From 17a5287fce73067939d4a47b727ad280b39df73e Mon Sep 17 00:00:00 2001
From: Vladimir Dubrovin <3proxy@3proxy.ru>
Date: Tue, 27 Oct 2026 19:46:10 +0300
Subject: [PATCH] Fibers: stacks of their own size, not a thread's

A fiber's stack was a thread's, PTHREAD_STACK_MIN included: 128K on
arm64 glibc, which is there for a thread's signals, and a loop's thread
takes none. It is BASESTACKSIZE with the service's stacksize added, and
the room kept for wolfSSL's handshake (TLSSTACKSIZE), as a thread's but
for that. Only reserved either way: measured with OpenSSL, a fiber holds
8K to 12K of it, TLS handshakes included.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 src/mainclient.c |  2 +-
 src/mainloop.c   | 14 +++++++++++---
 src/proxymain.c  |  2 +-
 3 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/src/mainclient.c b/src/mainclient.c
index ac1f2f0..f9f2f88 100644
--- a/src/mainclient.c
+++ b/src/mainclient.c
@@ -278,7 +278,7 @@ static int srvspawn(struct srvstart *s, SOCKET client_sock){
 
  /* on a loop: what is posted to it made now, so that posting it, done
     once the client is counted, cannot fail */
- if(loopwanted(srv)) job = loopjobnew(need);
+ if(loopwanted(srv)) job = loopjobnew(srv->stacksize);
 
  /* an idle worker if one has the stack this service needs */
  _3proxy_mutex_lock(&tpool.mutex);
diff --git a/src/mainloop.c b/src/mainloop.c
index 881f84f..d642301 100644
--- a/src/mainloop.c
+++ b/src/mainloop.c
@@ -100,7 +100,15 @@ static int loopsfailed;
 /* the loop of this thread, NULL but in a loop's thread */
 static LTLS struct looper *curlooper;
 
-static size_t fiberstack(size_t need){
+/* A fiber's stack: a thread's, the service's stacksize added, with room
+   kept for wolfSSL (TLSSTACKSIZE), which unless built for a small stack
+   takes much of it in a handshake; reserved only, a page held as it is
+   used. Not PTHREAD_STACK_MIN, which is for a thread's signals: a loop's
+   thread takes none. What the C library would want a big stack for, its
+   resolver, runs on the thread's own (onthreadstack()). */
+static size_t fiberstack(int extra){
+	size_t need = BASESTACKSIZE + TLSSTACKSIZE + (extra > 0? (size_t)extra : 0);
+
 #ifdef _WIN32
 	/* only reserved: Windows commits as it is used, and takes some for
 	   itself */
@@ -1233,7 +1241,7 @@ static int loopwanted(struct srvparam *srv){
 }
 
 /* What srvspawn() hands to a loop, made before: posting cannot fail. */
-static struct loopjob *loopjobnew(size_t stacksize){
+static struct loopjob *loopjobnew(int stacksize){
 	struct loopjob *job = malloc(sizeof(*job));
 
 	if(job){
@@ -1264,7 +1272,7 @@ static int onlooper(void){
 static int loopwanted(struct srvparam *srv){
 	return 0;
 }
-static struct loopjob *loopjobnew(size_t stacksize){
+static struct loopjob *loopjobnew(int stacksize){
 	return NULL;
 }
 static void loopspawn(struct loopjob *job, struct clientparam *param){
diff --git a/src/proxymain.c b/src/proxymain.c
index 6688a5b..0b2e1af 100644
--- a/src/proxymain.c
+++ b/src/proxymain.c
@@ -84,7 +84,7 @@ static int poolpark(struct clientparam *param);
 static int srvspawn(struct srvstart *s, SOCKET client_sock);
 struct loopjob;
 static int loopwanted(struct srvparam *srv);
-static struct loopjob *loopjobnew(size_t stacksize);
+static struct loopjob *loopjobnew(int stacksize);
 static void loopspawn(struct loopjob *job, struct clientparam *param);
 static int onlooper(void);
 static void filterswap(struct clientparam *param, unsigned char **cur, unsigned char *now);