| /* |
| * Copyright (c) 2024 Intel Corporation |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| */ |
| |
| /* |
| * @file measure time for various condition variable operations |
| * 1. Block waiting for a condition variable |
| * 2. Signal a condition variable (with context switch) |
| */ |
| |
| #include <zephyr/kernel.h> |
| #include <zephyr/timing/timing.h> |
| #include "utils.h" |
| #include "timing_sc.h" |
| |
| static K_CONDVAR_DEFINE(condvar); |
| static K_MUTEX_DEFINE(mutex); |
| |
| static void start_thread_entry(void *p1, void *p2, void *p3) |
| { |
| uint32_t num_iterations = (uint32_t)(uintptr_t)p1; |
| uint32_t i; |
| timing_t start; |
| timing_t finish; |
| uint64_t sum[2] = {0ull, 0ull}; |
| |
| k_mutex_lock(&mutex, K_FOREVER); |
| |
| k_thread_start(&alt_thread); |
| |
| for (i = 0; i < num_iterations; i++) { |
| /* 1. Get the first timestamp and block on condvar */ |
| |
| start = timing_timestamp_get(); |
| k_condvar_wait(&condvar, &mutex, K_FOREVER); |
| |
| /* 3. Get the final timstamp */ |
| |
| finish = timing_timestamp_get(); |
| |
| sum[0] += timing_cycles_get(&start, ×tamp.sample); |
| sum[1] += timing_cycles_get(×tamp.sample, &finish); |
| } |
| |
| /* Wait for alt_thread to finish */ |
| |
| k_thread_join(&alt_thread, K_FOREVER); |
| |
| timestamp.cycles = sum[0]; |
| k_sem_take(&pause_sem, K_FOREVER); |
| |
| timestamp.cycles = sum[1]; |
| } |
| |
| static void alt_thread_entry(void *p1, void *p2, void *p3) |
| { |
| uint32_t num_iterations = (uint32_t)(uintptr_t)p1; |
| uint32_t i; |
| |
| for (i = 0; i < num_iterations; i++) { |
| |
| /* 2. Get midpoint timestamp and signal the condvar */ |
| |
| timestamp.sample = timing_timestamp_get(); |
| k_condvar_signal(&condvar); |
| } |
| } |
| |
| int condvar_blocking_ops(uint32_t num_iterations, uint32_t start_options, |
| uint32_t alt_options) |
| { |
| int priority; |
| char tag[50]; |
| char description[120]; |
| uint64_t cycles; |
| |
| priority = k_thread_priority_get(k_current_get()); |
| |
| timing_start(); |
| |
| k_thread_create(&start_thread, start_stack, |
| K_THREAD_STACK_SIZEOF(start_stack), |
| start_thread_entry, |
| (void *)(uintptr_t)num_iterations, |
| NULL, NULL, |
| priority - 2, start_options, K_FOREVER); |
| |
| k_thread_create(&alt_thread, alt_stack, |
| K_THREAD_STACK_SIZEOF(alt_stack), |
| alt_thread_entry, |
| (void *)(uintptr_t)num_iterations, |
| NULL, NULL, |
| priority - 1, alt_options, K_FOREVER); |
| |
| k_thread_access_grant(&start_thread, &alt_thread, |
| &condvar, &mutex, &pause_sem); |
| k_thread_access_grant(&alt_thread, &condvar); |
| |
| /* Start test thread */ |
| |
| k_thread_start(&start_thread); |
| |
| /* Stats gathered. Display them. */ |
| |
| snprintf(tag, sizeof(tag), "condvar.wait.blocking.%c_to_%c", |
| (start_options & K_USER) ? 'u' : 'k', |
| (alt_options & K_USER) ? 'u' : 'k'); |
| snprintf(description, sizeof(description), |
| "%-40s - Wait for a condvar (context switch)", tag); |
| |
| cycles = timestamp.cycles; |
| PRINT_STATS_AVG(description, (uint32_t)cycles, |
| num_iterations, false, ""); |
| |
| k_sem_give(&pause_sem); |
| |
| snprintf(tag, sizeof(tag), "condvar.signal.wake+ctx.%c_to_%c", |
| (alt_options & K_USER) ? 'u' : 'k', |
| (start_options & K_USER) ? 'u' : 'k'); |
| snprintf(description, sizeof(description), |
| "%-40s - Signal a condvar (context switch)", tag); |
| cycles = timestamp.cycles; |
| PRINT_STATS_AVG(description, (uint32_t)cycles, |
| num_iterations, false, ""); |
| |
| k_thread_join(&start_thread, K_FOREVER); |
| |
| timing_stop(); |
| |
| return 0; |
| } |