upload android base code part4

android/hardware/libhardware/modules/gralloc/mapper.cpp

@@ -0,0 +1,187 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <errno.h>
+#include <limits.h>
+#include <pthread.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <cutils/atomic.h>
+#include <log/log.h>
+
+#include <hardware/hardware.h>
+#include <hardware/gralloc.h>
+
+#include "gralloc_priv.h"
+
+
+/*****************************************************************************/
+
+static int gralloc_map(gralloc_module_t const* /*module*/,
+        buffer_handle_t handle,
+        void** vaddr)
+{
+    private_handle_t* hnd = (private_handle_t*)handle;
+    if (!(hnd->flags & private_handle_t::PRIV_FLAGS_FRAMEBUFFER)) {
+        size_t size = hnd->size;
+        void* mappedAddress = mmap(0, size,
+                PROT_READ|PROT_WRITE, MAP_SHARED, hnd->fd, 0);
+        if (mappedAddress == MAP_FAILED) {
+            ALOGE("Could not mmap %s", strerror(errno));
+            return -errno;
+        }
+        hnd->base = uintptr_t(mappedAddress) + hnd->offset;
+        //ALOGD("gralloc_map() succeeded fd=%d, off=%d, size=%d, vaddr=%p",
+        //        hnd->fd, hnd->offset, hnd->size, mappedAddress);
+    }
+    *vaddr = (void*)hnd->base;
+    return 0;
+}
+
+static int gralloc_unmap(gralloc_module_t const* /*module*/,
+        buffer_handle_t handle)
+{
+    private_handle_t* hnd = (private_handle_t*)handle;
+    if (!(hnd->flags & private_handle_t::PRIV_FLAGS_FRAMEBUFFER)) {
+        void* base = (void*)hnd->base;
+        size_t size = hnd->size;
+        //ALOGD("unmapping from %p, size=%d", base, size);
+        if (munmap(base, size) < 0) {
+            ALOGE("Could not unmap %s", strerror(errno));
+        }
+    }
+    hnd->base = 0;
+    return 0;
+}
+
+/*****************************************************************************/
+
+int gralloc_register_buffer(gralloc_module_t const* module,
+        buffer_handle_t handle)
+{
+    if (private_handle_t::validate(handle) < 0)
+        return -EINVAL;
+
+    // *** WARNING WARNING WARNING ***
+    //
+    // If a buffer handle is passed from the process that allocated it to a
+    // different process, and then back to the allocator process, we will
+    // create a second mapping of the buffer. If the process reads and writes
+    // through both mappings, normal memory ordering guarantees may be
+    // violated, depending on the processor cache implementation*.
+    //
+    // If you are deriving a new gralloc implementation from this code, don't
+    // do this. A "real" gralloc should provide a single reference-counted
+    // mapping for each buffer in a process.
+    //
+    // In the current system, there is one case that needs a buffer to be
+    // registered in the same process that allocated it. The SurfaceFlinger
+    // process acts as the IGraphicBufferAlloc Binder provider, so all gralloc
+    // allocations happen in its process. After returning the buffer handle to
+    // the IGraphicBufferAlloc client, SurfaceFlinger free's its handle to the
+    // buffer (unmapping it from the SurfaceFlinger process). If
+    // SurfaceFlinger later acts as the producer end of the buffer queue the
+    // buffer belongs to, it will get a new handle to the buffer in response
+    // to IGraphicBufferProducer::requestBuffer(). Like any buffer handle
+    // received through Binder, the SurfaceFlinger process will register it.
+    // Since it already freed its original handle, it will only end up with
+    // one mapping to the buffer and there will be no problem.
+    //
+    // Currently SurfaceFlinger only acts as a buffer producer for a remote
+    // consumer when taking screenshots and when using virtual displays.
+    //
+    // Eventually, each application should be allowed to make its own gralloc
+    // allocations, solving the problem. Also, this ashmem-based gralloc
+    // should go away, replaced with a real ion-based gralloc.
+    //
+    // * Specifically, associative virtually-indexed caches are likely to have
+    //   problems. Most modern L1 caches fit that description.
+
+    private_handle_t* hnd = (private_handle_t*)handle;
+    ALOGD_IF(hnd->pid == getpid(),
+            "Registering a buffer in the process that created it. "
+            "This may cause memory ordering problems.");
+
+    void *vaddr;
+    return gralloc_map(module, handle, &vaddr);
+}
+
+int gralloc_unregister_buffer(gralloc_module_t const* module,
+        buffer_handle_t handle)
+{
+    if (private_handle_t::validate(handle) < 0)
+        return -EINVAL;
+
+    private_handle_t* hnd = (private_handle_t*)handle;
+    if (hnd->base)
+        gralloc_unmap(module, handle);
+
+    return 0;
+}
+
+int mapBuffer(gralloc_module_t const* module,
+        private_handle_t* hnd)
+{
+    void* vaddr;
+    return gralloc_map(module, hnd, &vaddr);
+}
+
+int terminateBuffer(gralloc_module_t const* module,
+        private_handle_t* hnd)
+{
+    if (hnd->base) {
+        // this buffer was mapped, unmap it now
+        gralloc_unmap(module, hnd);
+    }
+
+    return 0;
+}
+
+int gralloc_lock(gralloc_module_t const* /*module*/,
+        buffer_handle_t handle, int /*usage*/,
+        int /*l*/, int /*t*/, int /*w*/, int /*h*/,
+        void** vaddr)
+{
+    // this is called when a buffer is being locked for software
+    // access. in thin implementation we have nothing to do since
+    // not synchronization with the h/w is needed.
+    // typically this is used to wait for the h/w to finish with
+    // this buffer if relevant. the data cache may need to be
+    // flushed or invalidated depending on the usage bits and the
+    // hardware.
+
+    if (private_handle_t::validate(handle) < 0)
+        return -EINVAL;
+
+    private_handle_t* hnd = (private_handle_t*)handle;
+    *vaddr = (void*)hnd->base;
+    return 0;
+}
+
+int gralloc_unlock(gralloc_module_t const* /*module*/,
+        buffer_handle_t handle)
+{
+    // we're done with a software buffer. nothing to do in this
+    // implementation. typically this is used to flush the data cache.
+
+    if (private_handle_t::validate(handle) < 0)
+        return -EINVAL;
+    return 0;
+}