Merge "Clear buffer on reconnect & check poll() result" into main (188eccc4) · Commits · e / os / android_frameworks_base

core/jni/com_android_internal_os_ZygoteCommandBuffer.cpp

+9 −5

Original line number	Diff line number	Diff line
		@@ -63,6 +63,7 @@ class NativeCommandBuffer {
		std::optional<std::pair<char, char>> readLine(FailFn fail_fn) {
		char* result = mBuffer + mNext;
		while (true) {
		// We have scanned up to, but not including mNext for this line's newline.
		if (mNext == mEnd) {
		if (mEnd == MAX_COMMAND_BYTES) {
		return {};
		@@ -89,7 +90,7 @@ class NativeCommandBuffer {
		} else {
		mNext = nl - mBuffer + 1;
		if (--mLinesLeft < 0) {
		fail_fn("ZygoteCommandBuffer.readLine attempted to read past mEnd of command");
		fail_fn("ZygoteCommandBuffer.readLine attempted to read past end of command");
		}
		return std::make_pair(result, nl);
		}
		@@ -125,8 +126,8 @@ class NativeCommandBuffer {
		mEnd += lineLen + 1;
		}

		// Clear mBuffer, start reading new command, return the number of arguments, leaving mBuffer
		// positioned at the beginning of first argument. Return 0 on EOF.
		// Start reading new command, return the number of arguments, leaving mBuffer positioned at the
		// beginning of first argument. Return 0 on EOF.
		template<class FailFn>
		int getCount(FailFn fail_fn) {
		mLinesLeft = 1;
		@@ -451,11 +452,14 @@ jboolean com_android_internal_os_ZygoteCommandBuffer_nativeForkRepeatedly(
		(CREATE_ERROR("Write unexpectedly returned short: %d < 5", res));
		}
		}
		for (;;) {
		// Clear buffer and get count from next command.
		n_buffer->clear();
		for (;;) {
		// Poll isn't strictly necessary for now. But without it, disconnect is hard to detect.
		int poll_res = TEMP_FAILURE_RETRY(poll(fd_structs, 2, -1 /* infinite timeout */));
		if (poll_res < 0) {
		fail_fn_z(CREATE_ERROR("Poll failed: %d: %s", errno, strerror(errno)));
		}
		if ((fd_structs[SESSION_IDX].revents & POLLIN) != 0) {
		if (n_buffer->getCount(fail_fn_z) != 0) {
		break;