Adding upstream version 14.5.upstream/14.5upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 449 insertions, 0 deletions

diff --git a/src/backend/utils/misc/ps_status.c b/src/backend/utils/misc/ps_status.c
new file mode 100644
index 0000000..bad8afb
--- /dev/null
+++ b/src/backend/utils/misc/ps_status.c
@@ -0,0 +1,449 @@
+/*--------------------------------------------------------------------
+ * ps_status.c
+ *
+ * Routines to support changing the ps display of PostgreSQL backends
+ * to contain some useful information. Mechanism differs wildly across
+ * platforms.
+ *
+ * src/backend/utils/misc/ps_status.c
+ *
+ * Copyright (c) 2000-2021, PostgreSQL Global Development Group
+ * various details abducted from various places
+ *--------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include <unistd.h>
+#ifdef HAVE_SYS_PSTAT_H
+#include <sys/pstat.h>			/* for HP-UX */
+#endif
+#ifdef HAVE_PS_STRINGS
+#include <machine/vmparam.h>	/* for old BSD */
+#include <sys/exec.h>
+#endif
+#if defined(__darwin__)
+#include <crt_externs.h>
+#endif
+
+#include "libpq/libpq.h"
+#include "miscadmin.h"
+#include "pgstat.h"
+#include "utils/guc.h"
+#include "utils/ps_status.h"
+
+extern char **environ;
+bool		update_process_title = true;
+
+
+/*
+ * Alternative ways of updating ps display:
+ *
+ * PS_USE_SETPROCTITLE_FAST
+ *	   use the function setproctitle_fast(const char *, ...)
+ *	   (newer FreeBSD systems)
+ * PS_USE_SETPROCTITLE
+ *	   use the function setproctitle(const char *, ...)
+ *	   (newer BSD systems)
+ * PS_USE_PSTAT
+ *	   use the pstat(PSTAT_SETCMD, )
+ *	   (HPUX)
+ * PS_USE_PS_STRINGS
+ *	   assign PS_STRINGS->ps_argvstr = "string"
+ *	   (some BSD systems)
+ * PS_USE_CHANGE_ARGV
+ *	   assign argv[0] = "string"
+ *	   (some other BSD systems)
+ * PS_USE_CLOBBER_ARGV
+ *	   write over the argv and environment area
+ *	   (Linux and most SysV-like systems)
+ * PS_USE_WIN32
+ *	   push the string out as the name of a Windows event
+ * PS_USE_NONE
+ *	   don't update ps display
+ *	   (This is the default, as it is safest.)
+ */
+#if defined(HAVE_SETPROCTITLE_FAST)
+#define PS_USE_SETPROCTITLE_FAST
+#elif defined(HAVE_SETPROCTITLE)
+#define PS_USE_SETPROCTITLE
+#elif defined(HAVE_PSTAT) && defined(PSTAT_SETCMD)
+#define PS_USE_PSTAT
+#elif defined(HAVE_PS_STRINGS)
+#define PS_USE_PS_STRINGS
+#elif (defined(BSD) || defined(__hurd__)) && !defined(__darwin__)
+#define PS_USE_CHANGE_ARGV
+#elif defined(__linux__) || defined(_AIX) || defined(__sgi) || (defined(sun) && !defined(BSD)) || defined(__svr5__) || defined(__darwin__)
+#define PS_USE_CLOBBER_ARGV
+#elif defined(WIN32)
+#define PS_USE_WIN32
+#else
+#define PS_USE_NONE
+#endif
+
+
+/* Different systems want the buffer padded differently */
+#if defined(_AIX) || defined(__linux__) || defined(__darwin__)
+#define PS_PADDING '\0'
+#else
+#define PS_PADDING ' '
+#endif
+
+
+#ifndef PS_USE_NONE
+
+#ifndef PS_USE_CLOBBER_ARGV
+/* all but one option need a buffer to write their ps line in */
+#define PS_BUFFER_SIZE 256
+static char ps_buffer[PS_BUFFER_SIZE];
+static const size_t ps_buffer_size = PS_BUFFER_SIZE;
+#else							/* PS_USE_CLOBBER_ARGV */
+static char *ps_buffer;			/* will point to argv area */
+static size_t ps_buffer_size;	/* space determined at run time */
+static size_t last_status_len;	/* use to minimize length of clobber */
+#endif							/* PS_USE_CLOBBER_ARGV */
+
+static size_t ps_buffer_cur_len;	/* nominal strlen(ps_buffer) */
+
+static size_t ps_buffer_fixed_size; /* size of the constant prefix */
+
+#endif							/* not PS_USE_NONE */
+
+/* save the original argv[] location here */
+static int	save_argc;
+static char **save_argv;
+
+
+/*
+ * Call this early in startup to save the original argc/argv values.
+ * If needed, we make a copy of the original argv[] array to preserve it
+ * from being clobbered by subsequent ps_display actions.
+ *
+ * (The original argv[] will not be overwritten by this routine, but may be
+ * overwritten during init_ps_display.  Also, the physical location of the
+ * environment strings may be moved, so this should be called before any code
+ * that might try to hang onto a getenv() result.)
+ *
+ * Note that in case of failure this cannot call elog() as that is not
+ * initialized yet.  We rely on write_stderr() instead.
+ */
+char	  **
+save_ps_display_args(int argc, char **argv)
+{
+	save_argc = argc;
+	save_argv = argv;
+
+#if defined(PS_USE_CLOBBER_ARGV)
+
+	/*
+	 * If we're going to overwrite the argv area, count the available space.
+	 * Also move the environment to make additional room.
+	 */
+	{
+		char	   *end_of_area = NULL;
+		char	  **new_environ;
+		int			i;
+
+		/*
+		 * check for contiguous argv strings
+		 */
+		for (i = 0; i < argc; i++)
+		{
+			if (i == 0 || end_of_area + 1 == argv[i])
+				end_of_area = argv[i] + strlen(argv[i]);
+		}
+
+		if (end_of_area == NULL)	/* probably can't happen? */
+		{
+			ps_buffer = NULL;
+			ps_buffer_size = 0;
+			return argv;
+		}
+
+		/*
+		 * check for contiguous environ strings following argv
+		 */
+		for (i = 0; environ[i] != NULL; i++)
+		{
+			if (end_of_area + 1 == environ[i])
+				end_of_area = environ[i] + strlen(environ[i]);
+		}
+
+		ps_buffer = argv[0];
+		last_status_len = ps_buffer_size = end_of_area - argv[0];
+
+		/*
+		 * move the environment out of the way
+		 */
+		new_environ = (char **) malloc((i + 1) * sizeof(char *));
+		if (!new_environ)
+		{
+			write_stderr("out of memory\n");
+			exit(1);
+		}
+		for (i = 0; environ[i] != NULL; i++)
+		{
+			new_environ[i] = strdup(environ[i]);
+			if (!new_environ[i])
+			{
+				write_stderr("out of memory\n");
+				exit(1);
+			}
+		}
+		new_environ[i] = NULL;
+		environ = new_environ;
+	}
+#endif							/* PS_USE_CLOBBER_ARGV */
+
+#if defined(PS_USE_CHANGE_ARGV) || defined(PS_USE_CLOBBER_ARGV)
+
+	/*
+	 * If we're going to change the original argv[] then make a copy for
+	 * argument parsing purposes.
+	 *
+	 * (NB: do NOT think to remove the copying of argv[], even though
+	 * postmaster.c finishes looking at argv[] long before we ever consider
+	 * changing the ps display.  On some platforms, getopt() keeps pointers
+	 * into the argv array, and will get horribly confused when it is
+	 * re-called to analyze a subprocess' argument string if the argv storage
+	 * has been clobbered meanwhile.  Other platforms have other dependencies
+	 * on argv[].
+	 */
+	{
+		char	  **new_argv;
+		int			i;
+
+		new_argv = (char **) malloc((argc + 1) * sizeof(char *));
+		if (!new_argv)
+		{
+			write_stderr("out of memory\n");
+			exit(1);
+		}
+		for (i = 0; i < argc; i++)
+		{
+			new_argv[i] = strdup(argv[i]);
+			if (!new_argv[i])
+			{
+				write_stderr("out of memory\n");
+				exit(1);
+			}
+		}
+		new_argv[argc] = NULL;
+
+#if defined(__darwin__)
+
+		/*
+		 * macOS (and perhaps other NeXT-derived platforms?) has a static copy
+		 * of the argv pointer, which we may fix like so:
+		 */
+		*_NSGetArgv() = new_argv;
+#endif
+
+		argv = new_argv;
+	}
+#endif							/* PS_USE_CHANGE_ARGV or PS_USE_CLOBBER_ARGV */
+
+	return argv;
+}
+
+/*
+ * Call this once during subprocess startup to set the identification
+ * values.
+ *
+ * If fixed_part is NULL, a default will be obtained from MyBackendType.
+ *
+ * At this point, the original argv[] array may be overwritten.
+ */
+void
+init_ps_display(const char *fixed_part)
+{
+#ifndef PS_USE_NONE
+	bool		save_update_process_title;
+#endif
+
+	Assert(fixed_part || MyBackendType);
+	if (!fixed_part)
+		fixed_part = GetBackendTypeDesc(MyBackendType);
+
+#ifndef PS_USE_NONE
+	/* no ps display for stand-alone backend */
+	if (!IsUnderPostmaster)
+		return;
+
+	/* no ps display if you didn't call save_ps_display_args() */
+	if (!save_argv)
+		return;
+
+#ifdef PS_USE_CLOBBER_ARGV
+	/* If ps_buffer is a pointer, it might still be null */
+	if (!ps_buffer)
+		return;
+#endif
+
+	/*
+	 * Overwrite argv[] to point at appropriate space, if needed
+	 */
+
+#ifdef PS_USE_CHANGE_ARGV
+	save_argv[0] = ps_buffer;
+	save_argv[1] = NULL;
+#endif							/* PS_USE_CHANGE_ARGV */
+
+#ifdef PS_USE_CLOBBER_ARGV
+	{
+		int			i;
+
+		/* make extra argv slots point at end_of_area (a NUL) */
+		for (i = 1; i < save_argc; i++)
+			save_argv[i] = ps_buffer + ps_buffer_size;
+	}
+#endif							/* PS_USE_CLOBBER_ARGV */
+
+	/*
+	 * Make fixed prefix of ps display.
+	 */
+
+#if defined(PS_USE_SETPROCTITLE) || defined(PS_USE_SETPROCTITLE_FAST)
+
+	/*
+	 * apparently setproctitle() already adds a `progname:' prefix to the ps
+	 * line
+	 */
+#define PROGRAM_NAME_PREFIX ""
+#else
+#define PROGRAM_NAME_PREFIX "postgres: "
+#endif
+
+	if (*cluster_name == '\0')
+	{
+		snprintf(ps_buffer, ps_buffer_size,
+				 PROGRAM_NAME_PREFIX "%s ",
+				 fixed_part);
+	}
+	else
+	{
+		snprintf(ps_buffer, ps_buffer_size,
+				 PROGRAM_NAME_PREFIX "%s: %s ",
+				 cluster_name, fixed_part);
+	}
+
+	ps_buffer_cur_len = ps_buffer_fixed_size = strlen(ps_buffer);
+
+	/*
+	 * On the first run, force the update.
+	 */
+	save_update_process_title = update_process_title;
+	update_process_title = true;
+	set_ps_display("");
+	update_process_title = save_update_process_title;
+#endif							/* not PS_USE_NONE */
+}
+
+
+
+/*
+ * Call this to update the ps status display to a fixed prefix plus an
+ * indication of what you're currently doing passed in the argument.
+ */
+void
+set_ps_display(const char *activity)
+{
+#ifndef PS_USE_NONE
+	/* update_process_title=off disables updates */
+	if (!update_process_title)
+		return;
+
+	/* no ps display for stand-alone backend */
+	if (!IsUnderPostmaster)
+		return;
+
+#ifdef PS_USE_CLOBBER_ARGV
+	/* If ps_buffer is a pointer, it might still be null */
+	if (!ps_buffer)
+		return;
+#endif
+
+	/* Update ps_buffer to contain both fixed part and activity */
+	strlcpy(ps_buffer + ps_buffer_fixed_size, activity,
+			ps_buffer_size - ps_buffer_fixed_size);
+	ps_buffer_cur_len = strlen(ps_buffer);
+
+	/* Transmit new setting to kernel, if necessary */
+
+#ifdef PS_USE_SETPROCTITLE
+	setproctitle("%s", ps_buffer);
+#elif defined(PS_USE_SETPROCTITLE_FAST)
+	setproctitle_fast("%s", ps_buffer);
+#endif
+
+#ifdef PS_USE_PSTAT
+	{
+		union pstun pst;
+
+		pst.pst_command = ps_buffer;
+		pstat(PSTAT_SETCMD, pst, ps_buffer_cur_len, 0, 0);
+	}
+#endif							/* PS_USE_PSTAT */
+
+#ifdef PS_USE_PS_STRINGS
+	PS_STRINGS->ps_nargvstr = 1;
+	PS_STRINGS->ps_argvstr = ps_buffer;
+#endif							/* PS_USE_PS_STRINGS */
+
+#ifdef PS_USE_CLOBBER_ARGV
+	/* pad unused memory; need only clobber remainder of old status string */
+	if (last_status_len > ps_buffer_cur_len)
+		MemSet(ps_buffer + ps_buffer_cur_len, PS_PADDING,
+			   last_status_len - ps_buffer_cur_len);
+	last_status_len = ps_buffer_cur_len;
+#endif							/* PS_USE_CLOBBER_ARGV */
+
+#ifdef PS_USE_WIN32
+	{
+		/*
+		 * Win32 does not support showing any changed arguments. To make it at
+		 * all possible to track which backend is doing what, we create a
+		 * named object that can be viewed with for example Process Explorer.
+		 */
+		static HANDLE ident_handle = INVALID_HANDLE_VALUE;
+		char		name[PS_BUFFER_SIZE + 32];
+
+		if (ident_handle != INVALID_HANDLE_VALUE)
+			CloseHandle(ident_handle);
+
+		sprintf(name, "pgident(%d): %s", MyProcPid, ps_buffer);
+
+		ident_handle = CreateEvent(NULL, TRUE, FALSE, name);
+	}
+#endif							/* PS_USE_WIN32 */
+#endif							/* not PS_USE_NONE */
+}
+
+
+/*
+ * Returns what's currently in the ps display, in case someone needs
+ * it.  Note that only the activity part is returned.  On some platforms
+ * the string will not be null-terminated, so return the effective
+ * length into *displen.
+ */
+const char *
+get_ps_display(int *displen)
+{
+#ifdef PS_USE_CLOBBER_ARGV
+	/* If ps_buffer is a pointer, it might still be null */
+	if (!ps_buffer)
+	{
+		*displen = 0;
+		return "";
+	}
+#endif
+
+#ifndef PS_USE_NONE
+	*displen = (int) (ps_buffer_cur_len - ps_buffer_fixed_size);
+
+	return ps_buffer + ps_buffer_fixed_size;
+#else
+	*displen = 0;
+	return "";
+#endif
+}