From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stepan Kasal Subject: [PATCH 09/13] Win32: reduce environment array reallocations Date: Thu, 17 Jul 2014 17:38:02 +0200 Message-ID: <1405611486-10176-10-git-send-email-kasal@ucw.cz> References: <1405611486-10176-1-git-send-email-kasal@ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: Karsten Blees , msysGit , Karsten Blees , Stepan Kasal To: GIT Mailing-list X-From: msysgit+bncBCU63DXMWULRBZ63T6PAKGQES63JOCQ@googlegroups.com Thu Jul 17 17:38:16 2014 Return-path: Envelope-to: gcvm-msysgit@m.gmane.org Received: from mail-wg0-f63.google.com ([74.125.82.63]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1X7nlA-0008Vj-65 for gcvm-msysgit@m.gmane.org; Thu, 17 Jul 2014 17:38:16 +0200 Received: by mail-wg0-f63.google.com with SMTP id b13sf266949wgh.28 for ; Thu, 17 Jul 2014 08:38:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlegroups.com; s=20120806; h=mime-version:from:to:cc:subject:date:message-id:in-reply-to :references:x-original-sender:x-original-authentication-results :precedence:mailing-list:list-id:list-post:list-help:list-archive :sender:list-subscribe:list-unsubscribe:content-type; bh=eE4AkwihWcG7qm9CGCHu61e0bpWKa3AXJ+/a4kitufU=; b=hkrQ+wzWAM1St11ln5/wi+Nwcxl0XEzKg3MUPLcRgnLMVEBcv5NiXA00WmXMxzgAQG yP/Ka6zvDEgHREPyGofYQQT7p2i43So590ttaJU5eSUDQANzaxWv3dNAM2twUAC1RCMa lKNRXVBFwDngH3hToJboiuj8V/N2MMGyZfAMNkiR1KE70daMXaCtebUIxKvK5Mn88Xay n66z1QOYQjlp9JAJZa5dP7uMyb0Gt4IpaQqRqyHC8fj7RU7pt6wi058WW9z7PeTZ6+j7 4tMkQog49tL6OXvvvU9cjxUToddokwNvKMurgm6qyBgjnfNb+ofH6yxDG9gC6HrJivR9 en9Q== X-Received: by 10.152.179.227 with SMTP id dj3mr393411lac.0.1405611495902; Thu, 17 Jul 2014 08:38:15 -0700 (PDT) X-BeenThere: msysgit@googlegroups.com Received: by 10.152.42.134 with SMTP id o6ls225489lal.4.gmail; Thu, 17 Jul 2014 08:38:14 -0700 (PDT) X-Received: by 10.152.87.226 with SMTP id bb2mr3031712lab.5.1405611494806; Thu, 17 Jul 2014 08:38:14 -0700 (PDT) Received: from jabberwock.ucw.cz (jabberwock.ucw.cz. [46.255.230.98]) by gmr-mx.google.com with ESMTP id o6si608385wij.1.2014.07.17.08.38.14 for ; Thu, 17 Jul 2014 08:38:14 -0700 (PDT) Received-SPF: none (google.com: kasal@ucw.cz does not designate permitted sender hosts) client-ip=46.255.230.98; Received: by jabberwock.ucw.cz (Postfix, from userid 1042) id 7E92E1C01AB; Thu, 17 Jul 2014 17:38:14 +0200 (CEST) X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1405611486-10176-1-git-send-email-kasal@ucw.cz> X-Original-Sender: kasal@ucw.cz X-Original-Authentication-Results: gmr-mx.google.com; spf=neutral (google.com: kasal@ucw.cz does not designate permitted sender hosts) smtp.mail=kasal@ucw.cz Precedence: list Mailing-list: list msysgit@googlegroups.com; contact msysgit+owners@googlegroups.com List-ID: X-Google-Group-Id: 152234828034 List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , Archived-At: From: Karsten Blees 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 Signed-off-by: Stepan Kasal --- 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 -- -- *** Please reply-to-all at all times *** *** (do not pretend to know who is subscribed and who is not) *** *** Please avoid top-posting. *** The msysGit Wiki is here: https://github.com/msysgit/msysgit/wiki - Github accounts are free. 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