[libcxxabi] r282703 - Revert r282692: Use fallback_malloc to allocate __cxa_eh_globals in case of dynamic memory exhaustion.
Igor Kudrin via cfe-commits
cfe-commits at lists.llvm.org
Thu Sep 29 01:11:57 PDT 2016
Author: ikudrin
Date: Thu Sep 29 03:11:57 2016
New Revision: 282703
URL: http://llvm.org/viewvc/llvm-project?rev=282703&view=rev
Log:
Revert r282692: Use fallback_malloc to allocate __cxa_eh_globals in case of dynamic memory exhaustion.
The test breaks build bots.
Added:
libcxxabi/trunk/src/fallback_malloc.ipp
- copied unchanged from r282691, libcxxabi/trunk/src/fallback_malloc.ipp
Removed:
libcxxabi/trunk/src/fallback_malloc.cpp
libcxxabi/trunk/src/fallback_malloc.h
libcxxabi/trunk/test/test_exception_storage_nodynmem.pass.cpp
Modified:
libcxxabi/trunk/src/CMakeLists.txt
libcxxabi/trunk/src/cxa_exception.cpp
libcxxabi/trunk/src/cxa_exception_storage.cpp
libcxxabi/trunk/test/test_fallback_malloc.pass.cpp
Modified: libcxxabi/trunk/src/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/libcxxabi/trunk/src/CMakeLists.txt?rev=282703&r1=282702&r2=282703&view=diff
==============================================================================
--- libcxxabi/trunk/src/CMakeLists.txt (original)
+++ libcxxabi/trunk/src/CMakeLists.txt Thu Sep 29 03:11:57 2016
@@ -12,7 +12,6 @@ set(LIBCXXABI_SOURCES
cxa_vector.cpp
cxa_virtual.cpp
exception.cpp
- fallback_malloc.cpp
private_typeinfo.cpp
stdexcept.cpp
typeinfo.cpp
Modified: libcxxabi/trunk/src/cxa_exception.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxxabi/trunk/src/cxa_exception.cpp?rev=282703&r1=282702&r2=282703&view=diff
==============================================================================
--- libcxxabi/trunk/src/cxa_exception.cpp (original)
+++ libcxxabi/trunk/src/cxa_exception.cpp Thu Sep 29 03:11:57 2016
@@ -15,10 +15,13 @@
#include "cxxabi.h"
#include <exception> // for std::terminate
+#include <cstdlib> // for malloc, free
#include <cstring> // for memset
+#ifndef _LIBCXXABI_HAS_NO_THREADS
+# include <pthread.h> // for fallback_malloc.ipp's mutexes
+#endif
#include "cxa_exception.hpp"
#include "cxa_handlers.hpp"
-#include "fallback_malloc.h"
// +---------------------------+-----------------------------+---------------+
// | __cxa_exception | _Unwind_Exception CLNGC++\0 | thrown object |
@@ -101,6 +104,20 @@ static inline int decrementHandlerCount
return --exception->handlerCount;
}
+#include "fallback_malloc.ipp"
+
+// Allocate some memory from _somewhere_
+static void *do_malloc(size_t size) {
+ void *ptr = std::malloc(size);
+ if (NULL == ptr) // if malloc fails, fall back to emergency stash
+ ptr = fallback_malloc(size);
+ return ptr;
+}
+
+static void do_free(void *ptr) {
+ is_fallback_ptr(ptr) ? fallback_free(ptr) : std::free(ptr);
+}
+
/*
If reason isn't _URC_FOREIGN_EXCEPTION_CAUGHT, then the terminateHandler
stored in exc is called. Otherwise the exceptionDestructor stored in
@@ -141,8 +158,7 @@ extern "C" {
// user's exception object.
_LIBCXXABI_FUNC_VIS void *__cxa_allocate_exception(size_t thrown_size) throw() {
size_t actual_size = cxa_exception_size_from_exception_thrown_size(thrown_size);
- __cxa_exception *exception_header =
- static_cast<__cxa_exception *>(__malloc_with_fallback(actual_size));
+ __cxa_exception* exception_header = static_cast<__cxa_exception*>(do_malloc(actual_size));
if (NULL == exception_header)
std::terminate();
std::memset(exception_header, 0, actual_size);
@@ -152,7 +168,7 @@ _LIBCXXABI_FUNC_VIS void *__cxa_allocate
// Free a __cxa_exception object allocated with __cxa_allocate_exception.
_LIBCXXABI_FUNC_VIS void __cxa_free_exception(void *thrown_object) throw() {
- __free_with_fallback(cxa_exception_from_thrown_object(thrown_object));
+ do_free(cxa_exception_from_thrown_object(thrown_object));
}
@@ -161,7 +177,7 @@ _LIBCXXABI_FUNC_VIS void __cxa_free_exce
// Otherwise, it will work like __cxa_allocate_exception.
void * __cxa_allocate_dependent_exception () {
size_t actual_size = sizeof(__cxa_dependent_exception);
- void *ptr = __malloc_with_fallback(actual_size);
+ void *ptr = do_malloc(actual_size);
if (NULL == ptr)
std::terminate();
std::memset(ptr, 0, actual_size);
@@ -172,7 +188,7 @@ void * __cxa_allocate_dependent_exceptio
// This function shall free a dependent_exception.
// It does not affect the reference count of the primary exception.
void __cxa_free_dependent_exception (void * dependent_exception) {
- __free_with_fallback(dependent_exception);
+ do_free(dependent_exception);
}
Modified: libcxxabi/trunk/src/cxa_exception_storage.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxxabi/trunk/src/cxa_exception_storage.cpp?rev=282703&r1=282702&r2=282703&view=diff
==============================================================================
--- libcxxabi/trunk/src/cxa_exception_storage.cpp (original)
+++ libcxxabi/trunk/src/cxa_exception_storage.cpp Thu Sep 29 03:11:57 2016
@@ -45,8 +45,8 @@ extern "C" {
#else
#include <pthread.h>
+#include <cstdlib> // for calloc, free
#include "abort_message.h"
-#include "fallback_malloc.h"
// In general, we treat all pthread errors as fatal.
// We cannot call std::terminate() because that will in turn
@@ -58,7 +58,7 @@ namespace {
pthread_once_t flag_ = PTHREAD_ONCE_INIT;
void destruct_ (void *p) {
- __free_with_fallback ( p );
+ std::free ( p );
if ( 0 != ::pthread_setspecific ( key_, NULL ) )
abort_message("cannot zero out thread value for __cxa_get_globals()");
}
@@ -77,7 +77,7 @@ extern "C" {
// If this is the first time we've been asked for these globals, create them
if ( NULL == retVal ) {
retVal = static_cast<__cxa_eh_globals*>
- (__calloc_with_fallback (1, sizeof (__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 ) )
Removed: libcxxabi/trunk/src/fallback_malloc.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxxabi/trunk/src/fallback_malloc.cpp?rev=282702&view=auto
==============================================================================
--- libcxxabi/trunk/src/fallback_malloc.cpp (original)
+++ libcxxabi/trunk/src/fallback_malloc.cpp (removed)
@@ -1,226 +0,0 @@
-//===------------------------ fallback_malloc.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.
-//
-//===----------------------------------------------------------------------===//
-
-#include "fallback_malloc.h"
-
-#include "config.h"
-
-#include <cstdlib> // for malloc, calloc, free
-#include <cstring> // for memset
-
-#ifndef _LIBCXXABI_HAS_NO_THREADS
-#include <pthread.h> // for mutexes
-#endif
-
-// A small, simple heap manager based (loosely) on
-// the startup heap manager from FreeBSD, optimized for space.
-//
-// Manages a fixed-size memory pool, supports malloc and free only.
-// No support for realloc.
-//
-// Allocates chunks in multiples of four bytes, with a four byte header
-// for each chunk. The overhead of each chunk is kept low by keeping pointers
-// as two byte offsets within the heap, rather than (4 or 8 byte) pointers.
-
-namespace {
-
-// When POSIX threads are not available, make the mutex operations a nop
-#ifndef _LIBCXXABI_HAS_NO_THREADS
-static pthread_mutex_t heap_mutex = PTHREAD_MUTEX_INITIALIZER;
-#else
-static void * heap_mutex = 0;
-#endif
-
-class mutexor {
-public:
-#ifndef _LIBCXXABI_HAS_NO_THREADS
- mutexor ( pthread_mutex_t *m ) : mtx_(m) { pthread_mutex_lock ( mtx_ ); }
- ~mutexor () { pthread_mutex_unlock ( mtx_ ); }
-#else
- mutexor ( void * ) {}
- ~mutexor () {}
-#endif
-private:
- mutexor ( const mutexor &rhs );
- mutexor & operator = ( const mutexor &rhs );
-#ifndef _LIBCXXABI_HAS_NO_THREADS
- pthread_mutex_t *mtx_;
-#endif
- };
-
-
-static const size_t HEAP_SIZE = 512;
-char heap [ HEAP_SIZE ] __attribute__((aligned));
-
-typedef unsigned short heap_offset;
-typedef unsigned short heap_size;
-
-struct heap_node {
- heap_offset next_node; // offset into heap
- heap_size len; // size in units of "sizeof(heap_node)"
-};
-
-static const heap_node *list_end = (heap_node *) ( &heap [ HEAP_SIZE ] ); // one past the end of the heap
-static heap_node *freelist = NULL;
-
-heap_node *node_from_offset ( const heap_offset offset )
- { return (heap_node *) ( heap + ( offset * sizeof (heap_node))); }
-
-heap_offset offset_from_node ( const heap_node *ptr )
- { return static_cast<heap_offset>(static_cast<size_t>(reinterpret_cast<const char *>(ptr) - heap) / sizeof (heap_node)); }
-
-void init_heap () {
- freelist = (heap_node *) heap;
- freelist->next_node = offset_from_node ( list_end );
- freelist->len = HEAP_SIZE / sizeof (heap_node);
- }
-
-// How big a chunk we allocate
-size_t alloc_size (size_t len)
- { return (len + sizeof(heap_node) - 1) / sizeof(heap_node) + 1; }
-
-bool is_fallback_ptr ( void *ptr )
- { return ptr >= heap && ptr < ( heap + HEAP_SIZE ); }
-
-void *fallback_malloc(size_t len) {
- heap_node *p, *prev;
- const size_t nelems = alloc_size ( len );
- mutexor mtx ( &heap_mutex );
-
- if ( NULL == freelist )
- init_heap ();
-
-// Walk the free list, looking for a "big enough" chunk
- for (p = freelist, prev = 0;
- p && p != list_end; prev = p, p = node_from_offset ( p->next_node)) {
-
- if (p->len > nelems) { // chunk is larger, shorten, and return the tail
- heap_node *q;
-
- p->len = static_cast<heap_size>(p->len - nelems);
- q = p + p->len;
- q->next_node = 0;
- q->len = static_cast<heap_size>(nelems);
- return (void *) (q + 1);
- }
-
- if (p->len == nelems) { // exact size match
- if (prev == 0)
- freelist = node_from_offset(p->next_node);
- else
- prev->next_node = p->next_node;
- p->next_node = 0;
- return (void *) (p + 1);
- }
- }
- return NULL; // couldn't find a spot big enough
-}
-
-// Return the start of the next block
-heap_node *after ( struct heap_node *p ) { return p + p->len; }
-
-void fallback_free (void *ptr) {
- struct heap_node *cp = ((struct heap_node *) ptr) - 1; // retrieve the chunk
- struct heap_node *p, *prev;
-
- mutexor mtx ( &heap_mutex );
-
-#ifdef DEBUG_FALLBACK_MALLOC
- std::cout << "Freeing item at " << offset_from_node ( cp ) << " of size " << cp->len << std::endl;
-#endif
-
- for (p = freelist, prev = 0;
- p && p != list_end; prev = p, p = node_from_offset (p->next_node)) {
-#ifdef DEBUG_FALLBACK_MALLOC
- std::cout << " p, cp, after (p), after(cp) "
- << offset_from_node ( p ) << ' '
- << offset_from_node ( cp ) << ' '
- << offset_from_node ( after ( p )) << ' '
- << offset_from_node ( after ( cp )) << std::endl;
-#endif
- if ( after ( p ) == cp ) {
-#ifdef DEBUG_FALLBACK_MALLOC
- std::cout << " Appending onto chunk at " << offset_from_node ( p ) << std::endl;
-#endif
- p->len = static_cast<heap_size>(p->len + cp->len); // make the free heap_node larger
- return;
- }
- else if ( after ( cp ) == p ) { // there's a free heap_node right after
-#ifdef DEBUG_FALLBACK_MALLOC
- std::cout << " Appending free chunk at " << offset_from_node ( p ) << std::endl;
-#endif
- cp->len = static_cast<heap_size>(cp->len + p->len);
- if ( prev == 0 ) {
- freelist = cp;
- cp->next_node = p->next_node;
- }
- else
- prev->next_node = offset_from_node(cp);
- return;
- }
- }
-// Nothing to merge with, add it to the start of the free list
-#ifdef DEBUG_FALLBACK_MALLOC
- std::cout << " Making new free list entry " << offset_from_node ( cp ) << std::endl;
-#endif
- cp->next_node = offset_from_node ( freelist );
- freelist = cp;
-}
-
-#ifdef INSTRUMENT_FALLBACK_MALLOC
-size_t print_free_list () {
- struct heap_node *p, *prev;
- heap_size total_free = 0;
- if ( NULL == freelist )
- init_heap ();
-
- for (p = freelist, prev = 0;
- p && p != list_end; prev = p, p = node_from_offset (p->next_node)) {
- std::cout << ( prev == 0 ? "" : " ") << "Offset: " << offset_from_node ( p )
- << "\tsize: " << p->len << " Next: " << p->next_node << std::endl;
- total_free += p->len;
- }
- std::cout << "Total Free space: " << total_free << std::endl;
- return total_free;
- }
-#endif
-} // end unnamed namespace
-
-namespace __cxxabiv1 {
-
-#pragma GCC visibility push(hidden)
-
-void * __malloc_with_fallback(size_t size) {
- void *ptr = std::malloc(size);
- if (NULL == ptr) // if malloc fails, fall back to emergency stash
- ptr = fallback_malloc(size);
- return ptr;
-}
-
-void * __calloc_with_fallback(size_t count, size_t size) {
- void *ptr = std::calloc(count, size);
- if (NULL != ptr)
- return ptr;
- // if calloc fails, fall back to emergency stash
- ptr = fallback_malloc(size * count);
- if (NULL != ptr)
- std::memset(ptr, 0, size * count);
- return ptr;
-}
-
-void __free_with_fallback(void *ptr) {
- if (is_fallback_ptr(ptr))
- fallback_free(ptr);
- else
- std::free(ptr);
-}
-
-#pragma GCC visibility pop
-
-} // namespace __cxxabiv1
Removed: libcxxabi/trunk/src/fallback_malloc.h
URL: http://llvm.org/viewvc/llvm-project/libcxxabi/trunk/src/fallback_malloc.h?rev=282702&view=auto
==============================================================================
--- libcxxabi/trunk/src/fallback_malloc.h (original)
+++ libcxxabi/trunk/src/fallback_malloc.h (removed)
@@ -1,31 +0,0 @@
-//===------------------------- fallback_malloc.h --------------------------===//
-//
-// 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.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _FALLBACK_MALLOC_H
-#define _FALLBACK_MALLOC_H
-
-#include <cstddef> // for size_t
-
-namespace __cxxabiv1 {
-
-#pragma GCC visibility push(hidden)
-
-// Allocate some memory from _somewhere_
-void * __malloc_with_fallback(size_t size);
-
-// Allocate and zero-initialize memory from _somewhere_
-void * __calloc_with_fallback(size_t count, size_t size);
-
-void __free_with_fallback(void *ptr);
-
-#pragma GCC visibility pop
-
-} // namespace __cxxabiv1
-
-#endif
Removed: libcxxabi/trunk/test/test_exception_storage_nodynmem.pass.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxxabi/trunk/test/test_exception_storage_nodynmem.pass.cpp?rev=282702&view=auto
==============================================================================
--- libcxxabi/trunk/test/test_exception_storage_nodynmem.pass.cpp (original)
+++ libcxxabi/trunk/test/test_exception_storage_nodynmem.pass.cpp (removed)
@@ -1,32 +0,0 @@
-//===--------------- test_exception_storage_nodynmem.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.
-//
-//===----------------------------------------------------------------------===//
-
-#include <assert.h>
-#include <cstdlib>
-
-static bool OverwrittenCallocCalled = false;
-
-// Override calloc to simulate exhaustion of dynamic memory
-void *calloc(size_t, size_t) {
- OverwrittenCallocCalled = true;
- return 0;
-}
-
-int main(int argc, char *argv[]) {
- // Run the test a couple of times
- // to ensure that fallback memory doesn't leak.
- for (int I = 0; I < 1000; ++I)
- try {
- throw 42;
- } catch (...) {
- }
-
- assert(OverwrittenCallocCalled);
- return 0;
-}
Modified: libcxxabi/trunk/test/test_fallback_malloc.pass.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxxabi/trunk/test/test_fallback_malloc.pass.cpp?rev=282703&r1=282702&r2=282703&view=diff
==============================================================================
--- libcxxabi/trunk/test/test_fallback_malloc.pass.cpp (original)
+++ libcxxabi/trunk/test/test_fallback_malloc.pass.cpp Thu Sep 29 03:11:57 2016
@@ -16,7 +16,7 @@ typedef std::deque<void *> container;
// #define DEBUG_FALLBACK_MALLOC
#define INSTRUMENT_FALLBACK_MALLOC
-#include "../src/fallback_malloc.cpp"
+#include "../src/fallback_malloc.ipp"
container alloc_series ( size_t sz ) {
container ptrs;
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