From 8cea25da893d72b9c13bf1ca7123db9445f7f69f Mon Sep 17 00:00:00 2001 From: Rob Swindell Date: Sun, 25 Oct 2020 23:22:18 -0700 Subject: [PATCH] Use a mutex to serial message saving among multiple clients/threads This work-around shouldn't be necessary, but at least on my Linux/Samba setup, when GitLab sends out notification emails to subscribers and creates 4+ simultaneous SMTP connections and sends email messages, sometimes (often) it ends up with a lock-timeout on the mail base. The file locking should handle the contention fine, but somehow I end up in scenarios where savemsg() takes 30 seconds to complete (the configured SMB lock-timeout is 30 seconds, likely not a coincidence) - and this causes other clients to timeout trying to lock the base. Just use a sharead-mutex here instead as a work-around. The wait time is indefinite, might want to consider using a timed-wait instead. --- src/sbbs3/mailsrvr.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/src/sbbs3/mailsrvr.c b/src/sbbs3/mailsrvr.c index 534268de4..a9a41f0fd 100644 --- a/src/sbbs3/mailsrvr.c +++ b/src/sbbs3/mailsrvr.c @@ -108,6 +108,8 @@ static int mailproc_count; static js_server_props_t js_server_props; static link_list_t current_logins; static link_list_t current_connections; +static savemsg_mutex_created = false; +static pthread_mutex_t savemsg_mutex; static const char* servprot_smtp = "SMTP"; static const char* servprot_submission = "SMTP"; @@ -3873,7 +3875,7 @@ static void smtp_thread(void* arg) safe_snprintf(rcpt_info, sizeof(rcpt_info), "'%s' %s", rcpt_name, angle_bracket(tmp, sizeof(tmp), rcpt_addr)); lprintf(LOG_DEBUG,"%04d %s %s Saving message data from %s to %s" ,socket, client.protocol, client_id, sender_info, rcpt_info); - + pthread_mutex_lock(&savemsg_mutex); /* E-mail */ smb.subnum=INVALID_SUB; /* creates message data, but no header or index records (since msg.to==NULL) */ @@ -3884,6 +3886,7 @@ static void smtp_thread(void* arg) free(msgbuf); if(i!=SMB_SUCCESS) { smb_close(&smb); + pthread_mutex_unlock(&savemsg_mutex); lprintf(LOG_CRIT,"%04d %s %s !ERROR %d (%s) saving message from %s to %s" ,socket, client.protocol, client_id, i, smb.last_error, sender_info, rcpt_info); sockprintf(socket,client.protocol,session, "452 ERROR %d (%s) saving message" @@ -4045,6 +4048,7 @@ static void smtp_thread(void* arg) smb_close_da(&smb); #endif smb_close(&smb); + pthread_mutex_unlock(&savemsg_mutex); continue; } if(buf[0]==0 && state==SMTP_STATE_DATA_HEADER) { @@ -5956,6 +5960,10 @@ static void cleanup(int code) mail_set=NULL; terminated=TRUE; + while(savemsg_mutex_created && pthread_mutex_destroy(&savemsg_mutex)==EBUSY) + mswait(1); + savemsg_mutex_created = false; + update_clients(); /* active_clients is destroyed below */ listFree(¤t_logins); @@ -6285,6 +6293,9 @@ void DLLCALL mail_server(void* arg) semfile_list_check(&initialized,shutdown_semfiles); } + pthread_mutex_init(&savemsg_mutex, NULL); + savemsg_mutex_created = true; + /* signal caller that we've started up successfully */ if(startup->started!=NULL) startup->started(startup->cbdata); -- GitLab