String::fromUTF8 (s);

    return defaultValue;
}

//==============================================================================
void MemoryMappedFile::openInternal (const File& file, AccessMode mode)
{
    jassert (mode == readOnly || mode == readWrite);

    if (range.getStart() > 0)
    {
        const long pageSize = sysconf (_SC_PAGE_SIZE);
        range.setStart (range.getStart() - (range.getStart() % pageSize));
    }

    fileHandle = open (file.getFullPathName().toUTF8(),
                       mode == readWrite ? (O_CREAT + O_RDWR) : O_RDONLY, 00644);

    if (fileHandle != -1)
    {
        void* m = mmap (0, (size_t) range.getLength(),
                        mode == readWrite ? (PROT_READ | PROT_WRITE) : PROT_READ,
                        MAP_SHARED, fileHandle,
                        (off_t) range.getStart());

        if (m != MAP_FAILED)
        {
            address = m;
            madvise (m, (size_t) range.getLength(), MADV_SEQUENTIAL);
        }
        else
        {
            range = Range<int64>();
        }
    }
}

MemoryMappedFile::~MemoryMappedFile()
{
    if (address != nullptr)
        munmap (address, (size_t) range.getLength());

    if (fileHandle != 0)
        close (fileHandle);
}

//==============================================================================
#if JUCE_PROJUCER_LIVE_BUILD
extern "C" const char* juce_getCurrentExecutablePath();
#endif

File juce_getExecutableFile();
File juce_getExecutableFile()
{
   #if JUCE_PROJUCER_LIVE_BUILD
    return File (juce_getCurrentExecutablePath());
   #elif JUCE_ANDROID
    return File (android.appFile);
   #else
    struct DLAddrReader
    {
        static String getFilename()
        {
            Dl_info exeInfo;
            dladdr ((void*) juce_getExecutableFile, &exeInfo);
            return CharPointer_UTF8 (exeInfo.dli_fname);
        }
    };

    static String filename (DLAddrReader::getFilename());
    return File::getCurrentWorkingDirectory().getChildFile (filename);
   #endif
}

//==============================================================================
int64 File::getBytesFreeOnVolume() const
{
    struct statfs buf;
    if (juce_doStatFS (*this, buf))
        return (int64) buf.f_bsize * (int64) buf.f_bavail; // Note: this returns space available to non-super user

    return 0;
}

int64 File::getVolumeTotalSize() const
{
    struct statfs buf;
    if (juce_doStatFS (*this, buf))
        return (int64) buf.f_bsize * (int64) buf.f_blocks;

    return 0;
}

String File::getVolumeLabel() const
{
   #if JUCE_MAC
    struct VolAttrBuf
    {
        u_int32_t       length;
        attrreference_t mountPointRef;
        char            mountPointSpace [MAXPATHLEN];
    } attrBuf;

    struct attrlist attrList;
    zerostruct (attrList); // (can't use "= { 0 }" on this object because it's typedef'ed as a C struct)
    attrList.bitmapcount = ATTR_BIT_MAP_COUNT;
    attrList.volattr = ATTR_VOL_INFO | ATTR_VOL_NAME;

    File f (*this);

    for (;;)
    {
        if (getattrlist (f.getFullPathName().toUTF8(), &attrList, &attrBuf, sizeof (attrBuf), 0) == 0)
            return String::fromUTF8 (((const char*) &attrBuf.mountPointRef) + attrBuf.mountPointRef.attr_dataoffset,
                                     (int) attrBuf.mountPointRef.attr_length);

        const File parent (f.getParentDirectory());

        if (f == parent)
            break;

        f = parent;
    }
   #endif

    return String::empty;
}

int File::getVolumeSerialNumber() const
{
    int result = 0;
/*    int fd = open (getFullPathName().toUTF8(), O_RDONLY | O_NONBLOCK);

    char info [512];

    #ifndef HDIO_GET_IDENTITY
     #define HDIO_GET_IDENTITY 0x030d
    #endif

    if (ioctl (fd, HDIO_GET_IDENTITY, info) == 0)
    {
        DBG (String (info + 20, 20));
        result = String (info + 20, 20).trim().getIntValue();
    }

    close (fd);*/
    return result;
}

//==============================================================================
void juce_runSystemCommand (const String&);
void juce_runSystemCommand (const String& command)
{
    int result = system (command.toUTF8());
    (void) result;
}

String juce_getOutputFromCommand (const String&);
String juce_getOutputFromCommand (const String& command)
{
    // slight bodge here, as we just pipe the output into a temp file and read it...
    const File tempFile (File::getSpecialLocation (File::tempDirectory)
                           .getNonexistentChildFile (String::toHexString (Random::getSystemRandom().nextInt()), ".tmp", false));

    juce_runSystemCommand (command + " > " + tempFile.getFullPathName());

    String result (tempFile.loadFileAsString());
    tempFile.deleteFile();
    return result;
}


//==============================================================================
#if JUCE_IOS
class InterProcessLock::Pimpl
{
public:
    Pimpl (const String&, int)
        : handle (1), refCount (1) // On iOS just fake success..
    {
    }

    int handle, refCount;
};

#else

class InterProcessLock::Pimpl
{
public:
    Pimpl (const String& lockName, const int timeOutMillisecs)
        : handle (0), refCount (1)
    {
       #if JUCE_MAC
        if (! createLockFile (File ("~/Library/Caches/com.juce.locks").getChildFile (lockName), timeOutMillisecs))
            // Fallback if the user's home folder is on a network drive with no ability to lock..
            createLockFile (File ("/tmp/com.juce.locks").getChildFile (lockName), timeOutMillisecs);

       #else
        File tempFolder ("/var/tmp");
        if (! tempFolder.isDirectory())
            tempFolder = "/tmp";

        createLockFile (tempFolder.getChildFile (lockName), timeOutMillisecs);
       #endif
    }

    ~Pimpl()
    {
        closeFile();
    }

    bool createLockFile (const File& file, const int timeOutMillisecs)
    {
        file.create();
        handle = open (file.getFullPathName().toUTF8(), O_RDWR);

        if (handle != 0)
        {
            struct flock fl;
            zerostruct (fl);

            fl.l_whence = SEEK_SET;
            fl.l_type = F_WRLCK;

            const int64 endTime = Time::currentTimeMillis() + timeOutMillisecs;

            for (;;)
            {
                const int result = fcntl (handle, F_SETLK, &fl);

                if (result >= 0)
                    return true;

                const int error = errno;

                if (error != EINTR)
                {
                    if (error == EBADF || error == ENOTSUP)
                        return false;

                    if (timeOutMillisecs == 0
                         || (timeOutMillisecs > 0 && Time::currentTimeMillis() >= endTime))
                        break;

                    Thread::sleep (10);
                }
            }
        }

        closeFile();
        return true; // only false if there's a file system error. Failure to lock still returns true.
    }

    void closeFile()
    {
        if (handle != 0)
        {
            struct flock fl;
            zerostruct (fl);

            fl.l_whence = SEEK_SET;
            fl.l_type = F_UNLCK;

            while (! (fcntl (handle, F_SETLKW, &fl) >= 0 || errno != EINTR))
            {}

            close (handle);
            handle = 0;
        }
    }

    int handle, refCount;
};
#endif

InterProcessLock::InterProcessLock (const String& nm)  : name (nm)
{
}

InterProcessLock::~InterProcessLock()
{
}

bool InterProcessLock::enter (const int timeOutMillisecs)
{
    const ScopedLock sl (lock);

    if (pimpl == nullptr)
    {
        pimpl = new Pimpl (name, timeOutMillisecs);

        if (pimpl->handle == 0)
            pimpl = nullptr;
    }
    else
    {
        pimpl->refCount++;
    }

    return pimpl != nullptr;
}

void InterProcessLock::exit()
{
    const ScopedLock sl (lock);

    // Trying to release the lock too many times!
    jassert (pimpl != nullptr);

    if (pimpl != nullptr && --(pimpl->refCount) == 0)
        pimpl = nullptr;
}

//==============================================================================
void JUCE_API juce_threadEntryPoint (void*);

extern "C" void* threadEntryProc (void*);
extern "C" void* threadEntryProc (void* userData)
{
    JUCE_AUTORELEASEPOOL
    {
       #if JUCE_ANDROID
        struct AndroidThreadScope
        {
            AndroidThreadScope()   { threadLocalJNIEnvHolder.attach(); }
            ~AndroidThreadScope()  { threadLocalJNIEnvHolder.detach(); }
        };

        const AndroidThreadScope androidEnv;
       #endif

        juce_threadEntryPoint (userData);
    }

    return nullptr;
}

void Thread::launchThread()
{
    threadHandle = 0;
    pthread_t handle = 0;

    if (pthread_create (&handle, 0, threadEntryProc, this) == 0)
    {
        pthread_detach (handle);
        threadHandle = (void*) handle;
        threadId = (ThreadID) threadHandle;
    }
}

void Thread::closeThreadHandle()
{
    threadId = 0;
    threadHandle = 0;
}

void Thread::killThread()
{
    if (threadHandle != 0)
    {
       #if JUCE_ANDROID
        jassertfalse; // pthread_cancel not available!
       #else
        pthread_cancel ((pthread_t) threadHandle);
       #endif
    }
}

void Thread::setCurrentThreadName (const String& name)
{
   #if JUCE_IOS || (JUCE_MAC && defined (MAC_OS_X_VERSION_10_5) && MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_X_VERSION_10_5)
    JUCE_AUTORELEASEPOOL
    {
        [[NSThread currentThread] setName: juceStringToNS (name)];
    }
   #elif JUCE_LINUX
    pthread_setname_np (pthread_self(), name.toRawUTF8());
   #endif
}

bool Thread::setThreadPriority (void* handle, int priority)
{
    struct sched_param param;
    int policy;
    priority = jlimit (0, 10, priority);

    if (handle == 0)
        handle = (void*) pthread_self();

    if (pthread_getschedparam ((pthread_t) handle, &policy, &param) != 0)
        return false;

    policy = priority == 0 ? SCHED_OTHER : SCHED_RR;

    const int minPriority = sched_get_priority_min (policy);
    const int maxPriority = sched_get_priority_max (policy);

    param.sched_priority = ((maxPriority - minPriority) * priority) / 10 + minPriority;
    return pthread_setschedparam ((pthread_t) handle, policy, &param) == 0;
}

Thread::ThreadID Thread::getCurrentThreadId()
{
    return (ThreadID) pthread_self();
}

void Thread::yield()
{
    sched_yield();
}

//==============================================================================
/* Remove this macro if you're having problems compiling the cpu affinity
   calls (the API for these has changed about quite a bit in various Linux
   versions, and a lot of distros seem to ship with obsolete versions)
*/
#if defined (CPU_ISSET) && ! defined (SUPPORT_AFFINITIES)
 #define SUPPORT_AFFINITIES 1
#endif

void Thread::setCurrentThreadAffinityMask (const uint32 affinityMask)
{
   #if SUPPORT_AFFINITIES
    cpu_set_t affinity;
    CPU_ZERO (&affinity);

    for (int i = 0; i < 32; ++i)
        if ((affinityMask & (1 << i)) != 0)
            CPU_SET (i, &affinity);

    /*
       N.B. If this line causes a compile error, then you've probably not got the latest
       version of glibc installed.

       If you don't want to update your copy of glibc and don't care about cpu affinities,
       then you can just disable all this stuff by setting the SUPPORT_AFFINITIES macro to 0.
    */
    sched_setaffinity (getpid(), sizeof (cpu_set_t), &affinity);
    sched_yield();

   #else
    /* affinities aren't supported because either the appropriate header files weren't found,
       or the SUPPORT_AFFINITIES macro was turned off
    */
    jassertfalse;
    (void) affinityMask;
   #endif
}

//==============================================================================
bool DynamicLibrary::open (const String& name)
{
    close();
    handle = dlopen (name.isEmpty() ? nullptr : name.toUTF8().getAddress(), RTLD_LOCAL | RTLD_NOW);
    return handle != nullptr;
}

void DynamicLibrary::close()
{
    if (handle != nullptr)
    {
        dlclose (handle);
        handle = nullptr;
    }
}

void* DynamicLibrary::getFunction (const String& functionName) noexcept
{
    return handle != nullptr ? dlsym (handle, functionName.toUTF8()) : nullptr;
}



//==============================================================================
class ChildProcess::ActiveProcess
{
public:
    ActiveProcess (const StringArray& arguments)
        : childPID (0), pipeHandle (0), readHandle (0)
    {
        int pipeHandles[2] = { 0 };

        if (pipe (pipeHandles) == 0)
        {
            const pid_t result = fork();

            if (result < 0)
            {
                close (pipeHandles[0]);
                close (pipeHandles[1]);
            }
            else if (result == 0)
            {
                // we're the child process..
                close (pipeHandles[0]);   // close the read handle
                dup2 (pipeHandles[1], 1); // turns the pipe into stdout
                dup2 (pipeHandles[1], 2); //  + stderr
                close (pipeHandles[1]);

                Array<char*> argv;
                for (int i = 0; i < arguments.size(); ++i)
                    if (arguments[i].isNotEmpty())
                        argv.add (arguments[i].toUTF8().getAddress());

                argv.add (nullptr);

                execvp (argv[0], argv.getRawDataPointer());
                exit (-1);
            }
            else
            {
                // we're the parent process..
                childPID = result;
                pipeHandle = pipeHandles[0];
                close (pipeHandles[1]); // close the write handle
            }
        }
    }

    ~ActiveProcess()
    {
        if (readHandle != 0)
            fclose (readHandle);

        if (pipeHandle != 0)
            close (pipeHandle);
    }

    bool isRunning() const
    {
        if (childPID != 0)
        {
            int childState;
            const int pid = waitpid (childPID, &childState, WNOHANG);
            return pid == 0 || ! (WIFEXITED (childState) || WIFSIGNALED (childState));
        }

        return false;
    }

    int read (void* const dest, const int numBytes)
    {
        jassert (dest != nullptr);

        #ifdef fdopen
         #error // the zlib headers define this function as NULL!
        #endif

        if (readHandle == 0 && childPID != 0)
            readHandle = fdopen (pipeHandle, "r");

        if (readHandle != 0)
            return (int) fread (dest, 1, (size_t) numBytes, readHandle);

        return 0;
    }

    bool killProcess() const
    {
        return ::kill (childPID, SIGKILL) == 0;
    }

    int childPID;

private:
    int pipeHandle;
    FILE* readHandle;

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (ActiveProcess)
};

bool ChildProcess::start (const String& command)
{
    return start (StringArray::fromTokens (command, true));
}

bool ChildProcess::start (const StringArray& args)
{
    if (args.size() == 0)
        return false;

    activeProcess = new ActiveProcess (args);

    if (activeProcess->childPID == 0)
        activeProcess = nullptr;

    return activeProcess != nullptr;
}

bool ChildProcess::isRunning() const
{
    return activeProcess != nullptr && activeProcess->isRunning();
}

int ChildProcess::readProcessOutput (void* dest, int numBytes)
{
    return activeProcess != nullptr ? activeProcess->read (dest, numBytes) : 0;
}

bool ChildProcess::kill()
{
    return activeProcess == nullptr || activeProcess->killProcess();
}

//==============================================================================
struct HighResolutionTimer::Pimpl
{
    Pimpl (HighResolutionTimer& t)  : owner (t), thread (0), shouldStop (false)
    {
    }

    ~Pimpl()
    {
        jassert (thread == 0);
    }

    void start (int newPeriod)
    {
        periodMs = newPeriod;

        if (thread == 0)
        {
            shouldStop = false;

            if (pthread_create (&thread, nullptr, timerThread, this) == 0)
                setThreadToRealtime (thread, newPeriod);
            else
                jassertfalse;
        }
    }

    void stop()
    {
        if (thread != 0)
        {
            shouldStop = true;

            while (thread != 0 && thread != pthread_self())
                Thread::yield();
        }
    }

    HighResolutionTimer& owner;
    int volatile periodMs;

private:
    pthread_t thread;
    bool volatile shouldStop;

    static void* timerThread (void* param)
    {
       #if ! JUCE_ANDROID
        int dummy;
        pthread_setcancelstate (PTHREAD_CANCEL_ENABLE, &dummy);
       #endif

        reinterpret_cast<Pimpl*> (param)->timerThread();
        return nullptr;
    }

    void timerThread()
    {
        Clock clock (periodMs);

        while (! shouldStop)
        {
            clock.wait();
            owner.hiResTimerCallback();
        }

        periodMs = 0;
        thread = 0;
    }

    struct Clock
    {
       #if JUCE_MAC || JUCE_IOS
        Clock (double millis) noexcept
        {
            mach_timebase_info_data_t timebase;
            (void) mach_timebase_info (&timebase);
            delta = (((uint64_t) (millis * 1000000.0)) * timebase.numer) / timebase.denom;
            time = mach_absolute_time();
        }

        void wait() noexcept
        {
            time += delta;
            mach_wait_until (time);
        }

        uint64_t time, delta;

       #elif JUCE_ANDROID
        Clock (double millis) noexcept  : delta ((uint64) (millis * 1000000))
        {
        }

        void wait() noexcept
        {
            struct timespec t;
            t.tv_sec  = (time_t) (delta / 1000000000);
            t.tv_nsec = (long)   (delta % 1000000000);
            nanosleep (&t, nullptr);
        }

        uint64 delta;
       #else
        Clock (double millis) noexcept  : delta ((uint64) (millis * 1000000))
        {
            struct timespec t;
            clock_gettime (CLOCK_MONOTONIC, &t);
            time = 1000000000 * (int64) t.tv_sec + t.tv_nsec;
        }

        void wait() noexcept
        {
            time += delta;

            struct timespec t;
            t.tv_sec  = (time_t) (time / 1000000000);
            t.tv_nsec = (long)   (time % 1000000000);

            clock_nanosleep (CLOCK_MONOTONIC, TIMER_ABSTIME, &t, nullptr);
        }

        uint64 time, delta;
       #endif
    };

    static bool setThreadToRealtime (pthread_t thread, uint64 periodMs)
    {
       #if JUCE_MAC || JUCE_IOS
        thread_time_constraint_policy_data_t policy;
        policy.period      = (uint32_t) (periodMs * 1000000);
        policy.computation = 50000;
        policy.constraint  = policy.period;
        policy.preemptible = true;

        return thread_policy_set (pthread_mach_thread_np (thread),
                                  THREAD_TIME_CONSTRAINT_POLICY,
                                  (thread_policy_t) &policy,
                                  THREAD_TIME_CONSTRAINT_POLICY_COUNT) == KERN_SUCCESS;

       #else
        (void) periodMs;
        struct sched_param param;
        param.sched_priority = sched_get_priority_max (SCHED_RR);
        return pthread_setschedparam (thread, SCHED_RR, &param) == 0;

       #endif
    }

    JUCE_DECLARE_NON_COPYABLE (Pimpl)
};
