lock.h

// Type your code here, or load an example.
#include <stdlib.h>
#include <stdio.h>
#include <pthread.h>

#define _CONCAT(t1, t2) t1 ## t2
#define CONCAT(t1, t2) _CONCAT(t1, t2)

#define CLEANUP_ATTR(fn) __attribute__((cleanup(fn)))
typedef void (*cleanup_handle_fn)(void *arg);

#define UNUSED_ATTR __attribute__((unused))
#define INLINE_ATTR __attribute__((always_inline))

typedef struct cleanup_callback_t {
  void *arg;
  cleanup_handle_fn cleanup_handle;
} cleanup_callback;

inline void cleanup_call(cleanup_callback *cleanup) INLINE_ATTR;

inline void cleanup_call(cleanup_callback *cleanup) {
  cleanup->cleanup_handle(cleanup->arg);
}

#define SCOPED_REGION(init, var) \
  if (0) { \
    CONCAT(_done_, __LINE__): \
    ; \
  } else for (init) for (var ;;) \
    if (1) \
      goto CONCAT(_body_, __LINE__); \
    else \
      while (1) \
        if (1) \
          goto CONCAT(_done_, __LINE__); \
        else \
          CONCAT(_body_, __LINE__):

// lock styled i.e. you initialise outside of the specific take
#define SCOPED_LOCK(acq, rel, lock) \
  SCOPED_REGION(cleanup_callback _locked_scope_tmp CLEANUP_ATTR(cleanup_call) \
    = ((cleanup_callback){ .arg = lock, .cleanup_handle = (cleanup_handle_fn)rel }); (acq(lock), 1);,)

#define SCOPED_WITH(type, name, init, rel, ...) \
  SCOPED_REGION(cleanup_callback _locked_scope_tmp CLEANUP_ATTR(cleanup_call) \
    = ((cleanup_callback){ .arg = init(__VA_ARGS__), .cleanup_handle = (cleanup_handle_fn)rel });;, \
    type name = (type)_locked_scope_tmp.arg)

// examples
#define SCOPED_MTX_LOCK(lock) \
  SCOPED_LOCK(pthread_mutex_lock, pthread_mutex_unlock, lock)

#define SCOPED_FILE(name, path, mode) \
  SCOPED_WITH(FILE *, name, fopen, fclose, path, mode)

/*
  i.e.
*/

void c(int x) {
    getchar();
}

static pthread_mutex_t ping_lock = PTHREAD_MUTEX_INITIALIZER;

void ex() {
    SCOPED_MTX_LOCK(&ping_lock) for (int i = 0; i < 10; i++) {
        c(i);
    }

    SCOPED_FILE(f, "my_file.txt", "r") {
        fprintf(f, "hello world\n");
    }
}