To allow seamless copy-paste, on Ctrl+v, a SET_CLIPBOARD request is
performed before injecting Ctrl+v.
But when HID keyboard is enabled, the Ctrl+v injection is not sent on
the same channel as the clipboard request, so they are not serialized,
and may occur in any order. If Ctrl+v happens to be injected before the
new clipboard content is set, then the old content is pasted instead,
which is incorrect.
To minimize the probability of occurrence of the wrong order, a delay of
2 milliseconds was added before injecting Ctrl+v. Then 5ms. But even
with 5ms, the wrong behavior sometimes happens.
To handle it properly, add an acknowledgement mechanism, so that Ctrl+v
is injected over AOA only after the SET_CLIPBOARD request has been
performed and acknowledged by the server.
Refs e4163321f0
Refs 45b0f8123a
PR #2814 <https://github.com/Genymobile/scrcpy/pull/2814>
The interruptible version of the function to check process success
(sc_process_check_success_intr()) did not accept a close parameter to
avoid a race condition. But as the result, the processes were not closed
at all.
Add a close parameter, and close the process separately to avoid the
race condition.
On Linux, socket functions are unblocked by shutdown(), but on Windows
they are unblocked by closesocket().
Expose net_interrupt() and net_close() to abstract these differences:
- net_interrupt() calls shutdown() on Linux and closesocket() on
Windows (if not already called);
- net_close() calls close() on Linux and closesocket() on Windows (if
not already called).
This simplifies the server code, and prevents a data race on close
(reported by TSAN) on Linux (but does not fix it on Windows):
WARNING: ThreadSanitizer: data race (pid=836124)
Write of size 8 at 0x7ba0000000d0 by main thread:
#0 close ../../../../src/libsanitizer/tsan/tsan_interceptors_posix.cpp:1690 (libtsan.so.0+0x359d8)
#1 net_close ../app/src/util/net.c:211 (scrcpy+0x1c76b)
#2 close_socket ../app/src/server.c:330 (scrcpy+0x19442)
#3 server_stop ../app/src/server.c:522 (scrcpy+0x19e33)
#4 scrcpy ../app/src/scrcpy.c:532 (scrcpy+0x156fc)
#5 main ../app/src/main.c:92 (scrcpy+0x622a)
Previous read of size 8 at 0x7ba0000000d0 by thread T6:
#0 recv ../../../../src/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:6603 (libtsan.so.0+0x4f4a6)
#1 net_recv ../app/src/util/net.c:167 (scrcpy+0x1c5a7)
#2 run_receiver ../app/src/receiver.c:76 (scrcpy+0x12819)
#3 <null> <null> (libSDL2-2.0.so.0+0x84f40)
The function sc_cond_timedwait() accepted a parameter representing the
max duration to wait, because it internally uses SDL_CondWaitTimeout().
Instead, accept a deadline, to be consistent with
pthread_cond_timedwait().
Commit 21d206f360 added mutex assertions.
However, the "locker" variable to trace the locker thread id was read
and written by several threads without any protection, so it was racy.
Reported by TSAN.
The functions SDL_malloc(), SDL_free() and SDL_strdup() were used only
because strdup() was not available everywhere.
Now that it is available, use the native version of these functions.
Small unsigned integers promote to signed int. As a consequence, if v is
a uint8_t, then (v << 24) yields an int, so the left shift is undefined
if the MSB is 1.
Cast to uint32_t to yield an unsigned value.
Reported by USAN (meson x -Db_sanitize=undefined):
runtime error: left shift of 255 by 24 places cannot be represented
in type 'int'
The current process could be waited both by run_file_handler() and
file_handler_stop().
To avoid the race condition, wait the process without closing, then
close with mutex locked.
There were two versions: process_wait() and process_wait_noclose().
Expose a single version with a flag (it was already implemented that way
internally).
The function process_wait() returned a bool (true if the process
terminated successfully) and provided the exit code via an output
parameter exit_code.
But the returned value was always equivalent to exit_code == 0, so just
return the exit code instead.
On Linux, waitpid() both waits for the process to terminate and reaps it
(closes its handle). On Windows, these actions are separated into
WaitForSingleObject() and CloseHandle().
Expose these actions separately, so that it is possible to send a signal
to a process while waiting for its termination without race condition.
This allows to wait for server termination normally, but kill the
process without race condition if it is not terminated after some delay.
The header scrcpy.h is intended to be the "public" API. It should not
depend on other internal headers.
Therefore, declare all required structs in this header and adapt
internal code.
The verbosity was set either to info (in release mode) or debug (in
debug mode).
Add a command-line argument to change it, so that users can enable debug
logs using the release:
scrcpy -Vdebug
The platform-specific code for net.c was implemented in sys/*/net.c.
But the differences are quite limited, so use ifdef-blocks in the single
net.c instead.
Romain Vimont
RipleyTom
Andrea Gelmini
Yu-Chen Lin