llvm-project/libcxxabi/src/cxa_exception_storage.cpp

88 lines
2.7 KiB
C++

//===--------------------- cxa_exception_storage.cpp ----------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//
// This file implements the storage for the "Caught Exception Stack"
// http://www.codesourcery.com/public/cxx-abi/abi-eh.html (section 2.2.2)
//
//===----------------------------------------------------------------------===//
#include "cxa_exception.hpp"
#ifdef HAS_THREAD_LOCAL
namespace __cxxabiv1 {
namespace {
__cxa_eh_globals * __globals () throw () {
static thread_local __cxa_eh_globals eh_globals;
return &eh_globals;
}
}
extern "C" {
__cxa_eh_globals * __cxa_get_globals () throw() { return __globals (); }
__cxa_eh_globals * __cxa_get_globals_fast () throw() { return __globals (); }
}
}
#else
#include <pthread.h>
#include <cstdlib> // for calloc, free
#include "abort_message.h"
// In general, we treat all pthread errors as fatal.
// We cannot call std::terminate() because that will in turn
// call __cxa_get_globals() and cause infinite recursion.
namespace __cxxabiv1 {
namespace {
pthread_once_t flag_ = PTHREAD_ONCE_INIT;
pthread_key_t key_;
void destruct_ (void *p) throw () {
std::free ( p );
if ( 0 != ::pthread_setspecific ( key_, NULL ) )
abort_message("cannot zero out thread value for __cxa_get_globals()");
}
void construct_ () throw () {
if ( 0 != pthread_key_create ( &key_, destruct_ ) )
abort_message("cannot create pthread key for __cxa_get_globals()");
}
}
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 ();
// If this is the first time we've been asked for these globals, create them
if ( NULL == retVal ) {
retVal = static_cast<__cxa_eh_globals*>
(std::calloc (1, sizeof (__cxa_eh_globals)));
if ( NULL == retVal )
abort_message("cannot allocate __cxa_eh_globals");
if ( 0 != pthread_setspecific ( key_, retVal ) )
abort_message("pthread_setspecific failure in __cxa_get_globals()");
}
return retVal;
}
__cxa_eh_globals * __cxa_get_globals_fast () throw () {
return static_cast<__cxa_eh_globals*>(::pthread_getspecific(key_));
}
}
}
#endif