From: Rich Felker <dalias@aerifal.cx>
Date: Wed, 23 May 2012 02:43:27 +0000 (-0400)
Subject: remove everything related to forkall
X-Git-Url: http://nsz.repo.hu/git/?p=musl;a=commitdiff_plain;h=0c29adfe427ab6ed98cb73644f8f52a76045245c

remove everything related to forkall

i made a best attempt, but the intended semantics of this function are
fundamentally contradictory. there is no consistent way to handle
ownership of locks when forking a multi-threaded process. the code
could have worked by accident for programs that only used normal
mutexes and nothing else (since they don't actually store or care
about their owner), but that's about it. broken-by-design interfaces
that aren't even in glibc (only solaris) don't belong in musl.
---

diff --git a/include/unistd.h b/include/unistd.h
index 693c54dc..e4e3ac59 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -168,7 +168,6 @@ char *getusershell(void);
 #endif
 
 #ifdef _GNU_SOURCE
-pid_t forkall(void);
 int setresuid(uid_t, uid_t, uid_t);
 int setresgid(gid_t, gid_t, gid_t);
 int getresuid(uid_t *, uid_t *, uid_t *);
diff --git a/src/internal/libc.h b/src/internal/libc.h
index 78fca47f..0ec3691e 100644
--- a/src/internal/libc.h
+++ b/src/internal/libc.h
@@ -52,7 +52,6 @@ void __unlockfile(FILE *);
 #define UNLOCK(x) (libc.threads_minus_1 ? (__unlock(x),1) : ((void)(x),1))
 
 void __synccall(void (*)(void *), void *);
-void __synccall_wait(void);
 int __setxid(int, int, int, int);
 
 extern char **__environ;
diff --git a/src/thread/forkall.c b/src/thread/forkall.c
deleted file mode 100644
index 6810ea50..00000000
--- a/src/thread/forkall.c
+++ /dev/null
@@ -1,68 +0,0 @@
-#if 0
-#include "pthread_impl.h"
-#include <setjmp.h>
-
-struct thread {
-	struct thread *next;
-	pthread_t td;
-	jmp_buf jb;
-	void *tmp, *stack;
-};
-
-struct ctx {
-	struct thread *list;
-	pthread_t caller;
-	pid_t pid;
-	size_t cnt;
-	pthread_barrier_t barrier;
-};
-
-static void restart_thread(pthread_t self)
-{
-	struct thread *t = self->start_arg;
-	self->start_arg = t->tmp;
-	self->pid = getpid();
-	longjmp(t->jb, 1);
-}
-
-static void do_forkall(void *p)
-{
-	struct ctx *c = p, *volatile cv = c;
-	char tmpstack[2048];
-	struct thread *tp, t = {
-		.td = __pthread_self(),
-		.next = c->list,
-		.stack = tmpstack+1024
-	};
-
-	if (t.td != c->caller) {
-		c->cnt++;
-		t.tmp = t.td->start_arg;
-		t.td->start_arg = &t;
-		if (setjmp(t.jb)) {
-			c = cv;
-			if (c->pid) return;
-			pthread_barrier_wait(&c->barrier);
-			return;
-		}
-		c->list = &t;
-		__synccall_wait();
-		return;
-	}
-	c->pid = syscall(SYS_fork);
-	if (c->pid) return;
-
-	pthread_barrier_init(&c->barrier, 0, c->cnt);
-	for (tp=c->list; tp; tp=tp->next)
-		if (__uniclone(tp->stack, restart_thread, tp->td) < 0)
-			_exit(127);
-	pthread_barrier_wait(&c->barrier);
-}
-
-pid_t forkall()
-{
-	struct ctx c = { .caller = pthread_self() };
-	__synccall(do_forkall, &c);
-	return c.pid;
-}
-#endif
diff --git a/src/thread/synccall.c b/src/thread/synccall.c
index 2cd25e4b..1520b3b4 100644
--- a/src/thread/synccall.c
+++ b/src/thread/synccall.c
@@ -47,14 +47,6 @@ static void handler(int sig, siginfo_t *si, void *ctx)
 	errno = old_errno;
 }
 
-void __synccall_wait()
-{
-	struct chain *ch = cur;
-	sem_post(&ch->sem2);
-	while (sem_wait(&ch->sem));
-	sem_post(&ch->sem);
-}
-
 void __synccall(void (*func)(void *), void *ctx)
 {
 	pthread_t self;