restructure

TMP/Practice/trash/poll.c

@@ -0,0 +1,133 @@
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <time.h>
+#include <signal.h>
+#include <poll.h>
+#define NUM 4
+#define errExit(msg)    do { perror(msg); _exit(EXIT_FAILURE); } while (0)
+#define errExit1(msg)    { perror(msg); _exit(EXIT_FAILURE); } 
+
+void child_handler(int sig) {
+    pid_t pid;
+    while((pid = waitpid(-1, NULL, WNOHANG)) > 0);
+}
+
+int main(int argc, char *argv[]) {
+
+  struct sigaction new_act, old_act;
+  sigemptyset (&new_act.sa_mask);
+  new_act.sa_flags = 0;
+  new_act.sa_handler = child_handler;
+
+  sigaction (SIGCHLD, &new_act, &old_act);
+
+  int pipefd[NUM][2];
+  pid_t cpid[NUM];
+
+  int nfds, num_open_fds;
+  struct pollfd *pfds;
+  int ready;
+
+  unsigned char i,tt;
+  char buf;
+  int rr;
+
+  if (argc != 2) {
+     fprintf(stderr, "Usage: %s <string>\n", argv[0]);
+     _exit(EXIT_FAILURE);
+  }
+
+  srand(time(NULL));
+
+  num_open_fds = nfds = NUM;
+  pfds = calloc(nfds, sizeof(struct pollfd));
+  if (pfds == NULL) errExit("malloc");
+
+  for (i=0;i<NUM;i++){           
+    tt=(unsigned char)rand()%9;
+    dprintf(STDOUT_FILENO,"child %d life time is %X\n",i,tt);
+           
+    if (pipe(pipefd[i]) == -1) errExit("pipe");
+    pfds[i].fd = pipefd[i][0];
+    pfds[i].events = POLLIN;
+    if ((cpid[i] = fork()) == -1) errExit("fork");
+
+    if (cpid[i] == 0) {    
+       close(pipefd[i][0]);
+       for (int j=0; j<i; j++){  
+           close(pipefd[j][0]);
+           close(pipefd[j][1]);
+       }
+       write(pipefd[i][1], argv[1], strlen(argv[1]));
+       write(pipefd[i][1], &i, 1);
+       write(pipefd[i][1], &tt, 1);
+       sleep(tt);
+       close(pipefd[i][1]);
+       _exit(EXIT_SUCCESS);
+    }  
+  }
+
+  for (int j=0; j<i; j++) close(pipefd[j][1]);
+
+  dprintf(STDOUT_FILENO,"Opened %d pipes, waiting...\n",num_open_fds);
+
+  while (num_open_fds > 0) {
+
+    do{
+      dprintf(STDOUT_FILENO,"\ntry poll:\n");
+      for (i = 0; i < NUM; i++) pfds[i].revents=0;
+      ready = poll(pfds, nfds, -1);
+      if(ready == -1)
+         switch (errno) {
+           case EINTR: dprintf(STDOUT_FILENO,"\nPoll interrupted, repeat.\n"); 
+                       continue;
+           default: errExit("poll");
+         }
+    } while (ready <= 0);
+
+    for (i = 0; i < NUM; i++) {
+       if (pfds[i].revents != 0) {
+          dprintf(STDOUT_FILENO,"  fd=%d; events: %7s%8s%9s%8s%8s  ", pfds[i].fd,
+                  (pfds[i].revents & POLLIN)  ? "POLLIN "  : "",
+                  (pfds[i].revents & POLLHUP) ? "POLLHUP " : "",
+                  (pfds[i].revents & POLLNVAL) ? "POLLNVAL " : "",
+                  (pfds[i].revents & POLLPRI) ? "POLLPRI " : "",
+                  (pfds[i].revents & POLLERR) ? "POLLERR " : "");
+          if (pfds[i].revents & POLLIN) {
+
+             do {
+                rr=read(pfds[i].fd, &buf, 1);
+                if (rr < 0)
+                   switch (errno) {
+                     case EINTR: dprintf(STDOUT_FILENO,"\nRead interrupted, repeat.\n"); 
+                                 continue;
+                     default: errExit("read");
+                   }
+               if(rr == 0 ) 
+                   dprintf(STDOUT_FILENO,"\n");
+               else
+                   dprintf(STDOUT_FILENO,"[%2X]",buf);
+             } while (rr > 0);
+
+          } 
+          else 
+          if ((pfds[i].revents & (POLLHUP | ~POLLIN))) {
+             dprintf(STDOUT_FILENO,"Closing [%d], pipefd %d, pfds.fd %d\n",i,pipefd[i][0],pfds[i].fd);
+             if (close(pfds[i].fd) < 0 ) errExit("close pfds");
+             pfds[i].fd = -1;
+             pfds[i].events=0;
+             num_open_fds--;
+             dprintf(STDOUT_FILENO,"Still opened fds %d\n",num_open_fds);
+          }
+       }
+    }
+  }
+
+  return EXIT_SUCCESS;
+}