[SYCL] Add a mutex to state-modifying program functions (#1204)

This is done in order to consistently report errors if the user
tries to compile/link/build the same program from multiple threads.

Signed-off-by: Sergey Semenov <[email protected]>

Author: sergey-semenov

sycl/source/detail/program_impl.cpp

@@ -15,7 +15,9 @@
 
 #include <algorithm>
 #include <fstream>
+#include <list>
 #include <memory>
+#include <mutex>
 
 __SYCL_INLINE_NAMESPACE(cl) {
 namespace sycl {
@@ -38,14 +40,26 @@ program_impl::program_impl(
     throw runtime_error("Non-empty vector of programs expected",
                         PI_INVALID_VALUE);
   }
+
+  // Sort the programs to avoid deadlocks due to locking multiple mutexes &
+  // verify that all programs are unique.
+  std::sort(ProgramList.begin(), ProgramList.end());
+  auto It = std::unique(ProgramList.begin(), ProgramList.end());
+  if (It != ProgramList.end()) {
+    throw runtime_error("Attempting to link a program with itself",
+                        PI_INVALID_PROGRAM);
+  }
+
   MContext = ProgramList[0]->MContext;
   MDevices = ProgramList[0]->MDevices;
   vector_class<device> DevicesSorted;
   if (!is_host()) {
     DevicesSorted = sort_devices_by_cl_device_id(MDevices);
   }
   check_device_feature_support<info::device::is_linker_available>(MDevices);
+  std::list<std::lock_guard<std::mutex>> Locks;
   for (const auto &Prg : ProgramList) {
+    Locks.emplace_back(Prg->MMutex);
     Prg->throw_if_state_is_not(program_state::compiled);
     if (Prg->MContext != MContext) {
       throw invalid_object_error(
@@ -184,6 +198,7 @@ cl_program program_impl::get() const {
 void program_impl::compile_with_kernel_name(string_class KernelName,
                                             string_class CompileOptions,
                                             OSModuleHandle M) {
+  std::lock_guard<std::mutex> Lock(MMutex);
   throw_if_state_is_not(program_state::none);
   MProgramModuleHandle = M;
   if (!is_host()) {
@@ -195,6 +210,7 @@ void program_impl::compile_with_kernel_name(string_class KernelName,
 
 void program_impl::compile_with_source(string_class KernelSource,
                                        string_class CompileOptions) {
+  std::lock_guard<std::mutex> Lock(MMutex);
   throw_if_state_is_not(program_state::none);
   // TODO should it throw if it's host?
   if (!is_host()) {
@@ -207,6 +223,7 @@ void program_impl::compile_with_source(string_class KernelSource,
 void program_impl::build_with_kernel_name(string_class KernelName,
                                           string_class BuildOptions,
                                           OSModuleHandle Module) {
+  std::lock_guard<std::mutex> Lock(MMutex);
   throw_if_state_is_not(program_state::none);
   MProgramModuleHandle = Module;
   if (!is_host()) {
@@ -227,6 +244,7 @@ void program_impl::build_with_kernel_name(string_class KernelName,
 
 void program_impl::build_with_source(string_class KernelSource,
                                      string_class BuildOptions) {
+  std::lock_guard<std::mutex> Lock(MMutex);
   throw_if_state_is_not(program_state::none);
   // TODO should it throw if it's host?
   if (!is_host()) {
@@ -237,6 +255,7 @@ void program_impl::build_with_source(string_class KernelSource,
 }
 
 void program_impl::link(string_class LinkOptions) {
+  std::lock_guard<std::mutex> Lock(MMutex);
   throw_if_state_is_not(program_state::compiled);
   if (!is_host()) {
     check_device_feature_support<info::device::is_linker_available>(MDevices);

sycl/source/detail/program_impl.hpp

@@ -20,6 +20,7 @@
 #include <cassert>
 #include <fstream>
 #include <memory>
+#include <mutex>
 
 __SYCL_INLINE_NAMESPACE(cl) {
 namespace sycl {
@@ -380,6 +381,7 @@ class program_impl {
 
   RT::PiProgram MProgram = nullptr;
   program_state MState = program_state::none;
+  std::mutex MMutex;
   ContextImplPtr MContext;
   bool MLinkable = false;
   vector_class<device> MDevices;