Crash recovery helper object. More...

#include "llvm/Support/CrashRecoveryContext.h"

Public Member Functions
	CrashRecoveryContext ()

	~CrashRecoveryContext ()

void	registerCleanup (CrashRecoveryContextCleanup *cleanup)
	Register cleanup handler, which is used when the recovery context is finished. More...

void	unregisterCleanup (CrashRecoveryContextCleanup *cleanup)

bool	RunSafely (function_ref< void()> Fn)
	Execute the provided callback function (with the given arguments) in a protected context. More...

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). More...

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(). More...

Static Public Member Functions
static void	Enable ()
	Enable crash recovery. More...

static void	Disable ()
	Disable crash recovery. More...

static CrashRecoveryContext *	GetCurrent ()
	Return the active context, if the code is currently executing in a thread which is in a protected context. More...

static bool	isRecoveringFromCrash ()
	Return true if the current thread is recovering from a crash. More...

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 ...
}

To assist recovery the class allows specifying set of actions that will be executed in any case, whether crash occurs or not. These actions may be used to reclaim resources in the case of crash.

Definition at line 47 of file CrashRecoveryContext.h.

Constructor & Destructor Documentation

◆ CrashRecoveryContext()

llvm::CrashRecoveryContext::CrashRecoveryContext ( )

inline

Definition at line 52 of file CrashRecoveryContext.h.

References cleanup(), Disable(), Enable(), GetCurrent(), isRecoveringFromCrash(), registerCleanup(), RunSafely(), unregisterCleanup(), and ~CrashRecoveryContext().

◆ ~CrashRecoveryContext()

CrashRecoveryContext::~CrashRecoveryContext ( )

Definition at line 86 of file CrashRecoveryContext.cpp.

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

Referenced by CrashRecoveryContext().

Member Function Documentation

◆ Disable()

void CrashRecoveryContext::Disable ( )

static

Disable crash recovery.

Definition at line 128 of file CrashRecoveryContext.cpp.

References uninstallExceptionOrSignalHandlers().

Referenced by CrashRecoveryContext(), CrashRecoverySignalHandler(), and unregisterCleanup().

◆ Enable()

void CrashRecoveryContext::Enable ( )

static

Enable crash recovery.

Definition at line 119 of file CrashRecoveryContext.cpp.

References installExceptionOrSignalHandlers().

Referenced by CrashRecoveryContext().

◆ GetCurrent()

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 108 of file CrashRecoveryContext.cpp.

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

◆ HandleCrash()

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 365 of file CrashRecoveryContext.cpp.

References assert().

Referenced by RunSafelyOnThread().

◆ isRecoveringFromCrash()

bool CrashRecoveryContext::isRecoveringFromCrash ( )

static

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

Definition at line 104 of file CrashRecoveryContext.cpp.

References tlIsRecoveringFromCrash.

Referenced by CrashRecoveryContext().

◆ registerCleanup()

void CrashRecoveryContext::registerCleanup ( CrashRecoveryContextCleanup * cleanup )

Register cleanup handler, which is used when the recovery context is finished.

The recovery context owns the handler.

Definition at line 136 of file CrashRecoveryContext.cpp.

References cleanup().

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

◆ RunSafely() [1/2]

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

Execute the provided 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.

Definition at line 347 of file CrashRecoveryContext.cpp.

References assert(), and llvm::Intrinsic::setjmp.

Referenced by CrashRecoveryContext(), RunSafely(), and unregisterCleanup().

◆ RunSafely() [2/2]

bool llvm::CrashRecoveryContext::RunSafely	(	void()(void )	Fn,
		void *	UserData
	)

inline

Definition at line 83 of file CrashRecoveryContext.h.

References RunSafely(), and RunSafelyOnThread().

◆ RunSafelyOnThread() [1/2]

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 404 of file CrashRecoveryContext.cpp.

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

Referenced by RunSafely(), and RunSafelyOnThread().