9ab1af8dff
Piece of code I used to validate that socketpair is a lot quicker than pthread_semaphores. Signed-off-by: Michel Pollet <buserror@gmail.com>
123 lines
2.6 KiB
C
123 lines
2.6 KiB
C
/*
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* Latency test for pthread 'conditions' vs using a good ol'
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* pair of linked sockets.
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* gcc -o semtest -O2 -g --std=c99 semtest.c -lpthread
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*
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*/
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#include <sys/socket.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
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#include <pthread.h>
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#include <unistd.h>
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#define TESTCOUNT 10000000
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pthread_mutex_t mutex;
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pthread_cond_t kidwake, dadwake;
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int flag_passed = 0;
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static void *thread_semaphore(void * param)
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{
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printf("kid started\n");
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pthread_mutex_lock(&mutex);
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pthread_cond_signal( &dadwake );
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pthread_mutex_unlock(&mutex);
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do {
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pthread_mutex_lock(&mutex);
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while (flag_passed == 0)
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pthread_cond_wait( &kidwake, &mutex );
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flag_passed = 0;
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pthread_cond_signal( &dadwake );
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pthread_mutex_unlock(&mutex);
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} while (1);
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return NULL;
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}
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int sock[2];
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static void * thread_socket(void * param)
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{
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printf("kid started\n");
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do {
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char b = 0;
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int r = read(sock[1], &b, 1);
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if (r != 1)
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perror("read");
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b = 0;
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write(sock[1], &b, 1); // tell the kid
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} while (1);
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return NULL;
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}
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int main(int argc, char ** argv)
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{
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int test = 0;
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for (int i = 1; i < argc; i++) {
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if (!strcmp(argv[i], "socket"))
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test = 1;
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else if (!strcmp(argv[i], "semaphore"))
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test = 2;
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else
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goto usage;
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}
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if (!test)
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goto usage;
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if (test == 1) {
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if (socketpair(PF_LOCAL, SOCK_STREAM, 0, sock)) {
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perror("socketpair");
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exit(1);
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}
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printf("Socket test start:\n");
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pthread_t t;
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pthread_create(&t, NULL, thread_socket, NULL);
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for (int ti = 0; ti < TESTCOUNT; ti++) {
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char b = 1;
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write(sock[0], &b, 1); // tell the kid
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int r = read(sock[0], &b, 1);
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if (r != 1)
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perror("read");
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if (!(ti % 100000)) {
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printf("."); fflush(stdout);
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}
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}
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} else {
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pthread_mutex_init(&mutex, NULL);
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pthread_cond_init( &kidwake, NULL );
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pthread_cond_init( &dadwake, NULL );
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printf("Semaphore test start:\n");
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pthread_t t;
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pthread_create(&t, NULL, thread_semaphore, NULL);
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pthread_mutex_lock(&mutex);
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printf("dad wait for kid\n");
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pthread_cond_wait( &dadwake, &mutex );
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pthread_mutex_unlock(&mutex);
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printf("dad has kid ready\n");
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for (int ti = 0; ti < TESTCOUNT; ti++) {
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pthread_mutex_lock(&mutex);
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flag_passed = 1;
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pthread_cond_signal( &kidwake );
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while (flag_passed == 1)
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pthread_cond_wait( &dadwake, &mutex );
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pthread_mutex_unlock(&mutex);
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if (!(ti % 100000)) {
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printf("."); fflush(stdout);
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}
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}
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}
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printf("\nDone\n");
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exit(0);
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usage:
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fprintf(stderr, "%s socket -- run semaphore latency test with sockets\n", argv[0]);
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fprintf(stderr, "%s semaphore -- run semaphore latency test with sockets\n", argv[0]);
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exit(1);
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}
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