/*
 * This is the thread routine for removing
 * items from the chat buffer and sending
 * them to the user.
 */

#include <strings.h>
#include <stdio.h>

#include "chat.h"

void *OutputToUser(void *ptArgs) {
  struct chatbuff * volatile G ;
  int   mySock ;
  struct linebuff myLineBuff ;
  int   myNextSlot ;
  int   stillConnected ;
  FILE *sockOut ;
  
  mySock = ((struct ptGenericArg *)ptArgs) -> sock ;
  G      = ((struct ptGenericArg *)ptArgs) -> G ;
  free(ptArgs) ;

  stillConnected = 1 ;
  /* This locking is really a little excessive */
  /* but perhaps there really aren't atomic integer reads */
  pthread_mutex_lock(&G->nextSlotMutex) ;
  myNextSlot = G->nextSlot ;
  pthread_mutex_unlock(&G->nextSlotMutex) ;

  if ((sockOut = fdopen(mySock, "w")) == (FILE *)NULL) {
    perror("fdopen") ;
    pthread_exit((void *)NULL) ;
  }

  while (stillConnected) {
    int i ;

    pthread_mutex_lock(&G->nextSlotMutex) ;
    while (myNextSlot == G->nextSlot)
      pthread_cond_wait(&G->nextSlotConditional, &G->nextSlotMutex) ;
    pthread_mutex_unlock(&G->nextSlotMutex) ;

    /* RW lock only needed if being lapped */
    pthread_rwlock_rdlock(&G->buffRWlock[myNextSlot]) ;
    bcopy((void *)&G->buff[myNextSlot],
	  (void *)&myLineBuff,
	  sizeof(struct linebuff));
    pthread_rwlock_unlock(&G->buffRWlock[myNextSlot]) ;
    for (i=0; i<myLineBuff.size && stillConnected; ++i)
      if (fputc((int) myLineBuff.buff[i], sockOut) == EOF)
	stillConnected = 0 ;
    if (stillConnected && (fflush(sockOut) == EOF))
      stillConnected = 0 ;
    pthread_mutex_lock(&G->nextSlotMutex) ;
    INCRSLOT(&myNextSlot) ;
    pthread_mutex_unlock(&G->nextSlotMutex) ;
  }

  return ((void *)NULL) ;
}