From dcc6ffd1841506b34bf494d032ec895c64e48787 Mon Sep 17 00:00:00 2001
From: Thomas Schmitt <scdbackup@gmx.net>
Date: Mon, 6 Dec 2010 17:05:35 +0100
Subject: [PATCH] Avoiding to start writer thread if
 iso_write_opts_set_will_cancel() is set to 1.

---
 libisofs/ecma119.c  | 32 +++++++++++++++++++++++++++-----
 libisofs/ecma119.h  |  1 +
 libisofs/libisofs.h | 12 +++++++-----
 3 files changed, 35 insertions(+), 10 deletions(-)

diff --git a/libisofs/ecma119.c b/libisofs/ecma119.c
index a25c08d..5b915e0 100644
--- a/libisofs/ecma119.c
+++ b/libisofs/ecma119.c
@@ -1732,6 +1732,8 @@ int ecma119_image_new(IsoImage *src, IsoWriteOpts *opts, Ecma119Image **img)
 
     target->empty_file_block = 0;
 
+    target->wthread_is_running = 0;
+
     for (i = 0; i < ISO_MAX_PARTITIONS; i++) {
         target->appended_partitions[i] = NULL;
         if (opts->appended_partitions[i] != NULL) {
@@ -2049,6 +2051,20 @@ int ecma119_image_new(IsoImage *src, IsoWriteOpts *opts, Ecma119Image **img)
     /* This was possibly altered by above overwrite buffer production */
     target->vol_space_size = target->curblock - target->ms_block;
 
+/*
+*/
+#define Libisofs_print_size_no_forK 1
+
+#ifdef Libisofs_print_size_no_forK
+    if (opts->will_cancel) {
+        iso_msg_debug(target->image->id,
+      "Will not start write thread because of iso_write_opts_set_will_cancel");
+        *img = target;
+        return ISO_SUCCESS;
+    }
+#endif
+
+
     /* 4. Create and start writing thread */
     if (target->md5_session_checksum) {
         /* After any fake writes are done: Initialize image checksum context */
@@ -2090,6 +2106,7 @@ int ecma119_image_new(IsoImage *src, IsoWriteOpts *opts, Ecma119Image **img)
         ret = ISO_THREAD_ERROR;
         goto target_cleanup;
     }
+    target->wthread_is_running= 1;
 
     /*
      * Notice that once we reach this point, target belongs to the writer
@@ -2146,8 +2163,11 @@ static void bs_free_data(struct burn_source *bs)
         iso_ring_buffer_reader_close(target->buffer, 0);
 
         /* wait until writer thread finishes */
-        pthread_join(target->wthread, NULL);
-        iso_msg_debug(target->image->id, "Writer thread joined");
+        if (target->wthread_is_running) {
+            pthread_join(target->wthread, NULL);
+            target->wthread_is_running = 0;
+            iso_msg_debug(target->image->id, "Writer thread joined");
+        }
     }
 
     iso_msg_debug(target->image->id,
@@ -2179,9 +2199,11 @@ int bs_cancel(struct burn_source *bs)
     }
 
     /* wait until writer thread finishes */
-    pthread_join(target->wthread, NULL);
-
-    iso_msg_debug(target->image->id, "Writer thread joined");
+    if (target->wthread_is_running) {
+        pthread_join(target->wthread, NULL);
+        target->wthread_is_running = 0;
+        iso_msg_debug(target->image->id, "Writer thread joined");
+    }
     return ISO_SUCCESS;
 }
 
diff --git a/libisofs/ecma119.h b/libisofs/ecma119.h
index 3f0cf22..46dfe96 100644
--- a/libisofs/ecma119.h
+++ b/libisofs/ecma119.h
@@ -586,6 +586,7 @@ struct ecma119_image
 
     /* writer thread descriptor */
     pthread_t wthread;
+    int wthread_is_running;
     pthread_attr_t th_attr;
 
     /* User settable PVD time stamps */
diff --git a/libisofs/libisofs.h b/libisofs/libisofs.h
index 2771455..f49c297 100644
--- a/libisofs/libisofs.h
+++ b/libisofs/libisofs.h
@@ -1206,11 +1206,13 @@ int iso_write_opts_new(IsoWriteOpts **opts, int profile);
 void iso_write_opts_free(IsoWriteOpts *opts);
 
 /**
- * Announce that only the image size is desired and that the write thread
- * will be cancelled by the .cancel() method of the struct burn_source that
- * consumes the image output stream.
- * This avoids to generate a MISHAP event when the effect of .cancel()
- * reaches the image generator thread.
+ * Announce that only the image size is desired, that the struct burn_source
+ * which is set to consume the image output stream will stay inactive,
+ * and that the write thread will be cancelled anyway by the .cancel() method
+ * of the struct burn_source.
+ * This avoids to create a write thread which would begin production of the
+ * image stream and would generate a MISHAP event when burn_source.cancel()
+ * gets into effect.
  * 
  * @param opts
  *      The option set to be manipulated.