Merge pull request #27 from nickwanninger/25-decouple-barriers-from-the-core-runtime

25 decouple barriers from the core runtime

Author: nickwanninger

.gitignore

@@ -5,6 +5,7 @@
 *.o
 /.config
 /build
+/build-*
 # nix
 /result
 /.clangd

CMakeLists.txt

@@ -5,11 +5,6 @@ set(Red "${Esc}[31m")
 set(ColorReset "${Esc}[m")
 
 function(alaska_switch OPT DEFAULT)
-  if (${OPT})
-   message(STATUS "${OPT} DEFINED")
-  endif()
-
-
   set(${OPT} ${DEFAULT} CACHE BOOL "")
 
   if(${OPT} MATCHES "ON|On|on|TRUE|true|1")
@@ -31,12 +26,19 @@ function(alaska_option OPT DEFAULT)
   message(STATUS "${Purple}OPTION${ColorReset} ${OPT} ${Green}${${OPT}}${ColorReset}")
 endfunction()
 
+function(alaska_option_nodef OPT DEFAULT)
+  set(${OPT} ${DEFAULT} CACHE STRING "")
+  message(STATUS "${Purple}OPTION${ColorReset} ${OPT} ${Green}${${OPT}}${ColorReset}")
+endfunction()
+
 
 alaska_switch(ALASKA_ENABLE_COMPILER ON)
 alaska_switch(ALASKA_ENABLE_TESTING  ON)
+alaska_switch(ALASKA_CORE_ONLY       OFF)
 
 alaska_option(ALASKA_SIZE_BITS 24)
 alaska_option(CMAKE_BUILD_TYPE Release)
+alaska_option_nodef(ALASKA_ENABLE_COMPONENTS "compiler;compiler-rts")
 
 set(ALASKA_VERSION 2)
 
@@ -45,6 +47,24 @@ set(CMAKE_C_COMPILER_WORKS 1)
 set(CMAKE_CXX_COMPILER_WORKS 1)
 
 
+# Check if the build type is Release
+if(CMAKE_BUILD_TYPE STREQUAL "Debug")
+  add_compile_definitions(ALASKA_ENABLE_LOGGING=1)
+endif()
+
+
+
+list(FIND ALASKA_ENABLE_COMPONENTS "compiler" INDEX)
+if (NOT INDEX EQUAL -1)
+  message(STATUS "compiler")
+endif()
+
+
+list(FIND ALASKA_ENABLE_COMPONENTS "compiler-rts" INDEX)
+if (NOT INDEX EQUAL -1)
+  message(STATUS "compiler-rts")
+endif()
+
 
 # -------------------------------------------------------------------------------------------
 
@@ -59,12 +79,6 @@ else()
   set(ALASKA_ENABLE_COMPILER FALSE)
 endif()
 
-
-# If we are building the core only, don't enable the compiler!
-if(ALASKA_CORE_ONLY)
-  set(ALASKA_ENABLE_COMPILER FALSE)
-endif()
-
 add_compile_definitions("ALASKA_INSTALL_PREFIX=\"${CMAKE_INSTALL_PREFIX}\"")
 add_definitions(-include "${CMAKE_CURRENT_SOURCE_DIR}/runtime/include/alaska/config.h")
 

Makefile

@@ -33,7 +33,7 @@ sanity: alaska
 test: alaska
 	@build/runtime/alaska_test
 
-.PHONY: alaska all 
+.PHONY: alaska all
 
 # Run compilation unit tests to validate that the compiler can
 # handle all the funky control flow in the GCC test suite
@@ -43,8 +43,15 @@ unit: alaska FORCE
 docs:
 	@doxygen Doxyfile
 
+
+# Defer to CMake to clean itself, if the build folder exists
 clean:
-	rm -rf build .*.o*
+	[ -d $(BUILD) ] && make -C $(BUILD) clean
+	rm -f .*.o*
+
+mrproper:
+	rm -rf $(BUILD) .*.o*
+
 
 docker:
 	docker build -t alaska .

runtime/CMakeLists.txt

@@ -56,9 +56,6 @@ set(CORE_SOURCES
   core/SizedPage.cpp
   core/LocalityPage.cpp
 
-
-  core/barrier.cpp
-
   # liballoc is a simple, small, malloc implementation that we embed
   # so alaska can temporially allocate objects w/o implementing a non-handle
   # allocator as well
@@ -69,16 +66,14 @@ set(CORE_SOURCES
 )
 
 
-find_library(LIBUNWIND_LIBRARIES NAMES unwind )
-message(STATUS "UNWIND: ${LIBUNWIND_LIBRARIES}")
 
-add_library(alaska_core STATIC ${CORE_SOURCES})
+add_library(alaska_core SHARED ${CORE_SOURCES})
 
 target_compile_options(alaska_core PRIVATE $<$<COMPILE_LANGUAGE:CXX>:-nostdlib++ -nostdinc++>)
 
 set_target_properties(alaska_core PROPERTIES LINKER_LANGUAGE C)
 set_target_properties(alaska_core PROPERTIES SOVERSION ${ALASKA_VERSION})
-target_link_libraries(alaska_core ${LIBUNWIND_LIBRARIES})
+# target_link_libraries(alaska_core ${LIBUNWIND_LIBRARIES})
 
 set_property(TARGET alaska_core PROPERTY POSITION_INDEPENDENT_CODE ON)
 target_link_libraries(alaska_core dl pthread)
@@ -102,12 +97,15 @@ install(
 # This defines the runtime that compiled code is linked against
 if(NOT ALASKA_CORE_ONLY) # -----------------------------------------------------------------------------------
 
+  find_library(LIBUNWIND_LIBRARIES NAMES unwind )
+  message(STATUS "UNWIND: ${LIBUNWIND_LIBRARIES}")
 
   add_library(alaska SHARED
     rt/init.cpp
     rt/halloc.cpp
     rt/threads.cpp
     rt/compat.c
+    rt/barrier.cpp
   )
 
   target_include_directories(alaska PUBLIC include/)

runtime/core/HandleTable.cpp

@@ -8,6 +8,9 @@
  * This is free software.  You are permitted to use, redistribute,
  * and modify it as specified in the file "LICENSE".
  */
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
 
 
 #include <alaska/HandleTable.hpp>
@@ -132,7 +135,7 @@ namespace alaska {
     return m_slabs[idx];
   }
 
-  slabidx_t HandleTable::mapping_slab_idx(Mapping *m) {
+  slabidx_t HandleTable::mapping_slab_idx(Mapping *m) const {
     auto byte_distance = (uintptr_t)m - (uintptr_t)m_table;
     return byte_distance / HandleTable::slab_size;
   }
@@ -151,6 +154,10 @@ namespace alaska {
   }
 
 
+  bool HandleTable::valid_handle(Mapping *m) const {
+    return mapping_slab_idx(m) < (slabidx_t)m_slabs.size();
+  }
+
   void HandleTable::put(Mapping *m, alaska::ThreadCache *owner) {
     log_trace("Putting handle %p", m);
     // Validate that the handle is in this table

runtime/core/LocalityPage.cpp

@@ -34,7 +34,7 @@ namespace alaska {
     md_bump_next--;
 
 
-    log_trace("setting md to %08lx", m.to_compact());
+    log_trace("setting md to %p", &m);
     md->mapping = const_cast<alaska::Mapping *>(&m);
     log_trace("set md!");
 

runtime/core/Runtime.cpp

@@ -12,22 +12,31 @@
 
 #include <alaska/Runtime.hpp>
 #include <alaska/SizeClass.hpp>
+#include <alaska/BarrierManager.hpp>
 #include "alaska/alaska.hpp"
 #include <stdlib.h>
 
 namespace alaska {
+  // The default instance of a barrier manager.
+  static BarrierManager global_nop_barrier_manager;
+  // The current global instance of the runtime, since we can only have one at a time
   static Runtime *g_runtime = nullptr;
 
 
   Runtime::Runtime() {
+    // Validate that there is not already a runtime (TODO: atomics?)
     ALASKA_ASSERT(g_runtime == nullptr, "Cannot create more than one runtime");
+    // Assign the global runtime to be this instance
     g_runtime = this;
+    // Attach a default barrier manager
+    this->barrier_manager = &global_nop_barrier_manager;
 
     log_debug("Created a new Alaska Runtime @ %p", this);
   }
 
   Runtime::~Runtime() {
     log_debug("Destroying Alaska Runtime");
+    // Unset the global instance so another runtime can be allocated
     g_runtime = nullptr;
   }
 
@@ -38,69 +47,6 @@ namespace alaska {
   }
 
 
-  // void* Runtime::halloc(size_t sz, bool zero) {
-  //   auto& rt = *this;
-  //   log_trace("halloc: allocating %lu bytes (zero=%d)", sz, zero);
-  //   // Just some big number.
-  //   if (sz > (1LLU << (uint64_t)(ALASKA_SIZE_BITS - ALASKA_SQUEEZE_BITS - 1)) - 1) {
-  //     log_debug(
-  //         "Allocation of size %zu deemed too big - using the system allocator instead...", sz);
-  //     return ::malloc(sz);
-  //   }
-
-
-
-  //   int sc = alaska::size_to_class(sz);
-  //   size_t rsz = alaska::class_to_size(sc);
-  //   log_trace("sz = %zu, sc = %d, rsz = %zu\n", sz, sc, rsz);
-
-  //   alaska::Mapping* m = rt.handle_table.get();
-  //   if (m == nullptr) {
-  //     log_fatal("halloc: out of handles");
-  //     abort();
-  //   }
-
-  //   void* p = rt.page.alloc(*m, sz);
-
-  //   if (p == nullptr) {
-  //     log_fatal("halloc: out of memory");
-  //     abort();
-  //   }
-  //   if (zero) {
-  //     memset(p, 0, sz);
-  //   }
-
-  //   m->set_pointer(p);
-
-  //   void* out = (void*)m->to_handle(0);
-  //   log_trace("halloc handle %p -> %p", out, p);
-  //   return out;
-  // }
-
-  // void Runtime::hfree(void* ptr) {
-  //   auto* m = alaska::Mapping::from_handle_safe(ptr);
-
-  //   log_trace("hfree: freeing %p (%p)", ptr, m->get_pointer());
-  //   this->page.release(*m, m->get_pointer());
-  // }
-
-
-
-  // void* Runtime::hrealloc(void* ptr, size_t size) {
-  //   log_trace("hrealloc(%p, %zu)", ptr, size);
-  //   if (size == 0) {
-  //     hfree(ptr);
-  //     return nullptr;
-  //   }
-
-  //   // TODO: Implement hrealloc function
-  //   log_fatal("hrealloc: not implemented");
-  //   abort();
-  //   return nullptr;
-  // }
-
-
-
   void Runtime::dump(FILE *stream) {
     //
     fprintf(stream, "Alaska Runtime Information:\n");

runtime/core/ThreadCache.cpp

@@ -59,10 +59,10 @@ namespace alaska {
     ALASKA_ASSERT(page != NULL, "calling hfree should always return a heap page");
 
     if (page->is_owned_by(this)) {
-      log_trace("Free handle %p locally", handle);
+      log_trace("Free handle %p locally (ptr = %p)", &m, ptr);
       page->release_local(m, ptr);
     } else {
-      log_trace("Free handle %p remotely", handle);
+      log_trace("Free handle %p remotely (ptr = %p)", &m, ptr);
       page->release_remote(m, ptr);
     }
   }
@@ -186,8 +186,11 @@ namespace alaska {
   void ThreadCache::hfree(void *handle) {
     alaska::Mapping *m = alaska::Mapping::from_handle_safe(handle);
     if (unlikely(m == nullptr)) {
+
+      // printf("attempt to free non handle %p\n", handle);
       bool worked = this->runtime.heap.huge_allocator.free(handle);
-      ALASKA_ASSERT(worked, "huge free failed");
+      (void)worked;
+      // ALASKA_ASSERT(worked, "huge free failed");
       return;
     }
     // Free the allocation behind a mapping
@@ -199,7 +202,10 @@ namespace alaska {
 
 
   size_t ThreadCache::get_size(void *handle) {
-    alaska::Mapping *m = alaska::Mapping::from_handle(handle);
+    alaska::Mapping *m = alaska::Mapping::from_handle_safe(handle);
+    if (m == nullptr) {
+      return this->runtime.heap.huge_allocator.size_of(handle);
+    }
     void *ptr = m->get_pointer();
     auto *page = this->runtime.heap.pt.get_unaligned(ptr);
     if (page == nullptr) return this->runtime.heap.huge_allocator.size_of(ptr);

runtime/include/alaska/BarrierManager.hpp

@@ -0,0 +1,28 @@
+#pragma once
+
+#include <alaska/alaska.hpp>
+
+
+namespace alaska {
+
+
+  // A BarrierManager exists to abstract the delivery of "barrier" events in alaksa. This is needed
+  // because different configurations of alaska require different mechanisms to "stop the world" and
+  // track all the pinned handles at a point in time. Some systems require sending signals to every
+  // thread, some don't require anything. Therefore, when a Runtime is constructed, a BarrierManager
+  // can be attached to it, effectively injecting the requirements of the runtime system into the
+  // core runtime's capabilities.
+  //
+  // This class also records some statistics about barrier events as they occur.
+  // The only requirement of this class is that when `::begin()` returns, all pinned handles must
+  // be marked as such, and when `::end()` returns they should be released. The core runtime relies
+  // on this to be the case for safe operation. If the user of the core runtime does not need to
+  // pin any handles, the barrier does not need to do anything.
+  struct BarrierManager : public alaska::InternalHeapAllocated {
+    virtual ~BarrierManager() = default;
+    virtual void begin(void){};
+    virtual void end(void){};
+
+    unsigned long barrier_count = 0;
+  };
+}  // namespace alaska

runtime/include/alaska/HandleTable.hpp

@@ -99,13 +99,15 @@ namespace alaska {
     alaska::HandleSlab *new_slab(ThreadCache *new_owner);
     alaska::HandleSlab *get_slab(slabidx_t idx);
     // Given a mapping, return the index of the slab it belongs to.
-    slabidx_t mapping_slab_idx(Mapping *m);
+    slabidx_t mapping_slab_idx(Mapping *m) const;
 
     auto slab_count() const { return m_slabs.size(); }
     auto capacity() const { return m_capacity; }
 
     void dump(FILE *stream);
 
+    bool valid_handle(alaska::Mapping *m) const;
+
 
     // Free/release *some* mapping
     void put(alaska::Mapping *m, alaska::ThreadCache *owner = (alaska::ThreadCache *)0x1000UL);