am 774f9299: libcutils: add support for app tracing (38e1bb86) · Commits · e / os / android_system_core

include/cutils/trace.h

+11 −1

Original line number	Diff line number	Diff line
		@@ -20,6 +20,7 @@
		#include <sys/cdefs.h>
		#include <sys/types.h>
		#include <stdint.h>
		#include <stdbool.h>
		#include <unistd.h>
		#include <cutils/compiler.h>

		@@ -62,7 +63,8 @@ __BEGIN_DECLS
		#define ATRACE_TAG_VIDEO (1<<9)
		#define ATRACE_TAG_CAMERA (1<<10)
		#define ATRACE_TAG_HAL (1<<11)
		#define ATRACE_TAG_LAST ATRACE_TAG_HAL
		#define ATRACE_TAG_APP (1<<12)
		#define ATRACE_TAG_LAST ATRACE_TAG_APP

		// Reserved for initialization.
		#define ATRACE_TAG_NOT_READY (1LL<<63)
		@@ -96,6 +98,14 @@ void atrace_setup();
		*/
		void atrace_update_tags();

		/**
		* Set whether the process is debuggable. By default the process is not
		* considered debuggable. If the process is not debuggable then application-
		* level tracing is not allowed unless the ro.debuggable system property is
		* set to '1'.
		*/
		void atrace_set_debuggable(bool debuggable);

		/**
		* Flag indicating whether setup has been completed, initialized to 0.
		* Nonzero indicates setup has completed.

libcutils/trace.c

+85 −5

Original line number	Diff line number	Diff line
		@@ -18,6 +18,7 @@
		#include <fcntl.h>
		#include <limits.h>
		#include <pthread.h>
		#include <stdbool.h>
		#include <stdlib.h>
		#include <string.h>
		#include <sys/types.h>
		@@ -32,9 +33,79 @@
		int32_t atrace_is_ready = 0;
		int atrace_marker_fd = -1;
		uint64_t atrace_enabled_tags = ATRACE_TAG_NOT_READY;
		static bool atrace_is_debuggable = false;
		static pthread_once_t atrace_once_control = PTHREAD_ONCE_INIT;
		static pthread_mutex_t atrace_tags_mutex = PTHREAD_MUTEX_INITIALIZER;

		// Set whether this process is debuggable, which determines whether
		// application-level tracing is allowed when the ro.debuggable system property
		// is not set to '1'.
		void atrace_set_debuggable(bool debuggable)
		{
		atrace_is_debuggable = debuggable;
		atrace_update_tags();
		}

		// Check whether the given command line matches one of the comma-separated
		// values listed in the app_cmdlines property.
		static bool atrace_is_cmdline_match(const char* cmdline) {
		char value[PROPERTY_VALUE_MAX];
		char* start = value;

		property_get("debug.atrace.app_cmdlines", value, "");

		while (start != NULL) {
		char* end = strchr(start, ',');

		if (end != NULL) {
		*end = '\0';
		end++;
		}

		if (strcmp(cmdline, start) == 0) {
		return true;
		}

		start = end;
		}

		return false;
		}

		// Determine whether application-level tracing is enabled for this process.
		static bool atrace_is_app_tracing_enabled()
		{
		bool sys_debuggable = false;
		bool proc_debuggable = false;
		char value[PROPERTY_VALUE_MAX];
		bool result = false;

		// Check whether the system is debuggable.
		property_get("ro.debuggable", value, "0");
		if (value[0] == '1') {
		sys_debuggable = true;
		}

		if (sys_debuggable \|\| atrace_is_debuggable) {
		// Check whether tracing is enabled for this process.
		FILE * file = fopen("/proc/self/cmdline", "r");
		if (file) {
		char cmdline[4096];
		if (fgets(cmdline, sizeof(cmdline), file)) {
		result = atrace_is_cmdline_match(cmdline);
		} else {
		ALOGE("Error reading cmdline: %s (%d)", strerror(errno), errno);
		}
		fclose(file);
		} else {
		ALOGE("Error opening /proc/self/cmdline: %s (%d)", strerror(errno),
		errno);
		}
		}

		return result;
		}

		// Read the sysprop and return the value tags should be set to
		static uint64_t atrace_get_property()
		{
		@@ -52,6 +123,15 @@ static uint64_t atrace_get_property()
		ALOGE("Error parsing trace property: Number too large: %s", value);
		return 0;
		}

		// Only set the "app" tag if this process was selected for app-level debug
		// tracing.
		if (atrace_is_app_tracing_enabled()) {
		tags \|= ATRACE_TAG_APP;
		} else {
		tags &= ~ATRACE_TAG_APP;
		}

		return (tags \| ATRACE_TAG_ALWAYS) & ATRACE_TAG_VALID_MASK;
		}