Remove the option to build thread_test.c outside configure.

Theoretically one could go into src/test/thread and build/run this
program there.  In practice, that hasn't worked since 96bf88d52,
and probably much longer on some platforms (likely including just
the sort of hoary leftovers where this test might be of interest).
While it wouldn't be too hard to repair the breakage, the fact that
nobody has noticed for two years shows that there is zero usefulness
in maintaining this build pathway.  Let's get rid of it and decree
that thread_test.c is *only* meant to be built/used in configure.

Given that decision, it makes sense to put thread_test.c under config/
and get rid of src/test/thread altogether, so that's what I did.

In passing, update src/test/README, which had been ignored by some
not-so-recent additions of subdirectories.

Discussion: https://postgr.es/m/227659.1603041612@sss.pgh.pa.us

1 files changed, 437 insertions, 0 deletions

diff --git a/config/thread_test.c b/config/thread_test.c
new file mode 100644
index 0000000000..ff2eace87d
--- /dev/null
+++ b/config/thread_test.c
@@ -0,0 +1,437 @@
+/*-------------------------------------------------------------------------
+ *
+ * thread_test.c
+ *		libc threading test program
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *	config/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.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+/* We cannot use c.h, as port.h will not exist yet */
+
+#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>
+#include <pthread.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);
+
+
+#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 int	strerror_threadsafe = 0;
+#endif
+
+#if !defined(WIN32) && !defined(HAVE_GETPWUID_R)
+static struct passwd *passwd_p1;
+static struct passwd *passwd_p2;
+static int	getpwuid_threadsafe = 0;
+#endif
+
+#if !defined(HAVE_GETADDRINFO) && !defined(HAVE_GETHOSTBYNAME_R)
+static struct hostent *hostent_p1;
+static struct hostent *hostent_p2;
+static char myhostname[MAXHOSTNAMELEN];
+static int	gethostbyname_threadsafe = 0;
+#endif
+
+static int	platform_is_threadsafe = 1;
+
+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;
+	}
+
+	/* Send stdout to 'config.log' */
+	close(1);
+	dup(5);
+
+#ifdef WIN32
+	err = WSAStartup(MAKEWORD(2, 2), &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 = 1;
+#endif
+
+#if !defined(WIN32) && !defined(HAVE_GETPWUID_R)
+	if (passwd_p1 != passwd_p2)
+		getpwuid_threadsafe = 1;
+#endif
+
+#if !defined(HAVE_GETADDRINFO) && !defined(HAVE_GETHOSTBYNAME_R)
+	if (hostent_p1 != hostent_p2)
+		gethostbyname_threadsafe = 1;
+#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 strerror_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 = 0;
+	}
+#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 = 0;
+	}
+#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 = 0;
+	}
+#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);
+}