SourceFormat Enforcement

[thirdparty/squid.git] / src / ipc / mem / PagePool.h

diff --git a/src/ipc/mem/PagePool.h b/src/ipc/mem/PagePool.h
index d151263f199a48c1e57a3a0e00292220a143fd88..09a0116974d8d581616a4e1d1f8ad54195ad0e04 100644 (file)
--- a/src/ipc/mem/PagePool.h
+++ b/src/ipc/mem/PagePool.h
@@ -1,62 +1,57 @@
 /*
- * $Id$
+ * Copyright (C) 1996-2015 The Squid Software Foundation and contributors
  *
+ * Squid software is distributed under GPLv2+ license and includes
+ * contributions from numerous individuals and organizations.
+ * Please see the COPYING and CONTRIBUTORS files for details.
  */
 
 #ifndef SQUID_IPC_MEM_PAGE_POOL_H
 #define SQUID_IPC_MEM_PAGE_POOL_H
 
+#include "ipc/mem/Page.h"
 #include "ipc/mem/PageStack.h"
-#include "ipc/mem/Segment.h"
+#include "ipc/mem/Pointer.h"
 
-namespace Ipc {
+namespace Ipc
+{
 
-namespace Mem {
-
-class PageId;
+namespace Mem
+{
 
 /// Atomic container of shared memory pages. Implemented using a collection of
 /// Segments, each with a PageStack index of free pages. All pools must be
 /// created by a single process.
-class PagePool {
+class PagePool
+{
 public:
-    /// creates a new shared page pool that can hold up to capacity pages of pageSize size
-    PagePool(const String &id, const unsigned int capacity, const size_t pageSize);
-    /// attaches to the identified shared page pool
-    PagePool(const String &id);
+    typedef Ipc::Mem::Owner<PageStack> Owner;
+
+    static Owner *Init(const char *const id, const unsigned int capacity, const size_t pageSize);
+
+    PagePool(const char *const id);
 
-    unsigned int capacity() const { return shared->theCapacity; }
+    unsigned int capacity() const { return pageIndex->capacity(); }
+    size_t pageSize() const { return pageIndex->pageSize(); }
     /// lower bound for the number of free pages
-    unsigned int size() const { return pageIndex.size(); }
-    size_t pageSize() const { return shared->thePageSize; }
+    unsigned int size() const { return pageIndex->size(); }
+    /// approximate number of shared memory pages used now
+    size_t level() const { return capacity() - size(); }
+    /// approximate number of shared memory pages used now for given purpose
+    size_t level(const int purpose) const;
 
     /// sets page ID and returns true unless no free pages are found
-    bool get(PageId &page);
+    bool get(const PageId::Purpose purpose, PageId &page);
     /// makes identified page available as a free page to future get() callers
     void put(PageId &page);
     /// converts page handler into a temporary writeable shared memory pointer
-    void *pagePointer(const PageId &page);
+    char *pagePointer(const PageId &page);
 
 private:
-    inline bool pageIdIsValid(const PageId &page) const;
-
-    struct Shared {
-        Shared(const unsigned int aCapacity, const size_t aPageSize);
-
-        /// total shared memory size required to share
-        static off_t MemSize(const unsigned int capacity, const size_t pageSize);
-
-        const unsigned int theId; ///< pool id
-        const unsigned int theCapacity; ///< number of pages in the pool
-        const size_t thePageSize; ///< page size
-
-        // TODO: add padding to make pages system page-aligned?
-        char theBuf[]; ///< pages storage
-    };
-
-    PageStack pageIndex; ///< free pages index
-    Segment shm; ///< shared memory segment to store metadata (and pages)
-    Shared *shared; ///< our metadata and page storage, shared among all pool users
+    Ipc::Mem::Pointer<PageStack> pageIndex; ///< free pages index
+    /// number of shared memory pages used now for each purpose
+    Atomic::Word *const theLevels;
+    char *const theBuf; ///< pages storage
 };
 
 } // namespace Mem
@@ -64,3 +59,4 @@ private:
 } // namespace Ipc
 
 #endif // SQUID_IPC_MEM_PAGE_POOL_H
+