DEV: tcploop: add optional support for epoll

When -e is passed, epoll is used instead of poll. The FD is added
then removed around the call to epoll_wait() so that we don't need
to track it. The only purpose is to compare events reported by each
syscall.

diff --git a/dev/tcploop/tcploop.c b/dev/tcploop/tcploop.c
index e87525887e01185c32345b2c74e80f4d6d25253c..d8e9f0f4b20d6ef4a18d80cb721a5350d925e124 100644 (file)
--- a/dev/tcploop/tcploop.c
+++ b/dev/tcploop/tcploop.c
@@ -33,6 +33,11 @@
 #include <sys/time.h>
 #include <sys/ioctl.h>
 #include <sys/wait.h>
+
+#ifdef __linux__
+#include <sys/epoll.h>
+#endif
+
 #include <arpa/inet.h>
 #include <netinet/in.h>
 #include <netinet/tcp.h>
@@ -77,6 +82,7 @@ volatile int nbproc = 0;
 static struct timeval start_time;
 static int showtime;
 static int verbose;
+static int use_epoll;
 static int pid;
 static int sock_type = SOCK_STREAM;
 static int sock_proto = IPPROTO_TCP;
@@ -105,6 +111,7 @@ __attribute__((noreturn)) void usage(int code, const char *arg0)
            "  -v           : verbose\n"
            "  -u           : use UDP instead of TCP (limited)\n"
            "  -t|-tt|-ttt  : show time (msec / relative / absolute)\n"
+           "  -e           : use epoll instead of poll on Linux\n"
            "actions :\n"
            "  A[<count>]   : Accepts <count> incoming sockets and closes count-1\n"
            "                 Note: fd=accept(fd)\n"
@@ -313,6 +320,31 @@ int wait_on_fd(int fd, int events, int ms)
        struct pollfd pollfd;
        int ret;
 
+#ifdef __linux__
+       while (use_epoll) {
+               struct epoll_event evt;
+               static int epoll_fd = -1;
+
+               if (epoll_fd == -1)
+                       epoll_fd = epoll_create(1024);
+               if (epoll_fd == -1)
+                       break;
+               evt.events = ((events & POLLIN) ? EPOLLIN : 0)      |
+                            ((events & POLLOUT) ? EPOLLOUT : 0)    |
+                            ((events & POLLRDHUP) ? EPOLLRDHUP : 0);
+               evt.data.fd = fd;
+               epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fd, &evt);
+
+               do {
+                       ret = epoll_wait(epoll_fd, &evt, 1, ms);
+               } while (ret == -1 && errno == EINTR);
+
+               evt.data.fd = fd;
+               epoll_ctl(epoll_fd, EPOLL_CTL_DEL, fd, &evt);
+               return ret;
+       }
+#endif
+
        do {
                pollfd.fd = fd;
                pollfd.events = events;
@@ -795,6 +827,8 @@ int main(int argc, char **argv)
                        showtime += 2;
                else if (strcmp(argv[0], "-ttt") == 0)
                        showtime += 3;
+               else if (strcmp(argv[0], "-e") == 0)
+                       use_epoll = 1;
                else if (strcmp(argv[0], "-v") == 0)
                        verbose ++;
                else if (strcmp(argv[0], "-u") == 0) {