From 921d157ee02aa37dea5083adfc0ff52ce9f792ad Mon Sep 17 00:00:00 2001
From: Sam Hocevar <sam@hocevar.net>
Date: Wed, 30 Nov 2011 18:31:34 +0000
Subject: [PATCH] core: implement Queue on Win32 and on the PS3.

---
 src/platform/ps3/threadbase.h | 61 ++++++++++++++++++++++++++++-------
 src/thread/threadbase.h       | 49 +++++++++++++++++++++++-----
 2 files changed, 91 insertions(+), 19 deletions(-)

diff --git a/src/platform/ps3/threadbase.h b/src/platform/ps3/threadbase.h
index 673c9eac..0a46b1be 100644
--- a/src/platform/ps3/threadbase.h
+++ b/src/platform/ps3/threadbase.h
@@ -52,34 +52,73 @@ private:
     sys_lwmutex_t m_mutex;
 };
 
-class ConditionBase
+class QueueBase
 {
 public:
-    ConditionBase()
+    QueueBase()
     {
-    }
+        m_start = m_count = 0;
+        m_poppers = m_pushers = 0;
 
-    ~ConditionBase()
-    {
-    }
+        sys_lwmutex_attribute_t mattr;
+        sys_lwmutex_attribute_initialize(mattr);
+        sys_lwmutex_create(&m_mutex, &mattr);
 
-    void Acquire()
-    {
+        sys_lwcond_attribute_t cattr;
+        sys_lwcond_attribute_initialize(cattr);
+        sys_lwcond_create(&m_empty_cond, &m_mutex, &cattr);
+        sys_lwcond_create(&m_full_cond, &m_mutex, &cattr);
     }
 
-    void Release()
+    ~QueueBase()
     {
+        while (sys_lwcond_destroy(&m_empty_cond) == EBUSY)
+            ;
+        while (sys_lwcond_destroy(&m_full_cond) == EBUSY)
+            ;
+        while (sys_lwmutex_destroy(&m_mutex) == EBUSY)
+            ;
     }
 
-    void Wait()
+    void Push(int value)
     {
+        /* FIXME: this is a copy of the pthread implementation, but we
+         * should really use libsync2 instead. */
+        sys_lwmutex_lock(&m_mutex, 0);
+        m_pushers++;
+        while (m_count == CAPACITY)
+            sys_lwcond_wait(&m_full_cond, 0);
+        m_pushers--;
+        m_values[(m_start + m_count) % CAPACITY] = value;
+        m_count++;
+        if (m_poppers)
+            sys_lwcond_signal(&m_empty_cond);
+        sys_lwmutex_unlock(&m_mutex);
     }
 
-    void Notify()
+    int Pop()
     {
+        sys_lwmutex_lock(&m_mutex, 0);
+        m_poppers++;
+        while (m_count == 0)
+            sys_lwcond_wait(&m_empty_cond, 0);
+        m_poppers--;
+        int ret = m_values[m_start];
+        m_start = (m_start + 1) % CAPACITY;
+        m_count--;
+        if (m_pushers)
+            sys_lwcond_signal(&m_full_cond);
+        sys_lwmutex_unlock(&m_mutex);
+        return ret;
     }
 
 private:
+    static size_t const CAPACITY = 100;
+    int m_values[CAPACITY];
+    size_t m_start, m_count;
+    size_t m_poppers, m_pushers;
+    sys_lwmutex_t m_mutex;
+    sys_lwcond_t m_empty_cond, m_full_cond;
 };
 
 class ThreadBase
diff --git a/src/thread/threadbase.h b/src/thread/threadbase.h
index c2083e6b..df992f70 100644
--- a/src/thread/threadbase.h
+++ b/src/thread/threadbase.h
@@ -80,13 +80,16 @@ class QueueBase
 public:
     QueueBase()
     {
-#if defined __linux__ || defined __native_client__
-        memset(m_values, 0, sizeof(m_values));
         m_start = m_count = 0;
+#if defined __linux__ || defined __native_client__
         m_poppers = m_pushers = 0;
         pthread_mutex_init(&m_mutex, NULL);
         pthread_cond_init(&m_empty_cond, NULL);
         pthread_cond_init(&m_full_cond, NULL);
+#elif defined _WIN32
+        m_empty_sem = CreateSemaphore(NULL, CAPACITY, CAPACITY, NULL);
+        m_full_sem = CreateSemaphore(NULL, 0, CAPACITY, NULL);
+        InitializeCriticalSection(&m_mutex);
 #endif
     }
 
@@ -96,6 +99,10 @@ public:
         pthread_cond_destroy(&m_empty_cond);
         pthread_cond_destroy(&m_full_cond);
         pthread_mutex_destroy(&m_mutex);
+#elif defined _WIN32
+        CloseHandle(m_empty_sem);
+        CloseHandle(m_full_sem);
+        DeleteCriticalSection(&m_mutex);
 #endif
     }
 
@@ -105,16 +112,26 @@ public:
         pthread_mutex_lock(&m_mutex);
         /* If queue is full, wait on the "full" cond var. */
         m_pushers++;
-        while (m_count == 100)
+        while (m_count == CAPACITY)
             pthread_cond_wait(&m_full_cond, &m_mutex);
         m_pushers--;
+#elif defined _WIN32
+        WaitForSingleObject(m_empty_sem, INFINITE);
+        EnterCriticalSection(&m_mutex);
+#endif
+
         /* Push value */
-        m_values[(m_start + m_count) % 100] = value;
+        m_values[(m_start + m_count) % CAPACITY] = value;
         m_count++;
+
+#if defined __linux__ || defined __native_client__
         /* If there were poppers waiting, signal the "empty" cond var. */
         if (m_poppers)
             pthread_cond_signal(&m_empty_cond);
         pthread_mutex_unlock(&m_mutex);
+#elif defined _WIN32
+        LeaveCriticalSection(&m_mutex);
+        ReleaseSemaphore(m_full_sem, 1, NULL);
 #endif
     }
 
@@ -129,24 +146,40 @@ public:
         while (m_count == 0)
             pthread_cond_wait(&m_empty_cond, &m_mutex);
         m_poppers--;
+#elif defined _WIN32
+        WaitForSingleObject(m_full_sem, INFINITE);
+        EnterCriticalSection(&m_mutex);
+#endif
+
         /* Pop value */
         int ret = m_values[m_start];
-        m_start = (m_start + 1) % 100;
+        m_start = (m_start + 1) % CAPACITY;
         m_count--;
+
+#if defined __linux__ || defined __native_client__
         /* If there were pushers waiting, signal the "full" cond var. */
         if (m_pushers)
             pthread_cond_signal(&m_full_cond);
         pthread_mutex_unlock(&m_mutex);
-        return ret;
+#else
+        LeaveCriticalSection(&m_mutex);
+        ReleaseSemaphore(m_empty_sem, 1, NULL);
 #endif
+
+        return ret;
     }
 
 private:
+    static size_t const CAPACITY = 100;
+    int m_values[CAPACITY];
+    size_t m_start, m_count;
 #if defined __linux__ || defined __native_client__
-    int m_values[100];
-    size_t m_poppers, m_pushers, m_start, m_count;
+    size_t m_poppers, m_pushers;
     pthread_mutex_t m_mutex;
     pthread_cond_t m_empty_cond, m_full_cond;
+#elif defined _WIN32
+    HANDLE m_empty_sem, m_full_sem;
+    CRITICAL_SECTION m_mutex;
 #endif
 };