greensea · September 22, 2015 07:40 · Sep 22, 2015
diff --git a/context_switch_bench.c b/context_switch_bench.c
@@ -0,0 +1,140 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <sys/eventfd.h>
+#include <sys/time.h>
+
+int g_loops = 0;
+int g_efd = 0;
+int g_stop = 0;
+
+pthread_mutex_t cond_mutex = PTHREAD_MUTEX_INITIALIZER;
+pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
+
+void* consumer_cond(void* ptr) {
+    pthread_mutex_lock(&cond_mutex);
+    while (g_loops > 0) {
+        g_loops--;
+        pthread_cond_wait(&cond, &cond_mutex);
+    }
+    pthread_mutex_unlock(&cond_mutex);
+
+    return NULL;
+}
+
+void* producer_cond(void* ptr) {
+    while (1 && !g_stop) {
+        pthread_mutex_lock(&cond_mutex);
+
+        pthread_cond_signal(&cond);
+        pthread_mutex_unlock(&cond_mutex);
+    }
+
+    return NULL;
+}
+
+
+void* consumer_eventfd(void* ptr) {
+    uint64_t buf;
+
+    while (g_loops > 0) {
+        g_loops--; 
+        read(g_efd, &buf, 8);
+    }
+
+    return NULL;
+}
+
+void* producer_eventfd(void* ptr) {
+    uint64_t buf = 1;
+    while (1 && !g_stop) {
+        write(g_efd, &buf, 8);
+    }
+
+    return NULL;
+}
+
+
+
+
+
+void bench(int loops, int pcnt, int ccnt) {
+    void* ret;
+    int i;
+    pthread_t tidc[ccnt], tidp[pcnt];
+    struct timeval tv1, tv2;
+    float elapse;
+
+    g_efd = eventfd(0, EFD_SEMAPHORE);
+
+
+    g_loops = loops;
+    g_stop = 0;
+
+    gettimeofday(&tv1, NULL);
+    for (i = 0; i < ccnt; i++) {
+        pthread_create(&tidc[i], NULL, consumer_cond, NULL);
+    }
+    for (i = 0; i < pcnt; i++) {
+        pthread_create(&tidp[i], NULL, producer_cond, NULL);
+    }
+
+    for (i = 0; i < ccnt; i++) {
+        pthread_join(tidc[i], &ret);
+    }
+    for (i = 0; i < pcnt; i++) {
+        g_stop = 1;
+        pthread_join(tidp[i], &ret);
+    }
+    gettimeofday(&tv2, NULL);
+
+
+    elapse = (tv2.tv_sec - tv1.tv_sec) * 1000 * 1000 + (tv2.tv_usec - tv1.tv_usec);
+    elapse /= 1000 * 1000;
+    printf("pthread_cond 耗时 %f 秒\n", elapse);
+
+
+
+
+    g_loops = loops;
+    g_stop = 0;
+
+    gettimeofday(&tv1, NULL);
+    for (i = 0; i < ccnt; i++) {
+        pthread_create(&tidc[i], NULL, consumer_eventfd, NULL);
+    }
+    for (i = 0; i < pcnt; i++) {
+        pthread_create(&tidp[i], NULL, producer_eventfd, NULL);
+    }
+
+    for (i = 0; i < ccnt; i++) {
+        pthread_join(tidc[i], &ret);
+    }
+    for (i = 0; i < pcnt; i++) {
+        g_stop = 1;
+        pthread_join(tidp[i], &ret);
+    }
+    gettimeofday(&tv2, NULL);
+
+
+    elapse = (tv2.tv_sec - tv1.tv_sec) * 1000 * 1000 + (tv2.tv_usec - tv1.tv_usec);
+    elapse /= 1000 * 1000;
+    printf("pthread_eventfd 耗时 %f 秒\n", elapse);
+
+
+
+}
+
+
+int main() {
+    int i;
+
+    for (i = 1; i <= 100000; i *= 10) {
+        printf("进行 %d 次循环测试\n", i);
+        bench(i, 1, 1);
+        printf("=============\n");
+    }
+
+    return 0;
+}