simplify and optimize FILE lock handling

diff --git a/src/internal/stdio_impl.h b/src/internal/stdio_impl.h
index 4e6d350..b977df6 100644 (file)
--- a/src/internal/stdio_impl.h
+++ b/src/internal/stdio_impl.h
@@ -23,8 +23,8 @@
 
 #define UNGET 4
 
 
 #define UNGET 4
 

-#define FLOCK(f) ((libc.lockfile && (f)->owner>=0) ? (libc.lockfile((f)),0) : 0)
-#define FUNLOCK(f) ((f)->lockcount && (--(f)->lockcount || ((f)->owner=(f)->lock=0)))
+#define FLOCK(f) ((libc.lockfile && (f)->lock>=0) ? (libc.lockfile((f)),0) : 0)
+#define FUNLOCK(f) ((f)->lockcount && (--(f)->lockcount || ((f)->lock=0)))

 
 #define F_PERM 1
 #define F_NORD 4
 
 #define F_PERM 1
 #define F_NORD 4


@@ -59,7 +59,6 @@ struct __FILE_s {
        off_t (*seek)(FILE *, off_t, int);
        int mode;
        int (*close)(FILE *);
        off_t (*seek)(FILE *, off_t, int);
        int mode;
        int (*close)(FILE *);

-       int owner;

 };
 
 size_t __stdio_read(FILE *, unsigned char *, size_t);
 };
 
 size_t __stdio_read(FILE *, unsigned char *, size_t);

diff --git a/src/stdio/__lockfile.c b/src/stdio/__lockfile.c
index e4320f0..93c9486 100644 (file)
--- a/src/stdio/__lockfile.c
+++ b/src/stdio/__lockfile.c
@@ -3,17 +3,18 @@
 
 void __lockfile(FILE *f)
 {
 
 void __lockfile(FILE *f)
 {

-       int spins;
-       if (f->owner < 0) return;
-       if (f->owner && f->owner == __pthread_self()->tid) {
+       int spins=100000;
+       int tid;
+
+       if (f->lock < 0) return;
+       tid = __pthread_self()->tid;
+       if (f->lock == tid) {

                while (f->lockcount == INT_MAX);
                f->lockcount++;
                return;
        }
                while (f->lockcount == INT_MAX);
                f->lockcount++;
                return;
        }

-       spins = 100000;
-       while (a_swap(&f->lock, 1))
+       while (f->lock || a_cas(&f->lock, 0, tid))

                if (spins) spins--, a_spin();
                else syscall(SYS_sched_yield);
                if (spins) spins--, a_spin();
                else syscall(SYS_sched_yield);

-       f->owner = __pthread_self()->tid;

        f->lockcount = 1;
 }
        f->lockcount = 1;
 }

diff --git a/src/stdio/ftrylockfile.c b/src/stdio/ftrylockfile.c
index 1d0a1ff..67f4b6a 100644 (file)
--- a/src/stdio/ftrylockfile.c
+++ b/src/stdio/ftrylockfile.c
@@ -3,16 +3,16 @@
 
 int ftrylockfile(FILE *f)
 {
 
 int ftrylockfile(FILE *f)
 {

+       int tid = pthread_self()->tid;

        if (!libc.lockfile) libc.lockfile = __lockfile;
        if (!libc.lockfile) libc.lockfile = __lockfile;

-       if (f->owner && f->owner == pthread_self()->tid) {
+       if (f->lock == tid) {

                if (f->lockcount == INT_MAX)
                        return -1;
                f->lockcount++;
                return 0;
        }
                if (f->lockcount == INT_MAX)
                        return -1;
                f->lockcount++;
                return 0;
        }

-       if (a_swap(&f->lock, 1))
+       if (f->lock || a_cas(&f->lock, 0, tid))

                return -1;
                return -1;

-       f->owner = pthread_self()->tid;

        f->lockcount = 1;
        return 0;
 }
        f->lockcount = 1;
        return 0;
 }

diff --git a/src/stdio/vsnprintf.c b/src/stdio/vsnprintf.c
index ff792e1..5d3f0c5 100644 (file)
--- a/src/stdio/vsnprintf.c
+++ b/src/stdio/vsnprintf.c
@@ -17,7 +17,7 @@ int vsnprintf(char *s, size_t n, const char *fmt, va_list ap)
        f.write = sn_write;
        f.buf_size = 1;
        f.buf = buf;
        f.write = sn_write;
        f.buf_size = 1;
        f.buf = buf;

-       f.owner = -1;
+       f.lock = -1;

        if (n > INT_MAX) {
                errno = EOVERFLOW;
                return -1;
        if (n > INT_MAX) {
                errno = EOVERFLOW;
                return -1;

diff --git a/src/stdio/vswprintf.c b/src/stdio/vswprintf.c
index 4ad581f..31ea187 100644 (file)
--- a/src/stdio/vswprintf.c
+++ b/src/stdio/vswprintf.c
@@ -32,7 +32,7 @@ int vswprintf(wchar_t *s, size_t n, const wchar_t *fmt, va_list ap)
        f.write = sw_write;
        f.buf_size = sizeof buf;
        f.buf = buf;
        f.write = sw_write;
        f.buf_size = sizeof buf;
        f.buf = buf;

-       f.owner = -1;
+       f.lock = -1;

        f.cookie = &c;
        if (!n) {
                return -1;
        f.cookie = &c;
        if (!n) {
                return -1;