From 419012b345212fae8addc0782a39351d523d58d6 Mon Sep 17 00:00:00 2001
From: "Sergey Semyonov (Serge)" <ion2@mail.ru>
Date: Sat, 23 Jan 2016 02:36:00 +0000
Subject: [PATCH] Fn77 - use -2 return value for EWOULDBLOCK.

git-svn-id: svn://kolibrios.org@6089 a494cfbc-eb01-0410-851d-a64ba20cac60
---
 kernel/trunk/core/sync.inc     | 15 ++++++++-------
 kernel/trunk/docs/sysfuncs.txt |  5 +++--
 2 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/kernel/trunk/core/sync.inc b/kernel/trunk/core/sync.inc
index afabc4c647..969e9505a9 100644
--- a/kernel/trunk/core/sync.inc
+++ b/kernel/trunk/core/sync.inc
@@ -132,10 +132,10 @@ align 4
         jnz     .futex_wait_timeout
         mov     ecx, [ebp+FUTEX.pointer]
         mov     eax, edx
-        lock cmpxchg [ecx], edx         ;wait until old_value == new_value
-        jz      .wait_slow
+        lock cmpxchg [ecx], edx
+        je      .wait_slow
 
-        mov     [esp+SYSCALL_STACK._eax], 0
+        mov     [esp+SYSCALL_STACK._eax], -2
         ret
 
 .wait_slow:
@@ -148,13 +148,13 @@ align 4
         lea     esi, [ebp+FUTEX.wait_list]
 
         list_add_tail esp, esi      ;esp= new waiter, esi= list head
-
+        mov     eax, edx
 .again:
         mov     [ebx+TASKDATA.state], 1
         call    change_task
 
         lock cmpxchg [ecx], edx
-        jz      .again
+        je      .again
 
         list_del esp
         add     esp, sizeof.MUTEX_WAITER
@@ -174,9 +174,9 @@ align 4
         mov     ecx, [ebp+FUTEX.pointer]
         mov     eax, edx
         lock cmpxchg [ecx], edx         ;wait until old_value == new_value
-        jz      .wait_slow_timeout
+        je      .wait_slow_timeout
 
-        mov     [esp+SYSCALL_STACK._eax], 0
+        mov     [esp+SYSCALL_STACK._eax], -2
         ret
 
 align 4
@@ -210,6 +210,7 @@ align 4
         test    eax, eax
         jz      .timeout
 
+        mov     eax, edx
         lock cmpxchg [ecx], edx
         jz      .again_timeout
 @@:
diff --git a/kernel/trunk/docs/sysfuncs.txt b/kernel/trunk/docs/sysfuncs.txt
index edb9a382c5..e559d12068 100644
--- a/kernel/trunk/docs/sysfuncs.txt
+++ b/kernel/trunk/docs/sysfuncs.txt
@@ -4794,8 +4794,9 @@ Parameters:
   * edx = control value
   * esi = timeout in system ticks or 0 for infinity
 Returned value:
-  * eax = 0 - successfull, -1 on timeout
-
+  * eax = 0 - successfull
+	 -1 - timeout
+	 -2 - futex dword does not have the same value as edx
 Remarks:
   * This functionn tests that the value at the futex dword still
     contains the expected control value, and if so, then sleeps