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Diffstat (limited to 'src/libmowgli/ext/proctitle.c')
-rw-r--r-- | src/libmowgli/ext/proctitle.c | 311 |
1 files changed, 311 insertions, 0 deletions
diff --git a/src/libmowgli/ext/proctitle.c b/src/libmowgli/ext/proctitle.c new file mode 100644 index 0000000..91885d5 --- /dev/null +++ b/src/libmowgli/ext/proctitle.c @@ -0,0 +1,311 @@ +/* + * Code has been calqued from PostgreSQL 9.1 by Elizabeth J. Myers. + * Below is their copyright header. + * + * Do note I've made extensive changes to this code, including adding + * Linux (and Irix?) prctl support. + */ + +/*-------------------------------------------------------------------- + * 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) 2000-2011, PostgreSQL Global Development Group + * various details abducted from various places + *-------------------------------------------------------------------- + */ + +#include "mowgli.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 +#ifdef HAVE_SYS_PRCTL_H +#include <sys/prctl.h> +#endif + +extern char **environ; + +/* + * Alternative ways of updating ps display: + * + * MOWGLI_SETPROC_USE_SETPROCTITLE + * use the function setproctitle(const char *, ...) + * (newer BSD systems) + * MOWGLI_SETPROC_USE_PSTAT + * use the pstat(PSTAT_SETCMD, ) + * (HPUX) + * MOWGLI_SETPROC_USE_PS_STRINGS + * assign PS_STRINGS->ps_argvstr = "string" + * (some BSD systems) + * MOWGLI_SETPROC_USE_PRCTL + * use prctl(PR_SET_NAME, ...) + * (Newer Linux and possibly Irix? -- Note some utilities don't use this name) + * MOWGLI_SETPROC_USE_CHANGE_ARGV + * assign argv[0] = "string" + * (some other BSD systems) + * MOWGLI_SETPROC_USE_CLOBBER_ARGV + * write over the argv and environment area + * (Old Linux and most SysV-like systems) + * MOWGLI_SETPROC_USE_WIN32 + * push the string out as the name of a Windows event + * MOWGLI_SETPROC_USE_NONE + * don't update ps display + * (This is the default, as it is safest.) + */ +#if defined(HAVE_SETPROCTITLE) +#define MOWGLI_SETPROC_USE_SETPROCTITLE +#elif defined(PR_SET_NAME) && defined(HAVE_SYS_PRCTL_H) +#define MOWGLI_SETPROC_USE_PRCTL +#elif defined(HAVE_PSTAT) && defined(PSTAT_SETCMD) +#define MOWGLI_SETPROC_USE_PSTAT +#elif defined(HAVE_PS_STRINGS) +#define MOWGLI_SETPROC_USE_PS_STRINGS +#elif (defined(BSD) || defined(__bsdi__) || defined(__hurd__)) && !defined(__darwin__) +#define MOWGLI_SETPROC_USE_CHANGE_ARGV +#elif defined(__linux__) || defined(_AIX) || defined(__sgi) || (defined(sun) && !defined(BSD)) || defined(ultrix) || defined(__ksr__) || defined(__osf__) || defined(__svr4__) || defined(__svr5__) || defined(__darwin__) +#define MOWGLI_SETPROC_USE_CLOBBER_ARGV +#elif defined(WIN32) +#define MOWGLI_SETPROC_USE_WIN32 +#else +#define MOWGLI_SETPROC_USE_NONE +#endif + + +/* Different systems want the buffer padded differently */ +#if defined(_AIX) || defined(__linux__) || defined(__svr4__) || defined(__darwin__) +#define PS_PADDING '\0' +#else +#define PS_PADDING ' ' +#endif + + +#ifndef MOWGLI_SETPROC_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 /* MOWGLI_SETPROC_USE_CLOBBER_ARGV */ +static char *ps_buffer; /* will point to argv area */ +static size_t ps_buffer_size; /* space determined at run time */ +#endif /* MOWGLI_SETPROC_USE_CLOBBER_ARGV */ + +static size_t ps_buffer_fixed_size; +static size_t ps_buffer_cur_len; /* nominal strlen(ps_buffer) */ + +/* 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 mowgli_proctitle_set. 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.) + */ +char ** +mowgli_proctitle_init(int argc, char **argv) +{ + save_argc = argc; + save_argv = argv; + +#if defined(MOWGLI_SETPROC_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]; + ps_buffer_size = end_of_area - argv[0]; + + /* + * move the environment out of the way + */ + new_environ = (char **) mowgli_alloc((i + 1) * sizeof(char *)); + for (i = 0; environ[i] != NULL; i++) + new_environ[i] = mowgli_strdup(environ[i]); + new_environ[i] = NULL; + environ = new_environ; + +#endif /* MOWGLI_SETPROC_USE_CLOBBER_ARGV */ + +#if defined(MOWGLI_SETPROC_USE_CHANGE_ARGV) || defined(MOWGLI_SETPROC_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[]. + * 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 **) mowgli_alloc((argc + 1) * sizeof(char *)); + for (i = 0; i < argc; i++) + new_argv[i] = mowgli_strdup(argv[i]); + new_argv[argc] = NULL; + +#if defined(__darwin__) + /* + * Darwin (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 /* MOWGLI_SETPROC_USE_CHANGE_ARGV or MOWGLI_SETPROC_USE_CLOBBER_ARGV */ + + return argv; +} + +void +mowgli_proctitle_set(const char *fmt, ...) +{ +#ifndef MOWGLI_SETPROC_USE_NONE + va_list va; + +#if defined(MOWGLI_SETPROC_USE_CHANGE_ARGV) || defined(MOWGLI_SETPROC_USE_CLOBBER_ARGV) + if (!save_argv) + return; +#endif + + va_start(va, fmt); + vsnprintf(ps_buffer, ps_buffer_size, fmt, va); + va_end(va); + + return_if_fail(*ps_buffer == '\0'); + + ps_buffer_cur_len = ps_buffer_fixed_size = strlen(ps_buffer); + +#ifdef MOWGLI_SETPROC_USE_CHANGE_ARGV + save_argv[0] = ps_buffer; + save_argv[1] = NULL; +#endif + +#ifdef MOWGLI_SETPROC_USE_CLOBBER_ARGV + for (int i = 1; i < save_argc; i++) + save_argv[i] = ps_buffer + ps_buffer_size; + + /* Pad unused bytes */ + printf("%d %d\n", ps_buffer_size, ps_buffer_cur_len); + memset(ps_buffer + ps_buffer_cur_len, PS_PADDING, ps_buffer_size - ps_buffer_cur_len + 1); +#endif + +#ifdef MOWGLI_SETPROC_USE_SETPROCTITLE + setproctitle("%s", ps_buffer); +#endif + +#ifdef MOWGLI_SETPROC_USE_PRCTL + /* Limit us to 16 chars to be safe */ + char procbuf[16]; + mowgli_strlcpy(procbuf, ps_buffer, sizeof(procbuf)); + prctl(PR_SET_NAME, procbuf, 0, 0, 0); + printf("%s\n", procbuf); +#endif + +#ifdef MOWGLI_SETPROC_USE_PSTAT + union pstun pst; + + pst.pst_command = ps_buffer; + pstat(PSTAT_SETCMD, pst, ps_buffer_cur_len, 0, 0); +#endif /* MOWGLI_SETPROC_USE_PSTAT */ + +#ifdef MOWGLI_SETPROC_USE_PS_STRINGS + PS_STRINGS->ps_nargvstr = 1; + PS_STRINGS->ps_argvstr = ps_buffer; +#endif /* MOWGLI_SETPROC_USE_PS_STRINGS */ + +#ifdef MOWGLI_SETPROC_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, "mowgli_ident(%d): %s", getpid(), ps_buffer); + + ident_handle = CreateEvent(NULL, TRUE, FALSE, name); +#endif /* MOWGLI_SETPROC_USE_WIN32 */ +#endif /* not MOWGLI_SETPROC_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 * +mowgli_proctitle_get(int *displen) +{ +#ifdef MOWGLI_SETPROC_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 - ps_buffer_fixed_size); + + return ps_buffer + ps_buffer_fixed_size; +} |