From 89e90b25e3c9a0a20a6789b81d2a831ba9e8959e Mon Sep 17 00:00:00 2001 From: Zachary Turner Date: Fri, 13 Jun 2014 21:20:44 +0000 Subject: Make the error-handling functions thread-safe. Prior to this change, error handling functions must be installed and removed only inside of an llvm_[start/stop]_multithreading pair. This change allows error handling functions to be installed any time, and from any thread. Reviewed by: chandlerc Differential Revision: http://reviews.llvm.org/D4140 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210937 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Support/ErrorHandling.cpp | 23 +++++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-) (limited to 'lib/Support') diff --git a/lib/Support/ErrorHandling.cpp b/lib/Support/ErrorHandling.cpp index 342c4f05cc..ae1d64db4b 100644 --- a/lib/Support/ErrorHandling.cpp +++ b/lib/Support/ErrorHandling.cpp @@ -19,6 +19,8 @@ #include "llvm/Config/config.h" #include "llvm/Support/Debug.h" #include "llvm/Support/Signals.h" +#include "llvm/Support/Mutex.h" +#include "llvm/Support/MutexGuard.h" #include "llvm/Support/Threading.h" #include "llvm/Support/raw_ostream.h" #include @@ -37,17 +39,20 @@ using namespace llvm; static fatal_error_handler_t ErrorHandler = nullptr; static void *ErrorHandlerUserData = nullptr; +static sys::Mutex ErrorHandlerMutex; + void llvm::install_fatal_error_handler(fatal_error_handler_t handler, void *user_data) { - assert(!llvm_is_multithreaded() && - "Cannot register error handlers after starting multithreaded mode!\n"); + llvm::MutexGuard Lock(ErrorHandlerMutex); assert(!ErrorHandler && "Error handler already registered!\n"); ErrorHandler = handler; ErrorHandlerUserData = user_data; } void llvm::remove_fatal_error_handler() { + llvm::MutexGuard Lock(ErrorHandlerMutex); ErrorHandler = nullptr; + ErrorHandlerUserData = nullptr; } void llvm::report_fatal_error(const char *Reason, bool GenCrashDiag) { @@ -63,8 +68,18 @@ void llvm::report_fatal_error(StringRef Reason, bool GenCrashDiag) { } void llvm::report_fatal_error(const Twine &Reason, bool GenCrashDiag) { - if (ErrorHandler) { - ErrorHandler(ErrorHandlerUserData, Reason.str(), GenCrashDiag); + llvm::fatal_error_handler_t handler = nullptr; + void* handlerData = nullptr; + { + // Only acquire the mutex while reading the handler, so as not to invoke a + // user-supplied callback under a lock. + llvm::MutexGuard Lock(ErrorHandlerMutex); + handler = ErrorHandler; + handlerData = ErrorHandlerUserData; + } + + if (handler) { + handler(handlerData, Reason.str(), GenCrashDiag); } else { // Blast the result out to stderr. We don't try hard to make sure this // succeeds (e.g. handling EINTR) and we can't use errs() here because -- cgit v1.2.3