Crash recovery helper object. More...

#include <CrashRecoveryContext.h>

Public Member Functions
	CrashRecoveryContext ()
	~CrashRecoveryContext ()
void	registerCleanup (CrashRecoveryContextCleanup *cleanup)
void	unregisterCleanup (CrashRecoveryContextCleanup *cleanup)
bool	RunSafely (function_ref< void()> Fn)
	Execute the provide callback function (with the given arguments) in a protected context.
bool	RunSafely (void(Fn)(void ), void *UserData)
bool	RunSafelyOnThread (function_ref< void()>, unsigned RequestedStackSize=0)
	Execute the provide callback function (with the given arguments) in a protected context which is run in another thread (optionally with a requested stack size).
bool	RunSafelyOnThread (void(Fn)(void ), void *UserData, unsigned RequestedStackSize=0)
void	HandleCrash ()
	Explicitly trigger a crash recovery in the current process, and return failure from RunSafely(). This function does not return.
const std::string &	getBacktrace () const
	Return a string containing the backtrace where the crash was detected; or empty if the backtrace wasn't recovered.
Static Public Member Functions
static void	Enable ()
	Enable crash recovery.
static void	Disable ()
	Disable crash recovery.
static CrashRecoveryContext *	GetCurrent ()
	Return the active context, if the code is currently executing in a thread which is in a protected context.
static bool	isRecoveringFromCrash ()
	Return true if the current thread is recovering from a crash.

Detailed Description

Crash recovery helper object.

This class implements support for running operations in a safe context so that crashes (memory errors, stack overflow, assertion violations) can be detected and control restored to the crashing thread. Crash detection is purely "best effort", the exact set of failures which can be recovered from is platform dependent.

Clients make use of this code by first calling CrashRecoveryContext::Enable(), and then executing unsafe operations via a CrashRecoveryContext object. For example:

void actual_work(void *);

void foo() { CrashRecoveryContext CRC;

if (!CRC.RunSafely(actual_work, 0)) { ... a crash was detected, report error to user ... }

... no crash was detected ... }

Crash recovery contexts may not be nested.

Definition at line 47 of file CrashRecoveryContext.h.

Constructor & Destructor Documentation

llvm::CrashRecoveryContext::CrashRecoveryContext ( ) [inline]

Definition at line 52 of file CrashRecoveryContext.h.

CrashRecoveryContext::~CrashRecoveryContext ( )

Definition at line 75 of file CrashRecoveryContext.cpp.

References llvm::CrashRecoveryContextCleanup::cleanupFired, llvm::CrashRecoveryContextCleanup::recoverResources(), and tlIsRecoveringFromCrash.

Member Function Documentation

void CrashRecoveryContext::Disable ( ) [static]

Disable crash recovery.

Definition at line 291 of file CrashRecoveryContext.cpp.

References gCrashRecoveryContextMutex, gCrashRecoveryEnabled, NumSignals, PrevActions, and Signals.

Referenced by CrashRecoverySignalHandler().

void CrashRecoveryContext::Enable ( ) [static]

Enable crash recovery.

Definition at line 272 of file CrashRecoveryContext.cpp.

References CrashRecoverySignalHandler(), gCrashRecoveryContextMutex, gCrashRecoveryEnabled, NumSignals, PrevActions, and Signals.

const std::string & CrashRecoveryContext::getBacktrace ( ) const

Return a string containing the backtrace where the crash was detected; or empty if the backtrace wasn't recovered.

This function is only valid when a crash has been detected (i.e., RunSafely() has returned false.

Definition at line 328 of file CrashRecoveryContext.cpp.

CrashRecoveryContext * CrashRecoveryContext::GetCurrent ( ) [static]

Return the active context, if the code is currently executing in a thread which is in a protected context.

Definition at line 96 of file CrashRecoveryContext.cpp.

References gCrashRecoveryEnabled.

Referenced by llvm::CrashRecoveryContextCleanupBase< CrashRecoveryContextDestructorCleanup< T >, T >::create().

void CrashRecoveryContext::HandleCrash ( )

Explicitly trigger a crash recovery in the current process, and return failure from RunSafely(). This function does not return.

Definition at line 322 of file CrashRecoveryContext.cpp.

bool CrashRecoveryContext::isRecoveringFromCrash ( ) [static]

Return true if the current thread is recovering from a crash.

Definition at line 92 of file CrashRecoveryContext.cpp.

References tlIsRecoveringFromCrash.

void CrashRecoveryContext::registerCleanup ( CrashRecoveryContextCleanup * cleanup )

Definition at line 107 of file CrashRecoveryContext.cpp.

References cleanup().

Referenced by llvm::CrashRecoveryContextCleanupRegistrar< T, Cleanup >::CrashRecoveryContextCleanupRegistrar().

bool CrashRecoveryContext::RunSafely ( function_ref< void()> Fn )

Execute the provide callback function (with the given arguments) in a protected context.

Returns:: True if the function completed successfully, and false if the function crashed (or HandleCrash was called explicitly). Clients should make as little assumptions as possible about the program state when RunSafely has returned false. Clients can use getBacktrace() to retrieve the backtrace of the crash on failures.

Definition at line 306 of file CrashRecoveryContext.cpp.

References gCrashRecoveryEnabled.

Referenced by RunSafely().

bool llvm::CrashRecoveryContext::RunSafely	(	void()(void )	Fn,
		void *	UserData
	)		`[inline]`

Definition at line 81 of file CrashRecoveryContext.h.

References RunSafely().

bool CrashRecoveryContext::RunSafelyOnThread	(	function_ref< void()>	Fn,
		unsigned	RequestedStackSize = `0`
	)

Execute the provide callback function (with the given arguments) in a protected context which is run in another thread (optionally with a requested stack size).

See RunSafely() and llvm_execute_on_thread().

On Darwin, if PRIO_DARWIN_BG is set on the calling thread, it will be propagated to the new thread as well.

Definition at line 368 of file CrashRecoveryContext.cpp.

References hasThreadBackgroundPriority(), llvm::llvm_execute_on_thread(), and RunSafelyOnThread_Dispatch().

Referenced by RunSafelyOnThread().

bool llvm::CrashRecoveryContext::RunSafelyOnThread	(	void()(void )	Fn,
		void *	UserData,
		unsigned	RequestedStackSize = `0`
	)		`[inline]`

Definition at line 94 of file CrashRecoveryContext.h.

References RunSafelyOnThread().

void CrashRecoveryContext::unregisterCleanup ( CrashRecoveryContextCleanup * cleanup )

Definition at line 118 of file CrashRecoveryContext.cpp.

References cleanup().

Referenced by llvm::CrashRecoveryContextCleanupRegistrar< T, Cleanup >::unregister().

The documentation for this class was generated from the following files:

Public Member Functions

Static Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation