[MEDIUM] fd: merge fd_list into fdtab

The fd_list[] used by sepoll was indexed on the fd number and was only
used to store the equivalent of an integer. Changing it to be merged
with fdtab reduces the number of pointer computations, the code size
and some initialization steps. It does not harm other pollers much
either, as only one integer was added to the fdtab array.

diff --git a/include/types/fd.h b/include/types/fd.h
index 63c59eead72fce669cf60cbcfdf31ecd4edfd1a5..f69886354b6abccb2aa8e3972fb8896edc109fbb 100644 (file)
--- a/include/types/fd.h
+++ b/include/types/fd.h
@@ -72,6 +72,10 @@ struct fdtab {
                struct buffer *b;            /* read/write buffer */
        } cb[DIR_SIZE];
        void *owner;                         /* the session (or proxy) associated with this fd */
+       struct {                             /* used by pollers which support speculative polling */
+               unsigned char e;             /* read and write events status. 4 bits, may be merged into flags' lower bits */
+               unsigned int s1;             /* Position in spec list+1. 0=not in list. */
+       } spec;
        unsigned short flags;                /* various flags precising the exact status of this fd */
        unsigned char state;                 /* the state of this fd */
        unsigned char ev;                    /* event seen in return of poll() : FD_POLL_* */

diff --git a/src/ev_sepoll.c b/src/ev_sepoll.c
index 5c27dbd83b7f80a2c0c086082853fb7581297def..248f1f4c7d0e981e07d8520c5019c6e4a9664fb7 100644 (file)
--- a/src/ev_sepoll.c
+++ b/src/ev_sepoll.c
@@ -1,7 +1,7 @@
 /*
  * FD polling functions for Speculative I/O combined with Linux epoll()
  *
- * Copyright 2000-2008 Willy Tarreau <w@1wt.eu>
+ * Copyright 2000-2009 Willy Tarreau <w@1wt.eu>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -149,18 +149,10 @@ static _syscall4 (int, epoll_wait, int, epfd, struct epoll_event *, events, int,
  */
 #define MIN_RETURN_EVENTS      25
 
-/* descriptor of one FD.
- * FIXME: should be a bit field */
-struct fd_status {
-       unsigned int e:4;       // read and write events status.
-       unsigned int s1:28;     // Position in spec list+1. 0=not in list. Should be last.
-};
-
 static int nbspec = 0;          // current size of the spec list
 static int absmaxevents = 0;    // absolute maximum amounts of polled events
 static int fd_created = 0;      // fd creation detector, reset upon poll() entry.
 
-static struct fd_status *fd_list = NULL;       // list of FDs
 static unsigned int *spec_list = NULL; // speculative I/O list
 
 /* private data */
@@ -175,27 +167,27 @@ static struct epoll_event ev;
 
 REGPRM1 static inline void alloc_spec_entry(const int fd)
 {
-       if (fd_list[fd].s1)
+       if (fdtab[fd].spec.s1)
                /* sometimes the entry already exists for the other direction */
                return;
-       fd_list[fd].s1 = nbspec + 1;
+       fdtab[fd].spec.s1 = nbspec + 1;
        spec_list[nbspec] = fd;
        nbspec++;
 }
 
 /* Removes entry used by fd <fd> from the spec list and replaces it with the
- * last one. The fd_list is adjusted to match the back reference if needed.
+ * last one. The fdtab.spec is adjusted to match the back reference if needed.
  * If the fd has no entry assigned, return immediately.
  */
 REGPRM1 static void release_spec_entry(int fd)
 {
        unsigned int pos;
 
-       pos = fd_list[fd].s1;
+       pos = fdtab[fd].spec.s1;
        if (!pos)
                return;
 
-       fd_list[fd].s1 = 0;
+       fdtab[fd].spec.s1 = 0;
        pos--;
        /* we have spec_list[pos]==fd */
 
@@ -205,8 +197,8 @@ REGPRM1 static void release_spec_entry(int fd)
 
        /* we replace current FD by the highest one, which may sometimes be the same */
        fd = spec_list[nbspec];
-       fd_list[fd].s1 = pos + 1;
        spec_list[pos] = fd;
+       fdtab[fd].spec.s1 = pos + 1;
 }
 
 /*
@@ -222,7 +214,7 @@ REGPRM2 static int __fd_is_set(const int fd, int dir)
                ABORT_NOW();
        }
 #endif
-       ret = ((unsigned)fd_list[fd].e >> dir) & FD_EV_MASK_DIR;
+       ret = ((unsigned)fdtab[fd].spec.e >> dir) & FD_EV_MASK_DIR;
        return (ret == FD_EV_SPEC || ret == FD_EV_WAIT);
 }
 
@@ -240,7 +232,7 @@ REGPRM2 static int __fd_set(const int fd, int dir)
                ABORT_NOW();
        }
 #endif
-       i = ((unsigned)fd_list[fd].e >> dir) & FD_EV_MASK_DIR;
+       i = ((unsigned)fdtab[fd].spec.e >> dir) & FD_EV_MASK_DIR;
 
        if (i != FD_EV_STOP) {
                if (unlikely(i != FD_EV_IDLE))
@@ -249,7 +241,7 @@ REGPRM2 static int __fd_set(const int fd, int dir)
                fd_created++;
                alloc_spec_entry(fd);
        }
-       fd_list[fd].e ^= (unsigned int)(FD_EV_IN_SL << dir);
+       fdtab[fd].spec.e ^= (unsigned int)(FD_EV_IN_SL << dir);
        return 1;
 }
 
@@ -263,7 +255,7 @@ REGPRM2 static int __fd_clr(const int fd, int dir)
                ABORT_NOW();
        }
 #endif
-       i = ((unsigned)fd_list[fd].e >> dir) & FD_EV_MASK_DIR;
+       i = ((unsigned)fdtab[fd].spec.e >> dir) & FD_EV_MASK_DIR;
 
        if (i != FD_EV_SPEC) {
                if (unlikely(i != FD_EV_WAIT))
@@ -275,7 +267,7 @@ REGPRM2 static int __fd_clr(const int fd, int dir)
                 */
                alloc_spec_entry(fd);
        }
-       fd_list[fd].e ^= (unsigned int)(FD_EV_IN_SL << dir);
+       fdtab[fd].spec.e ^= (unsigned int)(FD_EV_IN_SL << dir);
        return 1;
 }
 
@@ -293,7 +285,7 @@ REGPRM1 static void __fd_rem(int fd)
 REGPRM1 static void __fd_clo(int fd)
 {
        release_spec_entry(fd);
-       fd_list[fd].e &= ~(FD_EV_MASK);
+       fdtab[fd].spec.e &= ~(FD_EV_MASK);
 }
 
 /*
@@ -326,7 +318,7 @@ REGPRM2 static void _do_poll(struct poller *p, int exp)
 
                spec_idx--;
                fd = spec_list[spec_idx];
-               eo = fd_list[fd].e;  /* save old events */
+               eo = fdtab[fd].spec.e;  /* save old events */
 
                if (looping && --fd_created < 0) {
                        /* we were just checking the newly created FDs */
@@ -344,8 +336,8 @@ REGPRM2 static void _do_poll(struct poller *p, int exp)
 
 #ifdef DEBUG_DEV
                if (fdtab[fd].state == FD_STCLOSE) {
-                       fprintf(stderr,"fd=%d, fdtab[].ev=%x, fd_list[].e=%x, .s=%d, idx=%d\n",
-                               fd, fdtab[fd].ev, fd_list[fd].e, fd_list[fd].s1, spec_idx);
+                       fprintf(stderr,"fd=%d, fdtab[].ev=%x, fdtab[].spec.e=%x, .s=%d, idx=%d\n",
+                               fd, fdtab[fd].ev, fdtab[fd].spec.e, fdtab[fd].spec.s1, spec_idx);
                }
 #endif
                done = 0;
@@ -356,14 +348,14 @@ REGPRM2 static void _do_poll(struct poller *p, int exp)
                                /* Pretend there is something to read */
                                fdtab[fd].ev |= FD_POLL_IN;
                                if (!fdtab[fd].cb[DIR_RD].f(fd))
-                                       fd_list[fd].e ^= (FD_EV_WAIT_R ^ FD_EV_SPEC_R);
+                                       fdtab[fd].spec.e ^= (FD_EV_WAIT_R ^ FD_EV_SPEC_R);
                                else
                                        done = 1;
                        }
                }
                else if ((eo & FD_EV_MASK_R) == FD_EV_STOP_R) {
                        /* This FD was being polled and is now being removed. */
-                       fd_list[fd].e &= ~FD_EV_MASK_R;
+                       fdtab[fd].spec.e &= ~FD_EV_MASK_R;
                }
                
                if ((eo & FD_EV_MASK_W) == FD_EV_SPEC_W) {
@@ -372,14 +364,14 @@ REGPRM2 static void _do_poll(struct poller *p, int exp)
                                /* Pretend there is something to write */
                                fdtab[fd].ev |= FD_POLL_OUT;
                                if (!fdtab[fd].cb[DIR_WR].f(fd))
-                                       fd_list[fd].e ^= (FD_EV_WAIT_W ^ FD_EV_SPEC_W);
+                                       fdtab[fd].spec.e ^= (FD_EV_WAIT_W ^ FD_EV_SPEC_W);
                                else
                                        done = 1;
                        }
                }
                else if ((eo & FD_EV_MASK_W) == FD_EV_STOP_W) {
                        /* This FD was being polled and is now being removed. */
-                       fd_list[fd].e &= ~FD_EV_MASK_W;
+                       fdtab[fd].spec.e &= ~FD_EV_MASK_W;
                }
 
                status += done;
@@ -393,9 +385,9 @@ REGPRM2 static void _do_poll(struct poller *p, int exp)
                 * have opposite changes for READ and WRITE too.
                 */
 
-               if ((eo ^ fd_list[fd].e) & FD_EV_RW_PL) {
+               if ((eo ^ fdtab[fd].spec.e) & FD_EV_RW_PL) {
                        /* poll status changed*/
-                       if ((fd_list[fd].e & FD_EV_RW_PL) == 0) {
+                       if ((fdtab[fd].spec.e & FD_EV_RW_PL) == 0) {
                                /* fd removed from poll list */
                                opcode = EPOLL_CTL_DEL;
                        }
@@ -410,10 +402,10 @@ REGPRM2 static void _do_poll(struct poller *p, int exp)
 
                        /* construct the epoll events based on new state */
                        ev.events = 0;
-                       if (fd_list[fd].e & FD_EV_WAIT_R)
+                       if (fdtab[fd].spec.e & FD_EV_WAIT_R)
                                ev.events |= EPOLLIN;
 
-                       if (fd_list[fd].e & FD_EV_WAIT_W)
+                       if (fdtab[fd].spec.e & FD_EV_WAIT_W)
                                ev.events |= EPOLLOUT;
 
                        ev.data.fd = fd;
@@ -421,7 +413,7 @@ REGPRM2 static void _do_poll(struct poller *p, int exp)
                }
 
 
-               if (!(fd_list[fd].e & FD_EV_RW_SL)) {
+               if (!(fdtab[fd].spec.e & FD_EV_RW_SL)) {
                        /* This fd switched to combinations of either WAIT or
                         * IDLE. It must be removed from the spec list.
                         */
@@ -515,14 +507,14 @@ REGPRM2 static void _do_poll(struct poller *p, int exp)
                        ((e & EPOLLERR) ? FD_POLL_ERR : 0) |
                        ((e & EPOLLHUP) ? FD_POLL_HUP : 0);
                
-               if ((fd_list[fd].e & FD_EV_MASK_R) == FD_EV_WAIT_R) {
+               if ((fdtab[fd].spec.e & FD_EV_MASK_R) == FD_EV_WAIT_R) {
                        if (fdtab[fd].state == FD_STCLOSE || fdtab[fd].state == FD_STERROR)
                                continue;
                        if (fdtab[fd].ev & (FD_POLL_IN|FD_POLL_HUP|FD_POLL_ERR))
                                fdtab[fd].cb[DIR_RD].f(fd);
                }
 
-               if ((fd_list[fd].e & FD_EV_MASK_W) == FD_EV_WAIT_W) {
+               if ((fdtab[fd].spec.e & FD_EV_MASK_W) == FD_EV_WAIT_W) {
                        if (fdtab[fd].state == FD_STCLOSE || fdtab[fd].state == FD_STERROR)
                                continue;
                        if (fdtab[fd].ev & (FD_POLL_OUT|FD_POLL_ERR))
@@ -550,7 +542,7 @@ REGPRM2 static void _do_poll(struct poller *p, int exp)
  */
 REGPRM1 static int _do_init(struct poller *p)
 {
-       __label__ fail_fd_list, fail_spec, fail_ee, fail_fd;
+       __label__ fail_spec, fail_ee, fail_fd;
 
        p->private = NULL;
 
@@ -569,14 +561,8 @@ REGPRM1 static int _do_init(struct poller *p)
        if ((spec_list = (uint32_t *)calloc(1, sizeof(uint32_t) * global.maxsock)) == NULL)
                goto fail_spec;
 
-       fd_list = (struct fd_status *)calloc(1, sizeof(struct fd_status) * global.maxsock);
-       if (fd_list == NULL)
-               goto fail_fd_list;
-
        return 1;
 
- fail_fd_list:
-       free(spec_list);
  fail_spec:
        free(epoll_events);
  fail_ee:
@@ -593,7 +579,6 @@ REGPRM1 static int _do_init(struct poller *p)
  */
 REGPRM1 static void _do_term(struct poller *p)
 {
-       free(fd_list);
        free(spec_list);
        free(epoll_events);
 
@@ -602,7 +587,6 @@ REGPRM1 static void _do_term(struct poller *p)
                epoll_fd = -1;
        }
 
-       fd_list = NULL;
        spec_list = NULL;
        epoll_events = NULL;