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Set blocking/non-blocking mode on a stream
(PHP 4 >= 4.3.0, PHP 5)
If mode is 0, the given stream will be switched to non-blocking mode, and if 1, it will be switched to blocking mode. This affects calls like fgets() and fread() that read from the stream. In non-blocking mode an fgets() call will always return right away while in blocking mode it will wait for data to become available on the stream.
Returns This function was previously called as set_socket_blocking() and later socket_set_blocking() but this usage is deprecated.
Note:
Prior to PHP 4.3, this function only worked on socket based streams. Since PHP 4.3, this function works for any stream that supports non-blocking mode (currently, regular files and socket streams). See also stream_select(). Code Examples / Notes » stream_set_blockingmagicaltux
When you use fwrite() on a non-blocking stream, data isn't discarded silently as t dot starling said. Remember that fwrite() returns an int, and this int represents the amount of data really written to the stream. So, if you see that fwrite() returns less than the amount of written data, it means you'll have to call fwrite() again in the future to write the remaining amount of data. You can use stream_select() to wait for the stream to be available for writing, then continue writing data to the stream. Non-blocking streams are useful as you can have more than one non-blocking stream, and wait for them to be available for writing. t dot starling
Warning: if you write too much data to a stream in non-blocking mode and fill the buffer, the excess will be silently discarded. Observed in PHP 4.4.0 under linux.
galvao
Please notice that this function will not work as for PHP 5.2.0 at least on Win32 systems. It probably won't work on Linux boxes either. PHP just ignores the function and blocking remains active. For more information take a look at Bug #36918. 22-mar-2007 08:33
A concise description of Blocking vs. Non-blocking: http://tinyurl.com/ype2j7 http://www.franz.com/support/documentation/7.0/ doc/streams.htm#block-non-block-3 5.2.1 Blocking behavior in simple-streams There are three modes of blocking behavior when writing items in a sequence to a stream or filling a sequence with items read from a stream. The issue is what to do when (for writing) the entire sequence cannot be written and (for reading) the entire sequence cannot be filled, but no EOF is encountered. (By `the entire sequence', we mean that part specified by start and end if those are supplied.) Here are the modes and a description of what happens in that mode if the whole operation does not complete and no EOF is encountered. 1. Blocking mode: the system blocks (waits or hangs) until the operation can be completed. 2. Blocking/Non-Blocking (B/NB) mode: the system only blocks on the first element of the sequence: if it cannot be written or read, the system blocks. If the first element is successfully written or read, and a subsequent element cannot be written or read, the function doing the writing/reading returns, typically with the return value(s) indicating exactly what was accomplished. 3. Non-Blocking mode: the system never blocks. If an element cannot be written or read, the function doing the writing/reading returns, typically with the return value(s) indicating exactly what was accomplished. |
Change Language
stream_bucket_append stream_bucket_make_writeable stream_bucket_new stream_bucket_prepend stream_context_create stream_context_get_default stream_context_get_options stream_context_set_option stream_context_set_params stream_copy_to_stream stream_encoding stream_filter_append stream_filter_prepend stream_filter_register stream_filter_remove stream_get_contents stream_get_filters stream_get_line stream_get_meta_data stream_get_transports stream_get_wrappers stream_register_wrapper stream_resolve_include_path stream_select stream_set_blocking stream_set_timeout stream_set_write_buffer stream_socket_accept stream_socket_client stream_socket_enable_crypto stream_socket_get_name stream_socket_pair stream_socket_recvfrom stream_socket_sendto stream_socket_server stream_socket_shutdown stream_wrapper_register stream_wrapper_restore stream_wrapper_unregister |
