1 files changed, 111 insertions, 0 deletions
diff --git a/3rd-party/zisofs_tools/workers.c b/3rd-party/zisofs_tools/workers.c
new file mode 100644
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--- /dev/null
+++ b/3rd-party/zisofs_tools/workers.c
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+/*
+ * This file has been modified for the cdrkit suite.
+ *
+ * The behaviour and appearence of the program code below can differ to a major
+ * extent from the version distributed by the original author(s).
+ *
+ * For details, see Changelog file distributed with the cdrkit package. If you
+ * received this file from another source then ask the distributing person for
+ * a log of modifications.
+ *
+ */
+
+#ident "$Id: workers.c,v 1.3 2006/07/04 04:57:42 hpa Exp $"
+/* ----------------------------------------------------------------------- *
+ *   
+ *   Copyright 2001-2006 H. Peter Anvin - All Rights Reserved
+ *
+ *   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, Inc., 675 Mass Ave, Cambridge MA 02139,
+ *   USA; either version 2 of the License, or (at your option) any later
+ *   version; incorporated herein by reference.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * workers.c
+ *
+ * Parallel job maintenance
+ */
+
+#include "mkzftree.h"		/* Must be included first! */
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <signal.h>
+#include <stdio.h>
+#include <sys/wait.h>
+
+/* Global option */
+extern int parallel;		/* Number of parallel jobs */
+
+/* Functions related to parallel execution */
+static volatile int work_threads = 0;
+static int is_worker = 0;
+
+/* This waits for one worker to finish */
+static void wait_for_one_worker(void)
+{
+  int status;
+
+  if ( wait(&status) > 0 ) {
+    work_threads--;
+    
+    if ( WIFSIGNALED(status) ) {
+      kill(getpid(), WTERMSIG(status));
+      exit(EX_SOFTWARE);
+    } else if ( WEXITSTATUS(status) ) {
+      exit(WEXITSTATUS(status));
+    }
+  }
+}  
+
+/* This waits for *all* workers to finish */
+void wait_for_all_workers(void)
+{
+  while ( work_threads )
+    wait_for_one_worker();
+}
+
+/* This returns 1 if the "job" at hand should be performed */
+int spawn_worker(void)
+{
+  pid_t f;
+  
+  if ( opt.parallel == 0 )
+    return 1;
+
+  fflush(NULL);
+
+  /* Wait for a work slot */
+  while ( work_threads >= opt.parallel )
+    wait_for_one_worker();
+  
+  /* Spawn worker process */
+  work_threads++;		/* Avoids race conditions */
+  f = fork();
+  if ( f == -1 ) {
+    work_threads--;
+    return 1;			/* Do it ourselves */
+  }
+
+  if ( f == 0 ) {
+    /* Worker process */
+    is_worker = 1;
+    return 1;
+  } else {
+    /* Control process */
+    return 0;
+  }
+}
+
+/* Routine to perform at the end of the job */
+void end_worker(int err)
+{
+  if ( is_worker ) {
+    exit(err);
+  }
+}
+