The Tor Browser: nsprpub/pr/src/md/unix/uxwrap.c@6474c204b198 (annotated)

nsprpub/pr/src/md/unix/uxwrap.c@6474c204b198 (annotated)

nsprpub/pr/src/md/unix/uxwrap.c

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 /*
  *------------------------------------------------------------------------
  * File: uxwrap.c
  *
  *     Our wrapped versions of the Unix select() and poll() system calls.
  *
  *------------------------------------------------------------------------
  */
 #include "primpl.h"
 #if defined(_PR_PTHREADS) || defined(_PR_GLOBAL_THREADS_ONLY) || defined(QNX)
 /* Do not wrap select() and poll(). */
 #else  /* defined(_PR_PTHREADS) || defined(_PR_GLOBAL_THREADS_ONLY) */
 /* The include files for select() */
 #ifdef IRIX
 #include <unistd.h>
 #include <bstring.h>
 #endif
 #include <string.h>
 #include <sys/types.h>
 #include <sys/time.h>
 #define ZAP_SET(_to, _width)				      \
     PR_BEGIN_MACRO					      \
 	memset(_to, 0,					      \
 	       ((_width + 8*sizeof(int)-1) / (8*sizeof(int))) \
 		* sizeof(int)				      \
 	       );					      \
     PR_END_MACRO
 /* see comments in ns/cmd/xfe/mozilla.c (look for "PR_XGetXtHackFD") */
 static int _pr_xt_hack_fd = -1;
 int PR_XGetXtHackFD(void)
 {
     int fds[2];
     if (_pr_xt_hack_fd == -1) {
         if (!pipe(fds)) {
             _pr_xt_hack_fd = fds[0];
         }
     }
     return _pr_xt_hack_fd;
 }
 static int (*_pr_xt_hack_okayToReleaseXLock)(void) = 0;
 void PR_SetXtHackOkayToReleaseXLockFn(int (*fn)(void))
 {
     _pr_xt_hack_okayToReleaseXLock = fn;
 }
 /*
  *-----------------------------------------------------------------------
  *  select() --
  *
  *    Wrap up the select system call so that we can deschedule
  *    a thread that tries to wait for i/o.
  *
  *-----------------------------------------------------------------------
  */
 #if defined(HPUX9)
 int select(size_t width, int *rl, int *wl, int *el, const struct timeval *tv)
 #elif defined(AIX_RENAME_SELECT)
 int wrap_select(unsigned long width, void *rl, void *wl, void *el,
         struct timeval *tv)
 #elif defined(_PR_SELECT_CONST_TIMEVAL)
 int select(int width, fd_set *rd, fd_set *wr, fd_set *ex,
         const struct timeval *tv)
 #else
 int select(int width, fd_set *rd, fd_set *wr, fd_set *ex, struct timeval *tv)
 #endif
 {
     int osfd;
     _PRUnixPollDesc *unixpds, *unixpd, *eunixpd;
     PRInt32 pdcnt;
     PRIntervalTime timeout;
     int retVal;
 #if defined(HPUX9) || defined(AIX_RENAME_SELECT)
     fd_set *rd = (fd_set*) rl;
     fd_set *wr = (fd_set*) wl;
     fd_set *ex = (fd_set*) el;
 #endif
 #if 0
     /*
      * Easy special case: zero timeout.  Simply call the native
      * select() with no fear of blocking.
      */
     if (tv != NULL && tv->tv_sec == 0 && tv->tv_usec == 0) {
 #if defined(HPUX9) || defined(AIX_RENAME_SELECT)
         return _MD_SELECT(width, rl, wl, el, tv);
 #else
         return _MD_SELECT(width, rd, wr, ex, tv);
 #endif
     }
 #endif
     if (!_pr_initialized) {
         _PR_ImplicitInitialization();
     }
 #ifndef _PR_LOCAL_THREADS_ONLY
     if (_PR_IS_NATIVE_THREAD(_PR_MD_CURRENT_THREAD())) {
         return _MD_SELECT(width, rd, wr, ex, tv);
     }
 #endif
     if (width < 0 || width > FD_SETSIZE) {
         errno = EINVAL;
         return -1;
     }
     /* Compute timeout */
     if (tv) {
         /*
          * These acceptable ranges for t_sec and t_usec are taken
          * from the select() man pages.
          */
         if (tv->tv_sec < 0 || tv->tv_sec > 100000000
                 || tv->tv_usec < 0 || tv->tv_usec >= 1000000) {
             errno = EINVAL;
             return -1;
         }
         /* Convert microseconds to ticks */
         timeout = PR_MicrosecondsToInterval(1000000*tv->tv_sec + tv->tv_usec);
     } else {
         /* tv being a NULL pointer means blocking indefinitely */
         timeout = PR_INTERVAL_NO_TIMEOUT;
     }
     /* Check for no descriptors case (just doing a timeout) */
     if ((!rd && !wr && !ex) || !width) {
         PR_Sleep(timeout);
         return 0;
     }
     /*
      * Set up for PR_Poll().  The PRPollDesc array is allocated
      * dynamically.  If this turns out to have high performance
      * penalty, one can change to use a large PRPollDesc array
      * on the stack, and allocate dynamically only when it turns
      * out to be not large enough.
      *
      * I allocate an array of size 'width', which is the maximum
      * number of fds we may need to poll.
      */
     unixpds = (_PRUnixPollDesc *) PR_CALLOC(width * sizeof(_PRUnixPollDesc));
     if (!unixpds) {
         errno = ENOMEM;
         return -1;
     }
     pdcnt = 0;
     unixpd = unixpds;
     for (osfd = 0; osfd < width; osfd++) {
         int in_flags = 0;
         if (rd && FD_ISSET(osfd, rd)) {
             in_flags |= _PR_UNIX_POLL_READ;
         }
         if (wr && FD_ISSET(osfd, wr)) {
             in_flags |= _PR_UNIX_POLL_WRITE;
         }
         if (ex && FD_ISSET(osfd, ex)) {
             in_flags |= _PR_UNIX_POLL_EXCEPT;
         }
         if (in_flags) {
             unixpd->osfd = osfd;
             unixpd->in_flags = in_flags;
             unixpd->out_flags = 0;
             unixpd++;
             pdcnt++;
         }
     }
     /*
      * see comments in mozilla/cmd/xfe/mozilla.c (look for
      * "PR_XGetXtHackFD")
      */
    {
      int needToLockXAgain;
      needToLockXAgain = 0;
      if (rd && (_pr_xt_hack_fd != -1)
              && FD_ISSET(_pr_xt_hack_fd, rd) && PR_XIsLocked()
              && (!_pr_xt_hack_okayToReleaseXLock
              || _pr_xt_hack_okayToReleaseXLock())) {
          PR_XUnlock();
          needToLockXAgain = 1;
      }
     /* This is the potentially blocking step */
     retVal = _PR_WaitForMultipleFDs(unixpds, pdcnt, timeout);
      if (needToLockXAgain) {
          PR_XLock();
      }
    }
     if (retVal > 0) {
         /* Compute select results */
         if (rd) ZAP_SET(rd, width);
         if (wr) ZAP_SET(wr, width);
         if (ex) ZAP_SET(ex, width);
         /*
          * The return value can be either the number of ready file
          * descriptors or the number of set bits in the three fd_set's.
          */
         retVal = 0;  /* we're going to recompute */
         eunixpd = unixpds + pdcnt;
         for (unixpd = unixpds; unixpd < eunixpd; unixpd++) {
             if (unixpd->out_flags) {
                 int nbits = 0;  /* The number of set bits on for this fd */
                 if (unixpd->out_flags & _PR_UNIX_POLL_NVAL) {
                     errno = EBADF;
                     PR_LOG(_pr_io_lm, PR_LOG_ERROR,
                             ("select returns EBADF for %d", unixpd->osfd));
                     retVal = -1;
                     break;
                 }
                 /*
                  * If a socket has a pending error, it is considered
                  * both readable and writable.  (See W. Richard Stevens,
                  * Unix Network Programming, Vol. 1, 2nd Ed., Section 6.3,
                  * pp. 153-154.)  We also consider a socket readable if
                  * it has a hangup condition.
                  */
                 if (rd && (unixpd->in_flags & _PR_UNIX_POLL_READ)
                         && (unixpd->out_flags & (_PR_UNIX_POLL_READ
                         | _PR_UNIX_POLL_ERR | _PR_UNIX_POLL_HUP))) {
                     FD_SET(unixpd->osfd, rd);
                     nbits++;
                 }
                 if (wr && (unixpd->in_flags & _PR_UNIX_POLL_WRITE)
                         && (unixpd->out_flags & (_PR_UNIX_POLL_WRITE
                         | _PR_UNIX_POLL_ERR))) {
                     FD_SET(unixpd->osfd, wr);
                     nbits++;
                 }
                 if (ex && (unixpd->in_flags & _PR_UNIX_POLL_WRITE)
                         && (unixpd->out_flags & PR_POLL_EXCEPT)) {
                     FD_SET(unixpd->osfd, ex);
                     nbits++;
                 }
                 PR_ASSERT(nbits > 0);
 #if defined(HPUX) || defined(SOLARIS) || defined(OSF1) || defined(AIX)
                 retVal += nbits;
 #else /* IRIX */
                 retVal += 1;
 #endif
             }
         }
     }
     PR_ASSERT(tv || retVal != 0);
     PR_LOG(_pr_io_lm, PR_LOG_MIN, ("select returns %d", retVal));
     PR_DELETE(unixpds);
     return retVal;
 }
 /*
  * Redefine poll, when supported on platforms, for local threads
  */
 /*
  * I am commenting out the poll() wrapper for Linux for now
  * because it is difficult to define _MD_POLL that works on all
  * Linux varieties.  People reported that glibc 2.0.7 on Debian
  * 2.0 Linux machines doesn't have the __syscall_poll symbol
  * defined.  (WTC 30 Nov. 1998)
  */
 #if defined(_PR_POLL_AVAILABLE) && !defined(LINUX)
 /*
  *-----------------------------------------------------------------------
  * poll() --
  *
  * RETURN VALUES:
  *     -1:  fails, errno indicates the error.
  *      0:  timed out, the revents bitmasks are not set.
  *      positive value: the number of file descriptors for which poll()
  *          has set the revents bitmask.
  *
  *-----------------------------------------------------------------------
  */
 #include <poll.h>
 #if defined(AIX_RENAME_SELECT)
 int wrap_poll(void *listptr, unsigned long nfds, long timeout)
 #elif (defined(AIX) && !defined(AIX_RENAME_SELECT))
 int poll(void *listptr, unsigned long nfds, long timeout)
 #elif defined(OSF1) || (defined(HPUX) && !defined(HPUX9))
 int poll(struct pollfd filedes[], unsigned int nfds, int timeout)
 #elif defined(HPUX9)
 int poll(struct pollfd filedes[], int nfds, int timeout)
 #elif defined(NETBSD)
 int poll(struct pollfd *filedes, nfds_t nfds, int timeout)
 #elif defined(OPENBSD)
 int poll(struct pollfd filedes[], nfds_t nfds, int timeout)
 #elif defined(FREEBSD)
 int poll(struct pollfd *filedes, unsigned nfds, int timeout)
 #else
 int poll(struct pollfd *filedes, unsigned long nfds, int timeout)
 #endif
 {
 #ifdef AIX
     struct pollfd *filedes = (struct pollfd *) listptr;
 #endif
     struct pollfd *pfd, *epfd;
     _PRUnixPollDesc *unixpds, *unixpd, *eunixpd;
     PRIntervalTime ticks;
     PRInt32 pdcnt;
     int ready;
     /*
      * Easy special case: zero timeout.  Simply call the native
      * poll() with no fear of blocking.
      */
     if (timeout == 0) {
 #if defined(AIX)
         return _MD_POLL(listptr, nfds, timeout);
 #else
         return _MD_POLL(filedes, nfds, timeout);
 #endif
     }
     if (!_pr_initialized) {
         _PR_ImplicitInitialization();
     }
 #ifndef _PR_LOCAL_THREADS_ONLY
     if (_PR_IS_NATIVE_THREAD(_PR_MD_CURRENT_THREAD())) {
     	return _MD_POLL(filedes, nfds, timeout);
     }
 #endif
     /* We do not support the pollmsg structures on AIX */
 #ifdef AIX
     PR_ASSERT((nfds & 0xff00) == 0);
 #endif
     if (timeout < 0 && timeout != -1) {
         errno = EINVAL;
         return -1;
     }
     /* Convert timeout from miliseconds to ticks */
     if (timeout == -1) {
         ticks = PR_INTERVAL_NO_TIMEOUT;
     } else {
         ticks = PR_MillisecondsToInterval(timeout);
     }
     /* Check for no descriptor case (just do a timeout) */
     if (nfds == 0) {
         PR_Sleep(ticks);
         return 0;
     }
     unixpds = (_PRUnixPollDesc *)
             PR_MALLOC(nfds * sizeof(_PRUnixPollDesc));
     if (NULL == unixpds) {
         errno = EAGAIN;
         return -1;
     }
     pdcnt = 0;
     epfd = filedes + nfds;
     unixpd = unixpds;
     for (pfd = filedes; pfd < epfd; pfd++) {
         /*
          * poll() ignores negative fd's.
          */
         if (pfd->fd >= 0) {
             unixpd->osfd = pfd->fd;
 #ifdef _PR_USE_POLL
             unixpd->in_flags = pfd->events;
 #else
             /*
              * Map the poll events to one of the three that can be
              * represented by the select fd_sets:
              *     POLLIN, POLLRDNORM  ===> readable
              *     POLLOUT, POLLWRNORM ===> writable
              *     POLLPRI, POLLRDBAND ===> exception
              *     POLLNORM, POLLWRBAND (and POLLMSG on some platforms)
              *     are ignored.
              *
              * The output events POLLERR and POLLHUP are never turned on.
              * POLLNVAL may be turned on.
              */
             unixpd->in_flags = 0;
             if (pfd->events & (POLLIN
 #ifdef POLLRDNORM
                     | POLLRDNORM
 #endif
                     )) {
                 unixpd->in_flags |= _PR_UNIX_POLL_READ;
             }
             if (pfd->events & (POLLOUT
 #ifdef POLLWRNORM
                     | POLLWRNORM
 #endif
                     )) {
                 unixpd->in_flags |= _PR_UNIX_POLL_WRITE;
             }
             if (pfd->events & (POLLPRI
 #ifdef POLLRDBAND
                     | POLLRDBAND
 #endif
                     )) {
                 unixpd->in_flags |= PR_POLL_EXCEPT;
             }
 #endif  /* _PR_USE_POLL */
             unixpd->out_flags = 0;
             unixpd++;
             pdcnt++;
         }
     }
     ready = _PR_WaitForMultipleFDs(unixpds, pdcnt, ticks);
     if (-1 == ready) {
         if (PR_GetError() == PR_PENDING_INTERRUPT_ERROR) {
             errno = EINTR;  /* XXX we aren't interrupted by a signal, but... */
         } else {
             errno = PR_GetOSError();
         }
     }
     if (ready <= 0) {
         goto done;
     }
     /*
      * Copy the out_flags from the _PRUnixPollDesc structures to the
      * user's pollfd structures and free the allocated memory
      */
     unixpd = unixpds;
     for (pfd = filedes; pfd < epfd; pfd++) {
         pfd->revents = 0;
         if (pfd->fd >= 0) {
 #ifdef _PR_USE_POLL
             pfd->revents = unixpd->out_flags;
 #else
             if (0 != unixpd->out_flags) {
                 if (unixpd->out_flags & _PR_UNIX_POLL_READ) {
                     if (pfd->events & POLLIN) {
                         pfd->revents |= POLLIN;
                     }
 #ifdef POLLRDNORM
                     if (pfd->events & POLLRDNORM) {
                         pfd->revents |= POLLRDNORM;
                     }
 #endif
                 }
                 if (unixpd->out_flags & _PR_UNIX_POLL_WRITE) {
                     if (pfd->events & POLLOUT) {
                         pfd->revents |= POLLOUT;
                     }
 #ifdef POLLWRNORM
                     if (pfd->events & POLLWRNORM) {
                         pfd->revents |= POLLWRNORM;
                     }
 #endif
                 }
                 if (unixpd->out_flags & _PR_UNIX_POLL_EXCEPT) {
                     if (pfd->events & POLLPRI) {
                         pfd->revents |= POLLPRI;
                     }
 #ifdef POLLRDBAND
                     if (pfd->events & POLLRDBAND) {
                         pfd->revents |= POLLRDBAND;
                     }
 #endif
                 }
                 if (unixpd->out_flags & _PR_UNIX_POLL_ERR) {
                     pfd->revents |= POLLERR;
                 }
                 if (unixpd->out_flags & _PR_UNIX_POLL_NVAL) {
                     pfd->revents |= POLLNVAL;
                 }
                 if (unixpd->out_flags & _PR_UNIX_POLL_HUP) {
                     pfd->revents |= POLLHUP;
                 }
             }
 #endif  /* _PR_USE_POLL */
             unixpd++;
         }
     }
 done:
     PR_DELETE(unixpds);
     return ready;
 }
 #endif  /* !defined(LINUX) */
 #endif  /* defined(_PR_PTHREADS) || defined(_PR_GLOBAL_THREADS_ONLY) */
 /* uxwrap.c */

The Tor Browser / annotate

nsprpub/pr/src/md/unix/uxwrap.c@6474c204b198 (annotated)

nsprpub/pr/src/md/unix/uxwrap.c