Android系统--Binder系统具体框架分析（一）补充

Android系统--Binder系统具体框架分析（一）补充

补充：对Binder驱动分析一的代码补充，添加saygoobye和saygoodbye_to服务

test_server.h

#ifndef _TEST_SERVER_H

#define _TEST_SERVER_H

#define HELLO_SVR_CMD_SAYHELLO 0

#define HELLO_SVR_CMD_SAYHELLO_TO 1

#define GOODBYE_SVR_CMD_SAYGOODBYE 0

#define GOODBYE_SVR_CMD_SAYGOODBYE_TO 1

#endif // _TEST_SERVER_H

test_server.c

/* Copyright 2008 The Android Open Source Project

 */

#include <stdio.h>

#include <stdlib.h>

#include <errno.h>

#include <linux/types.h>

#include<stdbool.h>

#include <string.h>

#include <private/android_filesystem_config.h>

#include "binder.h"

#include "test_server.h"

int svcmgr_publish(struct binder_state *bs, uint32_t target, const char *name, void *ptr)

{

    int status;

    unsigned iodata[512/4];

    struct binder_io msg, reply;

    bio_init(&msg, iodata, sizeof(iodata), 4);  //分配binder_io结构体空间

    bio_put_uint32(&msg, 0);  // strict mode header

    bio_put_string16_x(&msg, SVC_MGR_NAME);

    bio_put_string16_x(&msg, name);  

    bio_put_obj(&msg, ptr);  //构造结构体

    if (binder_call(bs, &msg, &reply, target, SVC_MGR_ADD_SERVICE))  //添加注册Binder服务

        return -1;

    status = bio_get_uint32(&reply);  //获得返回值

    binder_done(bs, &msg, &reply);   //结束标志

    return status;

}

void sayhello(void)

{

	static int cnt = 0;

	fprintf(stderr, "say hello : %d\n", cnt++);

}

int sayhello_to(char *name)

{

	static int cnt = 0;

	fprintf(stderr, "say hello to %s : %d\n", name, cnt++);

	return cnt;

}

void saygoodbye(void)

{

	static int cnt = 0;

	fprintf(stderr, "say goodbye : %d\n", cnt++);

}

int saygoodbye_to(char *name)

{

	static int cnt = 0;

	fprintf(stderr, "say goodbye to %s : %d\n", name, cnt++);

	return cnt;

}

int hello_service_handler(struct binder_state *bs,

                   struct binder_transaction_data *txn,

                   struct binder_io *msg,

                   struct binder_io *reply)

{

	/* 根据txn->code知道要调用哪一个函数

	 * 如果需要参数, 可以从msg取出

	 * 如果要返回结果, 可以把结果放入reply

	 */

	/* sayhello

	 * sayhello_to

	 */

    uint16_t *s;

	char name[512];

    size_t len;

    uint32_t handle;

    uint32_t strict_policy;

	int i;

    // Equivalent to Parcel::enforceInterface(), reading the RPC

    // header with the strict mode policy mask and the interface name.

    // Note that we ignore the strict_policy and don't propagate it

    // further (since we do no outbound RPCs anyway).

    strict_policy = bio_get_uint32(msg);

    //获得处理函数标志，并调用处理函数

    switch(txn->code) {

    case HELLO_SVR_CMD_SAYHELLO:

		sayhello();

        return 0;

    case HELLO_SVR_CMD_SAYHELLO_TO:

		/* 从msg里取出字符串 */

		s = bio_get_string16(msg, &len);

		if (s == NULL) {

			return -1;

		}

		for (i = 0; i < len; i++)

			name[i] = s[i];

		name[i] = '\0';

		/* 处理 */

		i = sayhello_to(name);

		/* 把结果放入reply */

		bio_put_uint32(reply, i);

        break;

    default:

        fprintf(stderr, "unknown code %d\n", txn->code);

        return -1;

    }

    return 0;

}

int goodbye_service_handler(struct binder_state *bs,

                   struct binder_transaction_data *txn,

                   struct binder_io *msg,

                   struct binder_io *reply)

{

	/* 根据txn->code知道要调用哪一个函数

	 * 如果需要参数, 可以从msg取出

	 * 如果要返回结果, 可以把结果放入reply

	 */

	/* sayhello

	 * sayhello_to

	 */

    uint16_t *s;

	char name[512];

    size_t len;

    uint32_t handle;

    uint32_t strict_policy;

	int i;

    // Equivalent to Parcel::enforceInterface(), reading the RPC

    // header with the strict mode policy mask and the interface name.

    // Note that we ignore the strict_policy and don't propagate it

    // further (since we do no outbound RPCs anyway).

    strict_policy = bio_get_uint32(msg);

    switch(txn->code) {

    case GOODBYE_SVR_CMD_SAYGOODBYE:

		saygoodbye();

        return 0;

    case GOODBYE_SVR_CMD_SAYGOODBYE_TO:

		/* 从msg里取出字符串 */

		s = bio_get_string16(msg, &len);

		if (s == NULL) {

			return -1;

		}

		for (i = 0; i < len; i++)

			name[i] = s[i];

		name[i] = '\0';

		/* 处理 */

		i = saygoodbye_to(name);

		/* 把结果放入reply */

		bio_put_uint32(reply, i);

        break;

    default:

        fprintf(stderr, "unknown code %d\n", txn->code);

        return -1;

    }

    return 0;

}

int test_server_handler(struct binder_state *bs,

                   struct binder_transaction_data *txn,

                   struct binder_io *msg,

                   struct binder_io *reply)

{

	int (*handler)(struct binder_state *bs,

                   struct binder_transaction_data *txn,

                   struct binder_io *msg,

                   struct binder_io *reply);  //构造处理方法

	handler = (int (*)(struct binder_state *bs,

                   struct binder_transaction_data *txn,

                   struct binder_io *msg,

                   struct binder_io *reply))txn->target.ptr;  //根据txn->target.ptr返回处理相应方法

	return handler(bs, txn, msg, reply);  //返回所调用的处理方法

}

int main(int argc, char **argv)

{

    int fd;

    struct binder_state *bs;

    uint32_t svcmgr = BINDER_SERVICE_MANAGER;

    uint32_t handle;

	int ret;

    bs = binder_open(128*1024);  //打开Binder驱动设备

    if (!bs) {

        fprintf(stderr, "failed to open binder driver\n");

        return -1;

    }

	/* add service */

	ret = svcmgr_publish(bs, svcmgr, "hello", hello_service_handler);  //注册

    if (ret) {

        fprintf(stderr, "failed to publish hello service\n");

        return -1;

    }

	ret = svcmgr_publish(bs, svcmgr, "goodbye", goodbye_service_handler);

    if (ret) {

        fprintf(stderr, "failed to publish goodbye service\n");

    }

#if 0

	while (1)

	{

		/* read data */

		/* parse data, and process */

		/* reply */

	}

#endif

    binder_loop(bs, test_server_handler);  //从队列中取出响应的处理函数

    return 0;

}

server.c

/* Copyright 2008 The Android Open Source Project

 */

#include <stdio.h>

#include <stdlib.h>

#include <errno.h>

#include <linux/types.h>

#include<stdbool.h>

#include <string.h>

#include <private/android_filesystem_config.h>

#include "binder.h"

#include "test_server.h"

uint32_t svcmgr_lookup(struct binder_state *bs, uint32_t target, const char *name)

{

    uint32_t handle;

    unsigned iodata[512/4];

    struct binder_io msg, reply;

    bio_init(&msg, iodata, sizeof(iodata), 4);

    bio_put_uint32(&msg, 0);  // strict mode header

    bio_put_string16_x(&msg, SVC_MGR_NAME);

    bio_put_string16_x(&msg, name);

    if (binder_call(bs, &msg, &reply, target, SVC_MGR_CHECK_SERVICE))

        return 0;

    handle = bio_get_ref(&reply);

    if (handle)

        binder_acquire(bs, handle);

    binder_done(bs, &msg, &reply);

    return handle;

}

struct binder_state *g_bs;

uint32_t g_hello_handle;

uint32_t g_goodbye_handle;

void sayhello(void)

{

    unsigned iodata[512/4];

    struct binder_io msg, reply;

	/* 构造binder_io */

    bio_init(&msg, iodata, sizeof(iodata), 4);

    bio_put_uint32(&msg, 0);  // strict mode header

	/* 放入参数 */

	/* 调用binder_call */

    if (binder_call(g_bs, &msg, &reply, g_hello_handle, HELLO_SVR_CMD_SAYHELLO))

        return ;

	/* 从reply中解析出返回值 */

    binder_done(g_bs, &msg, &reply);

}

int sayhello_to(char *name)

{

	unsigned iodata[512/4];

	struct binder_io msg, reply;

	int ret;

	/* 构造binder_io */

	bio_init(&msg, iodata, sizeof(iodata), 4);

	bio_put_uint32(&msg, 0);  // strict mode header

	/* 放入参数 */

    bio_put_string16_x(&msg, name);

	/* 调用binder_call */

	if (binder_call(g_bs, &msg, &reply, g_hello_handle, HELLO_SVR_CMD_SAYHELLO_TO))

		return 0;

	/* 从reply中解析出返回值 */

	ret = bio_get_uint32(&reply);

	binder_done(g_bs, &msg, &reply);

	return ret;

}

void saygoodbye(void)

{

    unsigned iodata[512/4];

    struct binder_io msg, reply;

	/* 构造binder_io */

    bio_init(&msg, iodata, sizeof(iodata), 4);

    bio_put_uint32(&msg, 0);  // strict mode header

	/* 放入参数 */

	/* 调用binder_call */

    if (binder_call(g_bs, &msg, &reply, g_goodbye_handle, GOODBYE_SVR_CMD_SAYGOODBYE))

        return ;

	/* 从reply中解析出返回值 */

    binder_done(g_bs, &msg, &reply);

}

int saygoodbye_to(char *name)

{

	unsigned iodata[512/4];

	struct binder_io msg, reply;

	int ret;

	/* 构造binder_io */

	bio_init(&msg, iodata, sizeof(iodata), 4);

	bio_put_uint32(&msg, 0);  // strict mode header

	/* 放入参数 */

    bio_put_string16_x(&msg, name);

	/* 调用binder_call */

	if (binder_call(g_bs, &msg, &reply, g_goodbye_handle, GOODBYE_SVR_CMD_SAYGOODBYE_TO))

		return 0;

	/* 从reply中解析出返回值 */

	ret = bio_get_uint32(&reply);

	binder_done(g_bs, &msg, &reply);

	return ret;

}

/* ./test_client hello

 * ./test_client hello <name>

 */

int main(int argc, char **argv)

{

    int fd;

    struct binder_state *bs;

    uint32_t svcmgr = BINDER_SERVICE_MANAGER;

    uint32_t handle;

	int ret;

	if (argc < 2){

        fprintf(stderr, "Usage:\n");

        fprintf(stderr, "%s <hello|goodbye>\n", argv[0]);

        fprintf(stderr, "%s <hello|goodbye> <name>\n", argv[0]);

        return -1;

	}

    bs = binder_open(128*1024);  //打开Binder驱动设备

    if (!bs) {

        fprintf(stderr, "failed to open binder driver\n");

        return -1;

    }

	g_bs = bs;

	/* get service */

	handle = svcmgr_lookup(bs, svcmgr, "goodbye");  //查找获取服务的引用

	if (!handle) {

        fprintf(stderr, "failed to get goodbye service\n");

        return -1;

	}

	g_goodbye_handle = handle;

	fprintf(stderr, "Handle for goodbye service = %d\n", g_goodbye_handle);

	handle = svcmgr_lookup(bs, svcmgr, "hello");

	if (!handle) {

        fprintf(stderr, "failed to get hello service\n");

        return -1;

	}

	g_hello_handle = handle;

	fprintf(stderr, "Handle for hello service = %d\n", g_hello_handle);

	/* send data to server */

	if (!strcmp(argv[1], "hello"))

	{

		if (argc == 2) {

			sayhello();

		} else if (argc == 3) {

			ret = sayhello_to(argv[2]);

	        fprintf(stderr, "get ret of sayhello_to = %d\n", ret);		

		}

	} else if (!strcmp(argv[1], "goodbye"))

	{

		if (argc == 2) {

			saygoodbye();

		} else if (argc == 3) {

			ret = saygoodbye_to(argv[2]);

	        fprintf(stderr, "get ret of sayhello_to = %d\n", ret);		

		}

	}

	binder_release(bs, handle);  //释放binder_acquire(bs, handle);

    return 0;

}