Actually free Process fd_map entries when a file is closed...

amazingly we never did that before.  Caused us to run out of
file descriptors in twolf.

sim/process.cc:
    Add free_fd() method to free closed target fd in simulator fd map.
    Rename open_fd() to alloc_fd() for symmetry with free_fd().
sim/process.hh:
    Add free_fd() method to free closed target fd in simulator fd map.
    Rename open_fd() to alloc_fd() for symmetry with free_fd().
    Crank up MAX_FD while we're at it.
sim/syscall_emul.cc:
    Call free_fd() on process when target closes a file.
sim/syscall_emul.hh:
    Process open_fd() renamed to alloc_fd().

--HG--
extra : convert_revision : d780f4ccfd5a0989230b0afbdbd276212b87550c

1 files changed, 5 insertions, 2 deletions

diff --git a/sim/process.hh b/sim/process.hh
index 28c16a444..2116ef632 100644
--- a/sim/process.hh
+++ b/sim/process.hh
@@ -124,7 +124,7 @@ class Process : public SimObject
 
   private:
     // file descriptor remapping support
-    static const int MAX_FD = 100;	// max legal fd value
+    static const int MAX_FD = 256;	// max legal fd value
     int fd_map[MAX_FD+1];
 
   public:
@@ -146,7 +146,10 @@ class Process : public SimObject
     void dup_fd(int sim_fd, int tgt_fd);
 
     // generate new target fd for sim_fd
-    int open_fd(int sim_fd);
+    int alloc_fd(int sim_fd);
+
+    // free target fd (e.g., after close)
+    void free_fd(int tgt_fd);
 
     // look up simulator fd for given target fd
     int sim_fd(int tgt_fd);