/****************************************************************************
 * include/nuttx/lib/setjmp.h
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.  The
 * ASF licenses this file to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the
 * License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations
 * under the License.
 *
 ****************************************************************************/

#ifndef __INCLUDE_NUTTX_LIB_SETJMP_H
#define __INCLUDE_NUTTX_LIB_SETJMP_H

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

/* If CONFIG_ARCH_SETJMP_H is defined, then the top-level Makefile will copy
 * this header file to include/setjmp.h where it will become the system
 * setjmp.h header file.  In this case, the architecture specific code must
 * provide an arch/<architecture>/include/setjmp.h file which will be
 * included below:
 */

#ifdef CONFIG_ARCH_SETJMP_H
#  include <arch/setjmp.h>
#  include <signal.h>

/****************************************************************************
 * Type Definitions
 ****************************************************************************/

struct sigsetjmp_buf_s
{
  jmp_buf  jmpbuf;               /* setjmp/longjmp buffer */
  int      savemask;             /* Flag indicating if mask was saved */
  sigset_t sigmask;              /* Saved signal mask */
};

typedef struct sigsetjmp_buf_s sigjmp_buf[1];

/****************************************************************************
 * Public Function Prototypes
 ****************************************************************************/

/****************************************************************************
 * Name: siglongjmp
 *
 * Description:
 *   Restores the program's execution context previously saved by
 *   sigsetjmp().
 *
 * Input Parameters:
 *   env - a pointer to a sigjmp_buf structure
 *   val - return value for sigsetjmp()
 *
 * Returned Value:
 *   This function does not return anything explicitly.
 *
 * Assumptions:
 *
 ****************************************************************************/

static inline_function void siglongjmp(sigjmp_buf env, int val)
{
  if (env->savemask)
    {
      sigprocmask(SIG_SETMASK, &env->sigmask, NULL);
    }

  longjmp(env->jmpbuf, val);
}

/****************************************************************************
 * Name: sigsetjmp
 *       int sigsetjmp(sigjmp_buf env, int savemask)
 *
 * Description:
 *   Saves the current program execution context including. It can
 *   optionally save the thread's current signal mask if the savemask
 *   parameter is non-zero.
 *
 * REVISIT:
 *  what if a signal is delivered between sigprocmask() and setjmp() ?
 *
 * Input Parameters:
 *   env - a pointer to a sigjmp_buf structure
 *   savemask - a flag used to determine if the signal mask is to be saved
 *
 * Returned Value:
 *   0      sigsetjmp called directly
 *   non-0  we justed returned from a siglongjmp()
 *
 * Assumptions:
 *
 ****************************************************************************/

#define sigsetjmp(env, _savemask)                   \
  ({                                                \
    int _ret;                                       \
    env->savemask = _savemask;                      \
    if (_savemask)                                  \
      {                                             \
        sigprocmask(0, NULL, &env->sigmask);        \
      }                                             \
    _ret = setjmp(env->jmpbuf);                     \
    _ret;                                           \
  })

#endif

#endif /* __INCLUDE_NUTTX_LIB_SETJMP_H */
