From 966e9d897bc413413c94d98d60721cbe92b98f27 Mon Sep 17 00:00:00 2001
From: "Sergey Semyonov (Serge)" <ion2@mail.ru>
Date: Sun, 4 Jan 2015 15:21:46 +0000
Subject: [PATCH] kernel: read/write locks, part 2

git-svn-id: svn://kolibrios.org@5344 a494cfbc-eb01-0410-851d-a64ba20cac60
---
 kernel/trunk/core/exports.inc |  3 ++
 kernel/trunk/core/sched.inc   | 99 +++++++++++++++++++++++++++++++++--
 2 files changed, 99 insertions(+), 3 deletions(-)

diff --git a/kernel/trunk/core/exports.inc b/kernel/trunk/core/exports.inc
index e11433db99..b35575c94b 100644
--- a/kernel/trunk/core/exports.inc
+++ b/kernel/trunk/core/exports.inc
@@ -45,8 +45,11 @@ __exports:
           release_pages,         'ReleasePages',       \
           alloc_dma24,           'AllocDMA24',         \      ; stdcall
 \
+          init_rwsem,            'InitRwsem',          \      ; gcc fastcall
           down_read,             'DownRead',           \      ; gcc fastcall
           down_write,            'DownWrite',          \      ; gcc fastcall
+          up_read,               'UpRead',             \      ; gcc fastcall
+          up_write,              'UpWrite',            \      ; gcc fastacll
           mutex_init,            'MutexInit',          \      ; gcc fastcall
           mutex_lock,            'MutexLock',          \      ; gcc fastcall
           mutex_unlock,          'MutexUnlock',        \      ; gcc fastcall
diff --git a/kernel/trunk/core/sched.inc b/kernel/trunk/core/sched.inc
index eccdc16e53..d5a23e749e 100644
--- a/kernel/trunk/core/sched.inc
+++ b/kernel/trunk/core/sched.inc
@@ -155,13 +155,15 @@ do_change_task:
 ;end.
 
 
-
 struct  MUTEX_WAITER
         list    LHEAD
         task    dd ?
         type    dd ?
 ends
 
+RWSEM_WAITING_FOR_WRITE equ 0
+RWSEM_WAITING_FOR_READ  equ 1
+
 ;void  __fastcall mutex_init(struct mutex *lock)
 
 align 4
@@ -234,6 +236,15 @@ mutex_unlock:
         ret
 
 
+;void __fastcall init_rwsem(struct rw_semaphore *sem)
+
+align 4
+init_rwsem:
+        mov     [ecx+RWSEM.wait_list.next], ecx
+        mov     [ecx+RWSEM.wait_list.prev], ecx
+        mov     [ecx+RWSEM.count], 0
+        ret
+
 ;void __fastcall down_read(struct rw_semaphore *sem)
 
 align 4
@@ -252,7 +263,7 @@ down_read:
 
         mov     eax, [TASK_BASE]
         mov     [esp+MUTEX_WAITER.task], eax
-        mov     [esp+MUTEX_WAITER.type], 1; RWSEM_WAITING_FOR_READ
+        mov     [esp+MUTEX_WAITER.type], RWSEM_WAITING_FOR_READ
         mov     [eax+TASKDATA.state], 1
 
         list_add_tail esp, ecx      ;esp= new waiter, ecx= list head
@@ -279,7 +290,7 @@ down_write:
 
         mov     edx, [TASK_BASE]
         mov     [esp+MUTEX_WAITER.task], edx
-        mov     [esp+MUTEX_WAITER.type], 2; RWSEM_WAITING_FOR_WRITE
+        mov     [esp+MUTEX_WAITER.type], RWSEM_WAITING_FOR_WRITE
         mov     [edx+TASKDATA.state], 1
 
         list_add_tail esp, ecx      ;esp= new waiter, ecx= list head
@@ -302,7 +313,89 @@ down_write:
         popfd
         ret
 
+;void __fastcall up_read(struct rw_semaphore *sem)
+
+align 4
+up_read:
+        pushfd
+        cli
+
+        dec     [ecx+RWSEM.count]
+        jnz     @F
+
+        mov     eax, [ecx+RWSEM.wait_list.next]
+        cmp     eax, ecx
+        je      @F
+
+        mov     eax, [eax+MUTEX_WAITER.task]
+        mov     [eax+TASKDATA.state], 0
+@@:
+        popfd
+        ret
+
+;void __fastcall up_write(struct rw_semaphore *sem)
+
+align 4
+up_write:
+
+        pushfd
+        cli
+
+        mov     eax, [ecx+RWSEM.wait_list.next]
+        mov     [ecx+RWSEM.count], 0
+
+        cmp     ecx, eax
+        je      .done
+
+        mov     edx, [eax+MUTEX_WAITER.type]
+        test    edx, edx
+        jnz     .wake
+
+        mov     eax, [eax+MUTEX_WAITER.task]
+        mov     [eax+TASKDATA.state], 0
+.done:
+        popfd
+        ret
+
+.wake:
+        push    ebx
+        push    esi
+        push    edi
+
+        xor     esi, esi
+        mov     edi, ecx
+
+.wake_list:
+
+        mov     ebx, [eax+MUTEX_WAITER.list.next]
+        list_del eax
+        mov     edx, [eax+MUTEX_WAITER.task]
+        mov     [edx+TASKDATA.state], 0
+        inc     esi
+        cmp     edi, ebx
+        je      .wake_done
+
+        mov     ecx, [ebx+MUTEX_WAITER.type]
+        test    ecx, ecx
+        jz      .wake_done
+
+        mov     eax, ebx
+        jmp     .wake_list
+
+.wake_done:
+        add     [edi+RWSEM.count], esi
+
+        pop     edi
+        pop     esi
+        pop     ebx
+        popfd
+        ret
+
+
 purge MUTEX_WAITER
+purge RWSEM_WAITING_FOR_WRITE
+purge RWSEM_WAITING_FOR_READ
+
 
 MAX_PRIORITY      = 0   ; highest, used for kernel tasks
 USER_PRIORITY     = 1   ; default