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#include <stdio.h>
#include <dlfcn.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <stdarg.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <signal.h>
void error(const char *file, int line,const char *str, ...) {
va_list fmt;
va_start(fmt, str);
fprintf(stderr, "error:%s %s:%d\n", strerror(errno), file, line);
vfprintf(stderr, str, fmt);
fprintf(stderr, "\n");
va_end(fmt);
}
#define ERROR_EXIT(ret, msg...) do { error(__FILE__, __LINE__, msg); ret } while(0)
#define ERROR(msg...) ERROR_EXIT(exit(1);, msg)
#define FAIL(ret, msg...) ERROR_EXIT(ret, msg)
#define PRINT_ERROR_STR(msg...) FAIL(;, msg)
#define safe_free(ptr) do { if(ptr) { free(ptr); ptr = NULL;} } while(0)
char *alloc_sprintf(const char * __format, ...) {
va_list fmt;
va_start(fmt, __format);
int len = vsnprintf(NULL, 0, __format, fmt);
va_end(fmt);
char *str = malloc(len+1);
if(str == NULL) ERROR("");
va_start(fmt, __format);
vsnprintf(str, len+1, __format, fmt);
va_end(fmt);
return str;
}
char *__client_fifo = NULL;
void __attribute__((destructor)) cleanup() {
safe_free(__client_fifo);
}
#define SERVER_FIFO "server-fifo"
#define CLIENT_FIFO (__client_fifo == NULL ? (__client_fifo = alloc_sprintf("client-fifo-%d", getpid())) : __client_fifo)
#define GET_CLIENT_FIFO(pid) alloc_sprintf("client-fifo-%d", pid)
#define GLOBAL_NUMBER_FILE "global_number_file"
struct client_info {
pid_t pid;
int incr;
};
unsigned long long int number = 0;
void sync_global(unsigned long long int *old, unsigned long long int *new) {
unsigned long long int buf;
int global_numberfd = open(GLOBAL_NUMBER_FILE, O_RDWR | O_SYNC | O_CREAT, 0666);
if(global_numberfd == -1) FAIL(return;,"");
ssize_t readsize = read(global_numberfd, &buf, sizeof(unsigned long long int));
if(readsize < 0) PRINT_ERROR_STR("");
lseek(global_numberfd, 0, SEEK_SET);
if(old) {
if(write(global_numberfd, old, sizeof(unsigned long long int)) != sizeof(unsigned long long int))
PRINT_ERROR_STR("");
}
if(readsize > 0 && new) *new = buf;
close(global_numberfd);
}
int server_fd;
int dummy_fd;
void on_server_exit() {
close(server_fd);
close(dummy_fd);
unlink(SERVER_FIFO);
sync_global(&number, NULL);
}
void handler(int sig) {
printf("server, sig:%s\n", strsignal(sig));
on_server_exit();
signal(sig, SIG_DFL);
raise(sig);
}
void destroy(int sig) {
printf("server, sig:%s\n", strsignal(sig));
on_server_exit();
unlink(GLOBAL_NUMBER_FILE);
_exit(0);
}
int server(int argc, char *argv[]) {
atexit(on_server_exit);
signal(SIGPIPE, handler);
signal(SIGINT, destroy);
signal(SIGTERM, destroy);
signal(SIGHUP, handler);
signal(19, handler);
if(mkfifo(SERVER_FIFO, 0666) == -1) ERROR("");
struct client_info buf;
ssize_t rd_size;
sync_global(NULL, &number);
printf("number = %llu\n", number);
for(int i = 0 ;; i++) {
if((server_fd = open(SERVER_FIFO, O_RDONLY)) == -1) ERROR("");
printf("i = %d\n", i);
while ((rd_size = read(server_fd, &buf, sizeof(struct client_info))) > 0) {
printf("server: handling request from %d,%d\n", buf.pid, buf.incr);
char *client_fifo = GET_CLIENT_FIFO(buf.pid);
if(access(client_fifo, F_OK | W_OK) != 0) ERROR_EXIT(goto cleanup_noaction;, "");
int client_fd;
if ((client_fd = open(client_fifo, O_WRONLY | O_NONBLOCK)) == -1) ERROR_EXIT(goto cleanup_noaction;, "");
int flag;
if((flag = fcntl(client_fd, F_GETFL)) == -1) ERROR_EXIT(goto cleanup;, "");
flag &= ~O_NONBLOCK;
if(fcntl(client_fd, F_SETFL, flag) == -1) ERROR_EXIT(goto cleanup;, "");
sigset_t sigset, oldset;
if(sigemptyset(&sigset) == -1) ERROR_EXIT(goto cleanup_nomask;, "");
if(sigemptyset(&oldset) == -1) ERROR_EXIT(goto cleanup_nomask;, "");
if(sigaddset(&sigset, SIGPIPE) == -1) ERROR_EXIT(goto cleanup_nomask;, "");
if(sigprocmask(SIG_SETMASK, &sigset, &oldset) == -1) ERROR_EXIT(goto cleanup_nomask;, "");
if (write(client_fd, &(unsigned long long int[1]) {number}, sizeof(unsigned long long int[1])) !=
sizeof(unsigned long long int[1])) ERROR_EXIT(goto cleanup;, "");
number += buf.incr;
cleanup:
if(sigprocmask(SIG_SETMASK, &oldset, NULL) == -1) ERROR_EXIT(goto cleanup;, "");
cleanup_nomask:
sync_global(&number, NULL);
close(client_fd);
cleanup_noaction:
safe_free(client_fifo);
}
sleep(1);
close(server_fd);
if(rd_size < 0) ERROR("");
}
return 0;
}
void clientdestroy(int sig) {
printf("client %d, sig:%s\n", getpid(), strsignal(sig));
unlink(CLIENT_FIFO);
signal(sig, SIG_DFL);
raise(sig);
}
int client(int argc, char *argv[]) {
int client_fd;
signal(SIGHUP, clientdestroy);
setbuf(stdout, NULL);
printf("client %d open\n", getpid());
if((server_fd = open(SERVER_FIFO, O_WRONLY)) == -1) ERROR("");
if(mkfifo(CLIENT_FIFO, 0666) == -1) ERROR("");
struct client_info info = {
.incr=atoi(argv[1]),
.pid=getpid()
};
printf("client %d write\n", getpid());
if(write(server_fd, &info, sizeof(struct client_info)) != sizeof(struct client_info)) {
ERROR("");
}
unsigned long long int n;
printf("client %d read\n", getpid());
printf("client %d open1\n", getpid());
if((client_fd = open(CLIENT_FIFO, O_RDONLY)) == -1) ERROR("");
if(read(client_fd, &n, sizeof(unsigned long long int)) != sizeof(unsigned long long int)) {
ERROR("");
}
printf("client %d get id: %llu\n", getpid(), n);
close(server_fd);
close(client_fd);
unlink(CLIENT_FIFO);
}
int main(int argc, char *argv[]) {
argv++;
argc--;
if(!strcmp("server", argv[0])) {
server(argc, argv);
} else if(!strcmp("client", argv[0])) {
client(argc, argv);
}
return 0;
}
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