#include "postgres.h"
#include <unistd.h>
#include "miscadmin.h"
#include "utils/guc.h"
#include "utils/ps_status.h"

Include dependency graph for ps_status.c:

Macros
#define	PS_USE_NONE

#define	PS_PADDING ' '

Functions
char **	save_ps_display_args (int argc, char **argv)

void	init_ps_display (const char *fixed_part)

void	set_ps_display_suffix (const char *suffix)

void	set_ps_display_remove_suffix (void)

void	set_ps_display_with_len (const char *activity, size_t len)

const char *	get_ps_display (int *displen)

Variables
char **	environ

bool	update_process_title = DEFAULT_UPDATE_PROCESS_TITLE

static int	save_argc

static char **	save_argv

Macro Definition Documentation

◆ PS_PADDING

#define PS_PADDING ' '

Definition at line 66 of file ps_status.c.

◆ PS_USE_NONE

#define PS_USE_NONE

Definition at line 58 of file ps_status.c.

Function Documentation

◆ get_ps_display()

const char* get_ps_display ( int * displen )

Definition at line 530 of file ps_status.c.

 {
 #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
 }

Referenced by log_status_format(), write_csvlog(), and write_jsonlog().

◆ init_ps_display()

void init_ps_display ( const char * fixed_part )

Definition at line 267 of file ps_status.c.

 {
 #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;
  
     /* make extra argv slots point at end_of_area (a NUL) */
     for (int 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 */
 }

References Assert, cluster_name, GetBackendTypeDesc(), i, IsUnderPostmaster, MyBackendType, save_argc, save_argv, set_ps_display(), snprintf, and update_process_title.

Referenced by AutoVacWorkerMain(), AuxiliaryProcessMainCommon(), BackendInitialize(), BackgroundWorkerMain(), ReplSlotSyncWorkerMain(), and SysLoggerMain().

◆ save_ps_display_args()

char** save_ps_display_args	(	int	argc,
		char **	argv
	)

Definition at line 117 of file ps_status.c.

 {
     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 strings 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])
             {
                 /*
                  * The musl dynamic linker keeps a static pointer to the
                  * initial value of LD_LIBRARY_PATH, if that is defined in the
                  * process's environment. Therefore, we must not overwrite the
                  * value of that setting and thus cannot advance end_of_area
                  * beyond it.  Musl does not define any identifying compiler
                  * symbol, so we have to do this unless we see a symbol
                  * identifying a Linux libc we know is safe.
                  */
 #if defined(__linux__) && (!defined(__GLIBC__) && !defined(__UCLIBC__))
                 if (strncmp(environ[i], "LD_LIBRARY_PATH=", 16) == 0)
                 {
                     /*
                      * We can overwrite the name, but stop at the equals sign.
                      * Future loop iterations will not find any more
                      * contiguous space, but we don't break early because we
                      * need to count the total number of environ[] entries.
                      */
                     end_of_area = environ[i] + 15;
                 }
                 else
 #endif
                 {
                     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;
     }
  
     /*
      * 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 has a static copy of the argv pointer, which we may fix like
          * so:
          */
         *_NSGetArgv() = new_argv;
 #endif
  
         argv = new_argv;
     }
 #endif                          /* PS_USE_CLOBBER_ARGV */
  
     return argv;
 }

References environ, exit(), i, malloc, save_argc, save_argv, and write_stderr.

Referenced by main().

◆ set_ps_display_remove_suffix()

void set_ps_display_remove_suffix ( void )

Definition at line 421 of file ps_status.c.

 {
 #ifndef PS_USE_NONE
     /* first, check if we need to update the process title */
     if (!update_ps_display_precheck())
         return;
  
     /* check we added a suffix */
     if (ps_buffer_nosuffix_len == 0)
         return;                 /* no suffix */
  
     /* remove the suffix from ps_buffer */
     ps_buffer[ps_buffer_nosuffix_len] = '\0';
     ps_buffer_cur_len = ps_buffer_nosuffix_len;
     ps_buffer_nosuffix_len = 0;
  
     Assert(ps_buffer_cur_len == strlen(ps_buffer));
  
     /* and set the new title */
     flush_ps_display();
 #endif                          /* not PS_USE_NONE */
 }

References Assert.

Referenced by LockBufferForCleanup(), ResolveRecoveryConflictWithVirtualXIDs(), SyncRepWaitForLSN(), and WaitOnLock().

◆ set_ps_display_suffix()

void set_ps_display_suffix ( const char * suffix )

Definition at line 369 of file ps_status.c.

 {
 #ifndef PS_USE_NONE
     size_t      len;
  
     /* first, check if we need to update the process title */
     if (!update_ps_display_precheck())
         return;
  
     /* if there's already a suffix, overwrite it */
     if (ps_buffer_nosuffix_len > 0)
         ps_buffer_cur_len = ps_buffer_nosuffix_len;
     else
         ps_buffer_nosuffix_len = ps_buffer_cur_len;
  
     len = strlen(suffix);
  
     /* check if we have enough space to append the suffix */
     if (ps_buffer_cur_len + len + 1 >= ps_buffer_size)
     {
         /* not enough space.  Check the buffer isn't full already */
         if (ps_buffer_cur_len < ps_buffer_size - 1)
         {
             /* append a space before the suffix */
             ps_buffer[ps_buffer_cur_len++] = ' ';
  
             /* just add what we can and fill the ps_buffer */
             memcpy(ps_buffer + ps_buffer_cur_len, suffix,
                    ps_buffer_size - ps_buffer_cur_len - 1);
             ps_buffer[ps_buffer_size - 1] = '\0';
             ps_buffer_cur_len = ps_buffer_size - 1;
         }
     }
     else
     {
         ps_buffer[ps_buffer_cur_len++] = ' ';
         memcpy(ps_buffer + ps_buffer_cur_len, suffix, len + 1);
         ps_buffer_cur_len = ps_buffer_cur_len + len;
     }
  
     Assert(strlen(ps_buffer) == ps_buffer_cur_len);
  
     /* and set the new title */
     flush_ps_display();
 #endif                          /* not PS_USE_NONE */
 }

References Assert, and len.

Referenced by LockBufferForCleanup(), ResolveRecoveryConflictWithVirtualXIDs(), SyncRepWaitForLSN(), and WaitOnLock().

◆ set_ps_display_with_len()

void set_ps_display_with_len	(	const char *	activity,
		size_t	len
	)

Definition at line 451 of file ps_status.c.

 {
     Assert(strlen(activity) == len);
  
 #ifndef PS_USE_NONE
     /* first, check if we need to update the process title */
     if (!update_ps_display_precheck())
         return;
  
     /* wipe out any suffix when the title is completely changed */
     ps_buffer_nosuffix_len = 0;
  
     /* Update ps_buffer to contain both fixed part and activity */
     if (ps_buffer_fixed_size + len >= ps_buffer_size)
     {
         /* handle the case where ps_buffer doesn't have enough space */
         memcpy(ps_buffer + ps_buffer_fixed_size, activity,
                ps_buffer_size - ps_buffer_fixed_size - 1);
         ps_buffer[ps_buffer_size - 1] = '\0';
         ps_buffer_cur_len = ps_buffer_size - 1;
     }
     else
     {
         memcpy(ps_buffer + ps_buffer_fixed_size, activity, len + 1);
         ps_buffer_cur_len = ps_buffer_fixed_size + len;
     }
     Assert(strlen(ps_buffer) == ps_buffer_cur_len);
  
     /* Transmit new setting to kernel, if necessary */
     flush_ps_display();
 #endif                          /* not PS_USE_NONE */
 }