greenplumn ps_status 源码
greenplumn ps_status 代码
文件路径：/src/backend/utils/misc/ps_status.c
/*--------------------------------------------------------------------
* 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
*
* Portions Copyright (c) 2005-2009, Greenplum inc
* Portions Copyright (c) 2012-Present VMware, Inc. or its affiliates.
* Copyright (c) 2000-2019, 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 "utils/ps_status.h"
#include "utils/guc.h"
#include "cdb/cdbvars.h" /* Gp_role, GpIdentity.segindex, currentSliceId */
extern char **environ;
extern int PostPortNumber; /* GPDB: Helps identify child processes */
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_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 */
static char ps_username[NAMEDATALEN]; /*CDB*/
/* save the original argv[] location here */
static int save_argc;
static char **save_argv;
/*
* GPDB: the real activity location, the location right after
* those "con1 seg1 cmd1" strings. Sometimes we need to modify
* the original activity string in the ps display output. Use
* this pointer to get the real original activity string instead
* of get_ps_display(). See MPP-2329.
*/
static size_t real_act_prefix_size;
/*
* 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. At this point, the original argv[] array may be overwritten.
*/
void
init_ps_display(const char *username, const char *dbname,
const char *host_info, const char *initial_str)
{
Assert(username);
Assert(dbname);
Assert(host_info);
StrNCpy(ps_username, username, sizeof(ps_username)); /*CDB*/
#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 "%5d, %s %s %s ",
PostPortNumber, username, dbname, host_info);
}
else
{
snprintf(ps_buffer, ps_buffer_size,
PROGRAM_NAME_PREFIX "%5d, %s: %s %s %s ",
PostPortNumber, cluster_name, username, dbname, host_info);
}
ps_buffer_cur_len = ps_buffer_fixed_size = strlen(ps_buffer);
real_act_prefix_size = ps_buffer_fixed_size;
set_ps_display(initial_str, true);
#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, bool force)
{
#ifndef PS_USE_NONE
/* update_process_title=off disables updates, unless force = true */
char *cp = ps_buffer + ps_buffer_fixed_size;
char *ep = ps_buffer + ps_buffer_size;
if (!force && !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
Assert(cp >= ps_buffer);
/* Add client session's global id. */
if (gp_session_id > 0 && ep - cp > 0 &&
strstr(ps_buffer, "dtx recovery process") == NULL &&
strstr(ps_buffer, "ftsprobe process") == NULL)
{
cp += snprintf(cp, ep - cp, "con%d ", gp_session_id);
/* Which segment is accessed by this qExec? */
if (Gp_role == GP_ROLE_EXECUTE && GpIdentity.segindex >= -1)
cp += snprintf(cp, ep - cp, "seg%d ", GpIdentity.segindex);
}
/* Add count of commands received from client session. */
if (gp_command_count > 0 && ep - cp > 0)
cp += snprintf(cp, ep - cp, "cmd%d ", gp_command_count);
/* Add slice number information */
if (currentSliceId > 0 && ep - cp > 0)
cp += snprintf(cp, ep - cp, "slice%d ", currentSliceId);
/*
* Calculate the size preceding the actual activity string start.
* snprintf returns the number of bytes that *would* have been written if
* enough space had been available. This means cp might go beyond, if
* truncation happened. Hence need below check for Min. (ep - 1) is
* performed because in normal case when no truncation happens, snprintf
* doesn't count null, so in truncation case as well it shouldn't be
* counted. End result simply intended here is really real_act_prefix_size
* = strlen(ps_buffer), for performance reasons kept this way.
*/
real_act_prefix_size = Min(cp, (ep-1)) - ps_buffer;
/* Append caller's activity string. */
strlcpy(ps_buffer + real_act_prefix_size, activity,
ps_buffer_size - real_act_prefix_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 with a given starting
* position. On some platforms the string will not be null-terminated,
* so return the effective length into *displen.
*/
static inline const char *
get_ps_display_from_position(size_t pos, 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
*displen = (int) (ps_buffer_cur_len - real_act_prefix_size);
return ps_buffer + pos;
}
/*
* 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)
{
return get_ps_display_from_position(ps_buffer_fixed_size, displen);
}
/* CDB: Get the "username" string saved by init_ps_display(). */
const char *
get_ps_display_username(void)
{
return ps_username;
}
/*
* Returns the real activity string in the ps display without prefix
* strings like "con1 seg1 cmd1" for GPDB. On some platforms the
* string will not be null-terminated, so return the effective length
* into *displen.
*/
const char *
get_real_act_ps_display(int *displen)
{
return get_ps_display_from_position(real_act_prefix_size, displen);
}
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