Adding experimental synchronous executor using inline command buffers.

This is mostly just the plumbing to enable #4680 by defining a new
`dylib-sync` runtime driver (pending #4298 to cleanup drivers).

This driver does not support recording/replaying command buffers and has
some gotchas with semaphores (no deadline waits, probably bugs, etc).

iree/base/api.h

@@ -841,6 +841,14 @@ static inline iree_timeout_t iree_immediate_timeout() {
   return timeout;
 }
 
+// Returns true if the |timeout| indicates an immediate/polling/nonblocking
+// timeout.
+static inline bool iree_timeout_is_immediate(iree_timeout_t timeout) {
+  return timeout.type == IREE_TIMEOUT_ABSOLUTE
+             ? timeout.nanos == IREE_TIME_INFINITE_PAST
+             : timeout.nanos == IREE_DURATION_ZERO;
+}
+
 // Returns a timeout that will never be reached.
 // This can be used with APIs that can wait to disable the early
 // deadline-exceeded returns when a condition is not met. It should be used with
@@ -852,6 +860,13 @@ static inline iree_timeout_t iree_infinite_timeout() {
   return timeout;
 }
 
+// Returns true if the |timeout| indicates an infinite/forever blocking timeout.
+static inline bool iree_timeout_is_infinite(iree_timeout_t timeout) {
+  return timeout.type == IREE_TIMEOUT_ABSOLUTE
+             ? timeout.nanos == IREE_TIME_INFINITE_FUTURE
+             : timeout.nanos == IREE_DURATION_INFINITE;
+}
+
 // Defines an absolute timeout with the given time in nanoseconds.
 static inline iree_timeout_t iree_make_deadline(iree_time_t deadline_ns) {
   iree_timeout_t timeout = {IREE_TIMEOUT_ABSOLUTE, deadline_ns};

iree/hal/cts/command_buffer_test.cc

@@ -33,6 +33,12 @@ namespace cts {
 using ::testing::ContainerEq;
 
 class CommandBufferTest : public CtsTestBase {
+ public:
+  CommandBufferTest() {
+    // TODO(#4680): command buffer recording so that this can run on sync HAL.
+    SkipUnavailableDriver("dylib-sync");
+  }
+
  protected:
   static constexpr iree_device_size_t kBufferSize = 4096;
 };

iree/hal/cts/cts_test_base.h

@@ -133,7 +133,7 @@ class CtsTestBase : public ::testing::TestWithParam<std::string> {
     driver_block_list_.insert(driver_name);
   }
   // Allow skipping tests for unsupported features.
-  void declareUnavailableDriver(const std::string& driver_name) {
+  void SkipUnavailableDriver(const std::string& driver_name) {
     driver_block_list_.insert(driver_name);
   }
 
@@ -170,7 +170,9 @@ struct GenerateTestName {
   template <class ParamType>
   std::string operator()(
       const ::testing::TestParamInfo<ParamType>& info) const {
-    return info.param;
+    std::string name = info.param;
+    std::replace(name.begin(), name.end(), '-', '_');
+    return name;
   }
 };
 

iree/hal/cts/event_test.cc

@@ -21,7 +21,13 @@ namespace iree {
 namespace hal {
 namespace cts {
 
-class EventTest : public CtsTestBase {};
+class EventTest : public CtsTestBase {
+ public:
+  EventTest() {
+    // TODO(#4680): command buffer recording so that this can run on sync HAL.
+    SkipUnavailableDriver("dylib-sync");
+  }
+};
 
 TEST_P(EventTest, Create) {
   iree_hal_event_t* event;

iree/hal/cts/semaphore_submission_test.cc

@@ -22,8 +22,12 @@ namespace cts {
 
 class SemaphoreSubmissionTest : public CtsTestBase {
  public:
-  // Disable cuda backend for this test as semaphores are not implemented yet.
-  SemaphoreSubmissionTest() { declareUnavailableDriver("cuda"); }
+  SemaphoreSubmissionTest() {
+    // Disable cuda backend for this test as semaphores are not implemented yet.
+    SkipUnavailableDriver("cuda");
+    // TODO(#4680): command buffer recording so that this can run on sync HAL.
+    SkipUnavailableDriver("dylib-sync");
+  }
 };
 
 TEST_P(SemaphoreSubmissionTest, SubmitWithNoCommandBuffers) {

iree/hal/cts/semaphore_test.cc

@@ -25,7 +25,7 @@ namespace cts {
 class SemaphoreTest : public CtsTestBase {
  public:
   // Disable cuda backend for this test as semaphores are not implemented yet.
-  SemaphoreTest() { declareUnavailableDriver("cuda"); }
+  SemaphoreTest() { SkipUnavailableDriver("cuda"); }
 };
 
 // Tests that a semaphore that is unused properly cleans itself up.

iree/hal/device.h

@@ -217,9 +217,13 @@ IREE_API_EXPORT iree_status_t IREE_API_CALL iree_hal_device_submit_and_wait(
 // Returns success if the wait is successful and semaphores have been signaled
 // satisfying the |wait_mode|.
 //
-// Returns DEADLINE_EXCEEDED if the |timeout| elapses without the |wait_mode|
-// being satisfied. Note that even on success only a subset of the semaphores
-// may have been signaled and each can be queried to see which ones.
+// Returns IREE_STATUS_DEADLINE_EXCEEDED if the |timeout| elapses without the
+// |wait_mode| being satisfied. Note that even on success only a subset of the
+// semaphores may have been signaled and each can be queried to see which ones.
+//
+// Returns IREE_STATUS_ABORTED if one or more semaphores has failed. Callers can
+// use iree_hal_semaphore_query on the semaphores to find the ones that have
+// failed and get the status.
 IREE_API_EXPORT iree_status_t IREE_API_CALL iree_hal_device_wait_semaphores(
     iree_hal_device_t* device, iree_hal_wait_mode_t wait_mode,
     const iree_hal_semaphore_list_t* semaphore_list, iree_timeout_t timeout);

iree/hal/drivers/BUILD

@@ -30,6 +30,7 @@ cc_library(
     ] + [
         # TODO(*): select() and only pull in based on build configuration.
         "//iree/hal/dylib/registration",
+        "//iree/hal/dylib/registration:sync",
         "//iree/hal/vmla/registration",
         "//iree/hal/vulkan/registration",
     ] + IREE_CUDA_DEPS,

iree/hal/drivers/CMakeLists.txt

@@ -20,6 +20,8 @@ if(${IREE_HAL_DRIVER_CUDA})
 endif()
 if(${IREE_HAL_DRIVER_DYLIB})
   list(APPEND IREE_HAL_DRIVER_MODULES iree::hal::dylib::registration)
+  # TODO(benvanik): add a IREE_HAL_DRIVER_DYLIB_SYNC or global flag.
+  list(APPEND IREE_HAL_DRIVER_MODULES iree::hal::dylib::registration::sync)
 endif()
 if(${IREE_HAL_DRIVER_VMLA})
   list(APPEND IREE_HAL_DRIVER_MODULES iree::hal::vmla::registration)
@@ -28,14 +30,6 @@ if(${IREE_HAL_DRIVER_VULKAN})
   list(APPEND IREE_HAL_DRIVER_MODULES iree::hal::vulkan::registration)
 endif()
 
-# TODO: Move to either hal/metal/CMakeLists.txt or
-# hal/metal/registration/CMakeLists.txt if bazel-to-cmake issues can be
-# resolved.
-if(APPLE)
-  find_library(Foundation Foundation)
-  find_library(Metal Metal)
-endif()
-
 iree_cc_library(
   NAME
     drivers
@@ -47,8 +41,5 @@ iree_cc_library(
     iree::base::api
     iree::base::tracing
     ${IREE_HAL_DRIVER_MODULES}
-    # TODO: Also move as above if bazel-to-cmake issues can be resolved.
-    $<$<PLATFORM_ID:Darwin>:${Foundation}>
-    $<$<PLATFORM_ID:Darwin>:${Metal}>
   PUBLIC
 )

iree/hal/drivers/init.c

@@ -24,6 +24,10 @@
 #include "iree/hal/dylib/registration/driver_module.h"
 #endif  // IREE_HAL_HAVE_DYLIB_DRIVER_MODULE
 
+#if defined(IREE_HAL_HAVE_DYLIB_SYNC_DRIVER_MODULE)
+#include "iree/hal/dylib/registration/driver_module_sync.h"
+#endif  // IREE_HAL_HAVE_DYLIB_SYNC_DRIVER_MODULE
+
 #if defined(IREE_HAL_HAVE_VMLA_DRIVER_MODULE)
 #include "iree/hal/vmla/registration/driver_module.h"
 #endif  // IREE_HAL_HAVE_VMLA_DRIVER_MODULE
@@ -46,6 +50,11 @@ iree_hal_register_all_available_drivers(iree_hal_driver_registry_t* registry) {
       z0, iree_hal_dylib_driver_module_register(registry));
 #endif  // IREE_HAL_HAVE_DYLIB_DRIVER_MODULE
 
+#if defined(IREE_HAL_HAVE_DYLIB_SYNC_DRIVER_MODULE)
+  IREE_RETURN_AND_END_ZONE_IF_ERROR(
+      z0, iree_hal_dylib_sync_driver_module_register(registry));
+#endif  // IREE_HAL_HAVE_DYLIB_SYNC_DRIVER_MODULE
+
 #if defined(IREE_HAL_HAVE_VMLA_DRIVER_MODULE)
   IREE_RETURN_AND_END_ZONE_IF_ERROR(
       z0, iree_hal_vmla_driver_module_register(registry));

iree/hal/dylib/registration/BUILD

@@ -43,3 +43,17 @@ cc_library(
         "@com_google_absl//absl/flags:flag",
     ],
 )
+
+cc_library(
+    name = "sync",
+    srcs = ["driver_module_sync.c"],
+    hdrs = ["driver_module_sync.h"],
+    defines = [
+        "IREE_HAL_HAVE_DYLIB_SYNC_DRIVER_MODULE=1",
+    ],
+    deps = [
+        "//iree/hal:api",
+        "//iree/hal/local:sync_driver",
+        "//iree/hal/local/loaders:legacy_library_loader",
+    ],
+)

iree/hal/dylib/registration/CMakeLists.txt

@@ -31,4 +31,20 @@ iree_cc_library(
   PUBLIC
 )
 
+iree_cc_library(
+  NAME
+    sync
+  HDRS
+    "driver_module_sync.h"
+  SRCS
+    "driver_module_sync.c"
+  DEPS
+    iree::hal::api
+    iree::hal::local::loaders::legacy_library_loader
+    iree::hal::local::sync_driver
+  DEFINES
+    "IREE_HAL_HAVE_DYLIB_SYNC_DRIVER_MODULE=1"
+  PUBLIC
+)
+
 ### BAZEL_TO_CMAKE_PRESERVES_ALL_CONTENT_BELOW_THIS_LINE ###

iree/hal/dylib/registration/driver_module_sync.c

@@ -0,0 +1,79 @@
+// Copyright 2020 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "iree/hal/dylib/registration/driver_module_sync.h"
+
+#include <inttypes.h>
+
+#include "iree/hal/local/loaders/legacy_library_loader.h"
+#include "iree/hal/local/sync_driver.h"
+
+// TODO(#4298): remove this driver registration and wrapper.
+// By having a single iree/hal/local/registration that then has the loaders
+// added to it based on compilation settings we can have a single set of flags
+// for everything.
+
+#define IREE_HAL_DYLIB_SYNC_DRIVER_ID 0x53444C4Cu  // SDLL
+
+static iree_status_t iree_hal_dylib_sync_driver_factory_enumerate(
+    void* self, const iree_hal_driver_info_t** out_driver_infos,
+    iree_host_size_t* out_driver_info_count) {
+  static const iree_hal_driver_info_t default_driver_info = {
+      .driver_id = IREE_HAL_DYLIB_SYNC_DRIVER_ID,
+      .driver_name = iree_string_view_literal("dylib-sync"),
+      .full_name = iree_string_view_literal("AOT compiled dynamic libraries"),
+  };
+  *out_driver_info_count = 1;
+  *out_driver_infos = &default_driver_info;
+  return iree_ok_status();
+}
+
+static iree_status_t iree_hal_dylib_sync_driver_factory_try_create(
+    void* self, iree_hal_driver_id_t driver_id, iree_allocator_t allocator,
+    iree_hal_driver_t** out_driver) {
+  if (driver_id != IREE_HAL_DYLIB_SYNC_DRIVER_ID) {
+    return iree_make_status(IREE_STATUS_UNAVAILABLE,
+                            "no driver with ID %016" PRIu64
+                            " is provided by this factory",
+                            driver_id);
+  }
+
+  iree_hal_sync_device_params_t default_params;
+  iree_hal_sync_device_params_initialize(&default_params);
+
+  iree_hal_executable_loader_t* dylib_loader = NULL;
+  iree_status_t status =
+      iree_hal_legacy_library_loader_create(allocator, &dylib_loader);
+  iree_hal_executable_loader_t* loaders[1] = {dylib_loader};
+
+  if (iree_status_is_ok(status)) {
+    status = iree_hal_sync_driver_create(
+        iree_make_cstring_view("dylib"), &default_params,
+        IREE_ARRAYSIZE(loaders), loaders, allocator, out_driver);
+  }
+
+  iree_hal_executable_loader_release(dylib_loader);
+  return status;
+}
+
+IREE_API_EXPORT iree_status_t IREE_API_CALL
+iree_hal_dylib_sync_driver_module_register(
+    iree_hal_driver_registry_t* registry) {
+  static const iree_hal_driver_factory_t factory = {
+      .self = NULL,
+      .enumerate = iree_hal_dylib_sync_driver_factory_enumerate,
+      .try_create = iree_hal_dylib_sync_driver_factory_try_create,
+  };
+  return iree_hal_driver_registry_register_factory(registry, &factory);
+}

iree/hal/dylib/registration/driver_module_sync.h

@@ -0,0 +1,34 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef IREE_HAL_DYLIB_REGISTRATION_DRIVER_MODULE_SYNC_H_
+#define IREE_HAL_DYLIB_REGISTRATION_DRIVER_MODULE_SYNC_H_
+
+#include "iree/hal/api.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif  // __cplusplus
+
+// DEPRECATED: this entire driver will be removed soon.
+// TODO(#3580): remove this entire driver w/ iree_hal_executable_library_t.
+IREE_API_EXPORT iree_status_t IREE_API_CALL
+iree_hal_dylib_sync_driver_module_register(
+    iree_hal_driver_registry_t* registry);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif  // __cplusplus
+
+#endif  // IREE_HAL_DYLIB_REGISTRATION_DRIVER_MODULE_SYNC_H_

iree/hal/local/BUILD

@@ -90,6 +90,34 @@ cc_library(
     ],
 )
 
+cc_library(
+    name = "sync_driver",
+    srcs = [
+        "sync_device.c",
+        "sync_driver.c",
+        "sync_event.c",
+        "sync_semaphore.c",
+    ],
+    hdrs = [
+        "sync_device.h",
+        "sync_driver.h",
+        "sync_event.h",
+        "sync_semaphore.h",
+    ],
+    deps = [
+        ":arena",
+        ":local",
+        "//iree/base:api",
+        "//iree/base:core_headers",
+        "//iree/base:synchronization",
+        "//iree/base:tracing",
+        "//iree/base/internal",
+        "//iree/base/internal:wait_handle",
+        "//iree/hal:api",
+        "//iree/task",
+    ],
+)
+
 cc_library(
     name = "task_driver",
     srcs = [