From 29b096a3a92496f2128036cf0c78b589ef0c3814 Mon Sep 17 00:00:00 2001
From: Xavier Leroy <xavier.leroy@inria.fr>
Date: Mon, 16 Jun 2003 12:31:14 +0000
Subject: Revu implementation Thread.exit dans systhreads (PR#1644)
git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@5599 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
---
otherlibs/systhreads/posix.c | 78 ++++++++++++++++++++++++++++++++++++--------
1 file changed, 65 insertions(+), 13 deletions(-)
(limited to 'otherlibs/systhreads/posix.c')
diff --git a/otherlibs/systhreads/posix.c b/otherlibs/systhreads/posix.c
index f6a7fa570..8effa65f8 100644
--- a/otherlibs/systhreads/posix.c
+++ b/otherlibs/systhreads/posix.c
@@ -78,6 +78,7 @@ struct caml_thread_struct {
value * gc_regs; /* Saved value of caml_gc_regs */
char * exception_pointer; /* Saved value of caml_exception_pointer */
struct caml__roots_block * local_roots; /* Saved value of local_roots */
+ struct longjmp_buffer * exit_buf; /* For thread exit */
#else
value * stack_low; /* The execution stack for this thread */
value * stack_high;
@@ -113,12 +114,15 @@ static pthread_key_t last_channel_locked_key;
static long thread_next_ident = 0;
/* Forward declarations */
-
value caml_threadstatus_new (void);
void caml_threadstatus_terminate (value);
int caml_threadstatus_wait (value);
static void caml_pthread_check (int, char *);
+/* Imports for the native-code compiler */
+extern struct longjmp_buffer caml_termination_jmpbuf;
+extern void (*caml_termination_hook)(void *);
+
/* Hook for scanning the stacks of the other threads */
static void (*prev_scan_roots_hook) (scanning_action);
@@ -332,6 +336,9 @@ value caml_thread_initialize(value unit) /* ML */
curr_thread->descr = descr;
curr_thread->next = curr_thread;
curr_thread->prev = curr_thread;
+#ifdef NATIVE_CODE
+ curr_thread->exit_buf = &caml_termination_jmpbuf;
+#endif
/* The stack-related fields will be filled in at the next
enter_blocking_section */
/* Associate the thread descriptor with the thread */
@@ -343,6 +350,9 @@ value caml_thread_initialize(value unit) /* ML */
enter_blocking_section_hook = caml_thread_enter_blocking_section;
prev_leave_blocking_section_hook = leave_blocking_section_hook;
leave_blocking_section_hook = caml_thread_leave_blocking_section;
+#ifdef NATIVE_CODE
+ caml_termination_hook = pthread_exit;
+#endif
channel_mutex_free = caml_io_mutex_free;
channel_mutex_lock = caml_io_mutex_lock;
channel_mutex_unlock = caml_io_mutex_unlock;
@@ -357,21 +367,12 @@ value caml_thread_initialize(value unit) /* ML */
return Val_unit;
}
-/* Create a thread */
+/* Thread cleanup at termination */
-static void * caml_thread_start(void * arg)
+static void caml_thread_stop(void)
{
- caml_thread_t th = (caml_thread_t) arg;
- value clos;
+ caml_thread_t th = curr_thread;
- /* Associate the thread descriptor with the thread */
- pthread_setspecific(thread_descriptor_key, (void *) th);
- /* Acquire the global mutex and set up the stack variables */
- leave_blocking_section();
- /* Callback the closure */
- clos = Start_closure(th->descr);
- modify(&(Start_closure(th->descr)), Val_unit);
- callback_exn(clos, Val_unit);
/* Signal that the thread has terminated */
caml_threadstatus_terminate(Terminated(th->descr));
/* Remove th from the doubly-linked list of threads */
@@ -387,6 +388,33 @@ static void * caml_thread_start(void * arg)
#endif
/* Free the thread descriptor */
stat_free(th);
+}
+
+/* Create a thread */
+
+static void * caml_thread_start(void * arg)
+{
+ caml_thread_t th = (caml_thread_t) arg;
+ value clos;
+ struct longjmp_buffer termination_buf;
+
+ /* Associate the thread descriptor with the thread */
+ pthread_setspecific(thread_descriptor_key, (void *) th);
+ /* Acquire the global mutex and set up the stack variables */
+ leave_blocking_section();
+#ifdef NATIVE_CODE
+ /* Setup termination handler (for caml_thread_exit) */
+ if (sigsetjmp(termination_buf.buf, 0) == 0) {
+ th->exit_buf = &termination_buf;
+#endif
+ /* Callback the closure */
+ clos = Start_closure(th->descr);
+ modify(&(Start_closure(th->descr)), Val_unit);
+ callback_exn(clos, Val_unit);
+ caml_thread_stop();
+#ifdef NATIVE_CODE
+ }
+#endif
/* The thread now stops running */
return NULL;
}
@@ -481,6 +509,30 @@ value caml_thread_uncaught_exception(value exn) /* ML */
return Val_unit;
}
+/* Terminate current thread */
+
+value caml_thread_exit(value unit) /* ML */
+{
+#ifdef NATIVE_CODE
+ /* We cannot call pthread_exit here because on some systems this
+ raises a C++ exception, and ocamlopt-generated stack frames
+ cannot be unwound. Instead, we longjmp to the thread creation
+ point (in caml_thread_start) or to the point in caml_main
+ where caml_termination_hook will be called. */
+ struct longjmp_buffer * exit_buf;
+ if (curr_thread == NULL) invalid_argument("Thread.exit: not initialized");
+ exit_buf = curr_thread->exit_buf;
+ caml_thread_stop();
+ siglongjmp(exit_buf->buf, 1);
+#else
+ /* No such problem in bytecode */
+ if (curr_thread == NULL) invalid_argument("Thread.exit: not initialized");
+ caml_thread_stop();
+ pthread_exit(NULL);
+#endif
+ return Val_unit; /* not reached */
+}
+
/* Allow re-scheduling */
value caml_thread_yield(value unit) /* ML */
--
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