From 4e91fa3834008778b10d6770f9872c50e1e75659 Mon Sep 17 00:00:00 2001 From: Argyrios Kyrtzidis Date: Wed, 19 Jun 2013 22:53:45 +0000 Subject: [PATCH] [Support/CrashRecoveryContext] Make sure CrashRecoveryContext does not clear the thread-local "CurrentContext" in the "parent" thread, when we are using CrashRecoveryContext::RunSafelyOnThread. When using CrashRecoveryContext::RunSafelyOnThread, we would set a CrashRecoveryContextImpl* to a thread-local variable for the "child" thread, but CrashRecoveryContext would erroneously clear it in the "parent" thread. The result was that if CrashRecoveryContext::RunSafelyOnThread was called again in the "child" thread it would mess up crash-recovery for its parent. A test for this will be added in the clang repository. rdar://14204560 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184380 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Support/CrashRecoveryContext.cpp | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/lib/Support/CrashRecoveryContext.cpp b/lib/Support/CrashRecoveryContext.cpp index 182c362cc75..d2a38958aef 100644 --- a/lib/Support/CrashRecoveryContext.cpp +++ b/lib/Support/CrashRecoveryContext.cpp @@ -28,16 +28,23 @@ struct CrashRecoveryContextImpl { std::string Backtrace; ::jmp_buf JumpBuffer; volatile unsigned Failed : 1; + unsigned SwitchedThread : 1; public: CrashRecoveryContextImpl(CrashRecoveryContext *CRC) : CRC(CRC), - Failed(false) { + Failed(false), + SwitchedThread(false) { CurrentContext.set(this); } ~CrashRecoveryContextImpl() { - CurrentContext.erase(); + if (!SwitchedThread) + CurrentContext.erase(); } + /// \brief Called when the separate crash-recovery thread was finished, to + /// indicate that we don't need to clear the thread-local CurrentContext. + void setSwitchedThread() { SwitchedThread = true; } + void HandleCrash() { // Eliminate the current context entry, to avoid re-entering in case the // cleanup code crashes. @@ -342,5 +349,7 @@ bool CrashRecoveryContext::RunSafelyOnThread(void (*Fn)(void*), void *UserData, unsigned RequestedStackSize) { RunSafelyOnThreadInfo Info = { Fn, UserData, this, false }; llvm_execute_on_thread(RunSafelyOnThread_Dispatch, &Info, RequestedStackSize); + if (CrashRecoveryContextImpl *CRC = (CrashRecoveryContextImpl *)Impl) + CRC->setSwitchedThread(); return Info.Result; }