Merge "cutils: add a way to disable tracing for a process" into jb-mr2-dev (25538257) · Commits · e / os / android_system_core

include/cutils/trace.h

+7 −1

Original line number	Diff line number	Diff line
		@@ -107,12 +107,18 @@ void atrace_update_tags();
		*/
		void atrace_set_debuggable(bool debuggable);

		/**
		* Set whether tracing is enabled for the current process. This is used to
		* prevent tracing within the Zygote process.
		*/
		void atrace_set_tracing_enabled(bool enabled);

		/**
		* Flag indicating whether setup has been completed, initialized to 0.
		* Nonzero indicates setup has completed.
		* Note: This does NOT indicate whether or not setup was successful.
		*/
		extern int32_t atrace_is_ready;
		extern volatile int32_t atrace_is_ready;

		/**
		* Set of ATRACE_TAG flags to trace for, initialized to ATRACE_TAG_NOT_READY.

libcutils/trace.c

+29 −11

Original line number	Diff line number	Diff line
		@@ -30,10 +30,11 @@
		#define LOG_TAG "cutils-trace"
		#include <cutils/log.h>

		int32_t atrace_is_ready = 0;
		volatile 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 volatile int32_t atrace_is_enabled = 1;
		static pthread_once_t atrace_once_control = PTHREAD_ONCE_INIT;
		static pthread_mutex_t atrace_tags_mutex = PTHREAD_MUTEX_INITIALIZER;

		@@ -46,9 +47,18 @@ void atrace_set_debuggable(bool debuggable)
		atrace_update_tags();
		}

		// Set whether tracing is enabled in this process. This is used to prevent
		// the Zygote process from tracing.
		void atrace_set_tracing_enabled(bool enabled)
		{
		android_atomic_release_store(enabled ? 1 : 0, &atrace_is_enabled);
		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) {
		static bool atrace_is_cmdline_match(const char* cmdline)
		{
		char value[PROPERTY_VALUE_MAX];
		char* start = value;

		@@ -140,10 +150,18 @@ void atrace_update_tags()
		{
		uint64_t tags;
		if (CC_UNLIKELY(android_atomic_acquire_load(&atrace_is_ready))) {
		if (android_atomic_acquire_load(&atrace_is_enabled)) {
		tags = atrace_get_property();
		pthread_mutex_lock(&atrace_tags_mutex);
		atrace_enabled_tags = tags;
		pthread_mutex_unlock(&atrace_tags_mutex);
		} else {
		// Tracing is disabled for this process, so we simply don't
		// initialize the tags.
		pthread_mutex_lock(&atrace_tags_mutex);
		atrace_enabled_tags = ATRACE_TAG_NOT_READY;
		pthread_mutex_unlock(&atrace_tags_mutex);
		}
		}
		}