It_ipc_pipe_002.cpp

/*
 * Copyright (c) 2013-2019 Huawei Technologies Co., Ltd. All rights reserved.
 * Copyright (c) 2020-2021 Huawei Device Co., Ltd. All rights reserved.
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 * 2. Redistributions in binary form must reproduce the above copyright notice, this list
 * of conditions and the following disclaimer in the documentation and/or other materials
 * provided with the distribution.
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 * 3. Neither the name of the copyright holder nor the names of its contributors may be used
 * to endorse or promote products derived from this software without specific prior written
 * permission.
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
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#include "it_test_signal.h"
#include "sys/shm.h"

static UINT32 Testcase(VOID)
{
    int pipeFd[2], ret, spid; // 2, pipe return 2 file descripter
    char buffer[20];          // 20, target buffer size
    int *sharedflag = NULL;
    int shmid;
    
    ret = pipe(pipeFd);
    ICUNIT_GOTO_EQUAL(ret, 0, ret, EXIT1);
    shmid = shmget((key_t)IPC_PRIVATE, sizeof(int), 0666 | IPC_CREAT); // 0666 the authority of the shm
    ICUNIT_ASSERT_NOT_EQUAL(shmid, -1, shmid);
    sharedflag = (int *)shmat(shmid, NULL, 0);
    *sharedflag = 0;

    spid = fork();
    ICUNIT_GOTO_NOT_EQUAL(spid, -1, spid, EXIT1);
    if (spid == 0) {
        sharedflag = (int *)shmat(shmid, NULL, 0);
        close(pipeFd[0]);
        ret = write(pipeFd[1], "hello world", 12); // 12, "hello world" length and '\0'
        printf("write first status: %d\n", ret);
        if (ret != 12) { // 12, "hello world" length and '\0'
            exit(11);    // 11, the value of son process unexpect exit, convenient to debug
        }
        *sharedflag = 1;
        close(pipeFd[1]);
        exit(RED_FLAG);
    }
    close(pipeFd[1]);
    // waitting for the sub process has written the sentence
    while (*sharedflag != 1) {
        usleep(1);
    }
    ret = read(pipeFd[0], buffer, 12);     // 12, "hello world" length and '\0'
    ICUNIT_GOTO_EQUAL(ret, 12, ret, EXIT); // 12, "hello world" length and '\0'
    ret = strcmp(buffer, "hello world");
    ICUNIT_GOTO_EQUAL(ret, 0, ret, EXIT);
    printf("read pipe success: %s\n", buffer);
    wait(&ret);
    printf("son return status: %d\n", WEXITSTATUS(ret));
    ICUNIT_GOTO_EQUAL(WEXITSTATUS(ret), RED_FLAG, WEXITSTATUS(ret), EXIT);
    printf("pipe ok\n");
    close(pipeFd[0]);
    return LOS_OK;
EXIT:
    close(pipeFd[0]);
EXIT1:
    return LOS_NOK;
}

VOID ItIpcPipe002(void)
{
    TEST_ADD_CASE(__FUNCTION__, Testcase, TEST_LIB, TEST_LIBC, TEST_LEVEL1, TEST_FUNCTION);
}