int fputs ( const char * str, FILE * stream )
{
//printf("INTERCEPTED fputs\n");
clock_t start = clock();
int ret = _fputs(str,stream);
clock_t end = clock();
double called_time = (double)(start-program_start)/(double)(CLOCKS_PER_SEC);
double exec_time = (double)(end-start)/(double)(CLOCKS_PER_SEC);
fprintf(logFile,"%lf %lf fputs %s %p = %d\n",called_time,exec_time,str,stream,ret);
return ret;
}
int fputs(const char *s, FILE *stream) {
// Get libc syscall function pointer & offset in image
libc_func(fputs, int, const char *, FILE *);
if (plr_checkInsidePLR()) {
// If already inside PLR code, just call original syscall & return
return _fputs(s, stream);
} else {
plr_setInsidePLR();
int fn = fileno(stream);
plrlog(LOG_SYSCALL, "[%d:fputs] Write '%s' to fileno %d\n", getpid(), s, fn);
syscallArgs_t args = {
.addr = _off_fputs,
.arg[0] = fn,
.arg[1] = crc32(0, s, strlen(s)),
};
plr_checkSyscallArgs(&args);
// Nested function actually performed by master process only
int ret;
fputsShmData_t shmDat;
int masterAct() {
// Call original libc function
ret = _fputs(s, stream);
// Flush/sync data to disk to help other processes see it
fflush(stream);
fsync(fn);
// Use ftell to get new file offset
shmDat.err = errno;
shmDat.ret = ret;
shmDat.offs = ftell(stream);
shmDat.eof = feof(stream);
shmDat.ferr = ferror(stream);
// Store return value in shared memory for slave processes
plr_copyToShm(&shmDat, sizeof(shmDat), 0);
if (shmDat.ferr) {
// Not sure how to handle passing ferror's to slaves yet, no way
// to manually set error state
plrlog(LOG_ERROR, "[%d:fputs] ERROR: ferror (%d) occurred (%d)\n", getpid(), shmDat.ferr, fn);
exit(1);
}
return 0;
}
// All processes call plr_masterAction() to synchronize at this point
plr_masterAction(masterAct);
if (!plr_isMasterProcess()) {
// Slaves copy return values from shared memory
plr_copyFromShm(&shmDat, sizeof(shmDat), 0);
// Slaves seek to new fd offset
// Can't use SEEK_CUR and advance by ret because the slave processes
// may have been forked from each other after the fd was opened, in which
// case the fd & its offset are shared, and that would advance more than needed
fseek(stream, shmDat.offs, SEEK_SET);
// Necessary to manually reset EOF flag because fseek clears it
if (shmDat.eof) {
// fgetc at EOF to set feof indicator
int c;
if ((c = fgetc(stream)) != EOF) {
const char *fmt = "[%d:fputs] ERROR: fgetc to cause EOF actually got data (%c %d), ftell = %d, feof = %d\n";
plrlog(LOG_ERROR, fmt, getpid(), c, c, ftell(stream), feof(stream));
exit(1);
}
}
if (shmDat.ferr) {
plrlog(LOG_ERROR, "[%d:fputs] ERROR: ferror (%d) from master (%d)\n", getpid(), shmDat.ferr, fn);
exit(1);
}
}
// TEMPORARY
// Slave processes sometimes end up with the wrong file offset, even after SEEK_SET
// Compare file state at exit to make sure everything is consistent
// Piggybacking off checkSyscallArgs mechanism to do this
syscallArgs_t exitState = {
.arg[0] = ftell(stream),
.arg[1] = feof(stream),
.arg[2] = ferror(stream),
};
plr_checkSyscallArgs(&exitState);
// All procs return same value & errno
ret = shmDat.ret;
errno = shmDat.err;
plr_clearInsidePLR();
return ret;
}
}
