Re: [LTP] [PATCH 2/3] mq_open/16-1: use tmp file to share info

[Wanlong Gao <gaowanlong@cn.fujitsu.com>]

On 08/09/2012 06:30 PM, Kang Kai wrote:
> In this test case, it uses a variable to share data between child and
> parent processes. But after fork there is a copy of the variable in
> child process and modify it will not affect the variable in the parent
> process. Then when the child process call mq_open() before parent process,
> the case will fail.
> 
> Use tmp file to replace the variable. Any modification in child process
> can be seen in parent process.
> 

Looks Ok in general.
A bit comment below.

> Signed-off-by: Kang Kai <kai.kang@windriver.com>
> ---
>  .../conformance/interfaces/mq_open/16-1.c          |   38 +++++++++++++++++--
>  1 files changed, 34 insertions(+), 4 deletions(-)
> 
> diff --git a/testcases/open_posix_testsuite/conformance/interfaces/mq_open/16-1.c b/testcases/open_posix_testsuite/conformance/interfaces/mq_open/16-1.c
> index b9a3215..ebd697b 100644
> --- a/testcases/open_posix_testsuite/conformance/interfaces/mq_open/16-1.c
> +++ b/testcases/open_posix_testsuite/conformance/interfaces/mq_open/16-1.c
> @@ -20,9 +20,11 @@
>   * this is fine (will have some false positives, but no false negatives).
>   */
>  
> +#include <sys/mman.h>
>  #include <sys/stat.h>
>  #include <sys/types.h>
>  #include <sys/wait.h>
> +#include <errno.h>
>  #include <fcntl.h>
>  #include <mqueue.h>
>  #include <signal.h>
> @@ -32,11 +34,15 @@
>  #include "posixtest.h"
>  
>  #define NAMESIZE 50
> +#define TNAME "mq_open/16-1.c"
>  
>  int main()
>  {
>         	char qname[NAMESIZE];
> +	char fname[NAMESIZE];
>  	int pid, succeeded=0;
> +	int fd;
> +	void *pa = NULL;
>  	mqd_t childqueue, queue;
>  
>  	/*
> @@ -47,6 +53,26 @@ int main()
>  
>         	sprintf(qname, "/mq_open_16-1_%d", getpid());
>  
> +	sprintf(fname, "/tmp/pts_mq_open_16_1_%d", getpid());
> +	unlink(fname);
> +	fd = open(fname, O_CREAT | O_RDWR | O_EXCL,
> +		 S_IRUSR | S_IWUSR);
> +	if (fd == -1) {
> +		printf(TNAME " Error at open(): %s\n", strerror(errno));
> +		exit(PTS_UNRESOLVED);
> +	}
> +	/* file is empty now, will cause "Bus error" */
> +	write(fd, "\0", 1);
> +	unlink(fname);
> +
> +	pa = mmap(NULL, sizeof(int), PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);

Why not use anonymous map? in that case you will not need to create a file.


Thanks,
Wanlong Gao


> +	if (pa == MAP_FAILED) {
> +		printf(TNAME " Error at mmap: %s\n", strerror(errno));
> +		close(fd);
> +		exit(PTS_FAIL);
> +	}
> +	*(int *)pa = 0;
> +
>  	if ((pid = fork()) == 0) {
>  		sigset_t mask;
>  		int sig;
> @@ -62,7 +88,7 @@ int main()
>          	childqueue = mq_open(qname, O_CREAT|O_EXCL|O_RDWR,
>  				S_IRUSR | S_IWUSR, NULL);
>          	if (childqueue != (mqd_t)-1) {
> -			succeeded++;
> +			++*(int *)pa;
>  #ifdef DEBUG
>  			printf("mq_open() in child succeeded\n");
>  		} else {
> @@ -79,7 +105,7 @@ int main()
>          	queue = mq_open(qname, O_CREAT | O_EXCL |O_RDWR,
>  				S_IRUSR | S_IWUSR, NULL);
>          	if (queue != (mqd_t)-1) {
> -			succeeded++;
> +			++*(int *)pa;
>  #ifdef DEBUG
>  			printf("mq_open() in parent succeeded\n");
>  		} else {
> @@ -93,13 +119,15 @@ int main()
>  			mq_close(queue);
>  			mq_close(childqueue);
>  			mq_unlink(qname);
> +			close(fd);
> +			munmap(pa, sizeof(int));
>  			return PTS_UNRESOLVED;
>  		}
>  
>  		mq_close(queue);
>  		mq_close(childqueue);
>  		mq_unlink(qname);
> -
> +		succeeded = *(int *)pa;
>  		if (succeeded==0) {
>  			printf("Test FAILED - mq_open() never succeeded\n");
>  			return PTS_FAIL;
> @@ -111,8 +139,10 @@ int main()
>  		}
>  
>          	printf("Test PASSED\n");
> +		close(fd);
> +		munmap(pa, sizeof(int));
>          	return PTS_PASS;
>  	}
>  
>  	return PTS_UNRESOLVED;
> -}
> \ No newline at end of file
> +}
> 


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