[PATCH 8/9] separate pthread_create and pthread_exit in two different TU

[Jens Gustedt <Jens.Gustedt@inria.fr>]

---
 src/thread/pthread_create.c |  124 ++---------------------------------------
 src/thread/pthread_exit.c   |  130 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 135 insertions(+), 119 deletions(-)
 create mode 100644 src/thread/pthread_exit.c

diff --git a/src/thread/pthread_create.c b/src/thread/pthread_create.c
index c1feb62..7bc7b0f 100644
--- a/src/thread/pthread_create.c
+++ b/src/thread/pthread_create.c
@@ -10,102 +10,16 @@ void *__mmap(void *, size_t, int, int, int, off_t);
 int __munmap(void *, size_t);
 int __mprotect(void *, size_t, int);
 _Noreturn void __thrd_exit(int);
+void __thread_enable(void);
+_Noreturn void __pthread_exit(void *);
+void *__copy_tls(unsigned char *);
+extern volatile size_t __pthread_tsd_size;
 
 static void dummy_0()
 {
 }
 weak_alias(dummy_0, __acquire_ptc);
 weak_alias(dummy_0, __release_ptc);
-weak_alias(dummy_0, __pthread_tsd_run_dtors);
-weak_alias(dummy_0, __do_private_robust_list);
-weak_alias(dummy_0, __do_orphaned_stdio_locks);
-
-_Noreturn void __pthread_exit(void *result)
-{
-	pthread_t self = __pthread_self();
-	sigset_t set;
-
-	self->result = result;
-
-	while (self->cancelbuf) {
-		void (*f)(void *) = self->cancelbuf->__f;
-		void *x = self->cancelbuf->__x;
-		self->cancelbuf = self->cancelbuf->__next;
-		f(x);
-	}
-
-	__pthread_tsd_run_dtors();
-
-	__lock(self->exitlock);
-
-	/* Mark this thread dead before decrementing count */
-	__lock(self->killlock);
-	self->dead = 1;
-
-	/* Block all signals before decrementing the live thread count.
-	 * This is important to ensure that dynamically allocated TLS
-	 * is not under-allocated/over-committed, and possibly for other
-	 * reasons as well. */
-	__block_all_sigs(&set);
-
-	/* Wait to unlock the kill lock, which governs functions like
-	 * pthread_kill which target a thread id, until signals have
-	 * been blocked. This precludes observation of the thread id
-	 * as a live thread (with application code running in it) after
-	 * the thread was reported dead by ESRCH being returned. */
-	__unlock(self->killlock);
-
-	/* It's impossible to determine whether this is "the last thread"
-	 * until performing the atomic decrement, since multiple threads
-	 * could exit at the same time. For the last thread, revert the
-	 * decrement and unblock signals to give the atexit handlers and
-	 * stdio cleanup code a consistent state. */
-	if (a_fetch_add(&libc.threads_minus_1, -1)==0) {
-		libc.threads_minus_1 = 0;
-		__restore_sigs(&set);
-		exit(0);
-	}
-
-	if (self->locale != &libc.global_locale) {
-		a_dec(&libc.uselocale_cnt);
-		if (self->locale->ctype_utf8)
-			a_dec(&libc.bytelocale_cnt_minus_1);
-	}
-
-	__do_private_robust_list();
-	__do_orphaned_stdio_locks();
-
-	if (self->detached && self->map_base) {
-		/* Detached threads must avoid the kernel clear_child_tid
-		 * feature, since the virtual address will have been
-		 * unmapped and possibly already reused by a new mapping
-		 * at the time the kernel would perform the write. In
-		 * the case of threads that started out detached, the
-		 * initial clone flags are correct, but if the thread was
-		 * detached later (== 2), we need to clear it here. */
-		if (self->detached == 2) __syscall(SYS_set_tid_address, 0);
-
-		/* The following call unmaps the thread's stack mapping
-		 * and then exits without touching the stack. */
-		__unmapself(self->map_base, self->map_size);
-	}
-
-	for (;;) __syscall(SYS_exit, 0);
-}
-
-void __do_cleanup_push(struct __ptcb *cb)
-{
-	if (!libc.has_thread_pointer) return;
-	struct pthread *self = __pthread_self();
-	cb->__next = self->cancelbuf;
-	self->cancelbuf = cb;
-}
-
-void __do_cleanup_pop(struct __ptcb *cb)
-{
-	if (!libc.has_thread_pointer) return;
-	__pthread_self()->cancelbuf = cb->__next;
-}
 
 static int start(void *p)
 {
@@ -135,24 +49,6 @@ static int start_c11(void *p)
 
 #define ROUND(x) (((x)+PAGE_SIZE-1)&-PAGE_SIZE)
 
-/* pthread_key_create.c overrides this */
-static volatile size_t dummy = 0;
-weak_alias(dummy, __pthread_tsd_size);
-static void *dummy_tsd[1] = { 0 };
-weak_alias(dummy_tsd, __pthread_tsd_main);
-
-static FILE *volatile dummy_file = 0;
-weak_alias(dummy_file, __stdin_used);
-weak_alias(dummy_file, __stdout_used);
-weak_alias(dummy_file, __stderr_used);
-
-static void init_file_lock(FILE *f)
-{
-	if (f && f->lock<0) f->lock = 0;
-}
-
-void *__copy_tls(unsigned char *);
-
 int __pthread_create(pthread_t *restrict res, const pthread_attr_t *restrict attrp, void *(*entry)(void *), void *restrict arg)
 {
 	int ret, c11 = (attrp == __ATTRP_C11_THREAD);
@@ -167,16 +63,7 @@ int __pthread_create(pthread_t *restrict res, const pthread_attr_t *restrict att
 
 	if (!libc.can_do_threads) return ENOSYS;
 	self = __pthread_self();
-	if (!libc.threaded) {
-		for (FILE *f=libc.ofl_head; f; f=f->next)
-			init_file_lock(f);
-		init_file_lock(__stdin_used);
-		init_file_lock(__stdout_used);
-		init_file_lock(__stderr_used);
-		__syscall(SYS_rt_sigprocmask, SIG_UNBLOCK, SIGPT_SET, 0, _NSIG/8);
-		self->tsd = (void **)__pthread_tsd_main;
-		libc.threaded = 1;
-	}
+	if (!libc.threaded) __thread_enable();
 	if (attrp && !c11) attr = *attrp;
 
 	__acquire_ptc();
@@ -273,5 +160,4 @@ fail_nomem:
 	return c11 ? ENOMEM : EAGAIN;
 }
 
-weak_alias(__pthread_exit, pthread_exit);
 weak_alias(__pthread_create, pthread_create);
diff --git a/src/thread/pthread_exit.c b/src/thread/pthread_exit.c
new file mode 100644
index 0000000..4f51269
--- /dev/null
+++ b/src/thread/pthread_exit.c
@@ -0,0 +1,130 @@
+#define _GNU_SOURCE
+#include "pthread_impl.h"
+#include "stdio_impl.h"
+#include "libc.h"
+#include <sys/mman.h>
+#include <threads.h>
+
+static void dummy_0()
+{
+}
+weak_alias(dummy_0, __pthread_tsd_run_dtors);
+weak_alias(dummy_0, __do_private_robust_list);
+weak_alias(dummy_0, __do_orphaned_stdio_locks);
+
+_Noreturn void __pthread_exit(void *result)
+{
+	pthread_t self = __pthread_self();
+	sigset_t set;
+
+	self->result = result;
+
+	while (self->cancelbuf) {
+		void (*f)(void *) = self->cancelbuf->__f;
+		void *x = self->cancelbuf->__x;
+		self->cancelbuf = self->cancelbuf->__next;
+		f(x);
+	}
+
+	__pthread_tsd_run_dtors();
+
+	__lock(self->exitlock);
+
+	/* Mark this thread dead before decrementing count */
+	__lock(self->killlock);
+	self->dead = 1;
+
+	/* Block all signals before decrementing the live thread count.
+	 * This is important to ensure that dynamically allocated TLS
+	 * is not under-allocated/over-committed, and possibly for other
+	 * reasons as well. */
+	__block_all_sigs(&set);
+
+	/* Wait to unlock the kill lock, which governs functions like
+	 * pthread_kill which target a thread id, until signals have
+	 * been blocked. This precludes observation of the thread id
+	 * as a live thread (with application code running in it) after
+	 * the thread was reported dead by ESRCH being returned. */
+	__unlock(self->killlock);
+
+	/* It's impossible to determine whether this is "the last thread"
+	 * until performing the atomic decrement, since multiple threads
+	 * could exit at the same time. For the last thread, revert the
+	 * decrement and unblock signals to give the atexit handlers and
+	 * stdio cleanup code a consistent state. */
+	if (a_fetch_add(&libc.threads_minus_1, -1)==0) {
+		libc.threads_minus_1 = 0;
+		__restore_sigs(&set);
+		exit(0);
+	}
+
+	if (self->locale != &libc.global_locale) {
+		a_dec(&libc.uselocale_cnt);
+		if (self->locale->ctype_utf8)
+			a_dec(&libc.bytelocale_cnt_minus_1);
+	}
+
+	__do_private_robust_list();
+	__do_orphaned_stdio_locks();
+
+	if (self->detached && self->map_base) {
+		/* Detached threads must avoid the kernel clear_child_tid
+		 * feature, since the virtual address will have been
+		 * unmapped and possibly already reused by a new mapping
+		 * at the time the kernel would perform the write. In
+		 * the case of threads that started out detached, the
+		 * initial clone flags are correct, but if the thread was
+		 * detached later (== 2), we need to clear it here. */
+		if (self->detached == 2) __syscall(SYS_set_tid_address, 0);
+
+		/* The following call unmaps the thread's stack mapping
+		 * and then exits without touching the stack. */
+		__unmapself(self->map_base, self->map_size);
+	}
+
+	for (;;) __syscall(SYS_exit, 0);
+}
+
+void __do_cleanup_push(struct __ptcb *cb)
+{
+	if (!libc.has_thread_pointer) return;
+	struct pthread *self = __pthread_self();
+	cb->__next = self->cancelbuf;
+	self->cancelbuf = cb;
+}
+
+void __do_cleanup_pop(struct __ptcb *cb)
+{
+	if (!libc.has_thread_pointer) return;
+	__pthread_self()->cancelbuf = cb->__next;
+}
+
+/* pthread_key_create.c overrides this */
+static volatile size_t dummy = 0;
+weak_alias(dummy, __pthread_tsd_size);
+static void *dummy_tsd[1] = { 0 };
+weak_alias(dummy_tsd, __pthread_tsd_main);
+
+static FILE *volatile dummy_file = 0;
+weak_alias(dummy_file, __stdin_used);
+weak_alias(dummy_file, __stdout_used);
+weak_alias(dummy_file, __stderr_used);
+
+static void init_file_lock(FILE *f)
+{
+	if (f && f->lock<0) f->lock = 0;
+}
+
+void __thread_enable(void)
+{
+	for (FILE *f=libc.ofl_head; f; f=f->next)
+		init_file_lock(f);
+	init_file_lock(__stdin_used);
+	init_file_lock(__stdout_used);
+	init_file_lock(__stderr_used);
+	__syscall(SYS_rt_sigprocmask, SIG_UNBLOCK, SIGPT_SET, 0, _NSIG/8);
+	__pthread_self()->tsd = (void **)__pthread_tsd_main;
+	libc.threaded = 1;
+}
+
+weak_alias(__pthread_exit, pthread_exit);
-- 
1.7.10.4