IMemory.cpp revision cab25d680e644d962041d05a319e485b96136a5d 
1/*
2 * Copyright (C) 2008 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#define LOG_TAG "IMemory"
18
19#include <stdint.h>
20#include <stdio.h>
21#include <stdlib.h>
22#include <fcntl.h>
23#include <unistd.h>
24
25#include <sys/types.h>
26#include <sys/mman.h>
27
28#include <binder/IMemory.h>
29#include <utils/KeyedVector.h>
30#include <utils/threads.h>
31#include <utils/Atomic.h>
32#include <binder/Parcel.h>
33#include <utils/CallStack.h>
34
35#define VERBOSE   0
36
37namespace android {
38// ---------------------------------------------------------------------------
39
40class HeapCache : public IBinder::DeathRecipient
41{
42public:
43    HeapCache();
44    virtual ~HeapCache();
45
46    virtual void binderDied(const wp<IBinder>& who);
47
48    sp<IMemoryHeap> find_heap(const sp<IBinder>& binder);
49    void free_heap(const sp<IBinder>& binder);
50    sp<IMemoryHeap> get_heap(const sp<IBinder>& binder);
51    void dump_heaps();
52
53private:
54    // For IMemory.cpp
55    struct heap_info_t {
56        sp<IMemoryHeap> heap;
57        int32_t         count;
58    };
59
60    void free_heap(const wp<IBinder>& binder);
61
62    Mutex mHeapCacheLock;
63    KeyedVector< wp<IBinder>, heap_info_t > mHeapCache;
64};
65
66static sp<HeapCache> gHeapCache = new HeapCache();
67
68/******************************************************************************/
69
70enum {
71    HEAP_ID = IBinder::FIRST_CALL_TRANSACTION
72};
73
74class BpMemoryHeap : public BpInterface<IMemoryHeap>
75{
76public:
77    BpMemoryHeap(const sp<IBinder>& impl);
78    virtual ~BpMemoryHeap();
79
80    virtual int getHeapID() const;
81    virtual void* getBase() const;
82    virtual size_t getSize() const;
83    virtual uint32_t getFlags() const;
84    virtual uint32_t getOffset() const;
85
86private:
87    friend class IMemory;
88    friend class HeapCache;
89
90    // for debugging in this module
91    static inline sp<IMemoryHeap> find_heap(const sp<IBinder>& binder) {
92        return gHeapCache->find_heap(binder);
93    }
94    static inline void free_heap(const sp<IBinder>& binder) {
95        gHeapCache->free_heap(binder);
96    }
97    static inline sp<IMemoryHeap> get_heap(const sp<IBinder>& binder) {
98        return gHeapCache->get_heap(binder);
99    }
100    static inline void dump_heaps() {
101        gHeapCache->dump_heaps();
102    }
103
104    void assertMapped() const;
105    void assertReallyMapped() const;
106
107    mutable volatile int32_t mHeapId;
108    mutable void*       mBase;
109    mutable size_t      mSize;
110    mutable uint32_t    mFlags;
111    mutable uint32_t    mOffset;
112    mutable bool        mRealHeap;
113    mutable Mutex       mLock;
114};
115
116// ----------------------------------------------------------------------------
117
118enum {
119    GET_MEMORY = IBinder::FIRST_CALL_TRANSACTION
120};
121
122class BpMemory : public BpInterface<IMemory>
123{
124public:
125    BpMemory(const sp<IBinder>& impl);
126    virtual ~BpMemory();
127    virtual sp<IMemoryHeap> getMemory(ssize_t* offset=0, size_t* size=0) const;
128
129private:
130    mutable sp<IMemoryHeap> mHeap;
131    mutable ssize_t mOffset;
132    mutable size_t mSize;
133};
134
135/******************************************************************************/
136
137void* IMemory::fastPointer(const sp<IBinder>& binder, ssize_t offset) const
138{
139    sp<IMemoryHeap> realHeap = BpMemoryHeap::get_heap(binder);
140    void* const base = realHeap->base();
141    if (base == MAP_FAILED)
142        return 0;
143    return static_cast<char*>(base) + offset;
144}
145
146void* IMemory::pointer() const {
147    ssize_t offset;
148    sp<IMemoryHeap> heap = getMemory(&offset);
149    void* const base = heap!=0 ? heap->base() : MAP_FAILED;
150    if (base == MAP_FAILED)
151        return 0;
152    return static_cast<char*>(base) + offset;
153}
154
155size_t IMemory::size() const {
156    size_t size;
157    getMemory(NULL, &size);
158    return size;
159}
160
161ssize_t IMemory::offset() const {
162    ssize_t offset;
163    getMemory(&offset);
164    return offset;
165}
166
167/******************************************************************************/
168
169BpMemory::BpMemory(const sp<IBinder>& impl)
170    : BpInterface<IMemory>(impl), mOffset(0), mSize(0)
171{
172}
173
174BpMemory::~BpMemory()
175{
176}
177
178sp<IMemoryHeap> BpMemory::getMemory(ssize_t* offset, size_t* size) const
179{
180    if (mHeap == 0) {
181        Parcel data, reply;
182        data.writeInterfaceToken(IMemory::getInterfaceDescriptor());
183        if (remote()->transact(GET_MEMORY, data, &reply) == NO_ERROR) {
184            sp<IBinder> heap = reply.readStrongBinder();
185            ssize_t o = reply.readInt32();
186            size_t s = reply.readInt32();
187            if (heap != 0) {
188                mHeap = interface_cast<IMemoryHeap>(heap);
189                if (mHeap != 0) {
190                    mOffset = o;
191                    mSize = s;
192                }
193            }
194        }
195    }
196    if (offset) *offset = mOffset;
197    if (size) *size = mSize;
198    return mHeap;
199}
200
201// ---------------------------------------------------------------------------
202
203IMPLEMENT_META_INTERFACE(Memory, "android.utils.IMemory");
204
205BnMemory::BnMemory() {
206}
207
208BnMemory::~BnMemory() {
209}
210
211status_t BnMemory::onTransact(
212    uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)
213{
214    switch(code) {
215        case GET_MEMORY: {
216            CHECK_INTERFACE(IMemory, data, reply);
217            ssize_t offset;
218            size_t size;
219            reply->writeStrongBinder( getMemory(&offset, &size)->asBinder() );
220            reply->writeInt32(offset);
221            reply->writeInt32(size);
222            return NO_ERROR;
223        } break;
224        default:
225            return BBinder::onTransact(code, data, reply, flags);
226    }
227}
228
229
230/******************************************************************************/
231
232BpMemoryHeap::BpMemoryHeap(const sp<IBinder>& impl)
233    : BpInterface<IMemoryHeap>(impl),
234        mHeapId(-1), mBase(MAP_FAILED), mSize(0), mFlags(0), mOffset(0), mRealHeap(false)
235{
236}
237
238BpMemoryHeap::~BpMemoryHeap() {
239    if (mHeapId != -1) {
240        close(mHeapId);
241        if (mRealHeap) {
242            // by construction we're the last one
243            if (mBase != MAP_FAILED) {
244                sp<IBinder> binder = const_cast<BpMemoryHeap*>(this)->asBinder();
245
246                if (VERBOSE) {
247                    ALOGD("UNMAPPING binder=%p, heap=%p, size=%d, fd=%d",
248                            binder.get(), this, mSize, mHeapId);
249                    CallStack stack(LOG_TAG);
250                }
251
252                munmap(mBase, mSize);
253            }
254        } else {
255            // remove from list only if it was mapped before
256            sp<IBinder> binder = const_cast<BpMemoryHeap*>(this)->asBinder();
257            free_heap(binder);
258        }
259    }
260}
261
262void BpMemoryHeap::assertMapped() const
263{
264    if (mHeapId == -1) {
265        sp<IBinder> binder(const_cast<BpMemoryHeap*>(this)->asBinder());
266        sp<BpMemoryHeap> heap(static_cast<BpMemoryHeap*>(find_heap(binder).get()));
267        heap->assertReallyMapped();
268        if (heap->mBase != MAP_FAILED) {
269            Mutex::Autolock _l(mLock);
270            if (mHeapId == -1) {
271                mBase   = heap->mBase;
272                mSize   = heap->mSize;
273                mOffset = heap->mOffset;
274                android_atomic_write( dup( heap->mHeapId ), &mHeapId );
275            }
276        } else {
277            // something went wrong
278            free_heap(binder);
279        }
280    }
281}
282
283void BpMemoryHeap::assertReallyMapped() const
284{
285    if (mHeapId == -1) {
286
287        // remote call without mLock held, worse case scenario, we end up
288        // calling transact() from multiple threads, but that's not a problem,
289        // only mmap below must be in the critical section.
290
291        Parcel data, reply;
292        data.writeInterfaceToken(IMemoryHeap::getInterfaceDescriptor());
293        status_t err = remote()->transact(HEAP_ID, data, &reply);
294        int parcel_fd = reply.readFileDescriptor();
295        ssize_t size = reply.readInt32();
296        uint32_t flags = reply.readInt32();
297        uint32_t offset = reply.readInt32();
298
299        ALOGE_IF(err, "binder=%p transaction failed fd=%d, size=%ld, err=%d (%s)",
300                asBinder().get(), parcel_fd, size, err, strerror(-err));
301
302        int fd = dup( parcel_fd );
303        ALOGE_IF(fd==-1, "cannot dup fd=%d, size=%ld, err=%d (%s)",
304                parcel_fd, size, err, strerror(errno));
305
306        int access = PROT_READ;
307        if (!(flags & READ_ONLY)) {
308            access |= PROT_WRITE;
309        }
310
311        Mutex::Autolock _l(mLock);
312        if (mHeapId == -1) {
313            mRealHeap = true;
314            mBase = mmap(0, size, access, MAP_SHARED, fd, offset);
315            if (mBase == MAP_FAILED) {
316                ALOGE("cannot map BpMemoryHeap (binder=%p), size=%ld, fd=%d (%s)",
317                        asBinder().get(), size, fd, strerror(errno));
318                close(fd);
319            } else {
320                mSize = size;
321                mFlags = flags;
322                mOffset = offset;
323                android_atomic_write(fd, &mHeapId);
324            }
325        }
326    }
327}
328
329int BpMemoryHeap::getHeapID() const {
330    assertMapped();
331    return mHeapId;
332}
333
334void* BpMemoryHeap::getBase() const {
335    assertMapped();
336    return mBase;
337}
338
339size_t BpMemoryHeap::getSize() const {
340    assertMapped();
341    return mSize;
342}
343
344uint32_t BpMemoryHeap::getFlags() const {
345    assertMapped();
346    return mFlags;
347}
348
349uint32_t BpMemoryHeap::getOffset() const {
350    assertMapped();
351    return mOffset;
352}
353
354// ---------------------------------------------------------------------------
355
356IMPLEMENT_META_INTERFACE(MemoryHeap, "android.utils.IMemoryHeap");
357
358BnMemoryHeap::BnMemoryHeap() {
359}
360
361BnMemoryHeap::~BnMemoryHeap() {
362}
363
364status_t BnMemoryHeap::onTransact(
365        uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)
366{
367    switch(code) {
368       case HEAP_ID: {
369            CHECK_INTERFACE(IMemoryHeap, data, reply);
370            reply->writeFileDescriptor(getHeapID());
371            reply->writeInt32(getSize());
372            reply->writeInt32(getFlags());
373            reply->writeInt32(getOffset());
374            return NO_ERROR;
375        } break;
376        default:
377            return BBinder::onTransact(code, data, reply, flags);
378    }
379}
380
381/*****************************************************************************/
382
383HeapCache::HeapCache()
384    : DeathRecipient()
385{
386}
387
388HeapCache::~HeapCache()
389{
390}
391
392void HeapCache::binderDied(const wp<IBinder>& binder)
393{
394    //ALOGD("binderDied binder=%p", binder.unsafe_get());
395    free_heap(binder);
396}
397
398sp<IMemoryHeap> HeapCache::find_heap(const sp<IBinder>& binder)
399{
400    Mutex::Autolock _l(mHeapCacheLock);
401    ssize_t i = mHeapCache.indexOfKey(binder);
402    if (i>=0) {
403        heap_info_t& info = mHeapCache.editValueAt(i);
404        ALOGD_IF(VERBOSE,
405                "found binder=%p, heap=%p, size=%d, fd=%d, count=%d",
406                binder.get(), info.heap.get(),
407                static_cast<BpMemoryHeap*>(info.heap.get())->mSize,
408                static_cast<BpMemoryHeap*>(info.heap.get())->mHeapId,
409                info.count);
410        android_atomic_inc(&info.count);
411        return info.heap;
412    } else {
413        heap_info_t info;
414        info.heap = interface_cast<IMemoryHeap>(binder);
415        info.count = 1;
416        //ALOGD("adding binder=%p, heap=%p, count=%d",
417        //      binder.get(), info.heap.get(), info.count);
418        mHeapCache.add(binder, info);
419        return info.heap;
420    }
421}
422
423void HeapCache::free_heap(const sp<IBinder>& binder)  {
424    free_heap( wp<IBinder>(binder) );
425}
426
427void HeapCache::free_heap(const wp<IBinder>& binder)
428{
429    sp<IMemoryHeap> rel;
430    {
431        Mutex::Autolock _l(mHeapCacheLock);
432        ssize_t i = mHeapCache.indexOfKey(binder);
433        if (i>=0) {
434            heap_info_t& info(mHeapCache.editValueAt(i));
435            int32_t c = android_atomic_dec(&info.count);
436            if (c == 1) {
437                ALOGD_IF(VERBOSE,
438                        "removing binder=%p, heap=%p, size=%d, fd=%d, count=%d",
439                        binder.unsafe_get(), info.heap.get(),
440                        static_cast<BpMemoryHeap*>(info.heap.get())->mSize,
441                        static_cast<BpMemoryHeap*>(info.heap.get())->mHeapId,
442                        info.count);
443                rel = mHeapCache.valueAt(i).heap;
444                mHeapCache.removeItemsAt(i);
445            }
446        } else {
447            ALOGE("free_heap binder=%p not found!!!", binder.unsafe_get());
448        }
449    }
450}
451
452sp<IMemoryHeap> HeapCache::get_heap(const sp<IBinder>& binder)
453{
454    sp<IMemoryHeap> realHeap;
455    Mutex::Autolock _l(mHeapCacheLock);
456    ssize_t i = mHeapCache.indexOfKey(binder);
457    if (i>=0)   realHeap = mHeapCache.valueAt(i).heap;
458    else        realHeap = interface_cast<IMemoryHeap>(binder);
459    return realHeap;
460}
461
462void HeapCache::dump_heaps()
463{
464    Mutex::Autolock _l(mHeapCacheLock);
465    int c = mHeapCache.size();
466    for (int i=0 ; i<c ; i++) {
467        const heap_info_t& info = mHeapCache.valueAt(i);
468        BpMemoryHeap const* h(static_cast<BpMemoryHeap const *>(info.heap.get()));
469        ALOGD("hey=%p, heap=%p, count=%d, (fd=%d, base=%p, size=%d)",
470                mHeapCache.keyAt(i).unsafe_get(),
471                info.heap.get(), info.count,
472                h->mHeapId, h->mBase, h->mSize);
473    }
474}
475
476
477// ---------------------------------------------------------------------------
478}; // namespace android
479