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-rw-r--r--src/thread/forkall.c66
1 files changed, 66 insertions, 0 deletions
diff --git a/src/thread/forkall.c b/src/thread/forkall.c
new file mode 100644
index 00000000..403818ec
--- /dev/null
+++ b/src/thread/forkall.c
@@ -0,0 +1,66 @@
+#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;
+}