tRidiculous amount of work for OpenBSD. - plan9port - [fork] Plan 9 from user space
(HTM) git clone git://src.adamsgaard.dk/plan9port
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---
(DIR) commit b20b42b837d396112c0bf08e610bc3e074f673b4
(DIR) parent c15ce40c4456d3bb6d44092bb22097ad93768c3a
(HTM) Author: rsc <devnull@localhost>
Date: Wed, 10 Aug 2005 18:48:31 +0000
Ridiculous amount of work for OpenBSD.
Diffstat:
M src/libthread/BSD.c | 7 -------
M src/libthread/FreeBSD.c | 6 ++++++
M src/libthread/OpenBSD.c | 164 ++++++++++++++++++++++++++++++-
3 files changed, 168 insertions(+), 9 deletions(-)
---
(DIR) diff --git a/src/libthread/BSD.c b/src/libthread/BSD.c
t@@ -397,13 +397,6 @@ _threadsetproc(Proc *p)
}
void
-_pthreadinit(void)
-{
- __isthreaded = 1;
- signal(SIGUSR2, sigusr2handler);
-}
-
-void
_threadpexit(void)
{
_exit(0);
(DIR) diff --git a/src/libthread/FreeBSD.c b/src/libthread/FreeBSD.c
t@@ -41,3 +41,9 @@ swapcontext(ucontext_t *oucp, ucontext_t *ucp)
return 0;
}
+void
+_pthreadinit(void)
+{
+ __isthreaded = 1;
+ signal(SIGUSR2, sigusr2handler);
+}
(DIR) diff --git a/src/libthread/OpenBSD.c b/src/libthread/OpenBSD.c
t@@ -1,8 +1,32 @@
#include "threadimpl.h"
-
#include "BSD.c"
-static spinlock_t mlock = { 0, 0, NULL, 0 };
+#include <dlfcn.h>
+
+#define MIN(a,b) ((a) < (b) ? (a) : (b))
+#define MAX(a,b) ((a) > (b) ? (a) : (b))
+
+enum {
+ FD_READ = 1,
+ FD_WRITE,
+ FD_RDWR,
+ FDTBL_MAXSIZE = 128
+};
+
+struct fd_entry {
+ QLock lock;
+ int fd;
+ int id;
+ short rc;
+ short wc;
+ short ref;
+};
+
+static struct fd_entry fd_entry1 = { .fd -1 };
+static struct fd_entry *fd_table = nil;
+static spinlock_t fd_table_lock = { 0, 0, nil, 0 };
+static spinlock_t mlock = { 0, 0, nil, 0 };
+static spinlock_t dl_lock = { 0, 0, nil, 0 };
void
_thread_malloc_lock(void)
t@@ -20,3 +44,139 @@ void
_thread_malloc_init(void)
{
}
+
+/*
+ * Must set errno on failure because the return value
+ * of _thread_fd_entry is propagated back to the caller
+ * of the thread-wrapped libc function.
+ */
+static struct fd_entry *
+_thread_fd_lookup(int fd)
+{
+ struct fd_entry *t;
+ static int cursize;
+ int newsize;
+
+ if(fd >= FDTBL_MAXSIZE) {
+ errno = EBADF;
+ return nil;
+ }
+
+ /*
+ * There are currently only a few libc functions using
+ * _thread_fd_*, which are rarely called by P9P programs.
+ * So the contention for these locks is very small and so
+ * far have usually been limited to a single fd. So
+ * rather than malloc the fd_table everytime we just use
+ * a single fd_entry until a lock request for another fd
+ * comes in.
+ */
+ if(fd_table == nil)
+ if(fd_entry1.fd == -1) {
+ fd_entry1.fd = fd;
+ return &fd_entry1;
+ } else if(fd_entry1.fd == fd)
+ return &fd_entry1;
+ else {
+ cursize = MAX(fd_entry1.fd, 16);
+ fd_table = malloc(cursize*sizeof(fd_table[0]));
+ if(fd_table == nil) {
+ errno = ENOMEM;
+ return nil;
+ }
+ memset(fd_table, 0, cursize*sizeof(fd_table[0]));
+ fd_table[fd_entry1.fd] = fd_entry1;
+ }
+ if(fd > cursize) {
+ newsize = MIN(cursize*2, FDTBL_MAXSIZE);
+ t = realloc(fd_table, newsize*sizeof(fd_table[0]));
+ if(t == nil) {
+ errno = ENOMEM;
+ return nil;
+ }
+ fd_table = t;
+ cursize = newsize;
+ memset(fd_table, 0, cursize*sizeof(fd_table[0]));
+ }
+
+ return &fd_table[fd];
+}
+
+/*
+ * Mutiple readers just share the lock by incrementing the read count.
+ * Writers must obtain an exclusive lock.
+ */
+int
+_thread_fd_lock(int fd, int type, struct timespec *time)
+{
+ struct fd_entry *fde;
+ int id;
+
+ _spinlock(&fd_table_lock);
+ fde = _thread_fd_lookup(fd);
+ if(fde == nil)
+ return -1;
+
+ if(type == FD_READ) {
+ if(fde->rc++ >= 1 && fde->wc == 0) {
+ _spinunlock(&fd_table_lock);
+ return 0;
+ }
+ } else
+ fde->wc++;
+ _spinunlock(&fd_table_lock);
+
+ /* handle recursion */
+ id = proc()->osprocid;
+ if(id == fde->id) {
+ fde->ref++;
+ return 0;
+ }
+
+ qlock(&fde->lock);
+ fde->id = id;
+ return 0;
+}
+
+void
+_thread_fd_unlock(int fd, int type)
+{
+ struct fd_entry *fde;
+ int id;
+
+ fde = _thread_fd_lookup(fd);
+ if(fde == nil) {
+ fprint(2, "_thread_fd_unlock: fd %d not in table!\n", fd);
+ return;
+ }
+
+ if(type == FD_READ && --fde->rc >= 1)
+ return;
+ else
+ fde->wc--;
+
+ id = proc()->osprocid;
+ if(id == fde->id && fde->ref > 0) {
+ fde->ref--;
+ return;
+ }
+ fde->id = 0;
+ qunlock(&fde->lock);
+}
+
+void
+_thread_dl_lock(int t)
+{
+ if(t)
+ _spinunlock(&dl_lock);
+ else
+ _spinlock(&dl_lock);
+}
+
+void
+_pthreadinit(void)
+{
+ __isthreaded = 1;
+ dlctl(nil, DL_SETTHREADLCK, _thread_dl_lock);
+ signal(SIGUSR2, sigusr2handler);
+}