hw3/xwrap.c


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#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include "xwrap.h"

#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#define RETRY_SEC     0
#define RETRY_NSEC    250000000

static const char fail_msg[] = "Fail to allocate memory. Retry ...\n";
static const size_t fail_len = STATIC_STRLEN (fail_msg);

int xatol (const char* str, long* result) {
    int errno_save, rval;
    long lres;
    char* endptr;

    errno_save = errno;
    errno = 0, rval = 0;

    lres = strtol (str, &endptr, 10);
    if (str == endptr || errno != 0) {
        rval = -1;
    } else {
        *result = lres;
    }

    errno = errno_save;

    return rval;
}

void* xmalloc (size_t size) {
    void* memptr;

    while ((memptr = malloc (size)) == NULL) {
        nanosleep (&(struct timespec) { RETRY_SEC, RETRY_NSEC }, NULL);
        write (STDERR_FILENO, fail_msg, fail_len);
    }

    return memptr;
}