[GitHub] [incubator-weex] ikantech commented on issue #2706: [Android] Weex failed on Android Q failed with targetSdkVersion=29

[GitBox <gi...@apache.org>]

ikantech commented on issue #2706:
URL: https://github.com/apache/incubator-weex/issues/2706#issuecomment-630758980


   基于 @nm-cmd 修改的代码，在Android Q上可以正常工作。我去掉了一些没有调用的函数。
   
   ```diff
   weex_core/Source/third_party/IPC/ashmem.h
   @@ -33,10 +33,7 @@ extern "C" {
    
    int ashmem_create_region(const char* name, size_t size);
    int ashmem_set_prot_region(int fd, int prot);
   -int ashmem_pin_region(int fd, size_t offset, size_t len);
   -int ashmem_unpin_region(int fd, size_t offset, size_t len);
    int ashmem_get_size_region(int fd);
   -int ashmem_purge_all(void);
    
    #ifdef __cplusplus
    }
   ```
   ```diff
   weex_core/Source/third_party/IPC/ashmem.c
   @@ -31,9 +31,44 @@
    
    #include "ashmem.h"
    #include <linux/ashmem.h>
   +#include <stdlib.h>
   +#include <sys/system_properties.h>
   +#include <dlfcn.h>
   +#include <pthread.h>
    
    #define ASHMEM_DEVICE "/dev/ashmem"
    
   +static int system_property_get_int(const char* name) {
   +    int result = 0;
   +    char value[PROP_VALUE_MAX] = {};
   +    if (__system_property_get(name, value) >= 1)
   +        result = atoi(value);
   +    return result;
   +}
   +
   +static int device_api_level() {
   +    static int s_api_level = -1;
   +    if (s_api_level < 0)
   +        s_api_level = system_property_get_int("ro.build.version.sdk");
   +    return s_api_level;
   +}
   +
   +typedef int(*ASharedMemory_createFunc)(const char *, size_t);
   +typedef size_t(*ASharedMemory_getSizeFunc)(int fd);
   +typedef int(*ASharedMemory_setProtFunc)(int fd, int prot);
   +
   +// Function pointers to shared memory functions.
   +typedef struct {
   +    ASharedMemory_createFunc create;
   +    ASharedMemory_getSizeFunc getSize;
   +    ASharedMemory_setProtFunc setProt;
   +} ASharedMemoryFuncs;
   +
   +static ASharedMemoryFuncs s_ashmem_funcs = {
   +        NULL, NULL, NULL
   +};
   +static pthread_once_t s_ashmem_funcs_once = PTHREAD_ONCE_INIT;
   +
    /*
     * ashmem_create_region - creates a new ashmem region and returns the file
     * descriptor, or <0 on error
   @@ -41,7 +76,7 @@
     * `name' is an optional label to give the region (visible in /proc/pid/maps)
     * `size' is the size of the region, in page-aligned bytes
     */
   -int ashmem_create_region(const char* name, size_t size)
   +static int ashmem_dev_create_region(const char* name, size_t size)
    {
        int fd, ret;
    
   @@ -69,34 +104,56 @@ error:
        return ret;
    }
    
   -int ashmem_set_prot_region(int fd, int prot)
   +static int ashmem_dev_set_prot_region(int fd, int prot)
    {
        return ioctl(fd, ASHMEM_SET_PROT_MASK, prot);
    }
    
   -int ashmem_pin_region(int fd, size_t offset, size_t len)
   +static size_t ashmem_dev_get_size_region(int fd)
    {
   -    struct ashmem_pin pin = { offset, len };
   -    return ioctl(fd, ASHMEM_PIN, &pin);
   +    return (size_t)ioctl(fd, ASHMEM_GET_SIZE, NULL);
    }
    
   -int ashmem_unpin_region(int fd, size_t offset, size_t len)
   -{
   -    struct ashmem_pin pin = { offset, len };
   -    return ioctl(fd, ASHMEM_UNPIN, &pin);
   +static void ashmem_init_funcs() {
   +    ASharedMemoryFuncs* funcs = &s_ashmem_funcs;
   +    // ANDROID_API_Q
   +    if (device_api_level() >= 29) {
   +        void * lib = dlopen("libandroid.so", RTLD_NOW);
   +        funcs->create =
   +                (ASharedMemory_createFunc)dlsym(lib, "ASharedMemory_create");
   +        funcs->getSize =
   +                (ASharedMemory_getSizeFunc)dlsym(lib, "ASharedMemory_getSize");
   +        funcs->setProt =
   +                (ASharedMemory_setProtFunc)dlsym(lib, "ASharedMemory_setProt");
   +    }
   +
   +    if(funcs->create == NULL) {
   +        funcs->create = &ashmem_dev_create_region;
   +    }
   +    if(funcs->getSize == NULL) {
   +        funcs->getSize = &ashmem_dev_get_size_region;
   +    }
   +    if(funcs->setProt == NULL) {
   +        funcs->setProt = &ashmem_dev_set_prot_region;
   +    }
    }
    
   -int ashmem_get_size_region(int fd)
   +static const ASharedMemoryFuncs* ashmem_get_funcs() {
   +    pthread_once(&s_ashmem_funcs_once, ashmem_init_funcs);
   +    return &s_ashmem_funcs;
   +}
   +
   +int ashmem_create_region(const char *name, size_t size)
    {
   -    return ioctl(fd, ASHMEM_GET_SIZE, NULL);
   +    return ashmem_get_funcs()->create(name, size);
    }
    
   -int ashmem_purge_all(void)
   +int ashmem_set_prot_region(int fd, int prot)
    {
   -    const int fd = open(ASHMEM_DEVICE, O_RDWR);
   -    if (fd < 0)
   -        return fd;
   -    const int ret = ioctl(fd, ASHMEM_PURGE_ALL_CACHES, 0);
   -    close(fd);
   -    return ret;
   +    return ashmem_get_funcs()->setProt(fd, prot);
    }
   +
   +int ashmem_get_size_region(int fd)
   +{
   +    return (int)ashmem_get_funcs()->getSize(fd);
   +}
   ```
   


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