Purge SkPurgeableMemoryBlock.

src/ports/SkPurgeableMemoryBlock_android.cpp

-/*
- * Copyright 2013 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#include "SkPurgeableMemoryBlock.h"
-
-#include "android/ashmem.h"
-#include <sys/mman.h>
-#include <unistd.h>
-
-bool SkPurgeableMemoryBlock::IsSupported() {
-    return true;
-}
-
-#ifdef SK_DEBUG
-bool SkPurgeableMemoryBlock::PlatformSupportsPurgingAllUnpinnedBlocks() {
-    return false;
-}
-
-bool SkPurgeableMemoryBlock::PurgeAllUnpinnedBlocks() {
-    return false;
-}
-
-bool SkPurgeableMemoryBlock::purge() {
-    SkASSERT(!fPinned);
-    if (-1 != fFD) {
-        ashmem_purge_all_caches(fFD);
-        return true;
-    } else {
-        return false;
-    }
-}
-#endif
-
-// ashmem likes lengths on page boundaries.
-static size_t round_to_page_size(size_t size) {
-    const size_t mask = getpagesize() - 1;
-    size_t newSize = (size + mask) & ~mask;
-    return newSize;
-}
-
-SkPurgeableMemoryBlock::SkPurgeableMemoryBlock(size_t size)
-    : fAddr(NULL)
-    , fSize(round_to_page_size(size))
-    , fPinned(false)
-    , fFD(-1) {
-}
-
-SkPurgeableMemoryBlock::~SkPurgeableMemoryBlock() {
-    if (-1 != fFD) {
-        munmap(fAddr, fSize);
-        close(fFD);
-    }
-}
-
-void* SkPurgeableMemoryBlock::pin(SkPurgeableMemoryBlock::PinResult* pinResult) {
-    SkASSERT(!fPinned);
-    if (-1 == fFD) {
-        int fd = ashmem_create_region(NULL, fSize);
-        if (-1 == fd) {
-            SkDebugf("ashmem_create_region failed\n");
-            return NULL;
-        }
-
-        int err = ashmem_set_prot_region(fd, PROT_READ | PROT_WRITE);
-        if (err != 0) {
-            SkDebugf("ashmem_set_prot_region failed\n");
-            close(fd);
-            return NULL;
-        }
-
-        void* addr = mmap(NULL, fSize, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
-        if (-1 == (long) addr) {
-            SkDebugf("mmap failed\n");
-            close(fd);
-            return NULL;
-        }
-        fAddr = addr;
-        fFD = fd;
-        (void) ashmem_pin_region(fd, 0, 0);
-        *pinResult = kUninitialized_PinResult;
-        fPinned = true;
-    } else {
-        int pin = ashmem_pin_region(fFD, 0, 0);
-        if (ASHMEM_NOT_PURGED == pin) {
-            fPinned = true;
-            *pinResult = kRetained_PinResult;
-        } else if (ASHMEM_WAS_PURGED == pin) {
-            fPinned = true;
-            *pinResult = kUninitialized_PinResult;
-        } else {
-            // Failed.
-            munmap(fAddr, fSize);
-            close(fFD);
-            fFD = -1;
-            fAddr = NULL;
-        }
-    }
-    return fAddr;
-}
-
-void SkPurgeableMemoryBlock::unpin() {
-    if (-1 != fFD) {
-        ashmem_unpin_region(fFD, 0, 0);
-        fPinned = false;
-    }
-}