doc/

2003-09-14  Marcus Brinkmann  <marcus@g10code.de>

	* gpgme.texi (Multi Threading): Correct documentation on memory
	synchronization requirement.

tests/
2003-09-14  Marcus Brinkmann  <marcus@g10code.de>

	* gpg/t-thread1.c (main): Call init_gpgme here.
	(initialize_gpgme): Function removed.

diff --git a/doc/ChangeLog b/doc/ChangeLog
index 11cc544b5f51126a6a251f75b45d742be4f188a4..de523fea9a94536802a745aeddb2d0b717289581 100644 (file)
--- a/doc/ChangeLog
+++ b/doc/ChangeLog
@@ -1,5 +1,8 @@
 2003-09-14  Marcus Brinkmann  <marcus@g10code.de>
 
+       * gpgme.texi (Multi Threading): Correct documentation on memory
+       synchronization requirement.
+
        * gpgme.texi (Locale): New section.
        (Multi Threading): Set locale in example.
 

diff --git a/doc/gpgme.texi b/doc/gpgme.texi
index eaa197c309d60fdaef5047d581e4272b50b6fc39..c76916e375b7c2c1c3f3c74a5cf30223fe4a9c81 100644 (file)
--- a/doc/gpgme.texi
+++ b/doc/gpgme.texi
@@ -551,51 +551,17 @@ For example, if you use GNU Pth, the right name is
 @item
 The function @code{gpgme_check_version} must be called before any
 other function in the library, because it initializes the thread
-support subsystem in @acronym{GPGME}.  To achieve this in all
-generality, it is necessary to synchronize the call to this function
-with all other calls to functions in the library, using the
-synchronization mechanisms available in your thread library.
-Otherwise, specific compiler or CPU memory cache optimizations could
-lead to the situation where a thread is started and uses
-@acronym{GPGME} before the effects of the initialization are visible
-for this thread.  It doesn't even suffice to call
-@code{gpgme_check_version} before creating this other
-thread@footnote{In SMP systems the new thread could be started on
-another CPU before the effects of the initialization are seen by that
-CPU's memory cache.  Not doing proper synchronization here leads to
-the same problems the double-checked locking idiom has.  You might
-find that if you don't do proper synchronization, it still works in
-most configurations.  Don't let this fool you.  Someday it might lead
-to subtle bugs when someone tries it on a DEC Alpha or an SMP
-machine.}.
-
-For example, if you are using POSIX threads, each thread that wants to
-call functions in @acronym{GPGME} could call the following function
-before any function in the library:
-
-@example
-#include <stdlib.h>
-#include <locale.h>
-#include <pthread.h>
-#include <gpgme.h>
-
-void
-initialize_gpgme (void)
-@{
-  static int gpgme_init;
-  static pthread_mutext_t gpgme_init_lock = PTHREAD_MUTEX_INITIALIZER;
-
-  pthread_mutex_lock (&gpgme_init_lock);
-  if (!gpgme_init)
-    @{
-      gpgme_check_version (NULL);
-      gpgme_set_locale (NULL, LC_CTYPE, setlocale (LC_CTYPE, NULL));
-      gpgme_set_locale (NULL, LC_MESSAGES, setlocale (LC_MESSAGES, NULL));
-      gpgme_init = 1;
-    @}
-  pthread_mutex_unlock (&gpgme_init_lock);
-@}
-@end example
+support subsystem in @acronym{GPGME}.  To achieve this in
+multi-threaded programs, you must synchronize the memory with respect
+to other threads that also want to use @acronym{GPGME}.  For this, it
+is sufficient to call @code{gpgme_check_version} before creating the
+other threads using @acronym{GPGME}@footnote{At least this is true for
+POSIX threads, as @code{pthread_create} is a function that
+synchronizes memory with respects to other threads.  There are many
+functions which have this property, a complete list can be found in
+POSIX, IEEE Std 1003.1-2003, Base Definitions, Issue 6, in the
+definition of the term ``Memory Synchronization''.  For other thread
+packages other, more relaxed or more strict rules may apply.}.
 
 @item
 Any @code{gpgme_data_t} and @code{gpgme_ctx_t} object must only be

diff --git a/tests/ChangeLog b/tests/ChangeLog
index 4a42e19be4875ce262813a15d467e1118f910a44..012566759bc4102eaa49ecad1bd36b3916598ef4 100644 (file)
--- a/tests/ChangeLog
+++ b/tests/ChangeLog
@@ -1,5 +1,8 @@
 2003-09-14  Marcus Brinkmann  <marcus@g10code.de>
 
+       * gpg/t-thread1.c (main): Call init_gpgme here.
+       (initialize_gpgme): Function removed.
+
        * gpg/t-thread1.c: New file.
        * gpg/Makefile.am (TESTS): Add t-thread1.c.
        (t_thread1_LDADD): New variable.

diff --git a/tests/gpg/t-thread1.c b/tests/gpg/t-thread1.c
index 5b765a54fab5f0da009ee366229eb9c0b40d278e..4c003b12ec30a59789315843665bdb950105d72f 100644 (file)
--- a/tests/gpg/t-thread1.c
+++ b/tests/gpg/t-thread1.c
@@ -31,22 +31,6 @@
 
 #define ROUNDS 20
 
-\f
-void
-initialize_gpgme (void)
-{
-  static int gpgme_init;
-  static pthread_mutex_t gpgme_init_lock = PTHREAD_MUTEX_INITIALIZER;
-
-  pthread_mutex_lock (&gpgme_init_lock);
-  if (!gpgme_init)
-    {
-      init_gpgme (GPGME_PROTOCOL_OpenPGP);
-      gpgme_init = 1;
-    }
-  pthread_mutex_unlock (&gpgme_init_lock);
-}
-
 \f
 void *
 thread_one (void *name)
@@ -156,6 +140,8 @@ main (int argc, char *argv[])
   pthread_t tone;
   pthread_t ttwo;
 
+  init_gpgme (GPGME_PROTOCOL_OpenPGP);
+
   pthread_create (&tone, NULL, thread_one, "A");
   pthread_create (&ttwo, NULL, thread_two, "A");