coreutils patch to multithread md5sum for parallel hashing (ala the HP-U (original) (raw)

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From: Brett L. Trotter
Subject: coreutils patch to multithread md5sum for parallel hashing (ala the HP-UX days)
Date: Wed, 24 Mar 2010 19:13:37 -0500
User-agent: Thunderbird 2.0.0.24 (X11/20100311)

Hello, this is my first post to the list, so I'll say in advance here I'm pleased to meet you all.

I've been out of C/C++ land for a while due to the economy, but found myself hashing a bunch of 46GB blu ray images and discs for verification lately and wanted a simple way to cut down the time involved without starting separate terminals, running screen, etc. HP-UX's md5sum had/has(?) a -n option for parallelizing the hashing. I did a quick implementation today, and it's probably nothing like the sort of code you folks write and likely can be optimized quite a bit, but I was sincerely hoping that the feature could make it into coreutils, either based on my code or someone else's.

It's a patch against the version in coreutils-5.97-23.el5_4.2.src.rpm on RHEL 5.4. It's been tested lightly, shows a performance -decrease- for small numbers of small files, but in increase for larger files or larger numbers of files. I haven't yet gotten around to making the ptach apply to the makefile.am, so I was manually adding -lpthread to the link lines for the *sum programs in the generated makefile.

Again, this is not anywhere near a production ready patch- and I'm aware that output ordering will be potentially out of order when N > 1 is used, but I'd love any thoughts, improvements, or reasons why md5sum shouldn't be able to parallel process like the old days.

-Brett

P.S. I've also attached the fully patched md5sum.c.

*** coreutils-5.97/src/md5sum.c 2010-03-24 11:29:26.000000000 -0500 --- coreutils-5.97/src/md5sum.c.threaded 2010-03-24 14:09:25.000000000 -0500

*** 40,45 **** --- 40,46 ---- #include "error.h" #include "quote.h" #include "stdio--.h"

*** 139,150 **** --- 140,165 ---- { "check", no_argument, NULL, 'c' }, { "status", no_argument, NULL, STATUS_OPTION }, { "text", no_argument, NULL, 't' },

*** 181,186 **** --- 196,204 ---- fputs (_("
-t, --text read in text mode (default)\n
"), stdout);

*** 592,607 **** && n_open_or_read_failures == 0); }

! int ! main (int argc, char *argv) { unsigned char bin_buffer_unaligned[DIGEST_BIN_BYTES+DIGEST_ALIGN]; / Make sure bin_buffer is properly aligned. */ unsigned char *bin_buffer = ptr_align (bin_buffer_unaligned, DIGEST_ALIGN); bool do_check = false; int opt;

--- 610,718 ---- && n_open_or_read_failures == 0); }

! void ! *thread_start(void node) { unsigned char bin_buffer_unaligned[DIGEST_BIN_BYTES+DIGEST_ALIGN]; / Make sure bin_buffer is properly aligned. */ unsigned char *bin_buffer = ptr_align (bin_buffer_unaligned, DIGEST_ALIGN);

*** 612,618 ****

atexit (close_stdout);

! while ((opt = getopt_long (argc, argv, "bctw", long_options, NULL)) != -1) switch (opt) { case 'b': --- 723,729 ----

atexit (close_stdout);

! while ((opt = getopt_long (argc, argv, "bctwn:", long_options, NULL)) != -1) switch (opt) { case 'b':

*** 632,637 **** --- 743,751 ---- status_only = false; warn = true; break;

*** 662,725 **** usage (EXIT_FAILURE); }

if (!O_BINARY && binary < 0)
  binary = 0;

if (optind == argc)
  argv[argc++] = "-";

for (; optind < argc; ++optind)
  {

! char *file = argv[optind]; ! ! if (do_check) ! ok &= digest_check (file); ! else ! { ! int file_is_binary = binary;

! if (! digest_file (file, &file_is_binary, bin_buffer)) ! ok = false; ! else ! { ! size_t i;

! /* Output a leading backslash if the file name contains ! a newline or backslash. */ ! if (strchr (file, '\n') || strchr (file, '\')) ! putchar ('\');

! for (i = 0; i < (digest_hex_bytes / 2); ++i) ! printf ("%02x", bin_buffer[i]);

! putchar (' '); ! if (file_is_binary) ! putchar ('*'); ! else ! putchar (' ');

! /* Translate each NEWLINE byte to the string, "\n", ! and each backslash to "\\". */ ! for (i = 0; i < strlen (file); ++i) ! { ! switch (file[i]) ! { ! case '\n': ! fputs ("\n", stdout); ! break;

! case '\': ! fputs ("\\", stdout); ! break;

! default: ! putchar (file[i]); ! break; ! } ! } ! putchar ('\n'); ! } ! } }

if (have_read_stdin && fclose (stdin) == EOF)

--- 776,868 ---- usage (EXIT_FAILURE); }

! while (1) ! { ! pthread_mutex_lock(&m_thread_pool);

! threads_running = 0; ! tmpnode = thread_pool; ! while (tmpnode != NULL) { ! threads_running++; ! if (tmpnode->next != NULL) tmpnode = tmpnode->next; ! else break; ! }

! /* see if we need to start a new thread / ! if (threads_running < threads_max) ! { ! if (thread_pool == NULL) ! { ! thread_pool = (struct thread_node*)xmalloc(sizeof(struct thread_node)); ! tmpnode = thread_pool; ! } else { ! tmpnode->next = (struct thread_node)xmalloc(sizeof(struct thread_node)); ! tmpnode = tmpnode->next; ! } ! ! if (tmpnode != NULL) ! { ! tmpnode->do_check = do_check; ! tmpnode->binary = binary; ! tmpnode->filename = strdup(argv[optind]); ! tmpnode->next = NULL; ! tmpnode->thread = NULL; ! ! pthread_attr_init(&attr); ! pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); ! pthread_create( &(tmpnode->thread), &attr, thread_start, (void *) tmpnode); ! } ! ! pthread_mutex_unlock(&m_thread_pool); ! break; ! }

! pthread_mutex_unlock(&m_thread_pool); ! }

! }

! /* wait for all threads */ ! while (1) ! { ! pthread_mutex_lock(&m_thread_pool);

! threads_running = 0; ! tmpnode = thread_pool; ! while (tmpnode != NULL) { ! threads_running++; ! tmpnode = tmpnode->next; ! }

! pthread_mutex_unlock(&m_thread_pool); ! if (threads_running == 0) break; }

if (have_read_stdin && fclose (stdin) == EOF)

/* Compute MD5, SHA1, SHA224, SHA256, SHA384 or SHA512 checksum of files or strings Copyright (C) 1995-2005 Free Software Foundation, Inc.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */

/* Written by Ulrich Drepper <address@hidden>. */

#include <config.h>

#include <getopt.h> #include <sys/types.h>

#include "system.h"

#if HASH_ALGO_MD5

include "md5.h"

#endif #if HASH_ALGO_SHA1

include "sha1.h"

#endif #if HASH_ALGO_SHA256 || HASH_ALGO_SHA224

include "sha256.h"

#endif #if HASH_ALGO_SHA512 || HASH_ALGO_SHA384

include "sha512.h"

#endif #include "getline.h" #include "error.h" #include "quote.h" #include "stdio--.h" #include <pthread.h>

/* The official name of this program (e.g., no `g' prefix). */ #if HASH_ALGO_MD5

define PROGRAM_NAME "md5sum"

define DIGEST_TYPE_STRING "MD5"

define DIGEST_STREAM md5_stream

define DIGEST_BUFFER md5_buffer

define DIGEST_BITS 128

define DIGEST_REFERENCE "RFC 1321"

define DIGEST_ALIGN 4

#elif HASH_ALGO_SHA1

define PROGRAM_NAME "sha1sum"

define DIGEST_TYPE_STRING "SHA1"

define DIGEST_STREAM sha1_stream

define DIGEST_BUFFER sha1_buffer

define DIGEST_BITS 160

define DIGEST_REFERENCE "FIPS-180-1"

define DIGEST_ALIGN 4

#elif HASH_ALGO_SHA256

define PROGRAM_NAME "sha256sum"

define DIGEST_TYPE_STRING "SHA256"

define DIGEST_STREAM sha256_stream

define DIGEST_BUFFER sha256_buffer

define DIGEST_BITS 256

define DIGEST_REFERENCE "FIPS-180-2"

define DIGEST_ALIGN 4

#elif HASH_ALGO_SHA224

define PROGRAM_NAME "sha224sum"

define DIGEST_TYPE_STRING "SHA224"

define DIGEST_STREAM sha224_stream

define DIGEST_BUFFER sha224_buffer

define DIGEST_BITS 224

define DIGEST_REFERENCE "RFC 3874"

define DIGEST_ALIGN 4

#elif HASH_ALGO_SHA512

define PROGRAM_NAME "sha512sum"

define DIGEST_TYPE_STRING "SHA512"

define DIGEST_STREAM sha512_stream

define DIGEST_BUFFER sha512_buffer

define DIGEST_BITS 512

define DIGEST_REFERENCE "FIPS-180-2"

define DIGEST_ALIGN 8

#elif HASH_ALGO_SHA384

define PROGRAM_NAME "sha384sum"

define DIGEST_TYPE_STRING "SHA384"

define DIGEST_STREAM sha384_stream

define DIGEST_BUFFER sha384_buffer

define DIGEST_BITS 384

define DIGEST_REFERENCE "FIPS-180-2"

define DIGEST_ALIGN 8

#else

error "Can't decide which hash algorithm to compile."

#endif

#define DIGEST_HEX_BYTES (DIGEST_BITS / 4) #define DIGEST_BIN_BYTES (DIGEST_BITS / 8)

#define AUTHORS "Ulrich Drepper", "Scott Miller", "David Madore"

/* The minimum length of a valid digest line. This length does not include any newline character at the end of a line. / #define MIN_DIGEST_LINE_LENGTH
(DIGEST_HEX_BYTES / length of hexadecimal message digest */ \

/* True if any of the files read were the standard input. */ static bool have_read_stdin;

/* The minimum length of a valid checksum line for the selected algorithm. */ static size_t min_digest_line_length;

/* Set to the length of a digest hex string for the selected algorithm. */ static size_t digest_hex_bytes;

/* With --check, don't generate any output. The exit code indicates success or failure. */ static bool status_only = false;

/* With --check, print a message to standard error warning about each improperly formatted checksum line. */ static bool warn = false;

/* The name this program was run with. */ char *program_name;

/* For long options that have no equivalent short option, use a non-character as a pseudo short option, starting with CHAR_MAX + 1. */ enum { STATUS_OPTION = CHAR_MAX + 1 };

static const struct option long_options[] = { { "binary", no_argument, NULL, 'b' }, { "check", no_argument, NULL, 'c' }, { "status", no_argument, NULL, STATUS_OPTION }, { "text", no_argument, NULL, 't' }, { "threads", no_argument, NULL, 'n' }, { "warn", no_argument, NULL, 'w' }, { GETOPT_HELP_OPTION_DECL }, { GETOPT_VERSION_OPTION_DECL }, { NULL, 0, NULL, 0 } };

struct thread_node { bool do_check; int binary; pthread_t thread; char *filename; struct thread_node *next; };

static pthread_mutex_t m_thread_pool; static struct thread_node *thread_pool = NULL; static bool ok = true;

void usage (int status) { if (status != EXIT_SUCCESS) fprintf (stderr, ("Try %s --help' for more information.\n"), program_name); else { printf (_("\ Usage: %s [OPTION] [FILE]...\n\ Print or check %s (%d-bit) checksums.\n\ With no FILE, or when FILE is -, read standard input.\n\ \n\ "), program_name, DIGEST_TYPE_STRING, DIGEST_BITS); if (O_BINARY) fputs (_("\ -b, --binary read in binary mode (default unless reading tty stdin)\n\ "), stdout); else fputs (_("\ -b, --binary read in binary mode\n\ "), stdout); printf (_("\ -c, --check read %s sums from the FILEs and check them\n"), DIGEST_TYPE_STRING); if (O_BINARY) fputs (_("\ -t, --text read in text mode (default if reading tty stdin)\n\ "), stdout); else fputs (_("\ -t, --text read in text mode (default)\n\ "), stdout); fputs (_("\ -nX, --threads=X process X (1 - 16) files in parallel\n\ "), stdout); fputs (_("\ \n\ The following two options are useful only when verifying checksums:\n\ --status don't output anything, status code shows success\n\ -w, --warn warn about improperly formatted checksum lines\n\ \n\ "), stdout); fputs (HELP_OPTION_DESCRIPTION, stdout); fputs (VERSION_OPTION_DESCRIPTION, stdout); printf (_("\ \n\ The sums are computed as described in %s. When checking, the input\n\ should be a former output of this program. The default mode is to print\n\ a line with checksum, a character indicating type (*' for binary, ` ' for\n
text), and name for each FILE.\n"), DIGEST_REFERENCE); printf (("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT); }

exit (status); }

#define ISWHITE(c) ((c) == ' ' || (c) == '\t')

/* Split the checksum string S (of length S_LEN) from a BSD 'md5' or 'sha1' command into two parts: a hexadecimal digest, and the file name. S is modified. Return true if successful. */

static bool bsd_split_3 (char *s, size_t s_len, unsigned char **hex_digest, char **file_name) { size_t i;

*file_name = s;

/* Find end of filename. The BSD 'md5' and 'sha1' commands do not escape filenames, so search backwards for the last ')'. */ i = s_len - 1; while (i && s[i] != ')') i--;

if (s[i] != ')') return false;

s[i++] = '\0';

while (ISWHITE (s[i])) i++;

if (s[i] != '=') return false;

i++;

while (ISWHITE (s[i])) i++;

*hex_digest = (unsigned char *) &s[i]; return true; }

/* Split the string S (of length S_LEN) into three parts: a hexadecimal digest, binary flag, and the file name. S is modified. Return true if successful. */

static bool split_3 (char *s, size_t s_len, unsigned char **hex_digest, int *binary, char **file_name) { size_t i; bool escaped_filename = false; size_t algo_name_len;

i = 0; while (ISWHITE (s[i])) ++i;

/* Check for BSD-style checksum line. */ algo_name_len = strlen (DIGEST_TYPE_STRING); if (strncmp (s + i, DIGEST_TYPE_STRING, algo_name_len) == 0) { if (strncmp (s + i + algo_name_len, " (", 2) == 0) { *binary = 0; return bsd_split_3 (s + i + algo_name_len + 2, s_len - (i + algo_name_len + 2), hex_digest, file_name); } }

/* Ignore this line if it is too short. Each line must have at least `min_digest_line_length - 1' (or one more, if the first is a backslash) more characters to contain correct message digest information. */ if (s_len - i < min_digest_line_length + (s[i] == '\')) return false;

if (s[i] == '\') { ++i; escaped_filename = true; } *hex_digest = (unsigned char *) &s[i];

/* The first field has to be the n-character hexadecimal representation of the message digest. If it is not followed immediately by a white space it's an error. */ i += digest_hex_bytes; if (!ISWHITE (s[i])) return false;

s[i++] = '\0';

if (s[i] != ' ' && s[i] != '*') return false; binary = (s[i++] == '');

/* All characters between the type indicator and end of line are significant -- that includes leading and trailing white space. */ *file_name = &s[i];

if (escaped_filename) { /* Translate each \n' string in the file name to a NEWLINE, and each \' string to a backslash. */

  char *dst = &s[i];

  while (i < s_len)
    {
      switch (s[i])
        {
        case '\\':
          if (i == s_len - 1)
            {
              /* A valid line does not end with a backslash.  */
              return false;
            }
          ++i;
          switch (s[i++])
            {
            case 'n':
              *dst++ = '\n';
              break;
            case '\\':
              *dst++ = '\\';
              break;
            default:
              /* Only `\' or `n' may follow a backslash.  */
              return false;
            }
          break;

        case '\0':
          /* The file name may not contain a NUL.  */
          return false;
          break;

        default:
          *dst++ = s[i++];
          break;
        }
    }
  *dst = '\0';
}

return true; }

static bool hex_digits (unsigned char const *s) { while (*s) { if (!ISXDIGIT (*s)) return false; ++s; } return true; }

/* An interface to the function, DIGEST_STREAM. Operate on FILENAME (it may be "-").

*BINARY indicates whether the file is binary. BINARY < 0 means it depends on whether binary mode makes any difference and the file is a terminal; in that case, clear *BINARY if the file was treated as text because it was a terminal.

Put the checksum in *BIN_RESULT, which must be properly aligned. Return true if successful. */

static bool digest_file (const char *filename, int *binary, unsigned char *bin_result) { FILE *fp; int err; bool is_stdin = STREQ (filename, "-");

if (is_stdin) { have_read_stdin = true; fp = stdin; if (O_BINARY && *binary) { if (*binary < 0) *binary = ! isatty (STDIN_FILENO); if (*binary) freopen (NULL, "rb", stdin); } } else { fp = fopen (filename, (O_BINARY && *binary ? "rb" : "r")); if (fp == NULL) { error (0, errno, "%s", filename); return false; } }

err = DIGEST_STREAM (fp, bin_result); if (err) { error (0, errno, "%s", filename); if (fp != stdin) fclose (fp); return false; }

if (!is_stdin && fclose (fp) != 0) { error (0, errno, "%s", filename); return false; }

return true; }

static bool digest_check (const char *checkfile_name) { FILE checkfile_stream; uintmax_t n_properly_formatted_lines = 0; uintmax_t n_mismatched_checksums = 0; uintmax_t n_open_or_read_failures = 0; unsigned char bin_buffer_unaligned[DIGEST_BIN_BYTES + DIGEST_ALIGN]; / Make sure bin_buffer is properly aligned. */ unsigned char *bin_buffer = ptr_align (bin_buffer_unaligned, DIGEST_ALIGN); uintmax_t line_number; char *line; size_t line_chars_allocated; bool is_stdin = STREQ (checkfile_name, "-");

if (is_stdin) { have_read_stdin = true; checkfile_name = _("standard input"); checkfile_stream = stdin; } else { checkfile_stream = fopen (checkfile_name, "r"); if (checkfile_stream == NULL) { error (0, errno, "%s", checkfile_name); return false; } }

line_number = 0; line = NULL; line_chars_allocated = 0; do { char *filename; int binary; unsigned char *hex_digest IF_LINT (= NULL); ssize_t line_length;

  ++line_number;
  if (line_number == 0)
    error (EXIT_FAILURE, 0, _("%s: too many checksum lines"),
           checkfile_name);

  line_length = getline (&line, &line_chars_allocated, checkfile_stream);
  if (line_length <= 0)
    break;

  /* Ignore comment lines, which begin with a '#' character.  */
  if (line[0] == '#')
    continue;

  /* Remove any trailing newline.  */
  if (line[line_length - 1] == '\n')
    line[--line_length] = '\0';

  if (! (split_3 (line, line_length, &hex_digest, &binary, &filename)
         && ! (is_stdin && STREQ (filename, "-"))
         && hex_digits (hex_digest)))
    {
      if (warn)
        {
          error (0, 0,
                 _("%s: %" PRIuMAX
                   ": improperly formatted %s checksum line"),
                 checkfile_name, line_number,
                 DIGEST_TYPE_STRING);
        }
    }
  else
    {
      static const char bin2hex[] = { '0', '1', '2', '3',
                                      '4', '5', '6', '7',
                                      '8', '9', 'a', 'b',
                                      'c', 'd', 'e', 'f' };
      bool ok;

      ++n_properly_formatted_lines;

      ok = digest_file (filename, &binary, bin_buffer);

      if (!ok)
        {
          ++n_open_or_read_failures;
          if (!status_only)
            {
              printf (_("%s: FAILED open or read\n"), filename);
              fflush (stdout);
            }
        }
      else
        {
          size_t digest_bin_bytes = digest_hex_bytes / 2;
          size_t cnt;
          /* Compare generated binary number with text representation
             in check file.  Ignore case of hex digits.  */
          for (cnt = 0; cnt < digest_bin_bytes; ++cnt)
            {
              if (TOLOWER (hex_digest[2 * cnt])
                  != bin2hex[bin_buffer[cnt] >> 4]
                  || (TOLOWER (hex_digest[2 * cnt + 1])
                      != (bin2hex[bin_buffer[cnt] & 0xf])))
                break;
            }
          if (cnt != digest_bin_bytes)
            ++n_mismatched_checksums;

          if (!status_only)
            {
              printf ("%s: %s\n", filename,
                      (cnt != digest_bin_bytes ? _("FAILED") : _("OK")));
              fflush (stdout);
            }
        }
    }
}

while (!feof (checkfile_stream) && !ferror (checkfile_stream));

free (line);

if (ferror (checkfile_stream)) { error (0, 0, _("%s: read error"), checkfile_name); return false; }

if (!is_stdin && fclose (checkfile_stream) != 0) { error (0, errno, "%s", checkfile_name); return false; }

if (n_properly_formatted_lines == 0) { /* Warn if no tests are found. */ error (0, 0, _("%s: no properly formatted %s checksum lines found"), checkfile_name, DIGEST_TYPE_STRING); } else { if (!status_only) { if (n_open_or_read_failures != 0) error (0, 0, ngettext ("WARNING: %" PRIuMAX " of %" PRIuMAX " listed file could not be read", "WARNING: %" PRIuMAX " of %" PRIuMAX " listed files could not be read", n_properly_formatted_lines), n_open_or_read_failures, n_properly_formatted_lines);

      if (n_mismatched_checksums != 0)
        {
          uintmax_t n_computed_checksums =
            (n_properly_formatted_lines - n_open_or_read_failures);
          error (0, 0,
                 ngettext ("WARNING: %" PRIuMAX " of %" PRIuMAX
                           " computed checksum did NOT match",
                           "WARNING: %" PRIuMAX " of %" PRIuMAX
                           " computed checksums did NOT match",
                           n_computed_checksums),
                 n_mismatched_checksums, n_computed_checksums);
        }
    }
}

return (n_properly_formatted_lines != 0 && n_mismatched_checksums == 0 && n_open_or_read_failures == 0); }

void *thread_start(void node) { unsigned char bin_buffer_unaligned[DIGEST_BIN_BYTES+DIGEST_ALIGN]; / Make sure bin_buffer is properly aligned. */ unsigned char *bin_buffer = ptr_align (bin_buffer_unaligned, DIGEST_ALIGN); struct thread_node tn = (struct thread_node) node; struct thread_node *tmp = NULL;

if ((node == NULL) || (thread_pool == NULL)) return NULL;

if (tn->filename != NULL) { if (tn->do_check) ok &= digest_check (tn->filename); else { int file_is_binary = tn->binary;

      if (! digest_file (tn->filename, &file_is_binary, bin_buffer))
        ok = false;
      else
        {
          size_t i;

          pthread_mutex_lock(&m_thread_pool);
          /* Output a leading backslash if the file name contains
             a newline or backslash.  */
          if (strchr (tn->filename, '\n') || strchr (tn->filename, '\\'))
            putchar ('\\');

          for (i = 0; i < (digest_hex_bytes / 2); ++i)
            printf ("%02x", bin_buffer[i]);

          putchar (' ');
          if (file_is_binary)
            putchar ('*');
          else
            putchar (' ');

          /* Translate each NEWLINE byte to the string, "\\n",
             and each backslash to "\\\\".  */
          for (i = 0; i < strlen (tn->filename); ++i)
            {
              switch (tn->filename[i])
                {
                case '\n':
                  fputs ("\\n", stdout);
                  break;

                case '\\':
                  fputs ("\\\\", stdout);
                  break;

                default:
                  putchar (tn->filename[i]);
                  break;
                }
            }
          putchar ('\n');
        }
        pthread_mutex_unlock(&m_thread_pool);
    }

}

/* thread cleanup / pthread_mutex_lock(&m_thread_pool); if (thread_pool != NULL) { if (thread_pool == tn) { / we're the first thread, set root to next (if any) */ thread_pool = thread_pool->next;

} else {
  tmp = thread_pool;
  while (tmp->next != NULL)
  {
     if (tmp->next == tn) {
       /* the next node is us, set next node to our next */
       tmp->next = tn->next;
       break;
     }
     tmp = tmp->next;
  }
}

free(tn->filename);
tn->filename = NULL;
tn->next = NULL;
free(tn);
tn = NULL;

} pthread_mutex_unlock(&m_thread_pool); }

int main (int argc, char **argv) { bool do_check = false; int opt; int binary = -1; int threads_max = -1; int threads_running = 0; struct thread_node *tmpnode = NULL; pthread_attr_t attr;

/* Setting values of global variables. */ initialize_main (&argc, &argv); program_name = argv[0]; setlocale (LC_ALL, ""); bindtextdomain (PACKAGE, LOCALEDIR); textdomain (PACKAGE);

atexit (close_stdout);

while ((opt = getopt_long (argc, argv, "bctwn:", long_options, NULL)) != -1) switch (opt) { case 'b': binary = 1; break; case 'c': do_check = true; break; case STATUS_OPTION: status_only = true; warn = false; break; case 't': binary = 0; break; case 'w': status_only = false; warn = true; break; case 'n': threads_max = atoi(optarg); break; case_GETOPT_HELP_CHAR; case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS); default: usage (EXIT_FAILURE); }

min_digest_line_length = MIN_DIGEST_LINE_LENGTH; digest_hex_bytes = DIGEST_HEX_BYTES;

if (0 <= binary && do_check) { error (0, 0, _("the --binary and --text options are meaningless when " "verifying checksums")); usage (EXIT_FAILURE); }

if (status_only & !do_check) { error (0, 0, _("the --status option is meaningful only when verifying checksums")); usage (EXIT_FAILURE); }

if (warn & !do_check) { error (0, 0, _("the --warn option is meaningful only when verifying checksums")); usage (EXIT_FAILURE); }

if ((threads_max != -1) && do_check) { error (0, 0, _("the --threads option is meaningless when " "verifying checksums")); usage (EXIT_FAILURE); }

if (threads_max == -1) threads_max = 1;

if (((threads_max < 1) || (threads_max > 16)) && !do_check) { error (0, 0, _("the --threads argument must be between 1 and 16")); usage (EXIT_FAILURE); }

if (!O_BINARY && binary < 0) binary = 0;

if (optind == argc) argv[argc++] = "-";

/* initialize thread apparatus */ thread_pool = NULL; pthread_mutex_init(&m_thread_pool, NULL);

for (; optind < argc; ++optind) { while (1) { pthread_mutex_lock(&m_thread_pool);

  threads_running = 0;
  tmpnode = thread_pool;
  while (tmpnode != NULL) {
    threads_running++;
    if (tmpnode->next != NULL) tmpnode = tmpnode->next;
    else break;
  }

  /* see if we need to start a new thread */
  if (threads_running < threads_max)
    {
      if (thread_pool == NULL) 
        {
          thread_pool = (struct thread_node*)xmalloc(sizeof(struct

thread_node)); tmpnode = thread_pool; } else { tmpnode->next = (struct thread_node*)xmalloc(sizeof(struct thread_node)); tmpnode = tmpnode->next; }

      if (tmpnode != NULL)
        {
          tmpnode->do_check = do_check;
          tmpnode->binary = binary;
          tmpnode->filename = strdup(argv[optind]);
          tmpnode->next = NULL;
          tmpnode->thread = NULL;

          pthread_attr_init(&attr);
          pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
          pthread_create( &(tmpnode->thread), &attr, thread_start, (void *)

tmpnode); }

      pthread_mutex_unlock(&m_thread_pool);
      break;
    }

  pthread_mutex_unlock(&m_thread_pool);
  }

}

/* wait for all threads */
while (1)
{
  pthread_mutex_lock(&m_thread_pool);

  threads_running = 0;
  tmpnode = thread_pool;
  while (tmpnode != NULL) {
    threads_running++;
    tmpnode = tmpnode->next;
  }

  pthread_mutex_unlock(&m_thread_pool);
  if (threads_running == 0) break;
}

if (have_read_stdin && fclose (stdin) == EOF) error (EXIT_FAILURE, errno, _("standard input"));

exit (ok ? EXIT_SUCCESS : EXIT_FAILURE); }