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authorUlrich Drepper <drepper@redhat.com>2007-05-15 06:49:29 +0000
committerUlrich Drepper <drepper@redhat.com>2007-05-15 06:49:29 +0000
commit2c1d61722625a1ee57ab284aad42acb7ec5662ca (patch)
tree0ea088eded588d3d43cb348687d7422598ab9382 /nptl
parent83d87915da34fc02d170ff8c356406040da2823f (diff)
downloadglibc-2c1d61722625a1ee57ab284aad42acb7ec5662ca.tar.gz
glibc-2c1d61722625a1ee57ab284aad42acb7ec5662ca.tar.xz
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* version.h (VERSION): Define to 6. glibc-2.6 cvs/glibc-2_6-base cvs/glibc-2_6
	* include/features.h (__GLIBC_MINOR__): Likewise.
Diffstat (limited to 'nptl')
-rw-r--r--nptl/ChangeLog7
-rw-r--r--nptl/TODO15
-rw-r--r--nptl/sysdeps/unix/sysv/linux/i386/i486/sem_post.S7
-rw-r--r--nptl/sysdeps/unix/sysv/linux/powerpc/sem_post.c14
-rw-r--r--nptl/sysdeps/unix/sysv/linux/sem_post.c14
-rw-r--r--nptl/sysdeps/unix/sysv/linux/sparc/sparc32/sem_post.c13
-rw-r--r--nptl/sysdeps/unix/sysv/linux/x86_64/sem_post.S9
7 files changed, 37 insertions, 42 deletions
diff --git a/nptl/ChangeLog b/nptl/ChangeLog
index 38ade7a96b..47d36966c5 100644
--- a/nptl/ChangeLog
+++ b/nptl/ChangeLog
@@ -1,12 +1,5 @@
 2007-05-14  Ulrich Drepper  <drepper@redhat.com>
 
-	* sysdeps/unix/sysv/linux/sem_post.c: Only wake threads if old
-	value of semaphore was zero.
-	* sysdeps/unix/sysv/linux/i386/i486/sem_post.S: Likewise.
-	* sysdeps/unix/sysv/linux/powerpc/sem_post.c: Likewise.
-	* sysdeps/unix/sysv/linux/sparc/sparc32/sem_post.c: Likewise.
-	* sysdeps/unix/sysv/linux/x86_64/sem_post.S: Likewise.
-
 	* sysdeps/unix/sysv/linux/x86_64/sem_wait.S: Remove unnecessary
 	extra cancellation test.
 	* sysdeps/unix/sysv/linux/x86_64/sem_timedwait.S: Likewise.
diff --git a/nptl/TODO b/nptl/TODO
index d597176512..70b8fe4f76 100644
--- a/nptl/TODO
+++ b/nptl/TODO
@@ -14,3 +14,18 @@ syscall needed.
 
 - test with threaded process terminating and semadj (?) being applied
   only after all threads are gone
+
+
+
+- semaphore changes:
+
+  - sem_post should only wake one thread and only when the state of
+    the semaphore changed from 0 to 1
+
+    this also requires that sem_wait and sem_timedwait don't drop the
+    post if they get canceled.
+
+  - possibly add counter field.  This requires reviving the
+    differences between old and new semaphose funtions.  The old ones
+    stay as they are now.  The new once can use an additional field
+    wich is the counter for the number of waiters
diff --git a/nptl/sysdeps/unix/sysv/linux/i386/i486/sem_post.S b/nptl/sysdeps/unix/sysv/linux/i386/i486/sem_post.S
index 2813c20ef8..71e96d2228 100644
--- a/nptl/sysdeps/unix/sysv/linux/i386/i486/sem_post.S
+++ b/nptl/sysdeps/unix/sysv/linux/i386/i486/sem_post.S
@@ -1,4 +1,4 @@
-/* Copyright (C) 2002, 2003, 2005, 2007 Free Software Foundation, Inc.
+/* Copyright (C) 2002, 2003, 2005 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
 
@@ -44,12 +44,9 @@ __new_sem_post:
 	LOCK
 	xaddl	%edx, (%ebx)
 
-	testl	%edx, %edx
-	jne	2f
-
 	movl	$SYS_futex, %eax
 	movl	$FUTEX_WAKE, %ecx
-	movl	$1, %edx
+	addl	$1, %edx
 	ENTER_KERNEL
 
 	testl	%eax, %eax
diff --git a/nptl/sysdeps/unix/sysv/linux/powerpc/sem_post.c b/nptl/sysdeps/unix/sysv/linux/powerpc/sem_post.c
index 86dd0ebb3b..91b9955181 100644
--- a/nptl/sysdeps/unix/sysv/linux/powerpc/sem_post.c
+++ b/nptl/sysdeps/unix/sysv/linux/powerpc/sem_post.c
@@ -1,5 +1,5 @@
 /* sem_post -- post to a POSIX semaphore.  Powerpc version.
-   Copyright (C) 2003, 2004, 2007 Free Software Foundation, Inc.
+   Copyright (C) 2003, 2004 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003.
 
@@ -32,14 +32,12 @@ __new_sem_post (sem_t *sem)
   int *futex = (int *) sem;
 
   __asm __volatile (__lll_rel_instr ::: "memory");
-  if (atomic_increment_val (futex) == 1)
+  int nr = atomic_increment_val (futex);
+  int err = lll_futex_wake (futex, nr);
+  if (__builtin_expect (err, 0) < 0)
     {
-      int err = lll_futex_wake (futex, 1);
-      if (__builtin_expect (err, 0) < 0)
-	{
-	  __set_errno (-err);
-	  return -1;
-	}
+      __set_errno (-err);
+      return -1;
     }
   return 0;
 }
diff --git a/nptl/sysdeps/unix/sysv/linux/sem_post.c b/nptl/sysdeps/unix/sysv/linux/sem_post.c
index 641ce661a1..671b43f7f7 100644
--- a/nptl/sysdeps/unix/sysv/linux/sem_post.c
+++ b/nptl/sysdeps/unix/sysv/linux/sem_post.c
@@ -1,5 +1,5 @@
 /* sem_post -- post to a POSIX semaphore.  Generic futex-using version.
-   Copyright (C) 2003, 2004, 2007 Free Software Foundation, Inc.
+   Copyright (C) 2003, 2004 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Jakub Jelinek <jakub@redhat.com>, 2003.
 
@@ -31,14 +31,12 @@ __new_sem_post (sem_t *sem)
 {
   int *futex = (int *) sem;
 
-  if (atomic_increment_val (futex) == 1)
+  int nr = atomic_increment_val (futex);
+  int err = lll_futex_wake (futex, nr);
+  if (__builtin_expect (err, 0) < 0)
     {
-      int err = lll_futex_wake (futex, 1);
-      if (__builtin_expect (err, 0) < 0)
-	{
-	  __set_errno (-err);
-	  return -1;
-	}
+      __set_errno (-err);
+      return -1;
     }
   return 0;
 }
diff --git a/nptl/sysdeps/unix/sysv/linux/sparc/sparc32/sem_post.c b/nptl/sysdeps/unix/sysv/linux/sparc/sparc32/sem_post.c
index ba77aa90bd..be1cc60b11 100644
--- a/nptl/sysdeps/unix/sysv/linux/sparc/sparc32/sem_post.c
+++ b/nptl/sysdeps/unix/sysv/linux/sparc/sparc32/sem_post.c
@@ -1,5 +1,5 @@
 /* sem_post -- post to a POSIX semaphore.  SPARC version.
-   Copyright (C) 2003, 2004, 2006, 2007 Free Software Foundation, Inc.
+   Copyright (C) 2003, 2004, 2006 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Jakub Jelinek <jakub@redhat.com>, 2003.
 
@@ -39,14 +39,11 @@ __new_sem_post (sem_t *sem)
       nr = ++*futex;
       __sparc32_atomic_do_unlock24 (futex + 1);
     }
-  if (nr == 1)
+  int err = lll_futex_wake (futex, nr);
+  if (__builtin_expect (err, 0) < 0)
     {
-      int err = lll_futex_wake (futex, 1);
-      if (__builtin_expect (err, 0) < 0)
-	{
-	  __set_errno (-err);
-	  return -1;
-	}
+      __set_errno (-err);
+      return -1;
     }
   return 0;
 }
diff --git a/nptl/sysdeps/unix/sysv/linux/x86_64/sem_post.S b/nptl/sysdeps/unix/sysv/linux/x86_64/sem_post.S
index cc3a9a9cee..7f608a5974 100644
--- a/nptl/sysdeps/unix/sysv/linux/x86_64/sem_post.S
+++ b/nptl/sysdeps/unix/sysv/linux/x86_64/sem_post.S
@@ -1,4 +1,4 @@
-/* Copyright (C) 2002, 2003, 2005, 2007 Free Software Foundation, Inc.
+/* Copyright (C) 2002, 2003, 2005 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
 
@@ -41,18 +41,15 @@ sem_post:
 	LOCK
 	xaddl	%edx, (%rdi)
 
-	testl	%edx, %edx
-	jne	2f
-
 	movl	$SYS_futex, %eax
 	movl	$FUTEX_WAKE, %esi
-	movl	$1, %edx
+	incl	%edx
 	syscall
 
 	testq	%rax, %rax
 	js	1f
 
-2:	xorl	%eax, %eax
+	xorl	%eax, %eax
 	retq
 
 1: