diff --git a/fsm/frontend.rl b/fsm/frontend.rl
index 25e262f..aac6709 100644
--- a/fsm/frontend.rl
+++ b/fsm/frontend.rl
@@ -5,8 +5,10 @@
 #include <sys/timerfd.h>
 #include <unistd.h>
 #include <npth.h>
+#include <pthread.h>
 
 static int cs;
+static pthread_mutext_t s_mutex;
 
 %%{
     machine frontend;
@@ -32,7 +34,7 @@ static int cs;
         xnpth_write(forwarded_fd, p, pe - p) != pe - p);
     }
 
-    foreign = OK @Process;
+    foreign = NOK | (OK @Process);
     internal = IDEMPOTENT ACK | IDEMPOTENT TIMEOUT{1,3} ACK;
 
     main := (foreign | internal)*;
diff --git a/fsm/wireprotocol.rl b/fsm/wireprotocol.rl
index a086b76..56eb108 100644
--- a/fsm/wireprotocol.rl
+++ b/fsm/wireprotocol.rl
@@ -19,6 +19,7 @@
         start = fpc;
     }
     action Frame_Accept {
+        assert(fpc - 1 >= start);
         xsend_message(a->to_fronted, (lrc != fc ? start : fpc - 1), fpc);
     }
 
diff --git a/main.c b/main.c
index 18741c3..27a1a17 100644
--- a/main.c
+++ b/main.c
@@ -1,27 +1,40 @@
 #include "log.h"
 #include "utils.h"
 #include "frob.h"
-#include "npthfix.h"
+#include "tasks.h"
 #include <unistd.h>
 #include <signal.h>
 #include <sys/resource.h>
 #include <pthread.h>
 
+union iopair {
+    int fd[2];
+    struct {
+        int r, w;
+    };
+};
+
+static union iopair get_main(void) {
+    union iopair ret = { .r = STDIN_FILENO, .w = STDOUT_FILENO };
+    ucsp_info_and_adjust_fds(&ret.w, &ret.r);
+    return ret;
+}
+
+static union iopair make_pipe(void) {
+    union iopair ret;
+    xpipe(ret.fd);
+    return ret;
+}
+
 int main(const int ac, const char* av[static const ac]) {
     if (ac != 3)
         return 1;
-    int fd_fo_main = STDOUT_FILENO, fd_fi_main = STDIN_FILENO;
-    ucsp_info_and_adjust_fds(&fd_fo_main, &fd_fi_main);
-    int frontend_pipe[2];
-    xpipe(frontend_pipe);
-    struct ThreadBag thr[] = {
-        npth_define(fsm_wireformat, "wp", .from_wire = fd_fi_main, .to_wire = fd_fo_main, .to_fronted = STDOUT_FILENO)
+    const union iopair foreign = get_main(), internal[] = { make_pipe() };
+    struct task* t[] = {
+        create_task("wp", fsm_wireformat, .from_wire = foreign.r, .to_wire = foreign.w, .to_fronted = internal[0].w)
     };
-    for (size_t i = 0; i < lengthof(thr); i++) {
-        pthread_create(&thr[i].handle, NULL, thr[i].entry, thr[i].arg);
-        pthread_setname_np(thr[i].handle, thr[i].name);
-    }
-    for (size_t i = 0; i < lengthof(thr); i++)
-        pthread_join(thr[i].handle, NULL);
-    return EXIT_SUCCESS;
+    int error = 0;
+    for (size_t i = 0; i < lengthof(t); i++)
+        error |= teardown_task(t[i]);
+    return error ? EXIT_FAILURE : EXIT_SUCCESS;
 }
diff --git a/npthfix.h b/npthfix.h
deleted file mode 100644
index 9bb83cf..0000000
--- a/npthfix.h
+++ /dev/null
@@ -1,24 +0,0 @@
-#pragma once
-#include <npth.h>
-#include <pthread.h>
-#include "utils.h"
-
-#define npth_define(Entry, Name, ...) \
-    { .entry = (npth_entry_t)Entry, .name = (Name), .arg = &(struct Entry ## _args){ __VA_ARGS__ } }
-
-typedef void* (* const npth_entry_t)(void*);
-typedef void (* const cleanup_t)(void*);
-
-struct ThreadBag {
-    npth_t handle;
-    const char* const name;
-    npth_entry_t entry;
-    void* const arg;
-};
-
-size_t xsend_message(int fd, const input_t* p, const input_t* pe) __attribute__((nonnull(2,3)));
-size_t xrecv_message(int fd, size_t size, input_t p[static size], const input_t** pe) __attribute__((nonnull(3,4)));
-
-inline size_t xsend_message_buf(const int fd, const size_t size, const input_t buf[static const size]) {
-    return xsend_message(fd, buf, buf + size);
-}
diff --git a/npthfix.c b/tasks.c
similarity index 52%
rename from npthfix.c
rename to tasks.c
index b713b11..e8766b1 100644
--- a/npthfix.c
+++ b/tasks.c
@@ -4,9 +4,27 @@
 #include <pthread.h>
 #include <assert.h>
 
-extern size_t xsend_message_buf(int fd, size_t size, const input_t buf[static size]);
+struct task {
+    pthread_t handle;
+};
 
-size_t xsend_message(const int fd, const input_t* const p, const input_t* const pe) {
+
+extern size_t send_message_buf(int fd, size_t size, const input_t buf[static size]);
+
+struct task* create_task_(const char* const name, entry_t entry, const void* const arg) {
+    struct task* const ret = xmalloc(sizeof struct task);
+    xpthread_create(&ret->handle, NULL, entry, arg);
+    xpthread_setname_np(ret->handle, name);
+    return ret;
+}
+
+int teardown_task(struct task*) {
+    union retval ret;
+    xpthread_join(task->handle, &ret.ptr);
+    return ret.num;
+}
+
+size_t send_message(const int fd, const input_t* const p, const input_t* const pe) {
     assert(p);
     assert(pe);
     assert(pe >= p);
@@ -18,7 +36,7 @@ size_t xsend_message(const int fd, const input_t* const p, const input_t* const
     return written;
 }
 
-size_t xrecv_message(const int fd, const size_t size, input_t p[static const size], const input_t** const pe) {
+size_t recv_message(const int fd, const size_t size, input_t p[static const size], const input_t** const pe) {
     assert(p);
     assert(pe);
     assert(*pe);
diff --git a/tasks.h b/tasks.h
new file mode 100644
index 0000000..221df8e
--- /dev/null
+++ b/tasks.h
@@ -0,0 +1,21 @@
+#pragma once
+#include "utils.h"
+
+typedef void* (* const entry_t)(void*);
+
+struct task;
+union retval {
+    void* ptr;
+    int num;
+};
+
+#define create_task(Name, Entry, ...) create_task_(Name, Entry, &(struct Entry ## _args){ __VA_ARGS__ });
+struct task* create_task_(const char* name, entry_t entry, const void* arg);
+int teardown_task(struct task*);
+
+size_t send_message(int fd, const input_t* p, const input_t* pe) __attribute__((nonnull(2,3)));
+size_t recv_message(int fd, size_t size, input_t p[static size], const input_t** pe) __attribute__((nonnull(3,4)));
+
+inline size_t send_message_buf(const int fd, const size_t size, const input_t buf[static const size]) {
+    return send_message(fd, buf, buf + size);
+}
diff --git a/utils.h b/utils.h
index 0253740..474332e 100644
--- a/utils.h
+++ b/utils.h
@@ -64,13 +64,9 @@
     v;\
 })
 
-#define xnpth_setname_np(...) XCALL(npth_setname_np, __VA_ARGS__)
-#define xnpth_create(...) XCALL(npth_create, __VA_ARGS__)
-#define xnpth_sigwait(...) XCALL(npth_sigwait, __VA_ARGS__)
-#define xnpth_join(...) XCALL(npth_join, __VA_ARGS__)
-#define xnpth_init(...) XCALL(npth_init, __VA_ARGS__)
-#define xnpth_read(...) XCALL(npth_read, __VA_ARGS__)
-#define xnpth_write(...) XCALL(npth_write, __VA_ARGS__)
+#define xpthread_create(...) XCALL(pthread_create, __VA_ARGS__)
+#define xpthread_join(...) XCALL(pthread_join, __VA_ARGS__)
+#define xpthread_setname_np(...) XCALL(pthread_setname_np, __VA_ARGS__)
 #define xfprintf(...) XCALL(fprintf, __VA_ARGS__)
 #define xfputs(...) XCALL(fputs, __VA_ARGS__)
 #define xfflush(...) XCALL(fflush, __VA_ARGS__)