feat(compiler): distributed execution - on-demand key transfer to rem…

…ote nodes.

compilers/concrete-compiler/compiler/include/concretelang/Runtime/context.h

@@ -31,6 +31,7 @@ typedef struct FFT {
   FFT() = delete;
   FFT(size_t polynomial_size);
   FFT(FFT &other) = delete;
+  FFT(const FFT &other) = delete;
   FFT(FFT &&other);
   ~FFT();
 
@@ -42,7 +43,7 @@ typedef struct RuntimeContext {
 
   RuntimeContext() = delete;
   RuntimeContext(ServerKeyset serverKeyset);
-  ~RuntimeContext() {
+  virtual ~RuntimeContext() {
 #ifdef CONCRETELANG_CUDA_SUPPORT
     for (int i = 0; i < num_devices; ++i) {
       if (bsk_gpu[i] != nullptr)
@@ -53,27 +54,30 @@ typedef struct RuntimeContext {
 #endif
   };
 
-  const uint64_t *keyswitch_key_buffer(size_t keyId) {
+  virtual const uint64_t *keyswitch_key_buffer(size_t keyId) {
     return serverKeyset.lweKeyswitchKeys[keyId].getBuffer().data();
   }
 
-  const std::complex<double> *fourier_bootstrap_key_buffer(size_t keyId) {
+  virtual const std::complex<double> *
+  fourier_bootstrap_key_buffer(size_t keyId) {
     return fourier_bootstrap_keys[keyId]->data();
   }
 
-  const uint64_t *fp_keyswitch_key_buffer(size_t keyId) {
+  virtual const uint64_t *fp_keyswitch_key_buffer(size_t keyId) {
     return serverKeyset.packingKeyswitchKeys[keyId].getRawPtr();
   }
 
-  const struct Fft *fft(size_t keyId) { return ffts[keyId].fft; }
+  virtual const struct Fft *fft(size_t keyId) { return ffts[keyId].fft; }
 
   const ServerKeyset getKeys() const { return serverKeyset; }
 
-private:
+protected:
   ServerKeyset serverKeyset;
   std::vector<std::shared_ptr<std::vector<std::complex<double>>>>
       fourier_bootstrap_keys;
   std::vector<FFT> ffts;
+  std::pair<FFT, std::shared_ptr<std::vector<std::complex<double>>>>
+  convert_to_fourier_domain(LweBootstrapKey &bsk);
 
 #ifdef CONCRETELANG_CUDA_SUPPORT
 public:
@@ -144,6 +148,24 @@ typedef struct RuntimeContext {
 #endif
 } RuntimeContext;
 
+struct DistributedRuntimeContext : public RuntimeContext {
+
+  using RuntimeContext::RuntimeContext;
+  const uint64_t *keyswitch_key_buffer(size_t keyId) override;
+  const std::complex<double> *
+  fourier_bootstrap_key_buffer(size_t keyId) override;
+  const uint64_t *fp_keyswitch_key_buffer(size_t keyId) override;
+  const struct Fft *fft(size_t keyId) override;
+
+private:
+  void getBSKonNode(size_t keyId);
+  std::mutex cm_guard;
+  std::map<size_t, LweKeyswitchKey> ksks;
+  std::map<size_t, std::shared_ptr<std::vector<std::complex<double>>>> fbks;
+  std::map<size_t, FFT> dffts;
+  std::map<size_t, PackingKeyswitchKey> pksks;
+};
+
 } // namespace concretelang
 } // namespace mlir
 

compilers/concrete-compiler/compiler/include/concretelang/Runtime/key_manager.hpp

@@ -33,10 +33,7 @@ namespace concretelang {
 namespace dfr {
 
 struct RuntimeContextManager;
-namespace {
-static void *dl_handle;
-static RuntimeContextManager *_dfr_node_level_runtime_context_manager;
-} // namespace
+extern RuntimeContextManager *_dfr_node_level_runtime_context_manager;
 
 template <typename LweKeyType> struct KeyWrapper {
   std::vector<LweKeyType> keys;
@@ -109,21 +106,40 @@ struct RuntimeContextManager {
   // TODO: this is only ok so long as we don't change keys. Once we
   // use multiple keys, should have a map.
   RuntimeContext *context;
+  bool allocated = false;
+  bool lazy_key_transfer = false;
 
-  RuntimeContextManager() {
+  RuntimeContextManager(bool lazy = false) : lazy_key_transfer(lazy) {
     context = nullptr;
     _dfr_node_level_runtime_context_manager = this;
   }
 
   void setContext(void *ctx) {
     assert(context == nullptr &&
            "Only one RuntimeContext can be used at a time.");
+    context = (RuntimeContext *)ctx;
+
+    if (lazy_key_transfer) {
+      if (!_dfr_is_root_node()) {
+        context =
+            new mlir::concretelang::DistributedRuntimeContext(ServerKeyset());
+        allocated = true;
+      }
+      return;
+    }
+
+    // When the root node does not require a context, we still need to
+    // broadcast an empty keyset to remote nodes as they cannot know
+    // ahead of time and avoid waiting for the broadcast. Instantiate
+    // an empty context for this.
+    if (_dfr_is_root_node() && ctx == nullptr) {
+      context = new mlir::concretelang::RuntimeContext(ServerKeyset());
+      allocated = true;
+    }
 
     // Root node broadcasts the evaluation keys and each remote
     // instantiates a local RuntimeContext.
     if (_dfr_is_root_node()) {
-      RuntimeContext *context = (RuntimeContext *)ctx;
-
       KeyWrapper<LweKeyswitchKey> kskw(context->getKeys().lweKeyswitchKeys);
       KeyWrapper<LweBootstrapKey> bskw(context->getKeys().lweBootstrapKeys);
       KeyWrapper<PackingKeyswitchKey> pkskw(
@@ -153,12 +169,23 @@ struct RuntimeContextManager {
 
   void clearContext() {
     if (context != nullptr)
-      delete context;
+      // On root node deallocate only if allocated independently here
+      if (!_dfr_is_root_node() || allocated)
+        delete context;
     context = nullptr;
   }
 };
 
+KeyWrapper<LweKeyswitchKey> getKsk(size_t keyId);
+KeyWrapper<LweBootstrapKey> getBsk(size_t keyId);
+KeyWrapper<PackingKeyswitchKey> getPKsk(size_t keyId);
+
+HPX_DEFINE_PLAIN_ACTION(getKsk, _get_ksk_action);
+HPX_DEFINE_PLAIN_ACTION(getBsk, _get_bsk_action);
+HPX_DEFINE_PLAIN_ACTION(getPKsk, _get_pksk_action);
+
 } // namespace dfr
 } // namespace concretelang
 } // namespace mlir
+
 #endif

compilers/concrete-compiler/compiler/include/concretelang/Runtime/workfunction_registry.hpp

@@ -22,8 +22,9 @@ namespace dfr {
 
 struct WorkFunctionRegistry;
 namespace {
+static void *dl_handle;
 static WorkFunctionRegistry *_dfr_node_level_work_function_registry;
-}
+} // namespace
 
 struct WorkFunctionRegistry {
   WorkFunctionRegistry() { _dfr_node_level_work_function_registry = this; }

compilers/concrete-compiler/compiler/lib/Runtime/CMakeLists.txt

@@ -1,10 +1,12 @@
 add_compile_options(-fsized-deallocation)
 
 if(CONCRETELANG_CUDA_SUPPORT)
-  add_library(ConcretelangRuntime SHARED context.cpp simulation.cpp wrappers.cpp DFRuntime.cpp GPUDFG.cpp)
+  add_library(ConcretelangRuntime SHARED context.cpp simulation.cpp wrappers.cpp DFRuntime.cpp key_manager.cpp
+                                         GPUDFG.cpp)
   target_link_libraries(ConcretelangRuntime PRIVATE hwloc)
 else()
-  add_library(ConcretelangRuntime SHARED context.cpp simulation.cpp wrappers.cpp DFRuntime.cpp StreamEmulator.cpp)
+  add_library(ConcretelangRuntime SHARED context.cpp simulation.cpp wrappers.cpp DFRuntime.cpp key_manager.cpp
+                                         StreamEmulator.cpp)
 endif()
 
 add_dependencies(ConcretelangRuntime concrete_cpu concrete_cpu_noise_model concrete-protocol)

compilers/concrete-compiler/compiler/lib/Runtime/DFRuntime.cpp

@@ -316,7 +316,16 @@ static inline void _dfr_start_impl(int argc, char *argv[]) {
   num_nodes = hpx::get_num_localities().get();
 
   new WorkFunctionRegistry();
-  new RuntimeContextManager();
+
+  char *env = getenv("DFR_LAZY_KEY_TRANSFER");
+  bool lazy = false;
+  if (env != nullptr)
+    if (!strncmp(env, "True", 4) || !strncmp(env, "true", 4) ||
+        !strncmp(env, "On", 2) || !strncmp(env, "on", 2) ||
+        !strncmp(env, "1", 1))
+      lazy = true;
+  new RuntimeContextManager(lazy);
+
   _dfr_jit_phase_barrier = new hpx::distributed::barrier(
       "phase_barrier", num_nodes, hpx::get_locality_id());
   _dfr_startup_barrier = new hpx::distributed::barrier(
@@ -351,14 +360,12 @@ void _dfr_start(int64_t use_dfr_p, void *ctx) {
 
     assert(init_guard == active && "DFR runtime failed to initialise");
 
-    // If DFR is used and a runtime context is needed, and execution is
-    // distributed, then broadcast from root to all compute nodes.
-    if (num_nodes > 1 && (ctx || !_dfr_is_root_node())) {
+    // If execution is distributed, then broadcast (possibly an empty)
+    // context from root to all compute nodes.
+    if (num_nodes > 1) {
       BEGIN_TIME(&broadcast_timer);
       _dfr_node_level_runtime_context_manager->setContext(ctx);
     }
-    // If this is not JIT, then the remote nodes never reach _dfr_stop,
-    // so root should not instantiate this barrier.
     if (_dfr_is_root_node())
       _dfr_startup_barrier->wait();