mirror of
https://github.com/postgres/postgres.git
synced 2025-05-28 00:03:23 -04:00
708 lines
18 KiB
C
708 lines
18 KiB
C
/*-------------------------------------------------------------------------
|
|
*
|
|
* dfmgr.c
|
|
* Dynamic function manager code.
|
|
*
|
|
* Portions Copyright (c) 1996-2013, PostgreSQL Global Development Group
|
|
* Portions Copyright (c) 1994, Regents of the University of California
|
|
*
|
|
*
|
|
* IDENTIFICATION
|
|
* src/backend/utils/fmgr/dfmgr.c
|
|
*
|
|
*-------------------------------------------------------------------------
|
|
*/
|
|
#include "postgres.h"
|
|
|
|
#include <sys/stat.h>
|
|
|
|
#ifndef WIN32_ONLY_COMPILER
|
|
#include "dynloader.h"
|
|
#else
|
|
#include "port/dynloader/win32.h"
|
|
#endif
|
|
#include "lib/stringinfo.h"
|
|
#include "miscadmin.h"
|
|
#include "utils/dynamic_loader.h"
|
|
#include "utils/hsearch.h"
|
|
|
|
|
|
/* signatures for PostgreSQL-specific library init/fini functions */
|
|
typedef void (*PG_init_t) (void);
|
|
typedef void (*PG_fini_t) (void);
|
|
|
|
/* hashtable entry for rendezvous variables */
|
|
typedef struct
|
|
{
|
|
char varName[NAMEDATALEN]; /* hash key (must be first) */
|
|
void *varValue;
|
|
} rendezvousHashEntry;
|
|
|
|
/*
|
|
* List of dynamically loaded files (kept in malloc'd memory).
|
|
*/
|
|
|
|
typedef struct df_files
|
|
{
|
|
struct df_files *next; /* List link */
|
|
dev_t device; /* Device file is on */
|
|
#ifndef WIN32 /* ensures we never again depend on this under
|
|
* win32 */
|
|
ino_t inode; /* Inode number of file */
|
|
#endif
|
|
void *handle; /* a handle for pg_dl* functions */
|
|
char filename[1]; /* Full pathname of file */
|
|
|
|
/*
|
|
* we allocate the block big enough for actual length of pathname.
|
|
* filename[] must be last item in struct!
|
|
*/
|
|
} DynamicFileList;
|
|
|
|
static DynamicFileList *file_list = NULL;
|
|
static DynamicFileList *file_tail = NULL;
|
|
|
|
/* stat() call under Win32 returns an st_ino field, but it has no meaning */
|
|
#ifndef WIN32
|
|
#define SAME_INODE(A,B) ((A).st_ino == (B).inode && (A).st_dev == (B).device)
|
|
#else
|
|
#define SAME_INODE(A,B) false
|
|
#endif
|
|
|
|
char *Dynamic_library_path;
|
|
|
|
static void *internal_load_library(const char *libname);
|
|
static void incompatible_module_error(const char *libname,
|
|
const Pg_magic_struct *module_magic_data);
|
|
static void internal_unload_library(const char *libname);
|
|
static bool file_exists(const char *name);
|
|
static char *expand_dynamic_library_name(const char *name);
|
|
static void check_restricted_library_name(const char *name);
|
|
static char *substitute_libpath_macro(const char *name);
|
|
static char *find_in_dynamic_libpath(const char *basename);
|
|
|
|
/* Magic structure that module needs to match to be accepted */
|
|
static const Pg_magic_struct magic_data = PG_MODULE_MAGIC_DATA;
|
|
|
|
|
|
/*
|
|
* Load the specified dynamic-link library file, and look for a function
|
|
* named funcname in it.
|
|
*
|
|
* If the function is not found, we raise an error if signalNotFound is true,
|
|
* else return (PGFunction) NULL. Note that errors in loading the library
|
|
* will provoke ereport() regardless of signalNotFound.
|
|
*
|
|
* If filehandle is not NULL, then *filehandle will be set to a handle
|
|
* identifying the library file. The filehandle can be used with
|
|
* lookup_external_function to lookup additional functions in the same file
|
|
* at less cost than repeating load_external_function.
|
|
*/
|
|
PGFunction
|
|
load_external_function(char *filename, char *funcname,
|
|
bool signalNotFound, void **filehandle)
|
|
{
|
|
char *fullname;
|
|
void *lib_handle;
|
|
PGFunction retval;
|
|
|
|
/* Expand the possibly-abbreviated filename to an exact path name */
|
|
fullname = expand_dynamic_library_name(filename);
|
|
|
|
/* Load the shared library, unless we already did */
|
|
lib_handle = internal_load_library(fullname);
|
|
|
|
/* Return handle if caller wants it */
|
|
if (filehandle)
|
|
*filehandle = lib_handle;
|
|
|
|
/* Look up the function within the library */
|
|
retval = (PGFunction) pg_dlsym(lib_handle, funcname);
|
|
|
|
if (retval == NULL && signalNotFound)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_UNDEFINED_FUNCTION),
|
|
errmsg("could not find function \"%s\" in file \"%s\"",
|
|
funcname, fullname)));
|
|
|
|
pfree(fullname);
|
|
return retval;
|
|
}
|
|
|
|
/*
|
|
* This function loads a shlib file without looking up any particular
|
|
* function in it. If the same shlib has previously been loaded,
|
|
* unload and reload it.
|
|
*
|
|
* When 'restricted' is true, only libraries in the presumed-secure
|
|
* directory $libdir/plugins may be referenced.
|
|
*/
|
|
void
|
|
load_file(const char *filename, bool restricted)
|
|
{
|
|
char *fullname;
|
|
|
|
/* Apply security restriction if requested */
|
|
if (restricted)
|
|
check_restricted_library_name(filename);
|
|
|
|
/* Expand the possibly-abbreviated filename to an exact path name */
|
|
fullname = expand_dynamic_library_name(filename);
|
|
|
|
/* Unload the library if currently loaded */
|
|
internal_unload_library(fullname);
|
|
|
|
/* Load the shared library */
|
|
(void) internal_load_library(fullname);
|
|
|
|
pfree(fullname);
|
|
}
|
|
|
|
/*
|
|
* Lookup a function whose library file is already loaded.
|
|
* Return (PGFunction) NULL if not found.
|
|
*/
|
|
PGFunction
|
|
lookup_external_function(void *filehandle, char *funcname)
|
|
{
|
|
return (PGFunction) pg_dlsym(filehandle, funcname);
|
|
}
|
|
|
|
|
|
/*
|
|
* Load the specified dynamic-link library file, unless it already is
|
|
* loaded. Return the pg_dl* handle for the file.
|
|
*
|
|
* Note: libname is expected to be an exact name for the library file.
|
|
*/
|
|
static void *
|
|
internal_load_library(const char *libname)
|
|
{
|
|
DynamicFileList *file_scanner;
|
|
PGModuleMagicFunction magic_func;
|
|
char *load_error;
|
|
struct stat stat_buf;
|
|
PG_init_t PG_init;
|
|
|
|
/*
|
|
* Scan the list of loaded FILES to see if the file has been loaded.
|
|
*/
|
|
for (file_scanner = file_list;
|
|
file_scanner != NULL &&
|
|
strcmp(libname, file_scanner->filename) != 0;
|
|
file_scanner = file_scanner->next)
|
|
;
|
|
|
|
if (file_scanner == NULL)
|
|
{
|
|
/*
|
|
* Check for same files - different paths (ie, symlink or link)
|
|
*/
|
|
if (stat(libname, &stat_buf) == -1)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not access file \"%s\": %m",
|
|
libname)));
|
|
|
|
for (file_scanner = file_list;
|
|
file_scanner != NULL &&
|
|
!SAME_INODE(stat_buf, *file_scanner);
|
|
file_scanner = file_scanner->next)
|
|
;
|
|
}
|
|
|
|
if (file_scanner == NULL)
|
|
{
|
|
/*
|
|
* File not loaded yet.
|
|
*/
|
|
file_scanner = (DynamicFileList *)
|
|
malloc(sizeof(DynamicFileList) + strlen(libname));
|
|
if (file_scanner == NULL)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_OUT_OF_MEMORY),
|
|
errmsg("out of memory")));
|
|
|
|
MemSet(file_scanner, 0, sizeof(DynamicFileList));
|
|
strcpy(file_scanner->filename, libname);
|
|
file_scanner->device = stat_buf.st_dev;
|
|
#ifndef WIN32
|
|
file_scanner->inode = stat_buf.st_ino;
|
|
#endif
|
|
file_scanner->next = NULL;
|
|
|
|
file_scanner->handle = pg_dlopen(file_scanner->filename);
|
|
if (file_scanner->handle == NULL)
|
|
{
|
|
load_error = (char *) pg_dlerror();
|
|
free((char *) file_scanner);
|
|
/* errcode_for_file_access might not be appropriate here? */
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not load library \"%s\": %s",
|
|
libname, load_error)));
|
|
}
|
|
|
|
/* Check the magic function to determine compatibility */
|
|
magic_func = (PGModuleMagicFunction)
|
|
pg_dlsym(file_scanner->handle, PG_MAGIC_FUNCTION_NAME_STRING);
|
|
if (magic_func)
|
|
{
|
|
const Pg_magic_struct *magic_data_ptr = (*magic_func) ();
|
|
|
|
if (magic_data_ptr->len != magic_data.len ||
|
|
memcmp(magic_data_ptr, &magic_data, magic_data.len) != 0)
|
|
{
|
|
/* copy data block before unlinking library */
|
|
Pg_magic_struct module_magic_data = *magic_data_ptr;
|
|
|
|
/* try to unlink library */
|
|
pg_dlclose(file_scanner->handle);
|
|
free((char *) file_scanner);
|
|
|
|
/* issue suitable complaint */
|
|
incompatible_module_error(libname, &module_magic_data);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* try to unlink library */
|
|
pg_dlclose(file_scanner->handle);
|
|
free((char *) file_scanner);
|
|
/* complain */
|
|
ereport(ERROR,
|
|
(errmsg("incompatible library \"%s\": missing magic block",
|
|
libname),
|
|
errhint("Extension libraries are required to use the PG_MODULE_MAGIC macro.")));
|
|
}
|
|
|
|
/*
|
|
* If the library has a _PG_init() function, call it.
|
|
*/
|
|
PG_init = (PG_init_t) pg_dlsym(file_scanner->handle, "_PG_init");
|
|
if (PG_init)
|
|
(*PG_init) ();
|
|
|
|
/* OK to link it into list */
|
|
if (file_list == NULL)
|
|
file_list = file_scanner;
|
|
else
|
|
file_tail->next = file_scanner;
|
|
file_tail = file_scanner;
|
|
}
|
|
|
|
return file_scanner->handle;
|
|
}
|
|
|
|
/*
|
|
* Report a suitable error for an incompatible magic block.
|
|
*/
|
|
static void
|
|
incompatible_module_error(const char *libname,
|
|
const Pg_magic_struct *module_magic_data)
|
|
{
|
|
StringInfoData details;
|
|
|
|
/*
|
|
* If the version doesn't match, just report that, because the rest of the
|
|
* block might not even have the fields we expect.
|
|
*/
|
|
if (magic_data.version != module_magic_data->version)
|
|
ereport(ERROR,
|
|
(errmsg("incompatible library \"%s\": version mismatch",
|
|
libname),
|
|
errdetail("Server is version %d.%d, library is version %d.%d.",
|
|
magic_data.version / 100,
|
|
magic_data.version % 100,
|
|
module_magic_data->version / 100,
|
|
module_magic_data->version % 100)));
|
|
|
|
/*
|
|
* Otherwise, spell out which fields don't agree.
|
|
*
|
|
* XXX this code has to be adjusted any time the set of fields in a magic
|
|
* block change!
|
|
*/
|
|
initStringInfo(&details);
|
|
|
|
if (module_magic_data->funcmaxargs != magic_data.funcmaxargs)
|
|
{
|
|
if (details.len)
|
|
appendStringInfoChar(&details, '\n');
|
|
appendStringInfo(&details,
|
|
_("Server has FUNC_MAX_ARGS = %d, library has %d."),
|
|
magic_data.funcmaxargs,
|
|
module_magic_data->funcmaxargs);
|
|
}
|
|
if (module_magic_data->indexmaxkeys != magic_data.indexmaxkeys)
|
|
{
|
|
if (details.len)
|
|
appendStringInfoChar(&details, '\n');
|
|
appendStringInfo(&details,
|
|
_("Server has INDEX_MAX_KEYS = %d, library has %d."),
|
|
magic_data.indexmaxkeys,
|
|
module_magic_data->indexmaxkeys);
|
|
}
|
|
if (module_magic_data->namedatalen != magic_data.namedatalen)
|
|
{
|
|
if (details.len)
|
|
appendStringInfoChar(&details, '\n');
|
|
appendStringInfo(&details,
|
|
_("Server has NAMEDATALEN = %d, library has %d."),
|
|
magic_data.namedatalen,
|
|
module_magic_data->namedatalen);
|
|
}
|
|
if (module_magic_data->float4byval != magic_data.float4byval)
|
|
{
|
|
if (details.len)
|
|
appendStringInfoChar(&details, '\n');
|
|
appendStringInfo(&details,
|
|
_("Server has FLOAT4PASSBYVAL = %s, library has %s."),
|
|
magic_data.float4byval ? "true" : "false",
|
|
module_magic_data->float4byval ? "true" : "false");
|
|
}
|
|
if (module_magic_data->float8byval != magic_data.float8byval)
|
|
{
|
|
if (details.len)
|
|
appendStringInfoChar(&details, '\n');
|
|
appendStringInfo(&details,
|
|
_("Server has FLOAT8PASSBYVAL = %s, library has %s."),
|
|
magic_data.float8byval ? "true" : "false",
|
|
module_magic_data->float8byval ? "true" : "false");
|
|
}
|
|
|
|
if (details.len == 0)
|
|
appendStringInfo(&details,
|
|
_("Magic block has unexpected length or padding difference."));
|
|
|
|
ereport(ERROR,
|
|
(errmsg("incompatible library \"%s\": magic block mismatch",
|
|
libname),
|
|
errdetail_internal("%s", details.data)));
|
|
}
|
|
|
|
/*
|
|
* Unload the specified dynamic-link library file, if it is loaded.
|
|
*
|
|
* Note: libname is expected to be an exact name for the library file.
|
|
*
|
|
* XXX for the moment, this is disabled, resulting in LOAD of an already-loaded
|
|
* library always being a no-op. We might re-enable it someday if we can
|
|
* convince ourselves we have safe protocols for un-hooking from hook function
|
|
* pointers, releasing custom GUC variables, and perhaps other things that
|
|
* are definitely unsafe currently.
|
|
*/
|
|
static void
|
|
internal_unload_library(const char *libname)
|
|
{
|
|
#ifdef NOT_USED
|
|
DynamicFileList *file_scanner,
|
|
*prv,
|
|
*nxt;
|
|
struct stat stat_buf;
|
|
PG_fini_t PG_fini;
|
|
|
|
/*
|
|
* We need to do stat() in order to determine whether this is the same
|
|
* file as a previously loaded file; it's also handy so as to give a good
|
|
* error message if bogus file name given.
|
|
*/
|
|
if (stat(libname, &stat_buf) == -1)
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not access file \"%s\": %m", libname)));
|
|
|
|
/*
|
|
* We have to zap all entries in the list that match on either filename or
|
|
* inode, else internal_load_library() will still think it's present.
|
|
*/
|
|
prv = NULL;
|
|
for (file_scanner = file_list; file_scanner != NULL; file_scanner = nxt)
|
|
{
|
|
nxt = file_scanner->next;
|
|
if (strcmp(libname, file_scanner->filename) == 0 ||
|
|
SAME_INODE(stat_buf, *file_scanner))
|
|
{
|
|
if (prv)
|
|
prv->next = nxt;
|
|
else
|
|
file_list = nxt;
|
|
|
|
/*
|
|
* If the library has a _PG_fini() function, call it.
|
|
*/
|
|
PG_fini = (PG_fini_t) pg_dlsym(file_scanner->handle, "_PG_fini");
|
|
if (PG_fini)
|
|
(*PG_fini) ();
|
|
|
|
clear_external_function_hash(file_scanner->handle);
|
|
pg_dlclose(file_scanner->handle);
|
|
free((char *) file_scanner);
|
|
/* prv does not change */
|
|
}
|
|
else
|
|
prv = file_scanner;
|
|
}
|
|
#endif /* NOT_USED */
|
|
}
|
|
|
|
static bool
|
|
file_exists(const char *name)
|
|
{
|
|
struct stat st;
|
|
|
|
AssertArg(name != NULL);
|
|
|
|
if (stat(name, &st) == 0)
|
|
return S_ISDIR(st.st_mode) ? false : true;
|
|
else if (!(errno == ENOENT || errno == ENOTDIR || errno == EACCES))
|
|
ereport(ERROR,
|
|
(errcode_for_file_access(),
|
|
errmsg("could not access file \"%s\": %m", name)));
|
|
|
|
return false;
|
|
}
|
|
|
|
|
|
/* Example format: ".so" */
|
|
#ifndef DLSUFFIX
|
|
#error "DLSUFFIX must be defined to compile this file."
|
|
#endif
|
|
|
|
/*
|
|
* If name contains a slash, check if the file exists, if so return
|
|
* the name. Else (no slash) try to expand using search path (see
|
|
* find_in_dynamic_libpath below); if that works, return the fully
|
|
* expanded file name. If the previous failed, append DLSUFFIX and
|
|
* try again. If all fails, just return the original name.
|
|
*
|
|
* The result will always be freshly palloc'd.
|
|
*/
|
|
static char *
|
|
expand_dynamic_library_name(const char *name)
|
|
{
|
|
bool have_slash;
|
|
char *new;
|
|
char *full;
|
|
|
|
AssertArg(name);
|
|
|
|
have_slash = (first_dir_separator(name) != NULL);
|
|
|
|
if (!have_slash)
|
|
{
|
|
full = find_in_dynamic_libpath(name);
|
|
if (full)
|
|
return full;
|
|
}
|
|
else
|
|
{
|
|
full = substitute_libpath_macro(name);
|
|
if (file_exists(full))
|
|
return full;
|
|
pfree(full);
|
|
}
|
|
|
|
new = palloc(strlen(name) + strlen(DLSUFFIX) + 1);
|
|
strcpy(new, name);
|
|
strcat(new, DLSUFFIX);
|
|
|
|
if (!have_slash)
|
|
{
|
|
full = find_in_dynamic_libpath(new);
|
|
pfree(new);
|
|
if (full)
|
|
return full;
|
|
}
|
|
else
|
|
{
|
|
full = substitute_libpath_macro(new);
|
|
pfree(new);
|
|
if (file_exists(full))
|
|
return full;
|
|
pfree(full);
|
|
}
|
|
|
|
/*
|
|
* If we can't find the file, just return the string as-is. The ensuing
|
|
* load attempt will fail and report a suitable message.
|
|
*/
|
|
return pstrdup(name);
|
|
}
|
|
|
|
/*
|
|
* Check a restricted library name. It must begin with "$libdir/plugins/"
|
|
* and there must not be any directory separators after that (this is
|
|
* sufficient to prevent ".." style attacks).
|
|
*/
|
|
static void
|
|
check_restricted_library_name(const char *name)
|
|
{
|
|
if (strncmp(name, "$libdir/plugins/", 16) != 0 ||
|
|
first_dir_separator(name + 16) != NULL)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
|
|
errmsg("access to library \"%s\" is not allowed",
|
|
name)));
|
|
}
|
|
|
|
/*
|
|
* Substitute for any macros appearing in the given string.
|
|
* Result is always freshly palloc'd.
|
|
*/
|
|
static char *
|
|
substitute_libpath_macro(const char *name)
|
|
{
|
|
const char *sep_ptr;
|
|
char *ret;
|
|
|
|
AssertArg(name != NULL);
|
|
|
|
/* Currently, we only recognize $libdir at the start of the string */
|
|
if (name[0] != '$')
|
|
return pstrdup(name);
|
|
|
|
if ((sep_ptr = first_dir_separator(name)) == NULL)
|
|
sep_ptr = name + strlen(name);
|
|
|
|
if (strlen("$libdir") != sep_ptr - name ||
|
|
strncmp(name, "$libdir", strlen("$libdir")) != 0)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INVALID_NAME),
|
|
errmsg("invalid macro name in dynamic library path: %s",
|
|
name)));
|
|
|
|
ret = palloc(strlen(pkglib_path) + strlen(sep_ptr) + 1);
|
|
|
|
strcpy(ret, pkglib_path);
|
|
strcat(ret, sep_ptr);
|
|
|
|
return ret;
|
|
}
|
|
|
|
|
|
/*
|
|
* Search for a file called 'basename' in the colon-separated search
|
|
* path Dynamic_library_path. If the file is found, the full file name
|
|
* is returned in freshly palloc'd memory. If the file is not found,
|
|
* return NULL.
|
|
*/
|
|
static char *
|
|
find_in_dynamic_libpath(const char *basename)
|
|
{
|
|
const char *p;
|
|
size_t baselen;
|
|
|
|
AssertArg(basename != NULL);
|
|
AssertArg(first_dir_separator(basename) == NULL);
|
|
AssertState(Dynamic_library_path != NULL);
|
|
|
|
p = Dynamic_library_path;
|
|
if (strlen(p) == 0)
|
|
return NULL;
|
|
|
|
baselen = strlen(basename);
|
|
|
|
for (;;)
|
|
{
|
|
size_t len;
|
|
char *piece;
|
|
char *mangled;
|
|
char *full;
|
|
|
|
piece = first_path_var_separator(p);
|
|
if (piece == p)
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INVALID_NAME),
|
|
errmsg("zero-length component in parameter \"dynamic_library_path\"")));
|
|
|
|
if (piece == NULL)
|
|
len = strlen(p);
|
|
else
|
|
len = piece - p;
|
|
|
|
piece = palloc(len + 1);
|
|
strlcpy(piece, p, len + 1);
|
|
|
|
mangled = substitute_libpath_macro(piece);
|
|
pfree(piece);
|
|
|
|
canonicalize_path(mangled);
|
|
|
|
/* only absolute paths */
|
|
if (!is_absolute_path(mangled))
|
|
ereport(ERROR,
|
|
(errcode(ERRCODE_INVALID_NAME),
|
|
errmsg("component in parameter \"dynamic_library_path\" is not an absolute path")));
|
|
|
|
full = palloc(strlen(mangled) + 1 + baselen + 1);
|
|
sprintf(full, "%s/%s", mangled, basename);
|
|
pfree(mangled);
|
|
|
|
elog(DEBUG3, "find_in_dynamic_libpath: trying \"%s\"", full);
|
|
|
|
if (file_exists(full))
|
|
return full;
|
|
|
|
pfree(full);
|
|
|
|
if (p[len] == '\0')
|
|
break;
|
|
else
|
|
p += len + 1;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
|
|
/*
|
|
* Find (or create) a rendezvous variable that one dynamically
|
|
* loaded library can use to meet up with another.
|
|
*
|
|
* On the first call of this function for a particular varName,
|
|
* a "rendezvous variable" is created with the given name.
|
|
* The value of the variable is a void pointer (initially set to NULL).
|
|
* Subsequent calls with the same varName just return the address of
|
|
* the existing variable. Once created, a rendezvous variable lasts
|
|
* for the life of the process.
|
|
*
|
|
* Dynamically loaded libraries can use rendezvous variables
|
|
* to find each other and share information: they just need to agree
|
|
* on the variable name and the data it will point to.
|
|
*/
|
|
void **
|
|
find_rendezvous_variable(const char *varName)
|
|
{
|
|
static HTAB *rendezvousHash = NULL;
|
|
|
|
rendezvousHashEntry *hentry;
|
|
bool found;
|
|
|
|
/* Create a hashtable if we haven't already done so in this process */
|
|
if (rendezvousHash == NULL)
|
|
{
|
|
HASHCTL ctl;
|
|
|
|
MemSet(&ctl, 0, sizeof(ctl));
|
|
ctl.keysize = NAMEDATALEN;
|
|
ctl.entrysize = sizeof(rendezvousHashEntry);
|
|
rendezvousHash = hash_create("Rendezvous variable hash",
|
|
16,
|
|
&ctl,
|
|
HASH_ELEM);
|
|
}
|
|
|
|
/* Find or create the hashtable entry for this varName */
|
|
hentry = (rendezvousHashEntry *) hash_search(rendezvousHash,
|
|
varName,
|
|
HASH_ENTER,
|
|
&found);
|
|
|
|
/* Initialize to NULL if first time */
|
|
if (!found)
|
|
hentry->varValue = NULL;
|
|
|
|
return &hentry->varValue;
|
|
}
|