Fixed bug reported by Stuart Midgley about what happens when there are no

[awesomized/libmemcached] / lib / memcached_io.c

diff --git a/lib/memcached_io.c b/lib/memcached_io.c
index 9277b6ba3a883a387829acc9130046843f3756f4..54844be445956547705d779bc1eb30934a4b0f1d 100644 (file)
--- a/lib/memcached_io.c
+++ b/lib/memcached_io.c
@@ -5,84 +5,85 @@
 #include "common.h"
 #include "memcached_io.h"
 #include <sys/select.h>
+#include <poll.h>
+
+static int io_wait(memcached_st *ptr, unsigned int server_key, unsigned read_or_write)
+{
+  struct pollfd fds[1];
+  short flags= 0;
+
+  if (read_or_write)
+    flags= POLLOUT |  POLLERR;
+  else
+    flags= POLLIN | POLLERR;
+
+  memset(&fds, 0, sizeof(struct pollfd));
+  fds[0].fd= ptr->hosts[server_key].fd;
+  fds[0].events= flags;
+
+  if (poll(fds, 1, -1) < 0)
+    return MEMCACHED_FAILURE;
+
+  return MEMCACHED_SUCCESS;
+}
 
 ssize_t memcached_io_read(memcached_st *ptr, unsigned  int server_key,
                           char *buffer, size_t length)
 {
-  size_t x;
   char *buffer_ptr;
 
   buffer_ptr= buffer;
 
-  for (x= 0, buffer_ptr= buffer; 
-       x < length; x++)
+  while (length)
   {
     if (!ptr->read_buffer_length)
     {
-      if (length > 1)
-      {
+      size_t data_read;
 
-        size_t data_read;
-        data_read= recv(ptr->hosts[server_key].fd, 
-                        buffer_ptr, 
-                        length - x, 0);
-        if (data_read == -1)
-        {
-          return -1;
-        }
-        if (data_read == 0)
-          return x;
-
-        data_read+= x;
-
-        return data_read;
-      }
-      else
+      while (1)
       {
-        size_t data_read;
-try_again:
-
         if (ptr->flags & MEM_NO_BLOCK)
         {
-          struct timeval local_tv;
-          fd_set set;
+          memcached_return rc;
 
-          memset(&local_tv, 0, sizeof(struct timeval));
-
-          local_tv.tv_sec= 0;
-          local_tv.tv_usec= 300;
-
-          FD_ZERO(&set);
-          FD_SET(ptr->hosts[server_key].fd, &set);
-
-          select(1, &set, NULL, NULL, &local_tv);
+          rc= io_wait(ptr, server_key, 0);
+          if (rc != MEMCACHED_SUCCESS)
+            return -1;
         }
 
-        data_read= recv(ptr->hosts[server_key].fd, 
+        data_read= read(ptr->hosts[server_key].fd, 
                         ptr->read_buffer, 
-                        MEMCACHED_MAX_BUFFER, 0);
+                        MEMCACHED_MAX_BUFFER);
         if (data_read == -1)
         {
-          if (errno == EAGAIN)
-            goto try_again;
-          return -1;
+          switch (errno)
+          {
+          case EAGAIN:
+            break;
+          default:
+            {
+              ptr->cached_errno= errno;
+              return -1;
+            }
+          }
         }
-        ptr->read_buffer_length= data_read;
-        ptr->read_ptr= ptr->read_buffer;
+        else if (data_read)
+          break;
+        /* If zero, just keep looping */
       }
 
-      if (ptr->read_buffer_length == -1)
-        return -1;
-      if (ptr->read_buffer_length == 0)
-        return x;
+      ptr->read_buffer_length= data_read;
+      ptr->read_ptr= ptr->read_buffer;
     }
+
     *buffer_ptr= *ptr->read_ptr;
-    buffer_ptr++;
+    length--;
     ptr->read_ptr++;
     ptr->read_buffer_length--;
+    buffer_ptr++;
   }
 
-  return length;
+  return (size_t)(buffer_ptr - buffer);
 }
 
 ssize_t memcached_io_write(memcached_st *ptr, unsigned int server_key,
@@ -101,13 +102,16 @@ ssize_t memcached_io_write(memcached_st *ptr, unsigned int server_key,
 
       sent_length= memcached_io_flush(ptr, server_key);
 
-      assert(sent_length == MEMCACHED_MAX_BUFFER);
+      WATCHPOINT_ASSERT(sent_length == MEMCACHED_MAX_BUFFER);
       ptr->write_buffer_offset= 0;
     }
   }
 
   if (with_flush)
-    memcached_io_flush(ptr, server_key);
+  {
+    if (memcached_io_flush(ptr, server_key) == -1)
+      return -1;
+  }
 
   return length;
 }
@@ -115,34 +119,58 @@ ssize_t memcached_io_write(memcached_st *ptr, unsigned int server_key,
 ssize_t memcached_io_flush(memcached_st *ptr, unsigned int server_key)
 {
   size_t sent_length;
+  size_t return_length;
+  char *write_ptr= ptr->write_buffer;
+  size_t write_length= ptr->write_buffer_offset;
+  unsigned int loop= 1;
 
   if (ptr->write_buffer_offset == 0)
     return 0;
 
-  if (ptr->flags & MEM_NO_BLOCK)
+  return_length= 0;
+  while (write_length)
   {
-    struct timeval local_tv;
-    fd_set set;
+    if (ptr->flags & MEM_NO_BLOCK)
+    {
+      memcached_return rc;
 
-    local_tv.tv_sec= 0;
-    local_tv.tv_usec= 300;
+      rc= io_wait(ptr, server_key, 1);
+      if (rc != MEMCACHED_SUCCESS)
+        return -1;
+    }
 
-    FD_ZERO(&set);
-    FD_SET(ptr->hosts[server_key].fd, &set);
+    sent_length= 0;
+    if ((ssize_t)(sent_length= write(ptr->hosts[server_key].fd, write_ptr, 
+                                     write_length)) == -1)
+    {
+      switch (errno)
+      {
+      case ENOBUFS:
+      case EAGAIN:
+        WATCHPOINT;
+        continue;
+        if (loop < 100)
+        {
+          loop++;
+          break;
+        }
+        /* Yes, we want to fall through */
+      default:
+        ptr->cached_errno= errno;
+        return -1;
+      }
+    }
 
-    select(1, NULL, &set, NULL, &local_tv);
-  }
-  if ((sent_length= send(ptr->hosts[server_key].fd, ptr->write_buffer, 
-                         ptr->write_buffer_offset, 0)) == -1)
-  {
-    return -1;
+    write_ptr+= sent_length;
+    write_length-= sent_length;
+    return_length+= sent_length;
   }
 
-  assert(sent_length == ptr->write_buffer_offset);
-
+  WATCHPOINT_ASSERT(write_length == 0);
+  WATCHPOINT_ASSERT(return_length == ptr->write_buffer_offset);
   ptr->write_buffer_offset= 0;
 
-  return sent_length;
+  return return_length;
 }
 
 /*