Lang Hames a6587cc70d [ORC] Change the locking scheme for ThreadSafeModule. ... ThreadSafeModule/ThreadSafeContext are used to manage lifetimes and locking for LLVMContexts in ORCv2. Prior to this patch contexts were locked as soon as an associated Module was emitted (to be compiled and linked), and were not unlocked until the emit call returned. This could lead to deadlocks if interdependent modules that shared contexts were compiled on different threads: when, during emission of the first module, the dependence was discovered the second module (which would provide the required symbol) could not be emitted as the thread emitting the first module still held the lock. This patch eliminates this possibility by moving to a finer-grained locking scheme. Each client holds the module lock only while they are actively operating on it. To make this finer grained locking simpler/safer to implement this patch removes the explicit lock method, 'getContextLock', from ThreadSafeModule and replaces it with a new method, 'withModuleDo', that implicitly locks the context, calls a user-supplied function object to operate on the Module, then implicitly unlocks the context before returning the result. ThreadSafeModule TSM = getModule(...); size_t NumFunctions = TSM.withModuleDo( [](Module &M) { // <- context locked before entry to lambda. return M.size(); }); Existing ORCv2 layers that operate on ThreadSafeModules are updated to use the new method. This method is used to introduce Module locking into each of the existing layers. llvm-svn: 367686		2019-08-02 15:21:37 +00:00
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BrainF
ExceptionDemo
Fibonacci
HowToUseJIT
HowToUseLLJIT
Kaleidoscope
LLJITExamples
ModuleMaker
OCaml-Kaleidoscope
ParallelJIT
CMakeLists.txt
LLVMBuild.txt