LLVM  3.7.0
Public Member Functions | Static Public Member Functions | List of all members
llvm::CrashRecoveryContext Class Reference

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. 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...
 
const std::string & getBacktrace () const
 Return a string containing the backtrace where the crash was detected; or empty if the backtrace wasn't recovered. More...
 

Static Public Member Functions

static void Enable ()
 Enable crash recovery. More...
 
static void Disable ()
 Disable crash recovery. More...
 
static CrashRecoveryContextGetCurrent ()
 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 ... }

Crash recovery contexts may not be nested.

Definition at line 44 of file CrashRecoveryContext.h.

Constructor & Destructor Documentation

llvm::CrashRecoveryContext::CrashRecoveryContext ( )
inline

Definition at line 49 of file CrashRecoveryContext.h.

CrashRecoveryContext::~CrashRecoveryContext ( )

Member Function Documentation

void CrashRecoveryContext::Disable ( )
static

Disable crash recovery.

Definition at line 289 of file CrashRecoveryContext.cpp.

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

Referenced by CrashRecoverySignalHandler().

void CrashRecoveryContext::Enable ( )
static
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 326 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 94 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 320 of file CrashRecoveryContext.cpp.

bool CrashRecoveryContext::isRecoveringFromCrash ( )
static

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

Definition at line 90 of file CrashRecoveryContext.cpp.

References tlIsRecoveringFromCrash.

void CrashRecoveryContext::registerCleanup ( CrashRecoveryContextCleanup cleanup)
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 304 of file CrashRecoveryContext.cpp.

References gCrashRecoveryEnabled.

Referenced by RunSafely().

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

Definition at line 78 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 366 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 91 of file CrashRecoveryContext.h.

References RunSafelyOnThread().

void CrashRecoveryContext::unregisterCleanup ( CrashRecoveryContextCleanup cleanup)

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