Changeset 18301 for lang/c/mpio/trunk/mp/fdnotify_impl.h

Timestamp:

08/27/08 15:40:53 (4 months ago)

Author:

frsyuki

Message:

lang/c/mpio: re-implemented mp::fdnotify with readv() system call

Files:

• lang/c/mpio/trunk/mp/fdnotify_impl.h (modified) (3 diffs)

lang/c/mpio/trunk/mp/fdnotify_impl.h

@@ -17 +17 @@
 //
 
-#ifndef MP_FD_NOTIFY_IMPL_H__
-#define MP_FD_NOTIFY_IMPL_H__
+#ifndef MP_FDNOTIFY_IMPL_H__
+#define MP_FDNOTIFY_IMPL_H__
 
-#include <sys/types.h>
-#include <sys/uio.h>
-#include <unistd.h>
 #include <fcntl.h>
 #include <errno.h>
@@ -30 +27 @@
 
 template <typename NotifyObject>
-fdnotify<NotifyObject>::fdnotify() : m_pos(0)
+fdnotify<NotifyObject>::fdnotify() : m_head(m_iovec), m_tail(m_iovec)
 {
-        if( pipe(m_pipe) < 0 ) {
+        if( ::pipe(m_pipe) < 0 ) {
                 throw fdnotify_exception("can't create pipe");
         }
-        if( fcntl(m_pipe[PIPE_READ], F_SETFL, O_NONBLOCK) < 0 ) {
+        if( ::fcntl(m_pipe[0], F_SETFL, O_NONBLOCK) < 0 ) {
                 close(m_pipe[0]);
                 close(m_pipe[1]);
                 throw fdnotify_exception("can't set non-blocking mode");
+        }
+        struct iovec* p = m_iovec;
+        struct iovec* const endp = m_iovec + MP_FDNOTIFY_VECTOR_SIZE;
+        NotifyObject* b = (NotifyObject*)m_buffer;
+        for(; p != endp; ++p, ++b) {
+                p->iov_base = (char*)b;
+                p->iov_len = sizeof(NotifyObject);
         }
 }
@@ -50 +54 @@
 
 template <typename NotifyObject>
-bool fdnotify<NotifyObject>::try_receive(NotifyObject* result)
+inline bool fdnotify<NotifyObject>::try_receive(NotifyObject* result)
 {
-        ssize_t len = read(m_pipe[PIPE_READ], m_buffer + m_pos, sizeof(NotifyObject) - m_pos);
-        if( len < 0 ) {
-                if(errno == EAGAIN || errno == EINTR ) {
+        if(m_head < m_tail) {
+                *result = *((NotifyObject*)m_head->iov_base);
+                ++m_head;
+                return true;
+        } else {
+                return receive_next(result);
+        }
+}
+
+template <typename NotifyObject>
+inline void fdnotify<NotifyObject>::send(const NotifyObject& obj)
+{
+        ssize_t len = ::write(m_pipe[1], (void*)&obj, sizeof(NotifyObject));
+        if(len != sizeof(NotifyObject)) {
+                throw fdnotify_exception("write-side pipe is broken or closed");
+        }
+}
+
+template <typename NotifyObject>
+bool fdnotify<NotifyObject>::receive_next(NotifyObject* result)
+{
+        ssize_t len = ::readv(m_pipe[0], m_iovec, MP_FDNOTIFY_VECTOR_SIZE);
+        if(len < 0) {
+                if(errno == EAGAIN || errno == EINTR) {
                         return false;
                 } else {
                         throw fdnotify_exception("read-side pipe is broken");
                 }
-        } else if( len == 0 ) {
+        } else if(len == 0) {
                 throw fdnotify_exception("read-side pipe is closed");
         }
-
-        m_pos += len;
-        if( m_pos == sizeof(NotifyObject) ) {
-                *result = *reinterpret_cast<NotifyObject*>(m_buffer);
-                m_pos = 0;
-                return true;
+        if(static_cast<size_t>(len) > sizeof(NotifyObject)) {
+                m_head = m_iovec+1;
+                m_tail = (struct iovec*)(((char*)m_iovec) + len);
         }
-        return false;
-}
-
-
-template <typename NotifyObject>
-void fdnotify<NotifyObject>::send(const NotifyObject& obj)
-{
-        const char* p = reinterpret_cast<const char*>(&obj);
-        ssize_t len = ::write(m_pipe[PIPE_WRITE], p, sizeof(NotifyObject));
-        if( len < static_cast<ssize_t>(sizeof(NotifyObject)) ) {
-                if( len < 0 && errno != EINTR && errno != EAGAIN  ) {
-                        throw fdnotify_exception("write-side pipe is broken");
-                }
-                send_all(p, p + sizeof(NotifyObject) - len);
-        }
-}
-
-
-template <typename NotifyObject>
-void fdnotify<NotifyObject>::send_all(const char* p, const char* const endp)
-{
-        do {
-                ssize_t len = ::write(m_pipe[PIPE_WRITE], p, endp - p);
-                if( len < 0 ) {
-                        if( errno != EINTR && errno != EAGAIN ) {
-                                throw fdnotify_exception("write-side pipe is broken");
-                        }
-                } else if( len == 0 ) {
-                        throw fdnotify_exception("write-side pipe is closed");
-                } else {
-                        p += len;
-                }
-        } while( p < endp );
+        *result = *((NotifyObject*)m_iovec[0].iov_base);
+        return true;
 }