Subversion Repositories Kolibri OS

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

mutex_init:

        mov     [ecx+MUTEX.wait_list.next], ecx

        mov     [ecx+MUTEX.wait_list.prev], ecx

        mov     [ecx+MUTEX.count], 1

        ret

;void  __fastcall mutex_lock(struct mutex *lock)

align 4

mutex_lock:

        dec     [ecx+MUTEX.count]

        jns     .done

        pushfd

        cli

        sub     esp, sizeof.MUTEX_WAITER

        list_add_tail esp, ecx      ;esp= new waiter, ecx= list head

        mov     edx, [TASK_BASE]

        mov     [esp+MUTEX_WAITER.task], edx

.forever:

        mov     eax, -1

        xchg    eax, [ecx+MUTEX.count]

        dec     eax

        jz      @F

        mov     [edx+TASKDATA.state], 1

        call    change_task

        jmp     .forever

@@:

        mov     eax, ecx

        list_del esp

        cmp     [eax+MUTEX.wait_list.next], eax

        jne     @F

        mov     [eax+MUTEX.count], 0

@@:

        add     esp, sizeof.MUTEX_WAITER

        popfd

.done:

        ret

;void  __fastcall mutex_unlock(struct mutex *lock)

align 4

mutex_unlock:

        pushfd

        cli

        mov     eax, [ecx+MUTEX.wait_list.next]

        cmp     eax, ecx

        mov     [ecx+MUTEX.count], 1

        je      @F

        mov     eax, [eax+MUTEX_WAITER.task]

        mov     [eax+TASKDATA.state], 0

@@:

        popfd

        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

down_read:

        pushfd

        cli

        mov     eax, [ecx+RWSEM.count]

        test    eax, eax

        js      @F

        cmp     ecx, [ecx+RWSEM.wait_list.next]

        je      .ok

@@:

        sub     esp, sizeof.MUTEX_WAITER

        mov     eax, [TASK_BASE]

        mov     [esp+MUTEX_WAITER.task], eax

        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

        call    change_task

        add     esp, sizeof.MUTEX_WAITER

        popfd

        ret

.ok:

        inc     eax

        mov     [ecx+RWSEM.count], eax

        popfd

        ret

;void __fastcall down_write(struct rw_semaphore *sem)

align 4

down_write:

        pushfd

        cli

        sub     esp, sizeof.MUTEX_WAITER

        mov     edx, [TASK_BASE]

        mov     [esp+MUTEX_WAITER.task], edx

        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

        xor     eax, eax

        not     eax

.forever:

        test    eax, [ecx+RWSEM.count]

        jz      @F

        mov     [edx+TASKDATA.state], 1

        call    change_task

        jmp     .forever

@@:

        mov     [ecx+RWSEM.count], eax

        list_del esp

        add     esp, sizeof.MUTEX_WAITER

        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