* include/ruby/thread.h (rb_thread_call_without_gvl2): change

  meaning of function.
  This function is called with same parameters of
  `rb_thread_call_without_gvl()'.
  However, if interrupts are detected, when return immediately.
* thread.c: implement `rb_thread_call_without_gvl2()'.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@37938 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 99 insertions, 86 deletions

diff --git a/thread.c b/thread.c
index ae203b274d..371607b1fa 100644
--- a/thread.c
+++ b/thread.c
@@ -91,10 +91,12 @@ struct rb_blocking_region_buffer {
     struct rb_unblock_callback oldubf;
 };
 
-static void set_unblock_function(rb_thread_t *th, rb_unblock_function_t *func, void *arg,
-				 struct rb_unblock_callback *old);
+static int set_unblock_function(rb_thread_t *th, rb_unblock_function_t *func, void *arg,
+				struct rb_unblock_callback *old, int fail_if_interrupted);
 static void reset_unblock_function(rb_thread_t *th, const struct rb_unblock_callback *old);
 
+static inline int blocking_region_begin(rb_thread_t *th, struct rb_blocking_region_buffer *region,
+					rb_unblock_function_t *ubf, void *arg, int fail_if_interrupted);
 static inline void blocking_region_end(rb_thread_t *th, struct rb_blocking_region_buffer *region);
 
 #define RB_GC_SAVE_MACHINE_CONTEXT(th) \
@@ -113,23 +115,13 @@ static inline void blocking_region_end(rb_thread_t *th, struct rb_blocking_regio
   rb_thread_set_current(_th_stored); \
 } while(0)
 
-#define blocking_region_begin(th, region, func, arg) \
-  do { \
-    (region)->prev_status = (th)->status; \
-    set_unblock_function((th), (func), (arg), &(region)->oldubf); \
-    (th)->blocking_region_buffer = (region); \
-    (th)->status = THREAD_STOPPED; \
-    thread_debug("enter blocking region (%p)\n", (void *)(th)); \
-    RB_GC_SAVE_MACHINE_CONTEXT(th); \
-    gvl_release((th)->vm); \
-  } while (0)
-
-#define BLOCKING_REGION(exec, ubf, ubfarg) do { \
+#define BLOCKING_REGION(exec, ubf, ubfarg, fail_if_interrupted) do { \
     rb_thread_t *__th = GET_THREAD(); \
     struct rb_blocking_region_buffer __region; \
-    blocking_region_begin(__th, &__region, (ubf), (ubfarg)); \
-    exec; \
-    blocking_region_end(__th, &__region); \
+    if (blocking_region_begin(__th, &__region, (ubf), (ubfarg), fail_if_interrupted)) { \
+	exec; \
+	blocking_region_end(__th, &__region); \
+    }; \
 } while(0)
 
 #if THREAD_DEBUG
@@ -260,12 +252,20 @@ rb_thread_lock_destroy(rb_thread_lock_t *lock)
     native_mutex_destroy(lock);
 }
 
-static void
+static int
 set_unblock_function(rb_thread_t *th, rb_unblock_function_t *func, void *arg,
-		     struct rb_unblock_callback *old)
+		     struct rb_unblock_callback *old, int fail_if_interrupted)
 {
   check_ints:
-    RUBY_VM_CHECK_INTS(th); /* check signal or so */
+    if (fail_if_interrupted) {
+	if (RUBY_VM_INTERRUPTED_ANY(th)) {
+	    return FALSE;
+	}
+    }
+    else {
+	RUBY_VM_CHECK_INTS(th);
+    }
+
     native_mutex_lock(&th->interrupt_lock);
     if (RUBY_VM_INTERRUPTED_ANY(th)) {
 	native_mutex_unlock(&th->interrupt_lock);
@@ -277,6 +277,8 @@ set_unblock_function(rb_thread_t *th, rb_unblock_function_t *func, void *arg,
 	th->unblock.arg = arg;
     }
     native_mutex_unlock(&th->interrupt_lock);
+
+    return TRUE;
 }
 
 static void
@@ -1075,6 +1077,24 @@ rb_thread_schedule(void)
 
 /* blocking region */
 
+static inline int
+blocking_region_begin(rb_thread_t *th, struct rb_blocking_region_buffer *region,
+		      rb_unblock_function_t *ubf, void *arg, int fail_if_interrupted)
+{
+    region->prev_status = th->status;
+    if (set_unblock_function(th, ubf, arg, &region->oldubf, fail_if_interrupted)) {
+	th->blocking_region_buffer = region;
+	th->status = THREAD_STOPPED;
+	thread_debug("enter blocking region (%p)\n", (void *)th);
+	RB_GC_SAVE_MACHINE_CONTEXT(th);
+	gvl_release(th->vm);
+	return TRUE;
+    }
+    else {
+	return FALSE;
+    }
+}
+
 static inline void
 blocking_region_end(rb_thread_t *th, struct rb_blocking_region_buffer *region)
 {
@@ -1094,7 +1114,7 @@ rb_thread_blocking_region_begin(void)
 {
     rb_thread_t *th = GET_THREAD();
     struct rb_blocking_region_buffer *region = ALLOC(struct rb_blocking_region_buffer);
-    blocking_region_begin(th, region, ubf_select, th);
+    blocking_region_begin(th, region, ubf_select, th, FALSE);
     return region;
 }
 
@@ -1109,24 +1129,54 @@ rb_thread_blocking_region_end(struct rb_blocking_region_buffer *region)
     errno = saved_errno;
 }
 
+static void *
+call_without_gvl(void *(*func)(void *), void *data1,
+		 rb_unblock_function_t *ubf, void *data2, int fail_if_interrupted)
+{
+    void *val = 0;
+
+    rb_thread_t *th = GET_THREAD();
+    int saved_errno = 0;
+
+    th->waiting_fd = -1;
+    if (ubf == RUBY_UBF_IO || ubf == RUBY_UBF_PROCESS) {
+	ubf = ubf_select;
+	data2 = th;
+    }
+
+    BLOCKING_REGION({
+	val = func(data1);
+	saved_errno = errno;
+    }, ubf, data2, fail_if_interrupted);
+
+    if (!fail_if_interrupted) {
+	RUBY_VM_CHECK_INTS_BLOCKING(th);
+    }
+
+    errno = saved_errno;
+
+    return val;
+}
+
 /*
  * rb_thread_call_without_gvl - permit concurrent/parallel execution.
- * rb_thread_call_without_gvl2 - permit concurrent/parallel execution with
- * optional interrupt checking.
+ * rb_thread_call_without_gvl2 - permit concurrent/parallel execution
+ *                               without interrupt proceess.
  *
  * rb_thread_call_without_gvl() does:
- *   (1) release GVL.
+ *   (1) Check interrupts.
+ *   (2) release GVL.
  *       Other Ruby threads may run in parallel.
- *   (2) call func with data1
- *   (3) acquire GVL.
+ *   (3) call func with data1
+ *   (4) acquire GVL.
  *       Other Ruby threads can not run in parallel any more.
- *   (4) Check interrupts.
+ *   (5) Check interrupts.
  *
  * rb_thread_call_without_gvl2() does:
- *   (1) release GVL.
- *   (2) call func with data1 and a pointer to the flags.
- *   (3) acquire GVL.
- *   (4) Check interrupts if (flags & RUBY_CALL_WO_GVL_FLAG_SKIP_CHECK_INTS) is 0.
+ *   (1) Check interrupt and return if interrupted.
+ *   (2) release GVL.
+ *   (3) call func with data1 and a pointer to the flags.
+ *   (4) acquire GVL.
  *
  * If another thread interrupts this thread (Thread#kill, signal delivery,
  * VM-shutdown request, and so on), `ubf()' is called (`ubf()' means
@@ -1144,7 +1194,7 @@ rb_thread_blocking_region_end(struct rb_blocking_region_buffer *region)
  * provide proper ubf(), your program will not stop for Control+C or other
  * shutdown events.
  *
- * "Check interrupts" on above list (4) means that check asynchronous
+ * "Check interrupts" on above list means that check asynchronous
  * interrupt events (such as Thread#kill, signal delivery, VM-shutdown
  * request, and so on) and call corresponding procedures
  * (such as `trap' for signals, raise an exception for Thread#raise).
@@ -1161,16 +1211,16 @@ rb_thread_blocking_region_end(struct rb_blocking_region_buffer *region)
  * `read_func()' and interrupts are checked. However, if an interrupt occurs
  * at (c), after *read* operation is completed, check intterrupts is harmful
  * because it causes irrevocable side-effect, the read data will vanish.  To
- * avoid such problem, the `read_func()' should be:
+ * avoid such problem, the `read_func()' should be used with
+ * `rb_thread_call_without_gvl2()'.
  *
- *   read_func(void *data, VALUE *flags) {
- *                   // (a) before read
- *     read(buffer); // (b) reading
- *                   // (c) after read
- *     if (read is complete) {
- *       *flags |= RUBY_CALL_WO_GVL_FLAG_SKIP_CHECK_INTS;
- *     }
- *   }
+ * If `rb_thread_call_without_gvl2()' detects interrupt, return its execution
+ * immediately. This function does not show when the execution was interrupted.
+ * For example, there are 4 possible timing (a), (b), (c) and before calling
+ * read_func(). You need to record progress of a read_func() and check
+ * the progress after `rb_thread_call_without_gvl2()'. You may need to call
+ * `rb_thread_check_ints()' correctly or your program can not process proper
+ * process such as `trap' and so on.
  *
  * NOTE: You can not execute most of Ruby C API and touch Ruby
  *       objects in `func()' and `ubf()', including raising an
@@ -1194,54 +1244,17 @@ rb_thread_blocking_region_end(struct rb_blocking_region_buffer *region)
  *   they will work without GVL, and may acquire GVL when GC is needed.
  */
 void *
-rb_thread_call_without_gvl2(void *(*func)(void *data, VALUE *flags), void *data1,
+rb_thread_call_without_gvl2(void *(*func)(void *), void *data1,
 			    rb_unblock_function_t *ubf, void *data2)
 {
-    void *val;
-    rb_thread_t *th = GET_THREAD();
-    int saved_errno = 0;
-    VALUE flags = 0;
-
-    th->waiting_fd = -1;
-    if (ubf == RUBY_UBF_IO || ubf == RUBY_UBF_PROCESS) {
-	ubf = ubf_select;
-	data2 = th;
-    }
-
-    BLOCKING_REGION({
-	val = func(data1, &flags);
-	saved_errno = errno;
-    }, ubf, data2);
-
-    if ((flags & RUBY_CALL_WO_GVL_FLAG_SKIP_CHECK_INTS) == 0) {
-	RUBY_VM_CHECK_INTS_BLOCKING(th);
-    }
-
-    errno = saved_errno;
-
-    return val;
-}
-
-struct without_gvl_wrapper_arg {
-    void *(*func)(void *data);
-    void *data;
-};
-
-static void *
-without_gvl_wrapper(void *data, VALUE *flags)
-{
-    struct without_gvl_wrapper_arg *arg = (struct without_gvl_wrapper_arg*)data;
-    return arg->func(arg->data);
+    return call_without_gvl(func, data1, ubf, data2, TRUE);
 }
 
 void *
 rb_thread_call_without_gvl(void *(*func)(void *data), void *data1,
 			    rb_unblock_function_t *ubf, void *data2)
 {
-    struct without_gvl_wrapper_arg arg;
-    arg.func = func;
-    arg.data = data1;
-    return rb_thread_call_without_gvl2(without_gvl_wrapper, &arg, ubf, data2);
+    return call_without_gvl(func, data1, ubf, data2, FALSE);
 }
 
 VALUE
@@ -1259,7 +1272,7 @@ rb_thread_io_blocking_region(rb_blocking_function_t *func, void *data1, int fd)
 	BLOCKING_REGION({
 	    val = func(data1);
 	    saved_errno = errno;
-	}, ubf_select, th);
+	}, ubf_select, th, FALSE);
     }
     TH_POP_TAG();
 
@@ -1343,7 +1356,7 @@ rb_thread_call_with_gvl(void *(*func)(void *), void *data1)
     /* enter to Ruby world: You can access Ruby values, methods and so on. */
     r = (*func)(data1);
     /* leave from Ruby world: You can not access Ruby values, etc. */
-    blocking_region_begin(th, brb, prev_unblock.func, prev_unblock.arg);
+    blocking_region_begin(th, brb, prev_unblock.func, prev_unblock.arg, FALSE);
     return r;
 }
 
@@ -3211,7 +3224,7 @@ do_select(int n, rb_fdset_t *read, rb_fdset_t *write, rb_fdset_t *except,
     BLOCKING_REGION({
 	    result = native_fd_select(n, read, write, except, timeout, th);
 	    if (result < 0) lerrno = errno;
-	}, ubf_select, th);
+	}, ubf_select, th, FALSE);
 
     RUBY_VM_CHECK_INTS_BLOCKING(th);
 
@@ -3437,7 +3450,7 @@ retry:
     BLOCKING_REGION({
 	result = ppoll(&fds, 1, timeout, NULL);
 	if (result < 0) lerrno = errno;
-    }, ubf_select, th);
+    }, ubf_select, th, FALSE);
 
     RUBY_VM_CHECK_INTS_BLOCKING(th);
 
@@ -4161,7 +4174,7 @@ rb_mutex_lock(VALUE self)
 	    int timeout_ms = 0;
 	    struct rb_unblock_callback oldubf;
 
-	    set_unblock_function(th, lock_interrupt, mutex, &oldubf);
+	    set_unblock_function(th, lock_interrupt, mutex, &oldubf, FALSE);
 	    th->status = THREAD_STOPPED_FOREVER;
 	    th->locking_mutex = self;