rt: Move generic implementation from sysdeps/pthread to rt

The pthread-based implementation is the generic one.  Replacing
the stubs makes it clear that they do not have to be adjusted for
the libpthread move.

Result of:

    git mv -f sysdeps/pthread/aio_misc.h sysdeps/generic/
    git mv sysdeps/pthread/timer_routines.c sysdeps/htl/
    git mv -f sysdeps/pthread/{aio,lio,timer}_*.c rt/

Followed by manual adjustment of the #include paths in
sysdeps/unix/sysv/linux/wordsize-64, and a move of the version
definitions formerly in sysdeps/pthread/Versions.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

1 files changed, 222 insertions, 14 deletions

diff --git a/rt/lio_listio.c b/rt/lio_listio.c
index db4ce68afc..2cab3c2254 100644
--- a/rt/lio_listio.c
+++ b/rt/lio_listio.c
@@ -1,6 +1,7 @@
-/* Enqueue a list of read or write requests.  Stub version.
-   Copyright (C) 2001-2021 Free Software Foundation, Inc.
+/* Enqueue and list of read or write requests.
+   Copyright (C) 1997-2021 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
 
    The GNU C Library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
@@ -16,25 +17,232 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
+#ifndef lio_listio
 #include <aio.h>
+#include <assert.h>
 #include <errno.h>
+#include <stdlib.h>
+#include <unistd.h>
 
-#ifdef BE_AIO64
-#define lio_listio	lio_listio64
-#define aiocb		aiocb64
-#define aio_read	aio_read64
-#define aio_write	aio_write64
-#define aio_suspend	aio_suspend64
+#include <aio_misc.h>
+
+#define LIO_OPCODE_BASE 0
+#endif
+
+#include <shlib-compat.h>
+
+
+/* We need this special structure to handle asynchronous I/O.  */
+struct async_waitlist
+  {
+    unsigned int counter;
+    struct sigevent sigev;
+    struct waitlist list[0];
+  };
+
+
+/* The code in glibc 2.1 to glibc 2.4 issued only one event when all
+   requests submitted with lio_listio finished.  The existing practice
+   is to issue events for the individual requests as well.  This is
+   what the new code does.  */
+#if SHLIB_COMPAT (librt, GLIBC_2_1, GLIBC_2_4)
+# define LIO_MODE(mode) ((mode) & 127)
+# define NO_INDIVIDUAL_EVENT_P(mode) ((mode) & 128)
+#else
+# define LIO_MODE(mode) mode
+# define NO_INDIVIDUAL_EVENT_P(mode) 0
+#endif
+
+
+static int
+lio_listio_internal (int mode, struct aiocb *const list[], int nent,
+		     struct sigevent *sig)
+{
+  struct sigevent defsigev;
+  struct requestlist *requests[nent];
+  int cnt;
+  volatile unsigned int total = 0;
+  int result = 0;
+
+  if (sig == NULL)
+    {
+      defsigev.sigev_notify = SIGEV_NONE;
+      sig = &defsigev;
+    }
+
+  /* Request the mutex.  */
+  pthread_mutex_lock (&__aio_requests_mutex);
+
+  /* Now we can enqueue all requests.  Since we already acquired the
+     mutex the enqueue function need not do this.  */
+  for (cnt = 0; cnt < nent; ++cnt)
+    if (list[cnt] != NULL && list[cnt]->aio_lio_opcode != LIO_NOP)
+      {
+	if (NO_INDIVIDUAL_EVENT_P (mode))
+	  list[cnt]->aio_sigevent.sigev_notify = SIGEV_NONE;
+
+	requests[cnt] = __aio_enqueue_request ((aiocb_union *) list[cnt],
+					       (list[cnt]->aio_lio_opcode
+						| LIO_OPCODE_BASE));
+
+	if (requests[cnt] != NULL)
+	  /* Successfully enqueued.  */
+	  ++total;
+	else
+	  /* Signal that we've seen an error.  `errno' and the error code
+	     of the aiocb will tell more.  */
+	  result = -1;
+      }
+    else
+      requests[cnt] = NULL;
+
+  if (total == 0)
+    {
+      /* We don't have anything to do except signalling if we work
+	 asynchronously.  */
+
+      /* Release the mutex.  We do this before raising a signal since the
+	 signal handler might do a `siglongjmp' and then the mutex is
+	 locked forever.  */
+      pthread_mutex_unlock (&__aio_requests_mutex);
+
+      if (LIO_MODE (mode) == LIO_NOWAIT)
+	__aio_notify_only (sig);
+
+      return result;
+    }
+  else if (LIO_MODE (mode) == LIO_WAIT)
+    {
+#ifndef DONT_NEED_AIO_MISC_COND
+      pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
+      int oldstate;
+#endif
+      struct waitlist waitlist[nent];
+
+      total = 0;
+      for (cnt = 0; cnt < nent; ++cnt)
+	{
+	  assert (requests[cnt] == NULL || list[cnt] != NULL);
+
+	  if (requests[cnt] != NULL && list[cnt]->aio_lio_opcode != LIO_NOP)
+	    {
+#ifndef DONT_NEED_AIO_MISC_COND
+	      waitlist[cnt].cond = &cond;
 #endif
+	      waitlist[cnt].result = &result;
+	      waitlist[cnt].next = requests[cnt]->waiting;
+	      waitlist[cnt].counterp = &total;
+	      waitlist[cnt].sigevp = NULL;
+	      requests[cnt]->waiting = &waitlist[cnt];
+	      ++total;
+	    }
+	}
 
+#ifdef DONT_NEED_AIO_MISC_COND
+      AIO_MISC_WAIT (result, total, NULL, 0);
+#else
+      /* Since `pthread_cond_wait'/`pthread_cond_timedwait' are cancellation
+	 points we must be careful.  We added entries to the waiting lists
+	 which we must remove.  So defer cancellation for now.  */
+      pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &oldstate);
 
+      while (total > 0)
+	pthread_cond_wait (&cond, &__aio_requests_mutex);
+
+      /* Now it's time to restore the cancellation state.  */
+      pthread_setcancelstate (oldstate, NULL);
+
+      /* Release the conditional variable.  */
+      if (pthread_cond_destroy (&cond) != 0)
+	/* This must never happen.  */
+	abort ();
+#endif
+
+      /* If any of the I/O requests failed, return -1 and set errno.  */
+      if (result != 0)
+	{
+	  __set_errno (result == EINTR ? EINTR : EIO);
+	  result = -1;
+	}
+    }
+  else
+    {
+      struct async_waitlist *waitlist;
+
+      waitlist = (struct async_waitlist *)
+	malloc (sizeof (struct async_waitlist)
+		+ (nent * sizeof (struct waitlist)));
+
+      if (waitlist == NULL)
+	{
+	  __set_errno (EAGAIN);
+	  result = -1;
+	}
+      else
+	{
+	  total = 0;
+
+	  for (cnt = 0; cnt < nent; ++cnt)
+	    {
+	      assert (requests[cnt] == NULL || list[cnt] != NULL);
+
+	      if (requests[cnt] != NULL
+		  && list[cnt]->aio_lio_opcode != LIO_NOP)
+		{
+#ifndef DONT_NEED_AIO_MISC_COND
+		  waitlist->list[cnt].cond = NULL;
+#endif
+		  waitlist->list[cnt].result = NULL;
+		  waitlist->list[cnt].next = requests[cnt]->waiting;
+		  waitlist->list[cnt].counterp = &waitlist->counter;
+		  waitlist->list[cnt].sigevp = &waitlist->sigev;
+		  requests[cnt]->waiting = &waitlist->list[cnt];
+		  ++total;
+		}
+	    }
+
+	  waitlist->counter = total;
+	  waitlist->sigev = *sig;
+	}
+    }
+
+  /* Release the mutex.  */
+  pthread_mutex_unlock (&__aio_requests_mutex);
+
+  return result;
+}
+
+
+#if SHLIB_COMPAT (librt, GLIBC_2_1, GLIBC_2_4)
 int
-lio_listio (int mode,
-	    struct aiocb *const list[], int nent,
-	    struct sigevent *sig)
+attribute_compat_text_section
+__lio_listio_21 (int mode, struct aiocb *const list[], int nent,
+		 struct sigevent *sig)
 {
-  __set_errno (ENOSYS);
-  return -1;
+  /* Check arguments.  */
+  if (mode != LIO_WAIT && mode != LIO_NOWAIT)
+    {
+      __set_errno (EINVAL);
+      return -1;
+    }
+
+  return lio_listio_internal (mode | LIO_NO_INDIVIDUAL_EVENT, list, nent, sig);
 }
+compat_symbol (librt, __lio_listio_21, lio_listio, GLIBC_2_1);
+#endif
 
-stub_warning (lio_listio)
+
+int
+__lio_listio_item_notify (int mode, struct aiocb *const list[], int nent,
+			  struct sigevent *sig)
+{
+    /* Check arguments.  */
+  if (mode != LIO_WAIT && mode != LIO_NOWAIT)
+    {
+      __set_errno (EINVAL);
+      return -1;
+    }
+
+  return lio_listio_internal (mode, list, nent, sig);
+}
+versioned_symbol (librt, __lio_listio_item_notify, lio_listio, GLIBC_2_4);