duktape-1.5.2/examples/eventloop/poll.c

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/*
 *  C wrapper for poll().
 */
 
#define _GNU_SOURCE
#include <errno.h>
#include <string.h>
#include <stdio.h>
#include <poll.h>
#include <time.h>
 
#include "duktape.h"
 
static int poll_poll(duk_context *ctx) {
    int timeout = duk_to_int(ctx, 1);
    int i, n, nchanged;
    int fd, rc;
    struct pollfd fds[20];
    struct timespec ts;
 
    memset(fds, 0, sizeof(fds));
 
    n = 0;
    duk_enum(ctx, 0, 0 /*enum_flags*/);
    while (duk_next(ctx, -1, 0)) {
        if ((size_t) n >= sizeof(fds) / sizeof(struct pollfd)) {
            return -1;
        }
 
        /* [... enum key] */
        duk_dup_top(ctx);  /* -> [... enum key key] */
        duk_get_prop(ctx, 0);  /* -> [... enum key val] */
        fd = duk_to_int(ctx, -2);
 
        duk_push_string(ctx, "events");
        duk_get_prop(ctx, -2);  /* -> [... enum key val events] */
 
        fds[n].fd = fd;
        fds[n].events = duk_to_int(ctx, -1);
        fds[n].revents = 0;
 
        duk_pop_n(ctx, 3);  /* -> [... enum] */
 
        n++;
    }
    /* leave enum on stack */
 
    memset(&ts, 0, sizeof(ts));
    ts.tv_nsec = (timeout % 1000) * 1000000;
    ts.tv_sec = timeout / 1000;
 
    /*rc = ppoll(fds, n, &ts, NULL);*/
    rc = poll(fds, n, timeout);
    if (rc < 0) {
        duk_error(ctx, DUK_ERR_ERROR, "%s (errno=%d)", strerror(errno), errno);
    }
 
    duk_push_array(ctx);
    nchanged = 0;
    for (i = 0; i < n; i++) {
        /* update revents */
 
        if (fds[i].revents) {
            duk_push_int(ctx, fds[i].fd);  /* -> [... retarr fd] */
            duk_put_prop_index(ctx, -2, nchanged);
            nchanged++;
        }
 
        duk_push_int(ctx, fds[i].fd);  /* -> [... retarr key] */
        duk_get_prop(ctx, 0);  /* -> [... retarr val] */
        duk_push_string(ctx, "revents");
        duk_push_int(ctx, fds[i].revents);  /* -> [... retarr val "revents" fds[i].revents] */
        duk_put_prop(ctx, -3);  /* -> [... retarr val] */
        duk_pop(ctx);
    }
 
    /* [retarr] */
 
    return 1;
}
 
static duk_function_list_entry poll_funcs[] = {
    { "poll", poll_poll, 2 },
    { NULL, NULL, 0 }
};
 
static duk_number_list_entry poll_consts[] = {
    { "POLLIN", (double) POLLIN },
    { "POLLPRI", (double) POLLPRI },
    { "POLLOUT", (double) POLLOUT },
#if 0
    /* Linux 2.6.17 and upwards, requires _GNU_SOURCE etc, not added
     * now because we don't use it.
     */
    { "POLLRDHUP", (double) POLLRDHUP },
#endif
    { "POLLERR", (double) POLLERR },
    { "POLLHUP", (double) POLLHUP },
    { "POLLNVAL", (double) POLLNVAL },
    { NULL, 0.0 }
};
 
void poll_register(duk_context *ctx) {
    /* Set global 'Poll' with functions and constants. */
    duk_push_global_object(ctx);
    duk_push_object(ctx);
    duk_put_function_list(ctx, -1, poll_funcs);
    duk_put_number_list(ctx, -1, poll_consts);
    duk_put_prop_string(ctx, -2, "Poll");
    duk_pop(ctx);
}