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Revert "zdtm: use a unix socket instead of a pipe to synchronizer processes"

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Unfortunately the kernel wakes up only one waiter even
if they waits with MSG_PEEK, so the introduced scheme doesn't work.

Reported-by: Mr Jenkins
travis-ci: success for Revert "zdtm: use a unix socket instead of a pipe to synchronizer processes"
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
This commit is contained in:
Andrei Vagin
2017-01-24 00:45:00 +03:00
committed by Pavel Emelyanov
parent d9486bd720
commit cf72cedd5f
2 changed files with 10 additions and 46 deletions
Download Patch File Download Diff File Expand all files Collapse all files

54
test/zdtm/lib/lock.c
View File

@@ -7,9 +7,6 @@
#include <unistd.h>
#include <linux/unistd.h>
#include <time.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/stat.h>
#include "zdtmtst.h"
@@ -22,52 +19,19 @@ static long sys_gettid(void)
void task_waiter_init(task_waiter_t *t)
{
struct sockaddr_un addr;
unsigned int addrlen;
struct stat st;
int sk;
datagen((void *)&t->seed, sizeof(t->seed), NULL);
t->seed = t->seed % TASK_WAITER_INITIAL;
sk = socket(AF_UNIX, SOCK_DGRAM, 0);
if (sk < 0) {
pr_perror("Unable to create a socket");
goto err;
if (pipe(t->pipes)) {
pr_perror("task_waiter_init failed");
exit(1);
}
if (fstat(sk, &st)) {
pr_perror("Unable to stat a file descriptor");
close(sk);
goto err;
}
addr.sun_family = AF_UNIX;
addrlen = snprintf(addr.sun_path, sizeof(addr.sun_path), "X/criu-zdtm-%lx", st.st_ino);
addrlen += sizeof(addr.sun_family);
addr.sun_path[0] = 0;
if (bind(sk, &addr, addrlen)) {
pr_perror("Unable to bind a socket");
close(sk);
goto err;
}
if (connect(sk, &addr, addrlen)) {
pr_perror("Unable to connect a socket");
close(sk);
goto err;
}
t->sk = sk;
return;
err:
exit(1);
}
void task_waiter_fini(task_waiter_t *t)
{
close(t->sk);
t->sk = -1;
close(t->pipes[0]);
close(t->pipes[1]);
}
void task_waiter_wait4(task_waiter_t *t, unsigned int lockid)
@@ -77,7 +41,7 @@ void task_waiter_wait4(task_waiter_t *t, unsigned int lockid)
unsigned int v;
for (;;) {
if (recv(t->sk, &v, sizeof(v), MSG_PEEK) != sizeof(v))
if (read(t->pipes[0], &v, sizeof(v)) != sizeof(v))
goto err;
/*
@@ -89,6 +53,8 @@ void task_waiter_wait4(task_waiter_t *t, unsigned int lockid)
* next attempt.
*/
if (v != lockid) {
if (write(t->pipes[1], &v, sizeof(v)) != sizeof(v))
goto err;
/*
* If we get a collision in access, lets sleep
* semi-random time magnitude to decrease probability
@@ -99,8 +65,6 @@ void task_waiter_wait4(task_waiter_t *t, unsigned int lockid)
} else
break;
}
if (recv(t->sk, &v, sizeof(v), 0) != sizeof(v))
goto err;
return;
@@ -111,7 +75,7 @@ err:
void task_waiter_complete(task_waiter_t *t, unsigned int lockid)
{
if (write(t->sk, &lockid, sizeof(lockid)) != sizeof(lockid)) {
if (write(t->pipes[1], &lockid, sizeof(lockid)) != sizeof(lockid)) {
pr_perror("task_waiter_complete failed");
exit(1);
}

2
test/zdtm/lib/zdtmtst.h
View File

@@ -129,7 +129,7 @@ extern int zdtm_seccomp;
typedef struct {
unsigned long seed;
int sk;
int pipes[2];
} task_waiter_t;
extern void task_waiter_init(task_waiter_t *t);