From 2cadc31ad075f56eaaf8261aaeac5fdc0628575f Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bvanassche@acm.org>
Date: Sun, 15 Feb 2009 10:40:44 +0000
Subject: [PATCH] Restored the previous method for passing arguments from the
 creator thread to the created thread, since the new approach made some
 regression tests fail. It is not yet clear to me why.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@9164
---
 drd/drd_pthread_intercepts.c | 58 ++++++++++++++++++++----------------
 1 file changed, 32 insertions(+), 26 deletions(-)

diff --git a/drd/drd_pthread_intercepts.c b/drd/drd_pthread_intercepts.c
index 3e78ef0a66..e953701bcb 100644
--- a/drd/drd_pthread_intercepts.c
+++ b/drd/drd_pthread_intercepts.c
@@ -40,9 +40,9 @@
    ------------------------------------------------------------------ */
 
 /*
-  Define _GNU_SOURCE to make sure that pthread_spinlock_t is available when
-  compiling with older glibc versions (2.3 or before).
-*/
+ * Define _GNU_SOURCE to make sure that pthread_spinlock_t is available when
+ * compiling with older glibc versions (2.3 or before).
+ */
 #ifndef _GNU_SOURCE
 #define _GNU_SOURCE
 #endif
@@ -73,7 +73,8 @@ typedef struct
   void* (*start)(void*);
   void* arg;
   int   detachstate;
-} VgPosixThreadArgs;
+  int   wrapper_started;
+} DrdPosixThreadArgs;
 
 
 /* Local function declarations. */
@@ -173,20 +174,15 @@ static void DRD_(set_joinable)(const pthread_t tid, const int joinable)
 static void* DRD_(thread_wrapper)(void* arg)
 {
   int res;
-  VgPosixThreadArgs* arg_ptr;
-  VgPosixThreadArgs arg_copy;
+  DrdPosixThreadArgs* arg_ptr;
+  DrdPosixThreadArgs arg_copy;
 
   VALGRIND_DO_CLIENT_REQUEST(res, 0, VG_USERREQ__DRD_SUPPRESS_CURRENT_STACK,
                              0, 0, 0, 0, 0);
 
-  arg_ptr = (VgPosixThreadArgs*)arg;
+  arg_ptr = (DrdPosixThreadArgs*)arg;
   arg_copy = *arg_ptr;
-
-  /*
-   * Free the memory 'arg_ptr' points at now such that it does not get
-   * leaked when the function called below throws a C++ exception.
-   */
-  free(arg_ptr);
+  arg_ptr->wrapper_started = 1;
 
   VALGRIND_DO_CLIENT_REQUEST(res, -1, VG_USERREQ__SET_PTHREADID,
                              pthread_self(), 0, 0, 0, 0);
@@ -276,42 +272,52 @@ PTH_FUNC(int, pthreadZucreateZa, // pthread_create*
   int    res;
   int    ret;
   OrigFn fn;
-  VgPosixThreadArgs* vgargs;
+  DrdPosixThreadArgs thread_args;
 
   VALGRIND_GET_ORIG_FN(fn);
 
-  vgargs = malloc(sizeof *vgargs);
-  assert(vgargs);
-  vgargs->start = start;
-  vgargs->arg   = arg;
+  DRD_IGNORE_VAR(thread_args.wrapper_started);
+  thread_args.start           = start;
+  thread_args.arg             = arg;
+  thread_args.wrapper_started = 0;
   /*
    * Find out whether the thread will be started as a joinable thread
    * or as a detached thread. If no thread attributes have been specified,
    * the new thread will be started as a joinable thread.
    */
-  vgargs->detachstate = PTHREAD_CREATE_JOINABLE;
+  thread_args.detachstate = PTHREAD_CREATE_JOINABLE;
   if (attr)
   {
-    if (pthread_attr_getdetachstate(attr, &vgargs->detachstate) != 0)
+    if (pthread_attr_getdetachstate(attr, &thread_args.detachstate) != 0)
     {
       assert(0);
     }
   }
-  assert(vgargs->detachstate == PTHREAD_CREATE_JOINABLE
-         || vgargs->detachstate == PTHREAD_CREATE_DETACHED);
+  assert(thread_args.detachstate == PTHREAD_CREATE_JOINABLE
+         || thread_args.detachstate == PTHREAD_CREATE_DETACHED);
 
   /* Suppress NPTL-specific conflicts between creator and created thread. */
   VALGRIND_DO_CLIENT_REQUEST(res, -1, VG_USERREQ__DRD_STOP_RECORDING,
                              0, 0, 0, 0, 0);
 
-  CALL_FN_W_WWWW(ret, fn, thread, attr, DRD_(thread_wrapper), vgargs);
+  CALL_FN_W_WWWW(ret, fn, thread, attr, DRD_(thread_wrapper), &thread_args);
 
   VALGRIND_DO_CLIENT_REQUEST(res, -1, VG_USERREQ__DRD_START_RECORDING,
                              0, 0, 0, 0, 0);
 
-  /* Free the memory 'vgargs' points at if pthread_create() failed. */
-  if (ret != 0)
-    free(vgargs);
+  if (ret == 0)
+  {
+    /*
+     * Wait until the thread wrapper started.
+     * @todo Find out why some regression tests fail if thread arguments are
+     *   passed via dynamically allocated memory and if the loop below is
+     *   removed.
+     */
+    while (! thread_args.wrapper_started)
+    {
+      sched_yield();
+    }
+  }
 
   return ret;
 }
-- 
2.47.3