!932 fix wirte optimization which fail to write pipe

Merge pull request !932 from Wang Yaofeng/write_optimization_come_back

libc-test/src/functionalext/supplement/stdio/fwrite.c

@@ -14,6 +14,9 @@
  */
 
 #include "functionalext.h"
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdlib.h>
 
 const char *path = "/data/test.txt";
 
@@ -71,10 +74,42 @@ void fwrite_0300(void)
     remove(path);
 }
 
+void fwrite_0400(void)
+{
+    pid_t childPid = 0;
+    int fds[2] = {0};
+    pipe(fds);
+    int pipeRead = 0;
+    int pipeWrite = 1;
+
+    char buf[1024] = {0};
+
+    childPid = fork();
+    EXPECT_NE("fwrite_0400", childPid, -1);
+    if (childPid == 0) {
+        // childr
+        dup2(fds[pipeWrite], STDOUT_FILENO);
+        dup2(fds[pipeRead], STDIN_FILENO);
+
+        close(fds[pipeWrite]);
+        close(fds[pipeRead]);
+
+        // exec
+        execl("/bin/sh", "/bin/sh", "-c", "/system/bin/bm get -u", NULL);
+        exit(0);
+    } else {
+        // parent
+        close(fds[pipeWrite]);
+        fcntl(fds[pipeRead], F_SETFD, F_DUPFD_CLOEXEC);
+        int cn = read(fds[pipeRead], buf, sizeof(buf));
+        EXPECT_MT("fwrite_0400", cn, 0);
+    }
+}
+
 int main(int argc, char *argv[])
 {
     fwrite_0100();
     fwrite_0200();
     fwrite_0300();
     return t_status;
-}
\ No newline at end of file
+}

musl_src.gni

@@ -2167,6 +2167,8 @@ musl_src_porting_file = [
   "src/stdio/__fdopen.c",
   "src/stdio/vfprintf.c",
   "src/stdio/__stdio_read.c",
+  "src/stdio/__stdio_write.c",
+  "src/stdio/__stdout_write.c",
   "src/stdio/fread.c",
   "src/stdio/fmemopen.c",
   "src/stdio/freopen.c",

porting/linux/user/src/internal/stdio_impl.h

@@ -63,6 +63,7 @@ hidden off_t __stdio_seek(FILE *, off_t, int);
 hidden int __stdio_close(FILE *);
 
 hidden int __fill_buffer(FILE *f);
+hidden ssize_t __flush_buffer(FILE *f);
 
 hidden int __toread(FILE *);
 hidden int __towrite(FILE *);

porting/linux/user/src/stdio/__stdio_write.c

+#include "stdio_impl.h"
+#include <sys/uio.h>
+#include <string.h>
+
+ssize_t __flush_buffer(FILE *f)
+{
+	ssize_t cnt = 0;
+	char *wbase = (char *)f->wbase;
+	size_t rem = f->wpos - f->wbase;
+	while (rem > 0) {
+		cnt = syscall(SYS_write, f->fd, wbase, rem);
+		if (cnt < 0) {
+			f->wpos = f->wbase = f->wend = 0;
+			f->flags |= F_ERR;
+			return cnt;
+		}
+		wbase += cnt;
+		rem -= cnt;
+	}
+
+	/* reset file buffer */
+	f->wend = f->buf + f->buf_size;
+	f->wpos = f->wbase = f->buf;
+	return cnt;
+}
+
+size_t __stdio_write(FILE *f, const unsigned char *buf, size_t len)
+{
+	size_t rem = len;
+	unsigned char *wbuf = (unsigned char *)buf;
+
+	/* flush buffer first */
+	ssize_t cnt = __flush_buffer(f);
+	if (cnt < 0) {
+		return 0;
+	}
+
+	for (;;) {
+		if (f->lbf < 0 && rem <= f->wend - f->wpos) {
+			memcpy(f->wpos, wbuf, rem);
+			f->wpos += rem;
+			return len;
+		}
+
+		/* write directly if
+		 * 1. file buffer < rem
+		 * 2. line buffer mode
+		 */
+		cnt = syscall(SYS_write, f->fd, wbuf, rem);
+		if (cnt < 0) {
+			f->wpos = f->wbase = f->wend = 0;
+			f->flags |= F_ERR;
+			return len - rem;
+		}
+
+		rem -= cnt;
+		wbuf += cnt;
+		if (rem == 0) {
+			break;
+		}
+	}
+
+	return len;
+}

porting/linux/user/src/stdio/__stdout_write.c

+#include "stdio_impl.h"
+#include <sys/ioctl.h>
+
+size_t __stdout_write(FILE *f, const unsigned char *buf, size_t len)
+{
+	struct winsize wsz;
+	f->write = __stdio_write;
+	/*
+	 * write directly at first time.
+	 * check f->flags & tty, and take effect later.
+	 */
+	size_t cnt = __stdio_write(f, buf, len);
+
+	if (!(f->flags & F_SVB) && __syscall(SYS_ioctl, f->fd, TIOCGWINSZ, &wsz))
+		f->lbf = -1;
+
+	return cnt;
+}