开启后则文件系统会调用fatfs为重入所做的文件互斥访问函数,与系统等待时间相关的仅为下面的函数。
#if _FS_REENTRANT
/* This function is called on entering file functions to lock the volume.
/ When a FALSE is returned, the file function fails with FR_TIMEOUT.
*/
int ff_req_grant ( /* TRUE:Got a grant to access the volume, FALSE:Could not get a grant */
_SYNC_t sobj /* Sync object to wait */
)
{
int ret;
ret = (int)(xSemaphoreTake(sobj, _FS_TIMEOUT) == pdTRUE); /* FreeRTOS */