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#include <stdlib.h>
#include <sys/types.h>
#include <assert.h>
#include <errno.h>
#include <limits.h>
#include <poll.h>
#include <unistd.h>
#ifndef SSIZE_MAX
#define SSIZE_MAX (SIZE_MAX / 2 - 1)
#endif
#include "safe_rw.h"
ssize_t
safe_write(const int fd, const void *const buf_, size_t count, const int timeout)
{
struct pollfd pfd;
const char * buf = (const char *) buf_;
ssize_t written;
pfd.fd = fd;
pfd.events = POLLOUT;
assert(count <= SSIZE_MAX);
while (count > (size_t) 0) {
while ((written = write(fd, buf, count)) <= (ssize_t) 0) {
if (errno == EAGAIN) {
if (poll(&pfd, (nfds_t) 1, timeout) == 0) {
errno = ETIMEDOUT;
goto ret;
}
} else if (errno != EINTR) {
goto ret;
}
}
buf += written;
count -= (size_t) written;
}
ret:
return (ssize_t)(buf - (const char *) buf_);
}
ssize_t
safe_read(const int fd, void *const buf_, size_t count)
{
unsigned char *buf = (unsigned char *) buf_;
ssize_t readnb;
assert(count <= SSIZE_MAX);
do {
while ((readnb = read(fd, buf, count)) < (ssize_t) 0 && errno == EINTR)
;
if (readnb < (ssize_t) 0) {
return readnb;
}
if (readnb == (ssize_t) 0) {
break;
}
count -= (size_t) readnb;
buf += readnb;
} while (count > (ssize_t) 0);
return (ssize_t)(buf - (unsigned char *) buf_);
}
ssize_t
safe_read_partial(const int fd, void *const buf_, const size_t max_count)
{
unsigned char *const buf = (unsigned char *) buf_;
ssize_t readnb;
assert(max_count <= SSIZE_MAX);
while ((readnb = read(fd, buf, max_count)) < (ssize_t) 0 && errno == EINTR)
;
return readnb;
}
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