MDK的C库API互斥调用底层处理接口

eric2013

MDK的C库函数多任务安全问题



接口函数：

[C] 纯文本查看 复制代码

// C/C++ Standard Library Multithreading Interface
// ===============================================

#if ( !defined(RTX_NO_MULTITHREAD_CLIB) && \
     ( defined(__CC_ARM) || \
      (defined(__ARMCC_VERSION) && (__ARMCC_VERSION >= 6010050))) && \
      !defined(__MICROLIB))

#define LIBSPACE_SIZE 96

//lint -esym(714,__user_perthread_libspace,_mutex_*) "Referenced by C library"
//lint -esym(765,__user_perthread_libspace,_mutex_*) "Global scope"
//lint -esym(9003, os_libspace*) "variables 'os_libspace*' defined at module scope"

// Memory for libspace
static uint32_t os_libspace[OS_THREAD_LIBSPACE_NUM+1][LIBSPACE_SIZE/4] \
__attribute__((section(".bss.os.libspace")));

// Thread IDs for libspace
static osThreadId_t os_libspace_id[OS_THREAD_LIBSPACE_NUM] \
__attribute__((section(".bss.os.libspace")));

// Check if Kernel has been started
static uint32_t os_kernel_is_active (void) {
  static uint8_t os_kernel_active = 0U;

  if (os_kernel_active == 0U) {
    if (osKernelGetState() > osKernelReady) {
      os_kernel_active = 1U;
    }
  }
  return (uint32_t)os_kernel_active;
}

// Provide libspace for current thread
void *__user_perthread_libspace (void);
void *__user_perthread_libspace (void) {
  osThreadId_t id;
  uint32_t     n;

  if (os_kernel_is_active() != 0U) {
    id = osThreadGetId();
    for (n = 0U; n < (uint32_t)OS_THREAD_LIBSPACE_NUM; n++) {
      if (os_libspace_id[n] == NULL) {
        os_libspace_id[n] = id;
      }
      if (os_libspace_id[n] == id) {
        break;
      }
    }
    if (n == (uint32_t)OS_THREAD_LIBSPACE_NUM) {
      (void)osRtxKernelErrorNotify(osRtxErrorClibSpace, id);
    }
  } else {
    n = OS_THREAD_LIBSPACE_NUM;
  }

  //lint -e{9087} "cast between pointers to different object types"
  return (void *)&os_libspace[n][0];
}

// Mutex identifier
typedef void *mutex;

//lint -save "Function prototypes defined in C library"
//lint -e970 "Use of 'int' outside of a typedef"
//lint -e818 "Pointer 'm' could be declared as pointing to const"

// Initialize mutex
__USED
int _mutex_initialize(mutex *m);
int _mutex_initialize(mutex *m) {
  int result;

  *m = osMutexNew(NULL);
  if (*m != NULL) {
    result = 1;
  } else {
    result = 0;
    (void)osRtxKernelErrorNotify(osRtxErrorClibMutex, m);
  }
  return result;
}

// Acquire mutex
__USED
void _mutex_acquire(mutex *m);
void _mutex_acquire(mutex *m) {
  if (os_kernel_is_active() != 0U) {
    (void)osMutexAcquire(*m, osWaitForever);
  }
}

// Release mutex
__USED
void _mutex_release(mutex *m);
void _mutex_release(mutex *m) {
  if (os_kernel_is_active() != 0U) {
    (void)osMutexRelease(*m);
  }
}

// Free mutex
__USED
void _mutex_free(mutex *m);
void _mutex_free(mutex *m) {
  (void)osMutexDelete(*m);
}

//lint -restore