otherchild.c

Apache V2.0.15 Alpha For Linuxhttpd-2_0_15-alpha.tar.Z

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#include "apr.h"
#include "misc.h"
#include "threadproc.h"
#include "fileio.h"
#ifdef HAVE_TIME_H
#include <sys/time.h>
#endif
#ifdef HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif
#if APR_HAVE_SYS_WAIT_H
#include <sys/wait.h>
#endif
#ifdef BEOS
#include <sys/socket.h> /* for fd_set definition! */
#endif

static apr_other_child_rec_t *other_children = NULL;

APR_DECLARE(void) apr_proc_other_child_register(apr_proc_t *pid,
                     void (*maintenance) (int reason, void *, int status),
                     void *data, apr_file_t *write_fd, apr_pool_t *p)
{
    apr_other_child_rec_t *ocr;

    ocr = apr_palloc(p, sizeof(*ocr));
    ocr->id = pid->pid;
    ocr->maintenance = maintenance;
    ocr->data = data;
    if (write_fd == NULL) {
        ocr->write_fd = -1;
    }
    else {
        ocr->write_fd = write_fd->filedes;
    }
    ocr->next = other_children;
    other_children = ocr;
}

APR_DECLARE(void) apr_proc_other_child_unregister(void *data)
{
    apr_other_child_rec_t **pocr, *nocr;

    for (pocr = &other_children; *pocr; pocr = &(*pocr)->next) {
        if ((*pocr)->data == data) {
            nocr = (*pocr)->next;
            (*(*pocr)->maintenance) (APR_OC_REASON_UNREGISTER, (*pocr)->data, -1);
            *pocr = nocr;
            /* XXX: um, well we've just wasted some space in pconf ? */
            return;
        }
    }
}

/* test to ensure that the write_fds are all still writable, otherwise
 * invoke the maintenance functions as appropriate */
void apr_proc_probe_writable_fds(void)
{
    fd_set writable_fds;
    int fd_max;
    apr_other_child_rec_t *ocr, *nocr; 
    struct timeval tv; 
    int rc;

    if (other_children == NULL)
        return;

    fd_max = 0;
    FD_ZERO(&writable_fds);
    do {
        for (ocr = other_children; ocr; ocr = ocr->next) {
            if (ocr->write_fd == -1)
                continue;
            FD_SET(ocr->write_fd, &writable_fds);
            if (ocr->write_fd > fd_max) {
                fd_max = ocr->write_fd;
            }
        }
        if (fd_max == 0)
            return;

        tv.tv_sec = 0;
        tv.tv_usec = 0;
        rc = select(fd_max + 1, NULL, &writable_fds, NULL, &tv);
    } while (rc == -1 && errno == EINTR);

    if (rc == -1) {
        /* XXX: uhh this could be really bad, we could have a bad file
         * descriptor due to a bug in one of the maintenance routines */
        return;
    }
    if (rc == 0)
        return;

    for (ocr = other_children; ocr; ocr = nocr) {
        nocr = ocr->next;
        if (ocr->write_fd == -1)
            continue;
        if (FD_ISSET(ocr->write_fd, &writable_fds))
            continue;
        (*ocr->maintenance) (APR_OC_REASON_UNWRITABLE, ocr->data, -1);
    }
}

APR_DECLARE(apr_status_t) apr_proc_other_child_read(apr_proc_t *pid, int status)
{
    apr_other_child_rec_t *ocr, *nocr;

    for (ocr = other_children; ocr; ocr = nocr) {
        nocr = ocr->next;
        if (ocr->id != pid->pid)
            continue;

        ocr->id = -1;
        (*ocr->maintenance) (APR_OC_REASON_DEATH, ocr->data, status);
        return 0;
    }
    return APR_CHILD_NOTDONE;
}

APR_DECLARE(void) apr_proc_other_child_check(void)
{
    apr_other_child_rec_t *ocr, *nocr;
    pid_t waitret; 
    int status;

    for (ocr = other_children; ocr; ocr = nocr) {
        nocr = ocr->next;
        if (ocr->id == -1)
            continue;

        waitret = waitpid(ocr->id, &status, WNOHANG);
        if (waitret == ocr->id) {
            ocr->id = -1;
            (*ocr->maintenance) (APR_OC_REASON_DEATH, ocr->data, status);
        }
        else if (waitret == 0) {
            (*ocr->maintenance) (APR_OC_REASON_RESTART, ocr->data, -1);
        }
        else if (waitret == -1) {
            /* uh what the heck? they didn't call unregister? */
            ocr->id = -1;
            (*ocr->maintenance) (APR_OC_REASON_LOST, ocr->data, -1);
        }
    }
}