Commit cb388896 authored by Jeff Trawick's avatar Jeff Trawick
Browse files

Prevent hangs of child processes when writing to piped loggers at 

the time of graceful restart. 

PR:          26467
Reviewed by: Joe Orton



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@170281 13f79535-47bb-0310-9956-ffa450edef68
parent 54e61c98

CHANGES

+3 −0
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@@ -2,6 +2,9 @@ Changes with Apache 2.1.5 














  [Remove entries to the current 2.0 section below, when backported]



























  *) Prevent hangs of child processes when writing to piped loggers at













     the time of graceful restart.  PR 26467.  [Jeff Trawick]













  















  *) mod_info: Show the Quick Handler [Paul Querna]





























  *) mod_ldap: Add the directive LDAPVerifyServerCert to specify 

































include/http_log.h



+10
−0






























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@@ -116,6 +116,16 @@ AP_DECLARE(apr_status_t) ap_replace_stderr_log(apr_pool_t *p,













int ap_open_logs(apr_pool_t *pconf, apr_pool_t *plog, 















                 apr_pool_t *ptemp, server_rec *s_main);





























/**













 * Perform special processing for piped loggers in MPM child













 * processes.













 * @param p Not used













 * @param s Not used













 * @tip ap_logs_child_init is not for use by modules; it is an













 * internal core function













 */













void ap_logs_child_init(apr_pool_t *p, server_rec *s);





























/* 















 * The primary logging functions, ap_log_error, ap_log_rerror, ap_log_cerror,















 * and ap_log_perror use a printf style format string to build the log message.  

































server/core.c



+1
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@@ -3755,6 +3755,7 @@ static void register_hooks(apr_pool_t *p)













    ap_hook_translate_name(ap_core_translate,NULL,NULL,APR_HOOK_REALLY_LAST);















    ap_hook_map_to_storage(core_map_to_storage,NULL,NULL,APR_HOOK_REALLY_LAST);















    ap_hook_open_logs(ap_open_logs,NULL,NULL,APR_HOOK_REALLY_FIRST);













    ap_hook_child_init(ap_logs_child_init,NULL,NULL,APR_HOOK_MIDDLE);















    ap_hook_handler(default_handler,NULL,NULL,APR_HOOK_REALLY_LAST);















    /* FIXME: I suspect we can eliminate the need for these do_nothings - Ben */















    ap_hook_type_checker(do_nothing,NULL,NULL,APR_HOOK_REALLY_LAST);

































server/log.c



+45
−0






























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@@ -141,6 +141,45 @@ static const TRANS priorities[] = {





























static apr_file_t *stderr_log = NULL;





























/* track pipe handles to close in child process */













typedef struct read_handle_t {













    struct read_handle_t *next;













    apr_file_t *handle;













} read_handle_t;



























static read_handle_t *read_handles;



























/* clear_handle_list() is called when plog is cleared; at that













 * point we need to forget about our old list of pipe read













 * handles













 */













static apr_status_t clear_handle_list(void *v)













{













    read_handles = NULL;













    return APR_SUCCESS;













}



























/* remember to close this handle in the child process */













static void close_handle_in_child(apr_pool_t *p, apr_file_t *f)













{













    read_handle_t *new_handle;



























    new_handle = apr_pcalloc(p, sizeof(read_handle_t));













    new_handle->next = read_handles;













    new_handle->handle = f;













    read_handles = new_handle;













}



























void ap_logs_child_init(apr_pool_t *p, server_rec *s)













{













    read_handle_t *cur = read_handles;



























    while (cur) {













        apr_file_close(cur->handle);













        cur = cur->next;













    }













}





























AP_DECLARE(void) ap_open_stderr_log(apr_pool_t *p)















{















    apr_file_open_stderr(&stderr_log, p);










@@ -218,6 +257,9 @@ static int log_child(apr_pool_t *p, const char *progname,













        if (rc == APR_SUCCESS) {















            apr_pool_note_subprocess(p, procnew, APR_KILL_AFTER_TIMEOUT);















            (*fpin) = procnew->in;













            /* read handle to pipe not kept open, so no need to call













             * close_handle_in_child()













             */















        }















    }


























@@ -294,6 +336,8 @@ int ap_open_logs(apr_pool_t *pconf, apr_pool_t *p /* plog */,













    int replace_stderr;















    apr_file_t *errfile = NULL;





























    apr_pool_cleanup_register(p, NULL, clear_handle_list,













                              apr_pool_cleanup_null);















    if (open_error_log(s_main, p) != OK) {















        return DONE;















    }










@@ -780,6 +824,7 @@ static int piped_log_spawn(piped_log *pl)













            ap_piped_log_write_fd(pl) = procnew->in;















            apr_proc_other_child_register(procnew, piped_log_maintenance, pl,















                                          ap_piped_log_write_fd(pl), pl->p);













            close_handle_in_child(pl->p, ap_piped_log_read_fd(pl));















        }















        else {















            char buf[120];