From: Angus Gratton <angus@espressif.com>
Date: Tue, 23 Aug 2016 09:10:52 +0000 (+0800)
Subject: Add hack of explicitly locking stdout
X-Git-Tag: v0.9~71^2~10
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=94104f0fe87f97dd3289110d087eee54154146aa;p=esp-idf

Add hack of explicitly locking stdout

This shouldn't be necessary as stdout is already locked by libc (see
comment.) Not sure which part isn't working.
---

diff --git a/components/esp32/syscalls.c b/components/esp32/syscalls.c
index a087c2caaa..8978154240 100644
--- a/components/esp32/syscalls.c
+++ b/components/esp32/syscalls.c
@@ -138,6 +138,13 @@ int _open_r(struct _reent *r, const char * path, int flags, int mode) {
 ssize_t _write_r(struct _reent *r, int fd, const void * data, size_t size) {
     const char* p = (const char*) data;
     if (fd == STDOUT_FILENO) {
+        /* THIS IS A HACK!!! The stdout "file" should be locked while
+           this code is called (it's locked fflush.c:280 before
+           __sflush_r is called.) It shouldn't be necessary to
+           re-lock, but due to some unknown bug it is...
+        */
+        static _lock_t stdout_lock;
+        _lock_acquire_recursive(&stdout_lock);
         while(size--) {
 #if CONFIG_NEWLIB_STDOUT_ADDCR
             if (*p=='\n') {
@@ -147,6 +154,7 @@ ssize_t _write_r(struct _reent *r, int fd, const void * data, size_t size) {
             uart_tx_one_char(*p);
             ++p;
         }
+        _lock_release_recursive(&stdout_lock);
     }
     return size;
 }