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csapp.c
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441 lines (352 loc) · 8.5 KB
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/*
* csapp.c - Functions for the CS:APP3e book
*
* Updated 8/2014 droh:
* - New versions of open_clientfd and open_listenfd are reentrant and
* protocol independent.
*
* - Added protocol-independent inet_ntop and inet_pton functions. The
* inet_ntoa and inet_aton functions are obsolete.
*
* Updated 7/2014 droh:
* - Aded reentrant sio (signal-safe I/O) routines
*
* Updated 4/2013 droh:
* - rio_readlineb: fixed edge case bug
* - rio_readnb: removed redundant EINTR check
*/
/* $begin csapp.c */
#include "csapp.h"
/**************************
* Error-handling functions
**************************/
/* $begin errorfuns */
/* $begin unixerror */
void unix_error(char *msg) /* Unix-style error */
{
fprintf(stderr, "%s: %s\n", msg, strerror(errno));
exit(0);
}
/* $end unixerror */
void posix_error(int code, char *msg) /* Posix-style error */
{
fprintf(stderr, "%s: %s\n", msg, strerror(code));
exit(0);
}
void gai_error(int code, char *msg) /* Getaddrinfo-style error */
{
fprintf(stderr, "%s: %s\n", msg, gai_strerror(code));
exit(0);
}
void app_error(char *msg) /* Application error */
{
fprintf(stderr, "%s\n", msg);
exit(0);
}
/* $end errorfuns */
void dns_error(char *msg) /* Obsolete gethostbyname error */
{
fprintf(stderr, "%s\n", msg);
exit(0);
}
/*********************************************
* Wrappers for Unix process control functions
********************************************/
/* $begin forkwrapper */
pid_t Fork(void)
{
pid_t pid;
if ((pid = fork()) < 0)
unix_error("Fork error");
return pid;
}
/* $end forkwrapper */
void Execve(const char *filename, char *const argv[], char *const envp[])
{
if (execve(filename, argv, envp) < 0)
unix_error("Execve error");
}
/* $begin wait */
pid_t Wait(int *status)
{
pid_t pid;
if ((pid = wait(status)) < 0)
unix_error("Wait error");
return pid;
}
/* $end wait */
pid_t Waitpid(pid_t pid, int *iptr, int options)
{
pid_t retpid;
if ((retpid = waitpid(pid, iptr, options)) < 0)
unix_error("Waitpid error");
return(retpid);
}
/* $begin kill */
void Kill(pid_t pid, int signum)
{
int rc;
if ((rc = kill(pid, signum)) < 0)
unix_error("Kill error");
}
/* $end kill */
void Pause()
{
(void)pause();
return;
}
unsigned int Sleep(unsigned int secs)
{
return sleep(secs);
}
unsigned int Alarm(unsigned int seconds) {
return alarm(seconds);
}
void Setpgid(pid_t pid, pid_t pgid) {
int rc;
if ((rc = setpgid(pid, pgid)) < 0)
unix_error("Setpgid error");
return;
}
pid_t Getpgrp(void) {
return getpgrp();
}
/********************************
* Wrappers for Unix I/O routines
********************************/
int Open(const char *pathname, int flags, mode_t mode)
{
int rc;
if ((rc = open(pathname, flags, mode)) < 0)
unix_error("Open error");
return rc;
}
ssize_t Read(int fd, void *buf, size_t count)
{
ssize_t rc;
if ((rc = read(fd, buf, count)) < 0)
unix_error("Read error");
return rc;
}
ssize_t Write(int fd, const void *buf, size_t count)
{
ssize_t rc;
if ((rc = write(fd, buf, count)) < 0)
unix_error("Write error");
return rc;
}
off_t Lseek(int fildes, off_t offset, int whence)
{
off_t rc;
if ((rc = lseek(fildes, offset, whence)) < 0)
unix_error("Lseek error");
return rc;
}
void Close(int fd)
{
int rc;
if ((rc = close(fd)) < 0)
unix_error("Close error");
}
int Select(int n, fd_set *readfds, fd_set *writefds,
fd_set *exceptfds, struct timeval *timeout)
{
int rc;
if ((rc = select(n, readfds, writefds, exceptfds, timeout)) < 0)
unix_error("Select error");
return rc;
}
int Dup2(int fd1, int fd2)
{
int rc;
if ((rc = dup2(fd1, fd2)) < 0)
unix_error("Dup2 error");
return rc;
}
void Stat(const char *filename, struct stat *buf)
{
if (stat(filename, buf) < 0)
unix_error("Stat error");
}
void Fstat(int fd, struct stat *buf)
{
if (fstat(fd, buf) < 0)
unix_error("Fstat error");
}
/*********************************
* Wrappers for directory function
*********************************/
DIR *Opendir(const char *name)
{
DIR *dirp = opendir(name);
if (!dirp)
unix_error("opendir error");
return dirp;
}
struct dirent *Readdir(DIR *dirp)
{
struct dirent *dep;
errno = 0;
dep = readdir(dirp);
if ((dep == NULL) && (errno != 0))
unix_error("readdir error");
return dep;
}
int Closedir(DIR *dirp)
{
int rc;
if ((rc = closedir(dirp)) < 0)
unix_error("closedir error");
return rc;
}
/***************************************
* Wrappers for memory mapping functions
***************************************/
void *Mmap(void *addr, size_t len, int prot, int flags, int fd, off_t offset)
{
void *ptr;
if ((ptr = mmap(addr, len, prot, flags, fd, offset)) == ((void *) -1))
unix_error("mmap error");
return(ptr);
}
void Munmap(void *start, size_t length)
{
if (munmap(start, length) < 0)
unix_error("munmap error");
}
/***************************************************
* Wrappers for dynamic storage allocation functions
***************************************************/
void *Malloc(size_t size)
{
void *p;
if ((p = malloc(size)) == NULL)
unix_error("Malloc error");
return p;
}
void *Realloc(void *ptr, size_t size)
{
void *p;
if ((p = realloc(ptr, size)) == NULL)
unix_error("Realloc error");
return p;
}
void *Calloc(size_t nmemb, size_t size)
{
void *p;
if ((p = calloc(nmemb, size)) == NULL)
unix_error("Calloc error");
return p;
}
void Free(void *ptr)
{
free(ptr);
}
/******************************************
* Wrappers for the Standard I/O functions.
******************************************/
void Fclose(FILE *fp)
{
if (fclose(fp) != 0)
unix_error("Fclose error");
}
FILE *Fdopen(int fd, const char *type)
{
FILE *fp;
if ((fp = fdopen(fd, type)) == NULL)
unix_error("Fdopen error");
return fp;
}
char *Fgets(char *ptr, int n, FILE *stream)
{
char *rptr;
if (((rptr = fgets(ptr, n, stream)) == NULL) && ferror(stream))
app_error("Fgets error");
return rptr;
}
FILE *Fopen(const char *filename, const char *mode)
{
FILE *fp;
if ((fp = fopen(filename, mode)) == NULL)
unix_error("Fopen error");
return fp;
}
void Fputs(const char *ptr, FILE *stream)
{
if (fputs(ptr, stream) == EOF)
unix_error("Fputs error");
}
size_t Fread(void *ptr, size_t size, size_t nmemb, FILE *stream)
{
size_t n;
if (((n = fread(ptr, size, nmemb, stream)) < nmemb) && ferror(stream))
unix_error("Fread error");
return n;
}
void Fwrite(const void *ptr, size_t size, size_t nmemb, FILE *stream)
{
if (fwrite(ptr, size, nmemb, stream) < nmemb)
unix_error("Fwrite error");
}
/************************************************
* Wrappers for Pthreads thread control functions
************************************************/
void Pthread_create(pthread_t *tidp, pthread_attr_t *attrp,
void * (*routine)(void *), void *argp)
{
int rc;
if ((rc = pthread_create(tidp, attrp, routine, argp)) != 0)
posix_error(rc, "Pthread_create error");
}
void Pthread_cancel(pthread_t tid) {
int rc;
if ((rc = pthread_cancel(tid)) != 0)
posix_error(rc, "Pthread_cancel error");
}
void Pthread_join(pthread_t tid, void **thread_return) {
int rc;
if ((rc = pthread_join(tid, thread_return)) != 0)
posix_error(rc, "Pthread_join error");
}
/* $begin detach */
void Pthread_detach(pthread_t tid) {
int rc;
if ((rc = pthread_detach(tid)) != 0)
posix_error(rc, "Pthread_detach error");
}
/* $end detach */
void Pthread_exit(void *retval) {
pthread_exit(retval);
}
pthread_t Pthread_self(void) {
return pthread_self();
}
void Pthread_once(pthread_once_t *once_control, void (*init_function)()) {
pthread_once(once_control, init_function);
}
/********************************
* Implementation of semaphores *
********************************/
void Sem_init(sem_t *sem, int pshared, unsigned int value) {
if (pshared != 0) {
unix_error("Shared semaphores are not supported");
}
sem->value = value;
pthread_mutex_init(&sem->lock, 0);
pthread_cond_init(&sem->cond, NULL);
}
void P(sem_t *sem) {
pthread_mutex_lock(&sem->lock);
while (sem->value == 0) {
pthread_cond_wait(&sem->cond, &sem->lock);
}
sem->value--;
pthread_mutex_unlock(&sem->lock);
}
void V(sem_t *sem) {
pthread_mutex_lock(&sem->lock);
sem->value++;
pthread_cond_broadcast(&sem->cond);
pthread_mutex_unlock(&sem->lock);
}
/* $end csapp.c */