Piotr Caban : msvcr100: Add reader_writer_lock implementation.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: a9c215cee3fee0df604c993e5ced26d4d525c7c2
URL:    http://source.winehq.org/git/wine.git/?a=commit;h=a9c215cee3fee0df604c993e5c...

Author: Piotr Caban 
Date:   Thu Jan 26 17:30:30 2017 +0100

msvcr100: Add reader_writer_lock implementation.

Signed-off-by: Piotr Caban 
Signed-off-by: Alexandre Julliard

---

dlls/msvcrt/lock.c | 177 ++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 170 insertions(+), 7 deletions(-)

diff --git a/dlls/msvcrt/lock.c b/dlls/msvcrt/lock.c
index 0aa1f1f..8c1061a 100644
--- a/dlls/msvcrt/lock.c
+++ b/dlls/msvcrt/lock.c
@@ -746,7 +746,17 @@ typedef struct
 DEFINE_THISCALL_WRAPPER(reader_writer_lock_ctor, 4)
 reader_writer_lock* __thiscall reader_writer_lock_ctor(reader_writer_lock *this)
 {
-    FIXME("(%p) stub\n", this);
+    TRACE("(%p)\n", this);
+
+    if (!keyed_event) {
+        HANDLE event;
+
+        NtCreateKeyedEvent(&event, GENERIC_READ|GENERIC_WRITE, NULL, 0);
+        if (InterlockedCompareExchangePointer(&keyed_event, event, NULL) != NULL)
+            NtClose(event);
+    }
+
+    memset(this, 0, sizeof(*this));
     return this;
 }

@@ -755,7 +765,42 @@ reader_writer_lock* __thiscall reader_writer_lock_ctor(reader_writer_lock *this)
 DEFINE_THISCALL_WRAPPER(reader_writer_lock_dtor, 4)
 void __thiscall reader_writer_lock_dtor(reader_writer_lock *this)
 {
-    FIXME("(%p) stub\n", this);
+    TRACE("(%p)\n", this);
+
+    if (this->thread_id != 0 || this->count)
+        WARN("destroying locked reader_writer_lock\n");
+}
+
+static inline void spin_wait_for_next_rwl(rwl_queue *q)
+{
+    SpinWait sw;
+
+    if(q->next) return;
+
+    SpinWait_ctor(&sw, &spin_wait_yield);
+    SpinWait__Reset(&sw);
+    while(!q->next)
+        SpinWait__SpinOnce(&sw);
+    SpinWait_dtor(&sw);
+}
+
+/* Remove when proper InterlockedOr implementation is added to wine */
+static LONG InterlockedOr(LONG *d, LONG v)
+{
+    LONG l;
+    while (~(l = *d) & v)
+        if (InterlockedCompareExchange(d, l|v, l) == l) break;
+    return l;
+}
+
+static LONG InterlockedAnd(LONG *d, LONG v)
+{
+    LONG l = *d, old;
+    while ((l & v) != l) {
+        if((old = InterlockedCompareExchange(d, l&v, l)) == l) break;
+        l = old;
+    }
+    return l;
 }

/* ?lock@reader_writer_lock@Concurrency@@QAEXXZ */
@@ -763,7 +808,30 @@ void __thiscall reader_writer_lock_dtor(reader_writer_lock *this)
 DEFINE_THISCALL_WRAPPER(reader_writer_lock_lock, 4)
 void __thiscall reader_writer_lock_lock(reader_writer_lock *this)
 {
-    FIXME("(%p) stub\n", this);
+    rwl_queue q = { NULL }, *last;
+
+    TRACE("(%p)\n", this);
+
+    if (this->thread_id == GetCurrentThreadId())
+        FIXME("throw improper_lock exception\n");
+
+    last = InterlockedExchangePointer((void**)&this->writer_tail, &q);
+    if (last) {
+        last->next = &q;
+        NtWaitForKeyedEvent(keyed_event, &q, 0, NULL);
+    } else {
+        this->writer_head = &q;
+        if (InterlockedOr(&this->count, WRITER_WAITING))
+            NtWaitForKeyedEvent(keyed_event, &q, 0, NULL);
+    }
+
+    this->thread_id = GetCurrentThreadId();
+    this->writer_head = &this->active;
+    this->active.next = NULL;
+    if (InterlockedCompareExchangePointer((void**)&this->writer_tail, &this->active, &q) != &q) {
+        spin_wait_for_next_rwl(&q);
+        this->active.next = q.next;
+    }
 }

/* ?lock_read@reader_writer_lock@Concurrency@@QAEXXZ */
@@ -771,7 +839,37 @@ void __thiscall reader_writer_lock_lock(reader_writer_lock *this)
 DEFINE_THISCALL_WRAPPER(reader_writer_lock_lock_read, 4)
 void __thiscall reader_writer_lock_lock_read(reader_writer_lock *this)
 {
-    FIXME("(%p) stub\n", this);
+    rwl_queue q;
+
+    TRACE("(%p)\n", this);
+
+    if (this->thread_id == GetCurrentThreadId())
+        FIXME("throw improper_lock exception\n");
+
+    do {
+        q.next = this->reader_head;
+    } while(InterlockedCompareExchangePointer((void**)&this->reader_head, &q, q.next) != q.next);
+
+    if (!q.next) {
+        rwl_queue *head;
+        LONG count;
+
+        while (!((count = this->count) & WRITER_WAITING))
+            if (InterlockedCompareExchange(&this->count, count+1, count) == count) break;
+
+        if (count & WRITER_WAITING)
+            NtWaitForKeyedEvent(keyed_event, &q, 0, NULL);
+
+        head = InterlockedExchangePointer((void**)&this->reader_head, NULL);
+        while(head && head != &q) {
+            rwl_queue *next = head->next;
+            InterlockedIncrement(&this->count);
+            NtReleaseKeyedEvent(keyed_event, head, 0, NULL);
+            head = next;
+        }
+    } else {
+        NtWaitForKeyedEvent(keyed_event, &q, 0, NULL);
+    }
 }

/* ?try_lock@reader_writer_lock@Concurrency@@QAE_NXZ */
@@ -779,7 +877,37 @@ void __thiscall reader_writer_lock_lock_read(reader_writer_lock *this)
 DEFINE_THISCALL_WRAPPER(reader_writer_lock_try_lock, 4)
 MSVCRT_bool __thiscall reader_writer_lock_try_lock(reader_writer_lock *this)
 {
-    FIXME("(%p) stub\n", this);
+    rwl_queue q = { NULL };
+
+    TRACE("(%p)\n", this);
+
+    if (this->thread_id == GetCurrentThreadId())
+        FIXME("throw improper_lock exception\n");
+
+    if (InterlockedCompareExchangePointer((void**)&this->writer_tail, &q, NULL))
+        return FALSE;
+    this->writer_head = &q;
+    if (!InterlockedCompareExchange(&this->count, WRITER_WAITING, 0)) {
+        this->thread_id = GetCurrentThreadId();
+        this->writer_head = &this->active;
+        this->active.next = NULL;
+        if (InterlockedCompareExchangePointer((void**)&this->writer_tail, &this->active, &q) != &q) {
+            spin_wait_for_next_rwl(&q);
+            this->active.next = q.next;
+        }
+        return TRUE;
+    }
+
+    if (InterlockedCompareExchangePointer((void**)&this->writer_tail, NULL, &q) == &q)
+        return FALSE;
+    spin_wait_for_next_rwl(&q);
+    this->writer_head = q.next;
+    if (!InterlockedOr(&this->count, WRITER_WAITING)) {
+        this->thread_id = GetCurrentThreadId();
+        this->writer_head = &this->active;
+        this->active.next = q.next;
+        return TRUE;
+    }
     return FALSE;
 }

@@ -788,7 +916,12 @@ MSVCRT_bool __thiscall reader_writer_lock_try_lock(reader_writer_lock *this)
 DEFINE_THISCALL_WRAPPER(reader_writer_lock_try_lock_read, 4)
 MSVCRT_bool __thiscall reader_writer_lock_try_lock_read(reader_writer_lock *this)
 {
-    FIXME("(%p) stub\n", this);
+    LONG count;
+
+    TRACE("(%p)\n", this);
+
+    while (!((count = this->count) & WRITER_WAITING))
+        if (InterlockedCompareExchange(&this->count, count+1, count) == count) return TRUE;
     return FALSE;
 }

@@ -797,7 +930,37 @@ MSVCRT_bool __thiscall reader_writer_lock_try_lock_read(reader_writer_lock *this
 DEFINE_THISCALL_WRAPPER(reader_writer_lock_unlock, 4)
 void __thiscall reader_writer_lock_unlock(reader_writer_lock *this)
 {
-    FIXME("(%p) stub\n", this);
+    LONG count;
+    rwl_queue *head, *next;
+
+    TRACE("(%p)\n", this);
+
+    if ((count = this->count) & ~WRITER_WAITING) {
+        count = InterlockedDecrement(&this->count);
+        if (count != WRITER_WAITING)
+            return;
+        NtReleaseKeyedEvent(keyed_event, this->writer_head, 0, NULL);
+        return;
+    }
+
+    this->thread_id = 0;
+    next = this->writer_head->next;
+    if (next) {
+        NtReleaseKeyedEvent(keyed_event, next, 0, NULL);
+        return;
+    }
+    InterlockedAnd(&this->count, ~WRITER_WAITING);
+    head = InterlockedExchangePointer((void**)&this->reader_head, NULL);
+    while (head) {
+        next = head->next;
+        InterlockedIncrement(&this->count);
+        NtReleaseKeyedEvent(keyed_event, head, 0, NULL);
+        head = next;
+    }
+
+    if (InterlockedCompareExchangePointer((void**)&this->writer_tail, NULL, this->writer_head) == this->writer_head)
+        return;
+    InterlockedOr(&this->count, WRITER_WAITING);
 }
 #endif