include fopen/fclose support

Calls to open() from within glibc cannot be intercepted (see <http://cygwin.com/ml/libc-alpha/2006-04/msg00094.html>); thus, include wrappers for fopen() and fclose() as well. This should possibly be done for fdopen() and freopen(), too, if there's need for it. [Patch corrected and original description translated by Julius Plenz] Signed-off-by: Julius Plenz <plenz@cis.fu-berlin.de>

include fopen/fclose support
241eade9 · Michael Weiser · Julius Plenz · 404fa61a · 241eade9
Commit 241eade9 authored Jul 11, 2012 by Michael Weiser Committed by Julius Plenz Jul 12, 2012
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nocache.c nocache.c +25 -0

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--- a/nocache.c
+++ b/nocache.c
@@ -33,6 +33,10 @@ int __openat_2(int dirfd, const char *pathname, int flags, mode_t mode)
 int dup(int oldfd);
 int dup2(int oldfd, int newfd);
 int close(int fd);
+FILE *fopen(const char *path, const char *mode);
+FILE *fopen64(const char *path, const char *mode)
+    __attribute__ ((alias ("fopen")));
+int fclose(FILE *fp);

 int (*_original_open)(const char *pathname, int flags, mode_t mode);
 int (*_original_creat)(const char *pathname, int flags, mode_t mode);
@@ -40,6 +44,8 @@ int (*_original_openat)(int dirfd, const char *pathname, int flags, mode_t mode)
 int (*_original_dup)(int fd);
 int (*_original_dup2)(int newfd, int oldfd);
 int (*_original_close)(int fd);
+FILE *(*_original_fopen)(const char *path, const char *mode);
+int (*_original_fclose)(FILE *fp);

 #define _MAX_FDS 1024

@@ -65,6 +71,9 @@ static void init(void)
    _original_dup = (int (*)(int)) dlsym(RTLD_NEXT, "dup");
    _original_dup2 = (int (*)(int, int)) dlsym(RTLD_NEXT, "dup2");
    _original_close = (int (*)(int)) dlsym(RTLD_NEXT, "close");
+    _original_fopen = (FILE *(*)(const char *, const char *)) dlsym(RTLD_NEXT, "fopen");
+    _original_fclose = (int (*)(FILE *)) dlsym(RTLD_NEXT, "fclose");
+
    PAGESIZE = getpagesize();
    for(i = 0; i < _MAX_FDS; i++)
        fds[i].fd = -1;
@@ -166,6 +175,22 @@ int close(int fd)
    return _original_close(fd);
 }

+FILE *fopen(const char *path, const char *mode)
+{
+    int fd;
+    FILE *fp;
+    if((fp = _original_fopen(path, mode)) != NULL)
+        if((fd = fileno(fp)) != -1)
+            store_pageinfo(fd);
+    return fp;
+}
+
+int fclose(FILE *fp)
+{
+    free_unclaimed_pages(fileno(fp));
+    return _original_fclose(fp);
+}
+
 static void store_pageinfo(int fd)
 {
    int i;