FD_CLR (3)           - synchronous I/O multiplexing
FD_ISSET (3)         - synchronous I/O multiplexing
FD_SET (3)           - synchronous I/O multiplexing
FD_ZERO (3)          - synchronous I/O multiplexing
__dev_mc_unsync (9)  - Remove synchronized addresses from device
__dev_uc_unsync (9)  - Remove synchronized addresses from device
__register_chrdev (9) - create and register a cdev occupying a range of minors
__unregister_chrdev (9) - unregister and destroy a cdev
_newselect (2)       - synchronous I/O multiplexing
ablkcipher_request_set_callback (9) - set asynchronous callback function
adjtime (3)          - correct the time to synchronize the system clock
aead_request_set_callback (9) - set asynchronous callback function
ahash_request_set_callback (9) - set asynchronous callback function
aio (7)              - POSIX asynchronous I/O overview
aio_cancel (3)       - cancel an outstanding asynchronous I/O request
aio_error (3)        - get error status of asynchronous I/O operation
aio_fsync (3)        - asynchronous file synchronization
aio_init (3)         - asynchronous I/O initialization
aio_read (3)         - asynchronous read
aio_return (3)       - get return status of asynchronous I/O operation
aio_suspend (3)      - wait for asynchronous I/O operation or timeout
aio_write (3)        - asynchronous write
akcipher_request_set_callback (9) - Sets an asynchronous callback.
alloc_chrdev_region (9) - register a range of char device numbers
ata_scsi_flush_xlat (9) - Translate SCSI SYNCHRONIZE CACHE command
blk_start_queue_async (9) - asynchronously restart a previously stopped queue
chroot (2)           - change root directory
chroot (8)           - run command or interactive shell with special root dir...
chrt (1)             - manipulate the real-time attributes of a process
cond_synchronize_rcu (9) - Conditionally wait for an RCU grace period
cond_synchronize_sched (9) - Conditionally wait for an RCU-sched grace period
crypto_alloc_blkcipher (9) - allocate synchronous block cipher handle
disk_clear_events (9) - synchronously check, clear and return pending events
dsync (1)            - Dovecot's mailbox synchronization utility
fdatasync (2)        - synchronize a file's in-core state with storage device
fence_is_later (9)   - return if f1 is chronologically later than f2
fence_later (9)      - return the chronologically later fence
fsync (2)            - synchronize a file's in-core state with storage device
gai_cancel (3)       - asynchronous network address and service translation
gai_error (3)        - asynchronous network address and service translation
gai_suspend (3)      - asynchronous network address and service translation
get_state_synchronize_rcu (9) - Snapshot current RCU state
get_state_synchronize_sched (9) - Snapshot current RCU-sched state
getaddrinfo_a (3)    - asynchronous network address and service translation
git-rev-list (1)     - Lists commit objects in reverse chronological order
input_mt_sync_frame (9) - synchronize mt frame
io_cancel (2)        - cancel an outstanding asynchronous I/O operation
io_destroy (2)       - destroy an asynchronous I/O context
io_getevents (2)     - read asynchronous I/O events from the completion queue
io_setup (2)         - create an asynchronous I/O context
io_submit (2)        - submit asynchronous I/O blocks for processing
ischroot (1)         - detect if running in a chroot
Mail::SpamAssassin::AsyncLoop (3pm) - scanner asynchronous event loop
memchr (3)           - scan memory for a character
memchr (9)           - Find a character in an area of memory.
memchr_inv (9)       - Find an unmatching character in an area of memory.
memrchr (3)          - scan memory for a character
mptscsih_synchronize_cache (9) - Send SYNCHRONIZE_CACHE to all disks.
msync (2)            - synchronize a file with a memory map
napi_synchronize (9) - wait until NAPI is not running
Net::DBus::ASyncReply (3pm) - asynchronous method reply handler
ordchr (3am)         - convert characters to strings and vice versa
pg_rewind (1)        - synchronize a PostgreSQL data directory with another d...
pselect (2)          - synchronous I/O multiplexing
pselect6 (2)         - synchronous I/O multiplexing
pure-ftpd-virtualchroot (8) - simple File Transfer Protocol server
rawmemchr (3)        - scan memory for a character
register_chrdev_region (9) - register a range of device numbers
request_firmware_nowait (9) - asynchronous version of request_firmware
rpc_call_async (9)   - Perform an asynchronous RPC call
rpc_call_sync (9)    - Perform a synchronous RPC call
rt_sigtimedwait (2)  - synchronously wait for queued signals
scsi_complete_async_scans (9) - Wait for asynchronous scans to complete
scsi_finish_async_scan (9) - asynchronous scan has finished
select (2)           - synchronous I/O multiplexing
select_tut (2)       - synchronous I/O multiplexing
sigevent (7)         - structure for notification from asynchronous routines
sigtimedwait (2)     - synchronously wait for queued signals
sigwaitinfo (2)      - synchronously wait for queued signals
skcipher_request_set_callback (9) - set asynchronous callback function
snd_soc_component_async_complete (9) - Ensure asynchronous I/O has completed
snd_soc_component_update_bits_async (9) - Perform asynchronous read/modify/wr...
spi_async (9)        - asynchronous SPI transfer
spi_read (9)         - SPI synchronous read
spi_sync (9)         - blocking/synchronous SPI data transfers
spi_sync_transfer (9) - synchronous SPI data transfer
spi_w8r16 (9)        - SPI synchronous 8 bit write followed by 16 bit read
spi_w8r16be (9)      - SPI synchronous 8 bit write followed by 16 bit big-end...
spi_w8r8 (9)         - SPI synchronous 8 bit write followed by 8 bit read
spi_write (9)        - SPI synchronous write
spi_write_then_read (9) - SPI synchronous write followed by read
strchr (3)           - locate character in string
strchr (9)           - Find the first occurrence of a character in a string
strchrnul (3)        - locate character in string
strchrnul (9)        - Find and return a character in a string, or end of string
strnchr (9)          - Find a character in a length limited string
strrchr (3)          - locate character in string
strrchr (9)          - Find the last occurrence of a character in a string
struct_ablkcipher_alg (9) - asynchronous block cipher definition
struct_ahash_alg (9) - asynchronous message digest definition
struct_blkcipher_alg (9) - synchronous block cipher definition
struct_fence (9)     - software synchronization primitive
struct_shash_alg (9) - synchronous message digest definition
svnsync (1)          - Subversion repository synchronization tool
synchronize_hardirq (9) - wait for pending hard IRQ handlers (on other CPUs)
synchronize_irq (9)  - wait for pending IRQ handlers (on other CPUs)
synchronize_net (9)  - Synchronize with packet receive processing
synchronize_rcu (9)  - wait until a grace period has elapsed.
synchronize_rcu_bh (9) - wait until an rcu_bh grace period has elapsed.
synchronize_rcu_tasks (9) - wait until an rcu-tasks grace period has elapsed.
synchronize_sched (9) - wait until an rcu-sched grace period has elapsed.
synchronize_srcu (9) - wait for prior SRCU read-side critical-section completion
synchronize_srcu_expedited (9) - Brute-force SRCU grace period
sys_rt_sigtimedwait (9) - synchronously wait for queued signals specified in ...
systemd-timesyncd (8) - Network Time Synchronization
systemd-timesyncd.service (8) - Network Time Synchronization
unregister_chrdev_region (9) - unregister a range of device numbers
usb_buffer_dmasync (9) - synchronize DMA and CPU view of buffer(s)
usb_buffer_dmasync_sg (9) - synchronize DMA and CPU view of scatterlist buffe...
usb_sg_wait (9)      - synchronously execute scatter/gather request
usb_submit_urb (9)   - issue an asynchronous transfer request for an endpoint
usb_unlink_anchored_urbs (9) - asynchronously cancel transfer requests en masse
wcschr (3)           - search a wide character in a wide-character string
wcsrchr (3)          - search a wide character in a wide-character string
wmemchr (3)          - search a wide character in a wide-character array
AnyEvent::DNS (3pm)  - fully asynchronous DNS resolution
AnyEvent::IO (3pm)   - the DBI of asynchronous I/O implementations
Async::Interrupt (3pm) - allow C/XS libraries to interrupt perl asynchronously