diff mbox series

[19/35] rt: Rework lio_listio implementation

Message ID 2c539ea80218c166aa60cf117b72b7191fdf53c3.1622761828.git.fweimer@redhat.com
State New
Headers show
Series Linux: Move librt into libc | expand

Commit Message

Florian Weimer June 3, 2021, 11:16 p.m. UTC
Move the common code into rt/lio_listio-common.c and include
the file in both rt/lio_listio.c and rt/lio_listio64.c.  The common
code automatically defines both public symbols for __WORDSIZE == 64.
---
 rt/lio_listio-common.c                        | 275 ++++++++++++++++++
 rt/lio_listio.c                               | 235 +--------------
 rt/lio_listio64.c                             |  27 +-
 .../unix/sysv/linux/wordsize-64/lio_listio.c  |  13 -
 .../sysv/linux/wordsize-64/lio_listio64.c     |   1 -
 5 files changed, 292 insertions(+), 259 deletions(-)
 create mode 100644 rt/lio_listio-common.c
 delete mode 100644 sysdeps/unix/sysv/linux/wordsize-64/lio_listio.c
 delete mode 100644 sysdeps/unix/sysv/linux/wordsize-64/lio_listio64.c
diff mbox series

Patch

diff --git a/rt/lio_listio-common.c b/rt/lio_listio-common.c
new file mode 100644
index 0000000000..a85753823f
--- /dev/null
+++ b/rt/lio_listio-common.c
@@ -0,0 +1,275 @@ 
+/* Enqueue and list of read or write requests.  Common code template.
+   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
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+/* The following macros must be defined before including this file:
+
+   LIO_LISTIO         The public symbol (lio_listio or lio_listio64).
+   AIOCB              Struct tag used by LIO_LISTIO (aiocb or aiocb64).
+   LIO_LISTIO_OLD     The internal symbol for the compat implementation.
+   LIO_LISTIO_NEW     The internal symbol for the current implementation.
+   LIO_OPCODE_BASE    Opcode shift for 64-bit version with 32-bit word size.
+
+   For __WORDSIZE == 64, LIO_LISTIO must always be lio_listio, and
+   lio_listio64 is automatically defined as well.  */
+
+#include <bits/wordsize.h>
+#if __WORDSIZE == 64
+/* We use an UGLY hack to prevent gcc from finding us cheating.  The
+   implementation of lio_listio and lio_listio64 are identical and so
+   we want to avoid code duplication by using aliases.  But gcc sees
+   the different parameter lists and prints a warning.  We define here
+   a function so that lio_listio64 has no prototype.  */
+# define lio_listio64 XXX
+# include <aio.h>
+/* And undo the hack.  */
+# undef lio_listio64
+#else
+# include <aio.h>
+#endif
+
+#include <assert.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <aio_misc.h>
+
+#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
+attribute_compat_text_section
+LIO_LISTIO_OLD (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 | LIO_NO_INDIVIDUAL_EVENT, list, nent, sig);
+}
+compat_symbol (librt, LIO_LISTIO_OLD, LIO_LISTIO, GLIBC_2_1);
+# if __WORDSIZE == 64
+compat_symbol (librt, LIO_LISTIO_OLD, lio_listio64, GLIBC_2_1);
+# endif
+#endif /* SHLIB_COMPAT */
+
+
+int
+LIO_LISTIO_NEW (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_NEW, LIO_LISTIO, GLIBC_2_4);
+#if __WORDSIZE == 64
+versioned_symbol (librt, LIO_LISTIO_NEW, lio_listio64, GLIBC_2_4);
+#endif
diff --git a/rt/lio_listio.c b/rt/lio_listio.c
index 2cab3c2254..bcc3bb1393 100644
--- a/rt/lio_listio.c
+++ b/rt/lio_listio.c
@@ -1,7 +1,6 @@ 
 /* Enqueue and list of read or write requests.
-   Copyright (C) 1997-2021 Free Software Foundation, Inc.
+   Copyright (C) 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
@@ -17,232 +16,10 @@ 
    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>
-
-#include <aio_misc.h>
-
+#define LIO_LISTIO lio_listio
+#define AIOCB aiocb
+#define LIO_LISTIO_OLD __lio_listio_21
+#define LIO_LISTIO_NEW __lio_listio_24
 #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
-attribute_compat_text_section
-__lio_listio_21 (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 | LIO_NO_INDIVIDUAL_EVENT, list, nent, sig);
-}
-compat_symbol (librt, __lio_listio_21, lio_listio, GLIBC_2_1);
-#endif
-
-
-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);
+#include "lio_listio-common.c"
diff --git a/rt/lio_listio64.c b/rt/lio_listio64.c
index 111c883a2f..597bf733a2 100644
--- a/rt/lio_listio64.c
+++ b/rt/lio_listio64.c
@@ -1,7 +1,6 @@ 
-/* Enqueue and list of read or write requests, 64bit offset version.
-   Copyright (C) 1997-2021 Free Software Foundation, Inc.
+/* Enqueue and list of read or write requests.
+   Copyright (C) 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
@@ -17,17 +16,13 @@ 
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-#include <aio.h>
-#include <assert.h>
-#include <errno.h>
-#include <stdlib.h>
-#include <unistd.h>
+#include <bits/wordsize.h>
+#if __WORDSIZE != 64
+# define AIOCB aiocb64
+# define LIO_LISTIO lio_listio64
+# define LIO_LISTIO_OLD __lio_listio64_21
+# define LIO_LISTIO_NEW __lio_listio64_24
+# define LIO_OPCODE_BASE 128
 
-#include <aio_misc.h>
-
-#define lio_listio lio_listio64
-#define __lio_listio_21 __lio_listio64_21
-#define __lio_listio_item_notify __lio_listio64_item_notify
-#define aiocb aiocb64
-#define LIO_OPCODE_BASE 128
-#include <lio_listio.c>
+# include "lio_listio-common.c"
+#endif
diff --git a/sysdeps/unix/sysv/linux/wordsize-64/lio_listio.c b/sysdeps/unix/sysv/linux/wordsize-64/lio_listio.c
deleted file mode 100644
index be9fe7a9c7..0000000000
--- a/sysdeps/unix/sysv/linux/wordsize-64/lio_listio.c
+++ /dev/null
@@ -1,13 +0,0 @@ 
-#define lio_listio64 __renamed_lio_listio64
-
-#include <rt/lio_listio.c>
-
-#undef lio_listio64
-
-#if SHLIB_COMPAT (librt, GLIBC_2_1, GLIBC_2_4)
-strong_alias (__lio_listio_21, __lio_listio64_21)
-compat_symbol (librt, __lio_listio64_21, lio_listio64, GLIBC_2_1);
-#endif
-
-strong_alias (__lio_listio_item_notify, __lio_listio64_item_notify)
-versioned_symbol (librt, __lio_listio64_item_notify, lio_listio64, GLIBC_2_4);
diff --git a/sysdeps/unix/sysv/linux/wordsize-64/lio_listio64.c b/sysdeps/unix/sysv/linux/wordsize-64/lio_listio64.c
deleted file mode 100644
index 1dabae3692..0000000000
--- a/sysdeps/unix/sysv/linux/wordsize-64/lio_listio64.c
+++ /dev/null
@@ -1 +0,0 @@ 
-/* Defined in lio_listio.c.  */