Author: hhinnant
Date: Mon Jan 23 17:55:58 2012
New Revision: 148750
URL: http://llvm.org/viewvc/llvm-project?rev=148750&view=rev
Log:
A lot of the code in cxa_exception.cpp depends on __cxa_get_globals_fast()
returning null if __cxa_get_globals() hasn't been called yet. However it
doesn't reliably do that, at least on OS X if __cxa_get_globals_fast() is
called prior to pthread_key_create() running. Our choice is to either limit
our use of __cxa_get_globals_fast() more than we have, or to have
__cxa_get_globals_fast() initialize with pthread_key_create() if necessary. I
chose the latter, and replaced pthread_once with a C++11 local static (which
should do the same thing).
Modified:
libcxxabi/trunk/src/cxa_exception_storage.cpp
Modified: libcxxabi/trunk/src/cxa_exception_storage.cpp
URL:
http://llvm.org/viewvc/llvm-project/libcxxabi/trunk/src/cxa_exception_storage.cpp?rev=148750&r1=148749&r2=148750&view=diff
==============================================================================
--- libcxxabi/trunk/src/cxa_exception_storage.cpp (original)
+++ libcxxabi/trunk/src/cxa_exception_storage.cpp Mon Jan 23 17:55:58 2012
@@ -42,7 +42,6 @@
namespace __cxxabiv1 {
namespace {
- pthread_once_t flag_ = PTHREAD_ONCE_INIT;
pthread_key_t key_;
void destruct_ (void *p) throw () {
@@ -51,17 +50,15 @@
abort_message("cannot zero out thread value for
__cxa_get_globals()");
}
- void construct_ () throw () {
+ int construct_ () throw () {
if ( 0 != pthread_key_create ( &key_, destruct_ ) )
abort_message("cannot create pthread key for __cxa_get_globals()");
+ return 0;
}
}
extern "C" {
__cxa_eh_globals * __cxa_get_globals () throw () {
- // First time through, create the key.
- if ( 0 != pthread_once ( &flag_, construct_ ) )
- abort_message("cannot run pthread_once for __cxa_get_globals()");
// Try to get the globals for this thread
__cxa_eh_globals* retVal = __cxa_get_globals_fast ();
@@ -79,6 +76,8 @@
}
__cxa_eh_globals * __cxa_get_globals_fast () throw () {
+ // First time through, create the key.
+ static int init = construct_();
return static_cast<__cxa_eh_globals*>(::pthread_getspecific(key_));
}
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