generic.c

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/*
Copyright (C) 2007-12 Andrea Vedaldi and Brian Fulkerson.
Copyright (C) 2013 Andrea Vedaldi.
All rights reserved.

This file is part of the VLFeat library and is made available under
the terms of the BSD license (see the COPYING file).
*/

#include "generic.h"

#include <assert.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <math.h>

#if defined(VL_OS_WIN)
#include <Windows.h>
#endif

#if ! defined(VL_DISABLE_THREADS) && defined(VL_THREADS_POSIX)
#include <pthread.h>
#endif

#if defined(VL_OS_MACOSX) || defined(VL_OS_LINUX)
#include <unistd.h>
#endif

#if defined(_OPENMP)
#include <omp.h>
#endif

/* ---------------------------------------------------------------- */
/*                                         Global and thread states */
/* ---------------------------------------------------------------- */

/* Thread state */
typedef struct _VlThreadState
{
  /* errors */
  int lastError ;
  char lastErrorMessage [VL_ERR_MSG_LEN] ;

  /* random number generator */
  VlRand rand ;

  /* time */
#if defined(VL_OS_WIN)
  LARGE_INTEGER ticFreq ;
  LARGE_INTEGER ticMark ;
#else
  clock_t ticMark ;
#endif
} VlThreadState ;

/* Gobal state */
typedef struct _VlState
{
  /* The thread state uses either a mutex (POSIX)
    or a critical section (Win) */
#if defined(VL_DISABLE_THREADS)
  VlThreadState * threadState ;
#else
#if defined(VL_THREADS_POSIX)
  pthread_key_t threadKey ;
  pthread_mutex_t mutex ;
  pthread_t mutexOwner ;
  pthread_cond_t mutexCondition ;
  size_t mutexCount ;
#elif defined(VL_THREADS_WIN)
  DWORD tlsIndex ;
  CRITICAL_SECTION mutex ;
#endif
#endif /* VL_DISABLE_THREADS */

  /* Configurable functions */
  int   (*printf_func)  (char const * format, ...) ;
  void *(*malloc_func)  (size_t) ;
  void *(*realloc_func) (void*,size_t) ;
  void *(*calloc_func)  (size_t, size_t) ;
  void  (*free_func)    (void*) ;

#if defined(VL_ARCH_IX86) || defined(VL_ARCH_X64) || defined(VL_ARCH_IA64)
  VlX86CpuInfo cpuInfo ;
#endif
  vl_size numCPUs ;
  vl_bool simdEnabled ;
  vl_size numThreads ;
} VlState ;

/* Global state instance */
VlState _vl_state ;

/* ----------------------------------------------------------------- */
VL_INLINE VlState * vl_get_state () ;
VL_INLINE VlThreadState * vl_get_thread_specific_state () ;
static void vl_lock_state (void) ;
static void vl_unlock_state (void) ;
static VlThreadState * vl_thread_specific_state_new (void) ;
static void vl_thread_specific_state_delete (VlThreadState * self) ;

char const *
vl_get_version_string ()
{
  return VL_VERSION_STRING ;
}

char *
vl_configuration_to_string_copy ()
{
  char * string = 0 ;
  int length = 0 ;
  char * staticString = vl_static_configuration_to_string_copy() ;
  char * cpuString =
#if defined(VL_ARCH_IX86) || defined(VL_ARCH_X64) || defined(VL_ARCH_IA64)
  _vl_x86cpu_info_to_string_copy(&vl_get_state()->cpuInfo) ;
#else
  "Generic CPU" ;
#endif
#if defined(DEBUG)
  int const debug = 1 ;
#else
  int const debug = 0 ;
#endif

  while (string == 0) {
    if (length > 0) {
      string = vl_malloc(sizeof(char) * length) ;
      if (string == NULL) break ;
    }
    length = snprintf(string, length,
                      "VLFeat version %s\n"
                      "    Static config: %s\n"
                      "    %" VL_FMT_SIZE " CPU(s): %s\n"
#if defined(_OPENMP)
                      "    OpenMP: max threads: %d (library: %" VL_FMT_SIZE ")\n"
#endif
                      "    Debug: %s\n",
                      vl_get_version_string (),
                      staticString,
                      vl_get_num_cpus(), cpuString,
#if defined(_OPENMP)
                      omp_get_max_threads(), vl_get_max_threads(),
#endif
                      VL_YESNO(debug)) ;
    length += 1 ;
  }

  if (staticString) vl_free(staticString) ;
  if (cpuString) vl_free(cpuString) ;
  return string ;
}

static int
do_nothing_printf (char const* format VL_UNUSED, ...)
{
  return 0 ;
}

static void
vl_lock_state (void)
{
#if ! defined(VL_DISABLE_THREADS)
#if   defined(VL_THREADS_POSIX)
  VlState * state = vl_get_state () ;
  pthread_t thisThread = pthread_self () ;
  pthread_mutex_lock (&state->mutex) ;
  if (state->mutexCount >= 1 &&
      pthread_equal (state->mutexOwner, thisThread)) {
    state->mutexCount ++ ;
  } else {
    while (state->mutexCount >= 1) {
      pthread_cond_wait (&state->mutexCondition, &state->mutex) ;
    }
    state->mutexOwner = thisThread ;
    state->mutexCount = 1 ;
  }
  pthread_mutex_unlock (&state->mutex) ;
#elif defined(VL_THREADS_WIN)
  EnterCriticalSection (&vl_get_state()->mutex) ;
#endif
#endif
}

static void
vl_unlock_state (void)
{
#if ! defined(VL_DISABLE_THREADS)
#if   defined(VL_THREADS_POSIX)
  VlState * state = vl_get_state () ;
  pthread_mutex_lock (&state->mutex) ;
  -- state->mutexCount ;
  if (state->mutexCount == 0) {
    pthread_cond_signal (&state->mutexCondition) ;
  }
  pthread_mutex_unlock (&state->mutex) ;
#elif defined(VL_THREADS_WIN)
  LeaveCriticalSection (&vl_get_state()->mutex) ;
#endif
#endif
}

VL_INLINE VlState *
vl_get_state (void)
{
  return &_vl_state ;
}

VL_INLINE VlThreadState *
vl_get_thread_specific_state (void)
{
#ifdef VL_DISABLE_THREADS
  return vl_get_state()->threadState ;
#else
  VlState * state ;
  VlThreadState * threadState ;

  vl_lock_state() ;
  state = vl_get_state() ;

#if defined(VL_THREADS_POSIX)
  threadState = (VlThreadState *) pthread_getspecific(state->threadKey) ;
#elif defined(VL_THREADS_WIN)
  threadState = (VlThreadState *) TlsGetValue(state->tlsIndex) ;
#endif

  if (! threadState) {
    threadState = vl_thread_specific_state_new () ;
  }

#if defined(VL_THREADS_POSIX)
  pthread_setspecific(state->threadKey, threadState) ;
#elif defined(VL_THREADS_WIN)
  TlsSetValue(state->tlsIndex, threadState) ;
#endif

  vl_unlock_state() ;
  return threadState ;
#endif
}

/* ---------------------------------------------------------------- */
vl_size
vl_get_num_cpus (void)
{
  return vl_get_state()->numCPUs ;
}

void
vl_set_simd_enabled (vl_bool x)
{
  vl_get_state()->simdEnabled = x ;
}

vl_bool
vl_get_simd_enabled (void)
{
  return vl_get_state()->simdEnabled ;
}

vl_bool
vl_cpu_has_avx (void)
{
#if defined(VL_ARCH_IX86) || defined(VL_ARCH_X64) || defined(VL_ARCH_IA64)
  return vl_get_state()->cpuInfo.hasAVX ;
#else
  return VL_FALSE ;
#endif
}

vl_bool
vl_cpu_has_sse3 (void)
{
#if defined(VL_ARCH_IX86) || defined(VL_ARCH_X64) || defined(VL_ARCH_IA64)
  return vl_get_state()->cpuInfo.hasSSE3 ;
#else
  return VL_FALSE ;
#endif
}

vl_bool
vl_cpu_has_sse2 (void)
{
#if defined(VL_ARCH_IX86) || defined(VL_ARCH_X64) || defined(VL_ARCH_IA64)
  return vl_get_state()->cpuInfo.hasSSE2 ;
#else
  return VL_FALSE ;
#endif
}

/* ---------------------------------------------------------------- */

vl_size
vl_get_thread_limit (void)
{
#if defined(_OPENMP)
#if _OPENMP >= 200805
  /* OpenMP version >= 3.0 */
  return omp_get_thread_limit() ;
#else
  return 0 ;
#endif
#else
  return 1 ;
#endif
}

vl_size
vl_get_max_threads (void)
{
#if defined(_OPENMP)
  return vl_get_state()->numThreads ;
#else
  return 1 ;
#endif
}

#if defined(_OPENMP)
void
vl_set_num_threads (vl_size numThreads)
{
  if (numThreads == 0) {
    numThreads = omp_get_max_threads() ;
  }
  vl_get_state()->numThreads = numThreads ;
}
#else
void
vl_set_num_threads (vl_size numThreads VL_UNUSED) { }
#endif

/* ---------------------------------------------------------------- */
int
vl_set_last_error (int error, char const * errorMessage, ...)
{
  VlThreadState * state = vl_get_thread_specific_state() ;
  va_list args;
  va_start(args, errorMessage) ;
  if (errorMessage) {
#ifdef VL_COMPILER_LCC
    vsprintf(state->lastErrorMessage, errorMessage, args) ;
#else
    vsnprintf(state->lastErrorMessage,
              sizeof(state->lastErrorMessage)/sizeof(char),
              errorMessage, args) ;
#endif
  } else {
    state->lastErrorMessage[0] = 0 ;
  }
  state->lastError = error ;
  va_end(args) ;
  return error ;
}

int
vl_get_last_error (void) {
  return vl_get_thread_specific_state()->lastError ;
}

char const *
vl_get_last_error_message (void)
{
  return vl_get_thread_specific_state()->lastErrorMessage ;
}

/* ---------------------------------------------------------------- */
void
vl_set_alloc_func (void *(*malloc_func)  (size_t),
                   void *(*realloc_func) (void*, size_t),
                   void *(*calloc_func)  (size_t, size_t),
                   void  (*free_func)    (void*))
{
  VlState * state ;
  vl_lock_state () ;
  state = vl_get_state() ;
  state->malloc_func  = malloc_func ;
  state->realloc_func = realloc_func ;
  state->calloc_func  = calloc_func ;
  state->free_func    = free_func ;
  vl_unlock_state () ;
}

void *
vl_malloc (size_t n)
{
  return (vl_get_state()->malloc_func)(n) ;
  //return (memalign)(32,n) ;
}


void *
vl_realloc (void* ptr, size_t n)
{
  return (vl_get_state()->realloc_func)(ptr, n) ;
}

void *
vl_calloc (size_t n, size_t size)
{
  return (vl_get_state()->calloc_func)(n, size) ;
}

void
vl_free (void *ptr)
{
  (vl_get_state()->free_func)(ptr) ;
}

/* ---------------------------------------------------------------- */

void
vl_set_printf_func (printf_func_t printf_func)
{
  vl_get_state()->printf_func = printf_func ? printf_func : do_nothing_printf ;
}

printf_func_t
vl_get_printf_func (void) {
  return vl_get_state()->printf_func ;
}

/* ---------------------------------------------------------------- */
double
vl_get_cpu_time ()
{
  #ifdef VL_OS_WIN
  VlThreadState * threadState = vl_get_thread_specific_state() ;
  LARGE_INTEGER mark ;
  QueryPerformanceCounter (&mark) ;
  return (double)mark.QuadPart / (double)threadState->ticFreq.QuadPart ;
#else
  return (double)clock() / (double)CLOCKS_PER_SEC ;
#endif
}

void
vl_tic (void)
{
  VlThreadState * threadState = vl_get_thread_specific_state() ;
#ifdef VL_OS_WIN
  QueryPerformanceCounter (&threadState->ticMark) ;
#else
  threadState->ticMark = clock() ;
#endif
}

double
vl_toc (void)
{
  VlThreadState * threadState = vl_get_thread_specific_state() ;
#ifdef VL_OS_WIN
  LARGE_INTEGER tocMark ;
  QueryPerformanceCounter(&tocMark) ;
  return (double) (tocMark.QuadPart - threadState->ticMark.QuadPart) /
    threadState->ticFreq.QuadPart ;
#else
  return (double) (clock() - threadState->ticMark) / CLOCKS_PER_SEC ;
#endif
}

/* ---------------------------------------------------------------- */
VL_EXPORT VlRand *
vl_get_rand (void)
{
  return &vl_get_thread_specific_state()->rand ;
}

/* ---------------------------------------------------------------- */
/*                    Library construction and destruction routines */
/*  --------------------------------------------------------------- */

static VlThreadState *
vl_thread_specific_state_new (void)
{
  VlThreadState * self ;
#if defined(DEBUG)
  printf("VLFeat DEBUG: thread constructor begins.\n") ;
#endif
  self = malloc(sizeof(VlThreadState)) ;
  self->lastError = 0 ;
  self->lastErrorMessage[0] = 0 ;
#if defined(VL_OS_WIN)
  QueryPerformanceFrequency (&self->ticFreq) ;
  self->ticMark.QuadPart = 0 ;
#else
  self->ticMark = 0 ;
#endif
  vl_rand_init (&self->rand) ;

  return self ;
}

static void
vl_thread_specific_state_delete (VlThreadState * self)
{
#if defined(DEBUG)
  printf("VLFeat DEBUG: thread destructor begins.\n") ;
#endif
  free (self) ;
}
/* ---------------------------------------------------------------- */
/*                                        DLL entry and exit points */
/* ---------------------------------------------------------------- */
/* A constructor and a destructor must be called to initialize or dispose of VLFeat
 * state when the DLL is loaded or unloaded. This is obtained
 * in different ways depending on the operating system.
 */

#if (defined(VL_OS_LINUX) || defined(VL_OS_MACOSX)) && defined(VL_COMPILER_GNUC)
static void vl_constructor () __attribute__ ((constructor)) ;
static void vl_destructor () __attribute__ ((destructor))  ;
#endif

#if defined(VL_OS_WIN)
static void vl_constructor () ;
static void vl_destructor () ;

BOOL WINAPI DllMain(
    HINSTANCE hinstDLL,  // handle to DLL module
    DWORD fdwReason,     // reason for calling function
    LPVOID lpReserved )  // reserved
{
  VlState * state ;
  VlThreadState * threadState ;
  switch (fdwReason) {
    case DLL_PROCESS_ATTACH:
      /* Initialize once for each new process */
      vl_constructor () ;
      break ;

    case DLL_THREAD_ATTACH:
      /* Do thread-specific initialization */
      break ;

    case DLL_THREAD_DETACH:
      /* Do thread-specific cleanup */
#if ! defined(VL_DISABLE_THREADS) && defined(VL_THREADS_WIN)
      state = vl_get_state() ;
      threadState = (VlThreadState*) TlsGetValue(state->tlsIndex) ;
      if (threadState) {
        vl_thread_specific_state_delete (threadState) ;
      }
#endif
      break;

    case DLL_PROCESS_DETACH:
      /* Perform any necessary cleanup */
      vl_destructor () ;
      break;
    }
    return TRUE ; /* Successful DLL_PROCESS_ATTACH */
}
#endif /* VL_OS_WIN */

/* ---------------------------------------------------------------- */
/*                               Library constructor and destructor */
/* ---------------------------------------------------------------- */

static void
vl_constructor (void)
{
  VlState * state ;
#if defined(DEBUG)
  printf("VLFeat DEBUG: constructor begins.\n") ;
#endif

  state = vl_get_state() ;

#if ! defined(VL_DISABLE_THREADS)
#if defined(DEBUG)
  printf("VLFeat DEBUG: constructing thread specific state.\n") ;
#endif
#if defined(VL_THREADS_POSIX)
  {
    typedef void (*destructorType)(void * );
    pthread_key_create (&state->threadKey,
                        (destructorType)
                          vl_thread_specific_state_delete) ;
    pthread_mutex_init (&state->mutex, NULL) ;
    pthread_cond_init (&state->mutexCondition, NULL) ;
  }
#elif defined(VL_THREADS_WIN)
  InitializeCriticalSection (&state->mutex) ;
  state->tlsIndex = TlsAlloc () ;
#endif
#else

/* threading support disabled */
#if defined(DEBUG)
  printf("VLFeat DEBUG: constructing the generic thread state instance (threading support disabled).\n") ;
#endif
  vl_get_state()->threadState = vl_thread_specific_state_new() ;
#endif

  state->malloc_func  = malloc ;
  state->realloc_func = realloc ;
  state->calloc_func  = calloc ;
  state->free_func    = free ;
  state->printf_func  = printf ;

  /* on x86 platforms read the CPUID register */
#if defined(VL_ARCH_IX86) || defined(VL_ARCH_X64) || defined(VL_ARCH_IA64)
  _vl_x86cpu_info_init (&state->cpuInfo) ;
#endif

  /* get the number of CPUs */
#if defined(VL_OS_WIN)
  {
    SYSTEM_INFO info;
    GetSystemInfo (&info) ;
    state->numCPUs = info.dwNumberOfProcessors ;
  }
#elif defined(VL_OS_MACOSX) || defined(VL_OS_LINUX)
  state->numCPUs = sysconf(_SC_NPROCESSORS_ONLN) ;
#else
  state->numCPUs = 1 ;
#endif
  state->simdEnabled = VL_TRUE ;

  /* get the number of (OpenMP) threads used by the library */
#if defined(_OPENMP)
  state->numThreads = omp_get_max_threads() ;
#else
  state->numThreads = 1 ;
#endif

#if defined(DEBUG)
  printf("VLFeat DEBUG: constructor ends.\n") ;
#endif
}

static void
vl_destructor ()
{
  VlState * state ;
#if defined(DEBUG)
  printf("VLFeat DEBUG: destructor begins.\n") ;
#endif

  state = vl_get_state() ;

#if ! defined(VL_DISABLE_THREADS)
#if defined(DEBUG)
  printf("VLFeat DEBUG: destroying a thread specific state instance.\n") ;
#endif
#if   defined(VL_THREADS_POSIX)
  {
    /* Delete the thread state of this thread as the
       destructor is not called by pthread_key_delete or after
       the key is deleted. When the library
       is unloaded, this thread should also be the last one
       using the library, so this is fine.
     */
    VlThreadState * threadState =
       pthread_getspecific(state->threadKey) ;
    if (threadState) {
      vl_thread_specific_state_delete (threadState) ;
      pthread_setspecific(state->threadKey, NULL) ;
    }
  }
  pthread_cond_destroy (&state->mutexCondition) ;
  pthread_mutex_destroy (&state->mutex) ;
  pthread_key_delete (state->threadKey) ;
#elif defined(VL_THREADS_WIN)
 {
    /* Delete the thread state of this thread as the
       destructor is not called by pthread_key_delete or after
       the key is deleted. When the library
       is unloaded, this thread should also be the last one
       using the library, so this is fine.
     */
    VlThreadState * threadState =
       TlsGetValue(state->tlsIndex) ;
    if (threadState) {
      vl_thread_specific_state_delete (threadState) ;
      TlsSetValue(state->tlsIndex, NULL) ;
    }
  }
  TlsFree (state->tlsIndex) ;
  DeleteCriticalSection (&state->mutex) ;
#endif
#else
#if defined(DEBUG)
  printf("VLFeat DEBUG: destroying the generic thread state instance (threading support disabled).\n") ;
#endif
  vl_thread_specific_state_delete(vl_get_state()->threadState) ;
#endif

#if defined(DEBUG)
  printf("VLFeat DEBUG: destructor ends.\n") ;
#endif
}