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Diffstat (limited to 'src/backend/utils/misc/ps_status.c')
| -rw-r--r-- | src/backend/utils/misc/ps_status.c | 254 |
1 files changed, 254 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 00000000000..edc82f35218 --- /dev/null +++ b/src/backend/utils/misc/ps_status.c @@ -0,0 +1,254 @@ +/*-------------------------------------------------------------------- + * ps_status.c + * + * Routines to support changing the ps display of PostgreSQL backends + * to contain some useful information. Differs wildly across + * platforms. + * + * $Header: /cvsroot/pgsql/src/backend/utils/misc/ps_status.c,v 1.1 2000/06/04 01:44:34 petere Exp $ + * + * Copyright 2000 by 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_MACHINE_VMPARAM_H +# include <machine/vmparam.h> /* for old BSD */ +#endif +#ifdef HAVE_SYS_EXEC_H +# include <sys/exec.h> /* for old BSD */ +#endif + +#include "miscadmin.h" + +#include "utils/ps_status.h" + +extern char **environ; + + +/*------ + * Alternative ways of updating ps display: + * + * 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_CHANCE_ARGV + * assign argv[0] = "string" + * (some other BSD systems) + * PS_USE_CLOBBER_ARGV + * write over the argv and environment area + * (most SysV-like systems) + * PS_USE_NONE + * don't update ps display + * (This is the default, as it is safest.) + */ +#if 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(__bsdi__) || defined(__hurd__) +# define PS_USE_CHANGE_ARGV +#elif defined(__linux__) || defined(_AIX4) || defined(_AIX3) || defined(__sgi) || (defined(sun) && !defined(BSD)) || defined(ultrix) || defined(__ksr__) || defined(__osf__) || defined(__QNX__) || defined(__svr4__) || defined(__svr5__) +# define PS_USE_CLOBBER_ARGV +#else +# define PS_USE_NONE +#endif + + +/* Different systems want the buffer padded differently */ +#if defined(_AIX3) || defined(__linux__) || defined(__QNX__) || defined(__svr4__) +# define PS_PADDING '\0' +#else +# define PS_PADDING ' ' +#endif + + +#ifndef PS_USE_CLOBBER_ARGV +/* all but one options 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 */ +#endif /* PS_USE_CLOBBER_ARGV */ + +static size_t ps_buffer_fixed_size; /* size of the constant prefix */ + + + +/* + * Call this once at backend start. + */ +void +init_ps_display(int argc, char *argv[], + const char * username, const char * dbname, + const char * host_info) +{ +#ifndef PS_USE_NONE + Assert(username); + Assert(dbname); + + /* no ps display for stand-alone backend */ + if (!IsUnderPostmaster) + return; + +# ifdef PS_USE_CHANGE_ARGV + argv[0] = ps_buffer; + argv[1] = NULL; +# endif /* PS_USE_CHANGE_ARGV */ + +# ifdef PS_USE_CLOBBER_ARGV + /* + * If we're going to overwrite the argv area, count the space. + */ + { + 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]); + + /* + * check for contiguous environ strings following argv + */ + for (i = 0; end_of_area != NULL && environ[i] != NULL; i++) + if (end_of_area + 1 == environ[i]) + end_of_area = environ[i] + strlen(environ[i]); + + if (end_of_area == NULL) + { + ps_buffer = NULL; + ps_buffer_size = 0; + } + else + { + ps_buffer = argv[0]; + ps_buffer_size = end_of_area - argv[0] - 1; + } + argv[1] = NULL; + + /* + * move the environment out of the way + */ + for (i = 0; environ[i] != NULL; i++) + ; + new_environ = malloc(sizeof (char *) * (i + 1)); + for (i = 0; environ[i] != NULL; i++) + new_environ[i] = strdup(environ[i]); + new_environ[i] = NULL; + environ = new_environ; + } +# endif /* PS_USE_CLOBBER_ARGV */ + + /* + * Make fixed prefix + */ +# ifdef PS_USE_SETPROCTITLE + /* apparently setproctitle() already adds a `progname:' prefix to + * the ps line */ + snprintf(ps_buffer, ps_buffer_size, + "%s %s %s ", + username, dbname, host_info); +# else + snprintf(ps_buffer, ps_buffer_size, + "postgres: %s %s %s ", + username, dbname, host_info); +# endif + + ps_buffer_fixed_size = strlen(ps_buffer); +#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 * value) +{ + /* no ps display for stand-alone backend */ + if (!IsUnderPostmaster) + return; + +#ifndef PS_USE_NONE + if (!ps_buffer) + return; +# ifdef PS_USE_SETPROCTITLE + setproctitle("%s%s", ps_buffer, value); + +# else /* not PS_USE_SETPROCTITLE */ + { + size_t vallen = strlen(value); + + strncpy(ps_buffer + ps_buffer_fixed_size, value, + ps_buffer_size - ps_buffer_fixed_size); + + if (ps_buffer_fixed_size + vallen >= ps_buffer_size) + ps_buffer[ps_buffer_size - 1] = 0; + else + ps_buffer[ps_buffer_fixed_size + vallen] = 0; + +# ifdef PS_USE_PSTAT + { + union pstun pst; + + pst.pst_command = ps_buffer; + pstat(PSTAT_SETCMD, pst, strlen(ps_buffer), 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 + { + char * cp; + /* pad unused memory */ + for(cp = ps_buffer + ps_buffer_fixed_size + vallen; + cp < ps_buffer + ps_buffer_size; + cp++) + *cp = PS_PADDING; + } +# endif /* PS_USE_CLOBBER_ARGV */ + } +# endif /* not USE_SETPROCTITLE */ +#endif /* not PS_USE_NONE */ +} + + +/* + * Returns what's currently in the ps display, in case someone needs + * it. + */ +const char * +get_ps_display(void) +{ + return ps_buffer + ps_buffer_fixed_size; +} |