thread_test.c

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/*-------------------------------------------------------------------------
 *
 * test_thread_funcs.c
 *      libc thread test program
 *
 * Portions Copyright (c) 1996-2013, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *  src/test/thread/thread_test.c
 *
 *  This program tests to see if your standard libc functions use
 *  pthread_setspecific()/pthread_getspecific() to be thread-safe.
 *  See src/port/thread.c for more details.
 *
 *  This program first tests to see if each function returns a constant
 *  memory pointer within the same thread, then, assuming it does, tests
 *  to see if the pointers are different for different threads.  If they
 *  are, the function is thread-safe.
 *
 *-------------------------------------------------------------------------
 */

#if !defined(IN_CONFIGURE) && !defined(WIN32)
#include "postgres.h"
#else
/* From src/include/c.h" */
#ifndef bool
typedef char bool;
#endif

#ifndef true
#define true    ((bool) 1)
#endif

#ifndef false
#define false   ((bool) 0)
#endif
#endif

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <netdb.h>
#include <sys/types.h>
#include <pwd.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>

/* CYGWIN requires this for MAXHOSTNAMELEN */
#ifdef __CYGWIN__
#include <sys/param.h>
#endif

#ifdef WIN32
#define MAXHOSTNAMELEN 63
#include <winsock2.h>
#endif


/* Test for POSIX.1c 2-arg sigwait() and fail on single-arg version */
#include <signal.h>
int         sigwait(const sigset_t *set, int *sig);


#if !defined(ENABLE_THREAD_SAFETY) && !defined(IN_CONFIGURE) && !defined(WIN32)
int
main(int argc, char *argv[])
{
    fprintf(stderr, "This PostgreSQL build does not support threads.\n");
    fprintf(stderr, "Perhaps rerun 'configure' using '--enable-thread-safety'.\n");
    return 1;
}
#else

/* This must be down here because this is the code that uses threads. */
#include <pthread.h>

#define     TEMP_FILENAME_1 "thread_test.1"
#define     TEMP_FILENAME_2 "thread_test.2"

static void func_call_1(void);
static void func_call_2(void);

static pthread_mutex_t init_mutex = PTHREAD_MUTEX_INITIALIZER;

static volatile int thread1_done = 0;
static volatile int thread2_done = 0;

static volatile int errno1_set = 0;
static volatile int errno2_set = 0;

#ifndef HAVE_STRERROR_R
static char *strerror_p1;
static char *strerror_p2;
static bool strerror_threadsafe = false;
#endif

#if !defined(WIN32) && !defined(HAVE_GETPWUID_R)
static struct passwd *passwd_p1;
static struct passwd *passwd_p2;
static bool getpwuid_threadsafe = false;
#endif

#if !defined(HAVE_GETADDRINFO) && !defined(HAVE_GETHOSTBYNAME_R)
static struct hostent *hostent_p1;
static struct hostent *hostent_p2;
static char myhostname[MAXHOSTNAMELEN];
static bool gethostbyname_threadsafe = false;
#endif

static bool platform_is_threadsafe = true;

int
main(int argc, char *argv[])
{
    pthread_t   thread1,
                thread2;
    int         rc;

#ifdef WIN32
    WSADATA     wsaData;
    int         err;
#endif

    if (argc > 1)
    {
        fprintf(stderr, "Usage: %s\n", argv[0]);
        return 1;
    }

#ifdef IN_CONFIGURE
    /* Send stdout to 'config.log' */
    close(1);
    dup(5);
#endif

#ifdef WIN32
    err = WSAStartup(MAKEWORD(1, 1), &wsaData);
    if (err != 0)
    {
        fprintf(stderr, "Cannot start the network subsystem - %d**\nexiting\n", err);
        exit(1);
    }
#endif

#if !defined(HAVE_GETADDRINFO) && !defined(HAVE_GETHOSTBYNAME_R)
    if (gethostname(myhostname, MAXHOSTNAMELEN) != 0)
    {
        fprintf(stderr, "Cannot get local hostname **\nexiting\n");
        exit(1);
    }
#endif

    /* Hold lock until we are ready for the child threads to exit. */
    pthread_mutex_lock(&init_mutex);

    rc = pthread_create(&thread1, NULL, (void *(*) (void *)) func_call_1, NULL);
    if (rc != 0)
    {
        fprintf(stderr, "Failed to create thread 1: %s **\nexiting\n",
                strerror(errno));
        exit(1);
    }
    rc = pthread_create(&thread2, NULL, (void *(*) (void *)) func_call_2, NULL);
    if (rc != 0)
    {
        /*
         * strerror() might not be thread-safe, and we already spawned thread
         * 1 that uses it, so avoid using it.
         */
        fprintf(stderr, "Failed to create thread 2 **\nexiting\n");
        exit(1);
    }

    while (thread1_done == 0 || thread2_done == 0)
        sched_yield();          /* if this is a portability problem, remove it */

    /* Test things while we have thread-local storage */

    /* If we got here, we didn't exit() from a thread */
#ifdef WIN32
    printf("Your GetLastError() is thread-safe.\n");
#else
    printf("Your errno is thread-safe.\n");
#endif

#ifndef HAVE_STRERROR_R
    if (strerror_p1 != strerror_p2)
        strerror_threadsafe = true;
#endif

#if !defined(WIN32) && !defined(HAVE_GETPWUID_R)
    if (passwd_p1 != passwd_p2)
        getpwuid_threadsafe = true;
#endif

#if !defined(HAVE_GETADDRINFO) && !defined(HAVE_GETHOSTBYNAME_R)
    if (hostent_p1 != hostent_p2)
        gethostbyname_threadsafe = true;
#endif

    /* close down threads */

    pthread_mutex_unlock(&init_mutex);  /* let children exit  */

    pthread_join(thread1, NULL);    /* clean up children */
    pthread_join(thread2, NULL);

    /* report results */

#ifdef HAVE_STRERROR_R
    printf("Your system has sterror_r();  it does not need strerror().\n");
#else
    printf("Your system uses strerror() which is ");
    if (strerror_threadsafe)
        printf("thread-safe.\n");
    else
    {
        printf("not thread-safe. **\n");
        platform_is_threadsafe = false;
    }
#endif

#ifdef WIN32
    printf("getpwuid_r()/getpwuid() are not applicable to Win32 platforms.\n");
#elif defined(HAVE_GETPWUID_R)
    printf("Your system has getpwuid_r();  it does not need getpwuid().\n");
#else
    printf("Your system uses getpwuid() which is ");
    if (getpwuid_threadsafe)
        printf("thread-safe.\n");
    else
    {
        printf("not thread-safe. **\n");
        platform_is_threadsafe = false;
    }
#endif

#ifdef HAVE_GETADDRINFO
    printf("Your system has getaddrinfo();  it does not need gethostbyname()\n"
           "  or gethostbyname_r().\n");
#elif defined(HAVE_GETHOSTBYNAME_R)
    printf("Your system has gethostbyname_r();  it does not need gethostbyname().\n");
#else
    printf("Your system uses gethostbyname which is ");
    if (gethostbyname_threadsafe)
        printf("thread-safe.\n");
    else
    {
        printf("not thread-safe. **\n");
        platform_is_threadsafe = false;
    }
#endif

    if (platform_is_threadsafe)
    {
        printf("\nYour platform is thread-safe.\n");
        return 0;
    }
    else
    {
        printf("\n** YOUR PLATFORM IS NOT THREAD-SAFE. **\n");
        return 1;
    }
}

/*
 * func_call_1
 */
static void
func_call_1(void)
{
#if !defined(HAVE_GETPWUID_R) || \
    (!defined(HAVE_GETADDRINFO) && \
     !defined(HAVE_GETHOSTBYNAME_R))
    void       *p;
#endif
#ifdef WIN32
    HANDLE      h1;
#else
    int         fd;
#endif

    unlink(TEMP_FILENAME_1);

    /* Set errno = EEXIST */

    /* create, then try to fail on exclusive create open */

    /*
     * It would be great to check errno here but if errno is not thread-safe
     * we might get a value from the other thread and mis-report the cause of
     * the failure.
     */
#ifdef WIN32
    if ((h1 = CreateFile(TEMP_FILENAME_1, GENERIC_WRITE, 0, NULL, OPEN_ALWAYS, 0, NULL)) ==
        INVALID_HANDLE_VALUE)
#else
    if ((fd = open(TEMP_FILENAME_1, O_RDWR | O_CREAT, 0600)) < 0)
#endif
    {
        fprintf(stderr, "Could not create file %s in current directory\n",
                TEMP_FILENAME_1);
        exit(1);
    }

#ifdef WIN32
    if (CreateFile(TEMP_FILENAME_1, GENERIC_WRITE, 0, NULL, CREATE_NEW, 0, NULL)
        != INVALID_HANDLE_VALUE)
#else
    if (open(TEMP_FILENAME_1, O_RDWR | O_CREAT | O_EXCL, 0600) >= 0)
#endif
    {
        fprintf(stderr,
                "Could not generate failure for exclusive file create of %s in current directory **\nexiting\n",
                TEMP_FILENAME_1);
        exit(1);
    }

    /*
     * Wait for other thread to set errno. We can't use thread-specific
     * locking here because it might affect errno.
     */
    errno1_set = 1;
    while (errno2_set == 0)
        sched_yield();

#ifdef WIN32
    if (GetLastError() != ERROR_FILE_EXISTS)
#else
    if (errno != EEXIST)
#endif
    {
#ifdef WIN32
        fprintf(stderr, "GetLastError() not thread-safe **\nexiting\n");
#else
        fprintf(stderr, "errno not thread-safe **\nexiting\n");
#endif
        unlink(TEMP_FILENAME_1);
        exit(1);
    }

#ifdef WIN32
    CloseHandle(h1);
#else
    close(fd);
#endif
    unlink(TEMP_FILENAME_1);

#ifndef HAVE_STRERROR_R

    /*
     * If strerror() uses sys_errlist, the pointer might change for different
     * errno values, so we don't check to see if it varies within the thread.
     */
    strerror_p1 = strerror(EACCES);
#endif

#if !defined(WIN32) && !defined(HAVE_GETPWUID_R)
    passwd_p1 = getpwuid(0);
    p = getpwuid(1);
    if (passwd_p1 != p)
    {
        printf("Your getpwuid() changes the static memory area between calls\n");
        passwd_p1 = NULL;       /* force thread-safe failure report */
    }
#endif

#if !defined(HAVE_GETADDRINFO) && !defined(HAVE_GETHOSTBYNAME_R)
    /* threads do this in opposite order */
    hostent_p1 = gethostbyname(myhostname);
    p = gethostbyname("localhost");
    if (hostent_p1 != p)
    {
        printf("Your gethostbyname() changes the static memory area between calls\n");
        hostent_p1 = NULL;      /* force thread-safe failure report */
    }
#endif

    thread1_done = 1;
    pthread_mutex_lock(&init_mutex);    /* wait for parent to test */
    pthread_mutex_unlock(&init_mutex);
}


/*
 * func_call_2
 */
static void
func_call_2(void)
{
#if !defined(HAVE_GETPWUID_R) || \
    (!defined(HAVE_GETADDRINFO) && \
     !defined(HAVE_GETHOSTBYNAME_R))
    void       *p;
#endif

    unlink(TEMP_FILENAME_2);

    /* Set errno = ENOENT */

    /* This will fail, but we can't check errno yet */
    if (unlink(TEMP_FILENAME_2) != -1)
    {
        fprintf(stderr,
                "Could not generate failure for unlink of %s in current directory **\nexiting\n",
                TEMP_FILENAME_2);
        exit(1);
    }

    /*
     * Wait for other thread to set errno. We can't use thread-specific
     * locking here because it might affect errno.
     */
    errno2_set = 1;
    while (errno1_set == 0)
        sched_yield();

#ifdef WIN32
    if (GetLastError() != ENOENT)
#else
    if (errno != ENOENT)
#endif
    {
#ifdef WIN32
        fprintf(stderr, "GetLastError() not thread-safe **\nexiting\n");
#else
        fprintf(stderr, "errno not thread-safe **\nexiting\n");
#endif
        exit(1);
    }

#ifndef HAVE_STRERROR_R

    /*
     * If strerror() uses sys_errlist, the pointer might change for different
     * errno values, so we don't check to see if it varies within the thread.
     */
    strerror_p2 = strerror(EINVAL);
#endif

#if !defined(WIN32) && !defined(HAVE_GETPWUID_R)
    passwd_p2 = getpwuid(2);
    p = getpwuid(3);
    if (passwd_p2 != p)
    {
        printf("Your getpwuid() changes the static memory area between calls\n");
        passwd_p2 = NULL;       /* force thread-safe failure report */
    }
#endif

#if !defined(HAVE_GETADDRINFO) && !defined(HAVE_GETHOSTBYNAME_R)
    /* threads do this in opposite order */
    hostent_p2 = gethostbyname("localhost");
    p = gethostbyname(myhostname);
    if (hostent_p2 != p)
    {
        printf("Your gethostbyname() changes the static memory area between calls\n");
        hostent_p2 = NULL;      /* force thread-safe failure report */
    }
#endif

    thread2_done = 1;
    pthread_mutex_lock(&init_mutex);    /* wait for parent to test */
    pthread_mutex_unlock(&init_mutex);
}

#endif   /* !ENABLE_THREAD_SAFETY && !IN_CONFIGURE */