* cygwin.din: Add sem_close, sem_getvalue, sem_open and sem_timedwait.

* pthread.cc (+mangle_sem_name): New function.
	(sem_open): Ditto.
	(sem_close: Ditto.
	(sem_timedwait): Ditto.
	(sem_getvalue): Ditto.
	* thread.cc (semaphore::semaphore): Rearrange member initialization.
	Use appropriate security attribute for process shared semaphores.
	(semaphore::semaphore): New constructor for named semaphores.
	(semaphore::~semaphore): Care for semaphore name.
	(semaphore::_post): Accomodate failing ReleaseSemaphore. Use value
	returned by ReleaseSemaphore vor currentvalue.
	(semaphore::_getvalue): New method.
	(semaphore::_timedwait): Ditto.
	(semaphore::_fixup_after_fork): Rearrange. Don't fail for process
	shared semaphores.
	(semaphore::open): New method.
	(semaphore::timedwait): Ditto.
	(semaphore::post): Fix return value.  Set errno appropriately.
	(semaphore::getvalue): New method.
	* thread.h (class semaphore): Add prototypes for open, getvalue,
	timedwait, _getvalue, _timedwait.  Add prototypes for new constructor.
	Add name member.
	* include/semaphore.h: Add prototypes for sem_open, sem_close,
	sem_timedwait and sem_getvalue.
	include/cygwin/version.h: Bump API minor number.

winsup/cygwin/pthread.cc

@@ -12,7 +12,9 @@
 
 #include "winsup.h"
 #include "thread.h"
-#include "errno.h"
+#include "cygerrno.h"
+#include <stdarg.h>
+#include <sys/fcntl.h>
 
 extern "C"
 {
@@ -157,6 +159,55 @@ sem_destroy (sem_t * sem)
   return semaphore::destroy (sem);
 }
 
+/* Mangle semaphore name to follow windows naming rules.  Prepend "Global\"
+   if running on terminal service aware machine.  Substitute invalid backslash
+   by forward slash characters, hoping not to collide. */
+static bool
+mangle_sem_name (char *mangled, const char *name)
+{
+  if (check_null_empty_str_errno (name))
+    return false;
+  int len = strlen (name);
+  if (len > MAX_PATH
+      || (wincap.has_terminal_services () && len > MAX_PATH - 7))
+    {
+      set_errno (EINVAL);
+      return false;
+    }
+  strcpy (mangled, wincap.has_terminal_services () ? "Global\\" : "");
+  char *d = mangled + strlen (mangled);
+  const char *s = name;
+  while (*s)
+    *d++ = (*s == '\\') ? '/' : *s++;
+  *d = '\0';
+  return true;
+}
+
+sem_t *
+sem_open (const char *name, int oflag, ...)
+{
+  mode_t mode = 0;
+  unsigned int value = 0;
+  if (oflag & O_CREAT)
+    {
+      va_list ap;
+      va_start (ap, oflag);
+      mode = va_arg (ap, mode_t);
+      value = va_arg (ap, unsigned int);
+      va_end (ap);
+    }
+  char mangled_name[MAX_PATH + 1];
+  if (!mangle_sem_name (mangled_name, name))
+    return NULL;
+  return semaphore::open (mangled_name, oflag, mode, value);
+}
+
+int
+sem_close (sem_t * sem)
+{
+  return semaphore::destroy (sem);
+}
+
 int
 sem_wait (sem_t * sem)
 {
@@ -169,10 +220,22 @@ sem_trywait (sem_t * sem)
   return semaphore::trywait (sem);
 }
 
+int
+sem_timedwait (sem_t * sem, const struct timespec *abstime)
+{
+  return semaphore::timedwait (sem, abstime);
+}
+
 int
 sem_post (sem_t * sem)
 {
   return semaphore::post (sem);
 }
 
+int
+sem_getvalue (sem_t * sem, int *sval)
+{
+  return semaphore::getvalue (sem, sval);
+}
+
 }