From: Karsten Blees <blees@xxxxxxx>
Move environment array reallocation from do_putenv to the respective
callers. Keep track of the environment size in a global variable. Use
ALLOC_GROW in mingw_putenv to reduce reallocations. Allocate a
sufficiently sized environment array in make_environment_block to prevent
reallocations.
Signed-off-by: Karsten Blees <blees@xxxxxxx>
Signed-off-by: Stepan Kasal <kasal@xxxxxx>
---
compat/mingw.c | 62 +++++++++++++++++++++++++++++++++-------------------------
1 file changed, 35 insertions(+), 27 deletions(-)
diff --git a/compat/mingw.c b/compat/mingw.c
index ffff592..e63fd6a 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -898,7 +898,12 @@ static char *path_lookup(const char *cmd, char **path, int exe_only)
return prog;
}
-static char **do_putenv(char **env, const char *name, int free_old);
+static int do_putenv(char **env, const char *name, int size, int free_old);
+
+/* used number of elements of environ array, including terminating NULL */
+static int environ_size = 0;
+/* allocated size of environ array, in bytes */
+static int environ_alloc = 0;
static int compareenv(const void *a, const void *b)
{
@@ -914,31 +919,28 @@ static int compareenv(const void *a, const void *b)
static wchar_t *make_environment_block(char **deltaenv)
{
wchar_t *wenvblk = NULL;
- int count = 0;
- char **e, **tmpenv;
- int size = 0, wenvsz = 0, wenvpos = 0;
+ char **tmpenv;
+ int i = 0, size = environ_size, wenvsz = 0, wenvpos = 0;
- while (environ[count])
- count++;
+ while (deltaenv && deltaenv[i])
+ i++;
- /* copy the environment */
- tmpenv = xmalloc(sizeof(*tmpenv) * (count + 1));
- memcpy(tmpenv, environ, sizeof(*tmpenv) * (count + 1));
+ /* copy the environment, leaving space for changes */
+ tmpenv = xmalloc((size + i) * sizeof(char*));
+ memcpy(tmpenv, environ, size * sizeof(char*));
/* merge supplied environment changes into the temporary environment */
- for (e = deltaenv; e && *e; e++)
- tmpenv = do_putenv(tmpenv, *e, 0);
+ for (i = 0; deltaenv && deltaenv[i]; i++)
+ size = do_putenv(tmpenv, deltaenv[i], size, 0);
/* environment must be sorted */
- for (count = 0; tmpenv[count]; )
- count++;
- qsort(tmpenv, count, sizeof(*tmpenv), compareenv);
+ qsort(tmpenv, size - 1, sizeof(char*), compareenv);
/* create environment block from temporary environment */
- for (e = tmpenv; *e; e++) {
- size = 2 * strlen(*e) + 2; /* +2 for final \0 */
+ for (i = 0; tmpenv[i]; i++) {
+ size = 2 * strlen(tmpenv[i]) + 2; /* +2 for final \0 */
ALLOC_GROW(wenvblk, (wenvpos + size) * sizeof(wchar_t), wenvsz);
- wenvpos += xutftowcs(&wenvblk[wenvpos], *e, size) + 1;
+ wenvpos += xutftowcs(&wenvblk[wenvpos], tmpenv[i], size) + 1;
}
/* add final \0 terminator */
wenvblk[wenvpos] = 0;
@@ -1205,19 +1207,19 @@ static int lookupenv(char **env, const char *name, size_t nmln)
/*
* If name contains '=', then sets the variable, otherwise it unsets it
+ * Size includes the terminating NULL. Env must have room for size + 1 entries
+ * (in case of insert). Returns the new size. Optionally frees removed entries.
*/
-static char **do_putenv(char **env, const char *name, int free_old)
+static int do_putenv(char **env, const char *name, int size, int free_old)
{
char *eq = strchrnul(name, '=');
int i = lookupenv(env, name, eq-name);
if (i < 0) {
if (*eq) {
- for (i = 0; env[i]; i++)
- ;
- env = xrealloc(env, (i+2)*sizeof(*env));
- env[i] = (char*) name;
- env[i+1] = NULL;
+ env[size - 1] = (char*) name;
+ env[size] = NULL;
+ size++;
}
}
else {
@@ -1225,11 +1227,13 @@ static char **do_putenv(char **env, const char *name, int free_old)
free(env[i]);
if (*eq)
env[i] = (char*) name;
- else
+ else {
for (; env[i]; i++)
env[i] = env[i+1];
+ size--;
+ }
}
- return env;
+ return size;
}
#undef getenv
@@ -1247,7 +1251,8 @@ char *mingw_getenv(const char *name)
int mingw_putenv(const char *namevalue)
{
- environ = do_putenv(environ, namevalue, 1);
+ ALLOC_GROW(environ, (environ_size + 1) * sizeof(char*), environ_alloc);
+ environ_size = do_putenv(environ, namevalue, environ_size, 1);
return 0;
}
@@ -2047,7 +2052,9 @@ void mingw_startup()
maxlen = max(maxlen, wcslen(wenv[i]));
/* nedmalloc can't free CRT memory, allocate resizable environment list */
- environ = xcalloc(i + 1, sizeof(char*));
+ environ = NULL;
+ environ_size = i + 1;
+ ALLOC_GROW(environ, environ_size * sizeof(char*), environ_alloc);
/* allocate buffer (wchar_t encodes to max 3 UTF-8 bytes) */
maxlen = 3 * maxlen + 1;
@@ -2064,6 +2071,7 @@ void mingw_startup()
len = xwcstoutf(buffer, wenv[i], maxlen);
environ[i] = xmemdupz(buffer, len);
}
+ environ[i] = NULL;
free(buffer);
/* initialize critical section for waitpid pinfo_t list */
--
2.0.0.9635.g0be03cb
--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html