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Windows exception handler does not survive stack overflows (#34). r=brian,

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thanks also to darin
 - All minidump writing is now done on a dedicated thread.  When a stack
   overflow exception occurs, the only work that needs to be done on the
   exception thread will easily fit within the guard page.

http://groups.google.com/group/airbag-dev/browse_thread/thread/3935e339d8354a75


git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@57 4c0a9323-5329-0410-9bdc-e9ce6186880e
This commit is contained in:
mmentovai 2006-10-31 16:49:38 +00:00
parent 12a5245bfe
commit b261019951
2 changed files with 145 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

97
src/client/windows/handler/exception_handler.cc
View File

@ -37,6 +37,14 @@
namespace google_airbag {
ExceptionHandler *ExceptionHandler::current_handler_ = NULL;
HANDLE ExceptionHandler::handler_thread_ = NULL;
CRITICAL_SECTION ExceptionHandler::handler_critical_section_;
HANDLE ExceptionHandler::handler_start_semaphore_ = NULL;
HANDLE ExceptionHandler::handler_finish_semaphore_ = NULL;
ExceptionHandler *ExceptionHandler::requesting_handler_ = NULL;
DWORD ExceptionHandler::requesting_thread_id_ = 0;
EXCEPTION_POINTERS *ExceptionHandler::exception_info_ = NULL;
bool ExceptionHandler::handler_return_value_ = false;
ExceptionHandler::ExceptionHandler(const wstring &dump_path,
MinidumpCallback callback,
@ -46,6 +54,22 @@ ExceptionHandler::ExceptionHandler(const wstring &dump_path,
dump_path_(dump_path), dbghelp_module_(NULL),
minidump_write_dump_(NULL), previous_handler_(current_handler_),
previous_filter_(NULL) {
if (!handler_thread_) {
// The first time an ExceptionHandler is created, set up the handler
// thread and the synchronization primitives.
InitializeCriticalSection(&handler_critical_section_);
handler_start_semaphore_ = CreateSemaphore(NULL, 0, 1, NULL);
handler_finish_semaphore_ = CreateSemaphore(NULL, 0, 1, NULL);
DWORD thread_id;
handler_thread_ = CreateThread(NULL, // lpThreadAttributes
64 * 1024, // dwStackSize
ExceptionHandlerThreadMain,
NULL, // lpParameter
0, // dwCreationFlags
&thread_id);
}
UpdateNextID();
dbghelp_module_ = LoadLibrary(L"dbghelp.dll");
if (dbghelp_module_) {
@ -66,18 +90,72 @@ ExceptionHandler::~ExceptionHandler() {
SetUnhandledExceptionFilter(previous_filter_);
current_handler_ = previous_handler_;
}
if (previous_handler_ == NULL) {
// When destroying the last ExceptionHandler, clean up the handler thread
// and synchronization primitives.
TerminateThread(handler_thread_, 1);
handler_thread_ = NULL;
DeleteCriticalSection(&handler_critical_section_);
CloseHandle(handler_start_semaphore_);
handler_start_semaphore_ = NULL;
CloseHandle(handler_finish_semaphore_);
handler_finish_semaphore_ = NULL;
}
}
// static
DWORD ExceptionHandler::ExceptionHandlerThreadMain(void *lpParameter) {
while (true) {
if (WaitForSingleObject(handler_start_semaphore_, INFINITE) ==
WAIT_OBJECT_0) {
// Perform the requested action.
handler_return_value_ = requesting_handler_->WriteMinidumpWithException(
requesting_thread_id_, exception_info_);
// Allow the requesting thread to proceed.
ReleaseSemaphore(handler_finish_semaphore_, 1, NULL);
}
}
// Not reached. This thread will be terminated by ExceptionHandler's
// destructor.
return 0;
}
// static
LONG ExceptionHandler::HandleException(EXCEPTION_POINTERS *exinfo) {
if (!current_handler_->WriteMinidumpWithException(exinfo)) {
return EXCEPTION_CONTINUE_SEARCH;
}
return EXCEPTION_EXECUTE_HANDLER;
return current_handler_->WriteMinidumpOnHandlerThread(exinfo) ?
EXCEPTION_EXECUTE_HANDLER : EXCEPTION_CONTINUE_SEARCH;
}
bool ExceptionHandler::WriteMinidumpOnHandlerThread(EXCEPTION_POINTERS *exinfo) {
EnterCriticalSection(&handler_critical_section_);
// Set up data to be passed in to the handler thread.
requesting_handler_ = this;
requesting_thread_id_ = GetCurrentThreadId();
exception_info_ = exinfo;
// This causes the handler thread to call WriteMinidumpWithException.
ReleaseSemaphore(handler_start_semaphore_, 1, NULL);
// Wait until WriteMinidumpWithException is done and collect its return value.
WaitForSingleObject(handler_finish_semaphore_, INFINITE);
bool status = handler_return_value_;
// Clean up.
requesting_handler_ = NULL;
requesting_thread_id_ = 0;
exception_info_ = NULL;
LeaveCriticalSection(&handler_critical_section_);
return status;
}
bool ExceptionHandler::WriteMinidump() {
bool success = WriteMinidumpWithException(NULL);
bool success = WriteMinidumpOnHandlerThread(NULL);
UpdateNextID();
return success;
}
@ -90,7 +168,8 @@ bool ExceptionHandler::WriteMinidump(const wstring &dump_path,
return handler.WriteMinidump();
}
bool ExceptionHandler::WriteMinidumpWithException(EXCEPTION_POINTERS *exinfo) {
bool ExceptionHandler::WriteMinidumpWithException(DWORD requesting_thread_id,
EXCEPTION_POINTERS *exinfo) {
wchar_t dump_file_name[MAX_PATH];
swprintf_s(dump_file_name, MAX_PATH, L"%s\\%s.dmp",
dump_path_.c_str(), next_minidump_id_.c_str());
@ -106,16 +185,18 @@ bool ExceptionHandler::WriteMinidumpWithException(EXCEPTION_POINTERS *exinfo) {
NULL);
if (dump_file != INVALID_HANDLE_VALUE) {
MINIDUMP_EXCEPTION_INFORMATION except_info;
except_info.ThreadId = GetCurrentThreadId();
except_info.ThreadId = requesting_thread_id;
except_info.ExceptionPointers = exinfo;
except_info.ClientPointers = FALSE;
// TODO(mmentovai): include IDs of handler and requesting threads.
// The explicit comparison to TRUE avoids a warning (C4800).
success = (minidump_write_dump_(GetCurrentProcess(),
GetCurrentProcessId(),
dump_file,
MiniDumpNormal,
&except_info,
exinfo ? &except_info : NULL,
NULL,
NULL) == TRUE);

59
src/client/windows/handler/exception_handler.h
View File

@ -116,12 +116,30 @@ class ExceptionHandler {
CONST PMINIDUMP_USER_STREAM_INFORMATION UserStreamParam,
CONST PMINIDUMP_CALLBACK_INFORMATION CallbackParam);
// This function does the actual writing of a minidump.
bool WriteMinidumpWithException(EXCEPTION_POINTERS *exinfo);
// Runs the main loop for the exception handler thread.
static DWORD WINAPI ExceptionHandlerThreadMain(void *lpParameter);
// Called when an unhandled exception occurs.
// Called on the exception thread when an unhandled exception occurs.
// Signals the exception handler thread to handle the exception.
static LONG WINAPI HandleException(EXCEPTION_POINTERS *exinfo);
// This is called on the exception thread or on another thread that
// the user wishes to produce a dump from. It calls
// WriteMinidumpWithException on the handler thread, avoiding stack
// overflows and inconsistent dumps due to writing the dump from
// the exception thread. If the dump is requested as a result of an
// exception, exinfo contains exception information, otherwise, it
// is NULL.
bool WriteMinidumpOnHandlerThread(EXCEPTION_POINTERS *exinfo);
// This function does the actual writing of a minidump. It is called
// on the handler thread. requesting_thread_id is the ID of the thread
// that requested the dump. If the dump is requested as a result of
// an exception, exinfo contains exception information, otherwise,
// it is NULL.
bool WriteMinidumpWithException(DWORD requesting_thread_id,
EXCEPTION_POINTERS *exinfo);
// Generates a new ID and stores it in next_minidump_id_.
void UpdateNextID();
@ -140,6 +158,41 @@ class ExceptionHandler {
// the currently-installed ExceptionHandler, of which there can be only 1
static ExceptionHandler *current_handler_;
// The exception handler thread, if one has been created.
static HANDLE handler_thread_;
// The critical section enforcing the requirement that only one exception be
// handled at a time.
static CRITICAL_SECTION handler_critical_section_;
// Semaphores used to move exception handling between the exception thread
// and the handler thread. handler_start_semaphore_ is signalled by the
// exception thread to wake up the handler thread when an exception occurs.
// handler_finish_semaphore_ is signalled by the handler thread to wake up
// the exception thread when handling is complete.
static HANDLE handler_start_semaphore_;
static HANDLE handler_finish_semaphore_;
// The next 3 fields are static data passed from the requesting thread to
// the handler thread.
// The ExceptionHandler through which a request to write a dump was routed.
// This will be the same as current_handler_ for exceptions, but
// user-requested dumps may be routed through any live ExceptionHandler.
static ExceptionHandler *requesting_handler_;
// The thread ID of the thread requesting the dump (either the exception
// thread or any other thread that called WriteMinidump directly).
static DWORD requesting_thread_id_;
// The exception info passed to the exception handler on the exception
// thread, if an exception occurred. NULL for user-requested dumps.
static EXCEPTION_POINTERS *exception_info_;
// The return value of the handler, passed from the handler thread back to
// the requesting thread.
static bool handler_return_value_;
// disallow copy ctor and operator=
explicit ExceptionHandler(const ExceptionHandler &);
void operator=(const ExceptionHandler &);