Merge "Emulator: enhance logcat -Q to handle qemu pipe device" am: a14b5bbd2c am: 1284bbbb52 (ee741214) · Commits · e / os / android_system_core

logcat/logcat.cpp

+54 −11

Original line number	Diff line number	Diff line
		@@ -41,6 +41,7 @@
		#include <vector>

		#include <android-base/file.h>
		#include <android-base/properties.h>
		#include <android-base/stringprintf.h>
		#include <android-base/strings.h>
		#include <cutils/sched_policy.h>
		@@ -1195,39 +1196,71 @@ static int __logcat(android_logcat_context_internal* context) {
		} break;

		case 'Q':
		#define KERNEL_OPTION "androidboot.logcat="
		#define LOGCAT_FILTER "androidboot.logcat="
		#define CONSOLE_PIPE_OPTION "androidboot.consolepipe="
		#define CONSOLE_OPTION "androidboot.console="
		#define QEMU_PROPERTY "ro.kernel.qemu"
		#define QEMU_CMDLINE "qemu.cmdline"
		// This is a hidden option used to start a version of logcat
		// in an emulated device only. It basically looks for
		// androidboot.logcat= on the kernel command line. If
		// something is found, it extracts a log filter and uses it to
		// run the program. If nothing is found, the program should
		// quit immediately.
		// run the program. The logcat output will go to consolepipe if
		// androiboot.consolepipe (e.g. qemu_pipe) is given, otherwise,
		// it goes to androidboot.console (e.g. tty)
		{
		std::string cmdline;
		// if not in emulator, exit quietly
		if (false == android::base::GetBoolProperty(QEMU_PROPERTY, false)) {
		context->retval = EXIT_SUCCESS;
		goto exit;
		}

		std::string cmdline = android::base::GetProperty(QEMU_CMDLINE, "");
		if (cmdline.empty()) {
		android::base::ReadFileToString("/proc/cmdline", &cmdline);
		}

		const char* logcat = strstr(cmdline.c_str(), KERNEL_OPTION);
		const char* logcatFilter = strstr(cmdline.c_str(), LOGCAT_FILTER);
		// if nothing found or invalid filters, exit quietly
		if (!logcat) {
		if (!logcatFilter) {
		context->retval = EXIT_SUCCESS;
		goto exit;
		}

		const char* p = logcat + strlen(KERNEL_OPTION);
		const char* p = logcatFilter + strlen(LOGCAT_FILTER);
		const char* q = strpbrk(p, " \t\n\r");
		if (!q) q = p + strlen(p);
		forceFilters = std::string(p, q);

		// redirect our output to the emulator console
		// redirect our output to the emulator console pipe or console
		const char* consolePipe =
		strstr(cmdline.c_str(), CONSOLE_PIPE_OPTION);
		const char* console =
		strstr(cmdline.c_str(), CONSOLE_OPTION);
		if (!console) break;

		if (consolePipe) {
		p = consolePipe + strlen(CONSOLE_PIPE_OPTION);
		} else if (console) {
		p = console + strlen(CONSOLE_OPTION);
		} else {
		context->retval = EXIT_FAILURE;
		goto exit;
		}

		q = strpbrk(p, " \t\n\r");
		int len = q ? q - p : strlen(p);
		std::string devname = "/dev/" + std::string(p, len);
		std::string pipePurpose("pipe:logcat");
		if (consolePipe) {
		// example: "qemu_pipe,pipe:logcat"
		// upon opening of /dev/qemu_pipe, the "pipe:logcat"
		// string with trailing '\0' should be written to the fd
		size_t pos = devname.find(",");
		if (pos != std::string::npos) {
		pipePurpose = devname.substr(pos + 1);
		devname = devname.substr(0, pos);
		}
		}
		cmdline.erase();

		if (context->error) {
		@@ -1239,6 +1272,16 @@ static int __logcat(android_logcat_context_internal* context) {
		devname.erase();
		if (!fp) break;

		if (consolePipe) {
		// need the trailing '\0'
		if(!android::base::WriteFully(fileno(fp), pipePurpose.c_str(),
		pipePurpose.size() + 1)) {
		fclose(fp);
		context->retval = EXIT_FAILURE;
		goto exit;
		}
		}

		// close output and error channels, replace with console
		android::close_output(context);
		android::close_error(context);