tests: Refactor parallel test execution

cpukit/libmisc/Makefile.am

@@ -162,6 +162,7 @@ noinst_LIBRARIES += libtestsupport.a
 libtestsupport_a_SOURCES =
 libtestsupport_a_SOURCES += testsupport/testbeginend.c
 libtestsupport_a_SOURCES += testsupport/testextension.c
+libtestsupport_a_SOURCES += testsupport/testparallel.c
 
 ## fsmount
 noinst_LIBRARIES += libfsmount.a

cpukit/libmisc/testsupport/test.h

@@ -17,6 +17,8 @@
 
 #include <rtems.h>
 #include <rtems/bspIo.h>
+#include <rtems/score/atomic.h>
+#include <rtems/score/smpbarrier.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -116,6 +118,117 @@ static inline int rtems_test_endk(void)
   return rtems_test_end_with_plugin(printk_plugin, NULL);
 }
 
+/**
+ * @brief Internal context for parallel job execution.
+ */
+typedef struct {
+  Atomic_Ulong stop;
+  SMP_barrier_Control barrier;
+  size_t worker_count;
+  rtems_id stop_worker_timer_id;
+  rtems_id master_id;
+} rtems_test_parallel_context;
+
+/**
+ * @brief Basic parallel job description.
+ */
+typedef struct {
+  /**
+   * @brief Job initialization handler.
+   *
+   * This handler executes only in the context of the master worker before the
+   * job body handler.
+   *
+   * @param[in] ctx The parallel context.
+   * @param[in] arg The user specified argument.
+   *
+   * @return The desired job body execution time in clock ticks.  See
+   *   rtems_test_parallel_stop_job().
+   */
+  rtems_interval (*init)(
+    rtems_test_parallel_context *ctx,
+    void *arg
+  );
+
+  /**
+   * @brief Job body handler.
+   *
+   * @param[in] ctx The parallel context.
+   * @param[in] arg The user specified argument.
+   * @param[in] worker_index The worker index.  It ranges from 0 to the
+   *   processor count minus one.
+   */
+  void (*body)(
+    rtems_test_parallel_context *ctx,
+    void *arg,
+    size_t worker_index
+  );
+
+  /**
+   * @brief Job finalization handler.
+   *
+   * This handler executes only in the context of the master worker after the
+   * job body handler.
+   *
+   * @param[in] ctx The parallel context.
+   * @param[in] arg The user specified argument.
+   */
+  void (*fini)(
+    rtems_test_parallel_context *ctx,
+    void *arg
+  );
+
+  void *arg;
+} rtems_test_parallel_job;
+
+/**
+ * @brief Indicates if a job body should stop its work loop.
+ *
+ * @param[in] ctx The parallel context.
+ *
+ * @retval true The job body should stop its work loop and return to the caller.
+ * @retval false Otherwise.
+ */
+static inline bool rtems_test_parallel_stop_job(
+  rtems_test_parallel_context *ctx
+)
+{
+  return _Atomic_Load_ulong(&ctx->stop, ATOMIC_ORDER_RELAXED) != 0;
+}
+
+/**
+ * @brief Indicates if a worker is the master worker.
+ *
+ * The master worker is the thread that called rtems_test_parallel().
+ *
+ * @param[in] worker_index The worker index.
+ *
+ * @retval true This is the master worker.
+ * @retval false Otherwise.
+ */
+static inline bool rtems_test_parallel_is_master_worker(size_t worker_index)
+{
+  return worker_index == 0;
+}
+
+/**
+ * @brief Runs a bunch of jobs in parallel on all processors of the system.
+ *
+ * There are SMP barriers before and after the job body.
+ *
+ * @param[in] ctx The parallel context.
+ * @param[in] non_master_worker_priority The task priority for non-master
+ *   workers.
+ * @param[in] jobs The table of jobs.
+ * @param[in] job_count The count of jobs in the job table.
+ */
+void rtems_test_parallel(
+  rtems_test_parallel_context *ctx,
+  rtems_task_priority non_master_worker_priority,
+  const rtems_test_parallel_job *jobs,
+  size_t job_count
+);
+
 /** @} */
 
 #ifdef __cplusplus

cpukit/libmisc/testsupport/testparallel.c

@@ -0,0 +1,155 @@
+/*
+ * Copyright (c) 2013-2015 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Dornierstr. 4
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.org/license/LICENSE.
+ */
+
+
+#ifdef HAVE_CONFIG_H
+  #include "config.h"
+#endif
+
+#include <rtems/test.h>
+#include <rtems/score/assert.h>
+#include <rtems.h>
+
+static void stop_worker_timer(rtems_id timer_id, void *arg)
+{
+  rtems_test_parallel_context *ctx = arg;
+
+  _Atomic_Store_ulong(&ctx->stop, 1, ATOMIC_ORDER_RELAXED);
+}
+
+static void start_worker_stop_timer(
+  rtems_test_parallel_context *ctx,
+  rtems_interval duration
+)
+{
+  rtems_status_code sc;
+
+  _Atomic_Store_ulong(&ctx->stop, 0, ATOMIC_ORDER_RELEASE);
+
+  sc = rtems_timer_fire_after(
+    ctx->stop_worker_timer_id,
+    duration,
+    stop_worker_timer,
+    ctx
+  );
+  _Assert(sc == RTEMS_SUCCESSFUL);
+}
+
+static void run_tests(
+  rtems_test_parallel_context *ctx,
+  const rtems_test_parallel_job *jobs,
+  size_t job_count,
+  size_t worker_index
+)
+{
+  SMP_barrier_State bs = SMP_BARRIER_STATE_INITIALIZER;
+  size_t i;
+
+  for (i = 0; i < job_count; ++i) {
+    const rtems_test_parallel_job *job = &jobs[i];
+
+    if (rtems_test_parallel_is_master_worker(worker_index)) {
+      rtems_interval duration = (*job->init)(ctx, job->arg);
+
+      start_worker_stop_timer(ctx, duration);
+    }
+
+    _SMP_barrier_Wait(&ctx->barrier, &bs, ctx->worker_count);
+
+    (*job->body)(ctx, job->arg, worker_index);
+
+    _SMP_barrier_Wait(&ctx->barrier, &bs, ctx->worker_count);
+
+    if (rtems_test_parallel_is_master_worker(worker_index)) {
+      (*job->fini)(ctx, job->arg);
+    }
+  }
+}
+
+typedef struct {
+  rtems_test_parallel_context *ctx;
+  const rtems_test_parallel_job *jobs;
+  size_t job_count;
+  size_t worker_index;
+} worker_arg;
+
+static void worker_task(rtems_task_argument arg)
+{
+  worker_arg warg = *(worker_arg *) arg;
+  rtems_status_code sc;
+
+  sc = rtems_event_transient_send(warg.ctx->master_id);
+  _Assert(sc == RTEMS_SUCCESSFUL);
+
+  run_tests(warg.ctx, warg.jobs, warg.job_count, warg.worker_index);
+
+  rtems_task_delete(RTEMS_SELF);
+}
+
+void rtems_test_parallel(
+  rtems_test_parallel_context *ctx,
+  rtems_task_priority non_master_worker_priority,
+  const rtems_test_parallel_job *jobs,
+  size_t job_count
+)
+{
+  rtems_status_code sc;
+  size_t worker_index;
+
+  _Atomic_Init_ulong(&ctx->stop, 0);
+  _SMP_barrier_Control_initialize(&ctx->barrier);
+  ctx->worker_count = rtems_get_processor_count();
+  ctx->master_id = rtems_task_self();
+
+  sc = rtems_timer_create(
+    rtems_build_name('S', 'T', 'O', 'P'),
+    &ctx->stop_worker_timer_id
+  );
+  if (sc != RTEMS_SUCCESSFUL) {
+    rtems_fatal_error_occurred(sc);
+  }
+
+  for (worker_index = 1; worker_index < ctx->worker_count; ++worker_index) {
+    worker_arg warg = {
+      .ctx = ctx,
+      .jobs = jobs,
+      .job_count = job_count,
+      .worker_index = worker_index
+    };
+    rtems_id worker_id;
+
+    sc = rtems_task_create(
+      rtems_build_name('W', 'O', 'R', 'K'),
+      non_master_worker_priority,
+      RTEMS_MINIMUM_STACK_SIZE,
+      RTEMS_DEFAULT_MODES,
+      RTEMS_DEFAULT_ATTRIBUTES,
+      &worker_id
+    );
+    if (sc != RTEMS_SUCCESSFUL) {
+      rtems_fatal_error_occurred(sc);
+    }
+
+    sc = rtems_task_start(worker_id, worker_task, (rtems_task_argument) &warg);
+    _Assert(sc == RTEMS_SUCCESSFUL);
+
+    sc = rtems_event_transient_receive(RTEMS_WAIT, RTEMS_NO_TIMEOUT);
+    _Assert(sc == RTEMS_SUCCESSFUL);
+  }
+
+  run_tests(ctx, jobs, job_count, 0);
+
+  sc = rtems_timer_delete(ctx->stop_worker_timer_id);
+  _Assert(sc == RTEMS_SUCCESSFUL);
+}