The Tor Browser: widget/gonk/libui/cutils_trace.h@ac0c01689b40 (annotated)

widget/gonk/libui/cutils_trace.h@ac0c01689b40 (annotated)

widget/gonk/libui/cutils_trace.h

Thu, 15 Jan 2015 15:59:08 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 15 Jan 2015 15:59:08 +0100
branch: TOR_BUG_9701
changeset 10: ac0c01689b40
permissions: -rw-r--r--

Implement a real Private Browsing Mode condition by changing the API/ABI;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /*
  * Copyright (C) 2012 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 #ifndef _LIBS_CUTILS_TRACE_H
 #define _LIBS_CUTILS_TRACE_H
 #include <sys/cdefs.h>
 #include <sys/types.h>
 #include <stdint.h>
 #include <stdbool.h>
 #include <unistd.h>
 #include <cutils/compiler.h>
 #ifdef ANDROID_SMP
 #include <cutils/atomic-inline.h>
 #else
 #include <cutils/atomic.h>
 #endif
 __BEGIN_DECLS
 /**
  * The ATRACE_TAG macro can be defined before including this header to trace
  * using one of the tags defined below.  It must be defined to one of the
  * following ATRACE_TAG_* macros.  The trace tag is used to filter tracing in
  * userland to avoid some of the runtime cost of tracing when it is not desired.
  *
  * Defining ATRACE_TAG to be ATRACE_TAG_ALWAYS will result in the tracing always
  * being enabled - this should ONLY be done for debug code, as userland tracing
  * has a performance cost even when the trace is not being recorded.  Defining
  * ATRACE_TAG to be ATRACE_TAG_NEVER or leaving ATRACE_TAG undefined will result
  * in the tracing always being disabled.
  *
  * ATRACE_TAG_HAL should be bitwise ORed with the relevant tags for tracing
  * within a hardware module.  For example a camera hardware module would set:
  * #define ATRACE_TAG  (ATRACE_TAG_CAMERA | ATRACE_TAG_HAL)
  *
  * Keep these in sync with frameworks/base/core/java/android/os/Trace.java.
  */
 #define ATRACE_TAG_NEVER            0       // This tag is never enabled.
 #define ATRACE_TAG_ALWAYS           (1<<0)  // This tag is always enabled.
 #define ATRACE_TAG_GRAPHICS         (1<<1)
 #define ATRACE_TAG_INPUT            (1<<2)
 #define ATRACE_TAG_VIEW             (1<<3)
 #define ATRACE_TAG_WEBVIEW          (1<<4)
 #define ATRACE_TAG_WINDOW_MANAGER   (1<<5)
 #define ATRACE_TAG_ACTIVITY_MANAGER (1<<6)
 #define ATRACE_TAG_SYNC_MANAGER     (1<<7)
 #define ATRACE_TAG_AUDIO            (1<<8)
 #define ATRACE_TAG_VIDEO            (1<<9)
 #define ATRACE_TAG_CAMERA           (1<<10)
 #define ATRACE_TAG_HAL              (1<<11)
 #define ATRACE_TAG_APP              (1<<12)
 #define ATRACE_TAG_RESOURCES        (1<<13)
 #define ATRACE_TAG_DALVIK           (1<<14)
 #define ATRACE_TAG_LAST             ATRACE_TAG_DALVIK
 // Reserved for initialization.
 #define ATRACE_TAG_NOT_READY        (1LL<<63)
 #define ATRACE_TAG_VALID_MASK ((ATRACE_TAG_LAST - 1) | ATRACE_TAG_LAST)
 #ifndef ATRACE_TAG
 #define ATRACE_TAG ATRACE_TAG_NEVER
 #elif ATRACE_TAG > ATRACE_TAG_VALID_MASK
 #error ATRACE_TAG must be defined to be one of the tags defined in cutils/trace.h
 #endif
 #ifdef HAVE_ANDROID_OS
 /**
  * Maximum size of a message that can be logged to the trace buffer.
  * Note this message includes a tag, the pid, and the string given as the name.
  * Names should be kept short to get the most use of the trace buffer.
  */
 #define ATRACE_MESSAGE_LENGTH 1024
 /**
  * Opens the trace file for writing and reads the property for initial tags.
  * The atrace.tags.enableflags property sets the tags to trace.
  * This function should not be explicitly called, the first call to any normal
  * trace function will cause it to be run safely.
  */
 void atrace_setup();
 /**
  * If tracing is ready, set atrace_enabled_tags to the system property
  * debug.atrace.tags.enableflags. Can be used as a sysprop change callback.
  */
 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);
 /**
  * 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 volatile int32_t atrace_is_ready;
 /**
  * Set of ATRACE_TAG flags to trace for, initialized to ATRACE_TAG_NOT_READY.
  * A value of zero indicates setup has failed.
  * Any other nonzero value indicates setup has succeeded, and tracing is on.
  */
 extern uint64_t atrace_enabled_tags;
 /**
  * Handle to the kernel's trace buffer, initialized to -1.
  * Any other value indicates setup has succeeded, and is a valid fd for tracing.
  */
 extern int atrace_marker_fd;
 /**
  * atrace_init readies the process for tracing by opening the trace_marker file.
  * Calling any trace function causes this to be run, so calling it is optional.
  * This can be explicitly run to avoid setup delay on first trace function.
  */
 #define ATRACE_INIT() atrace_init()
 static inline void atrace_init()
 {
     if (CC_UNLIKELY(!android_atomic_acquire_load(&atrace_is_ready))) {
         atrace_setup();
     }
 }
 /**
  * Get the mask of all tags currently enabled.
  * It can be used as a guard condition around more expensive trace calculations.
  * Every trace function calls this, which ensures atrace_init is run.
  */
 #define ATRACE_GET_ENABLED_TAGS() atrace_get_enabled_tags()
 static inline uint64_t atrace_get_enabled_tags()
 {
     atrace_init();
     return atrace_enabled_tags;
 }
 /**
  * Test if a given tag is currently enabled.
  * Returns nonzero if the tag is enabled, otherwise zero.
  * It can be used as a guard condition around more expensive trace calculations.
  */
 #define ATRACE_ENABLED() atrace_is_tag_enabled(ATRACE_TAG)
 static inline uint64_t atrace_is_tag_enabled(uint64_t tag)
 {
     return atrace_get_enabled_tags() & tag;
 }
 /**
  * Trace the beginning of a context.  name is used to identify the context.
  * This is often used to time function execution.
  */
 #define ATRACE_BEGIN(name) atrace_begin(ATRACE_TAG, name)
 static inline void atrace_begin(uint64_t tag, const char* name)
 {
     if (CC_UNLIKELY(atrace_is_tag_enabled(tag))) {
         char buf[ATRACE_MESSAGE_LENGTH];
         size_t len;
         len = snprintf(buf, ATRACE_MESSAGE_LENGTH, "B|%d|%s", getpid(), name);
         write(atrace_marker_fd, buf, len);
     }
 }
 /**
  * Trace the end of a context.
  * This should match up (and occur after) a corresponding ATRACE_BEGIN.
  */
 #define ATRACE_END() atrace_end(ATRACE_TAG)
 static inline void atrace_end(uint64_t tag)
 {
     if (CC_UNLIKELY(atrace_is_tag_enabled(tag))) {
         char c = 'E';
         write(atrace_marker_fd, &c, 1);
     }
 }
 /**
  * Trace the beginning of an asynchronous event. Unlike ATRACE_BEGIN/ATRACE_END
  * contexts, asynchronous events do not need to be nested. The name describes
  * the event, and the cookie provides a unique identifier for distinguishing
  * simultaneous events. The name and cookie used to begin an event must be
  * used to end it.
  */
 #define ATRACE_ASYNC_BEGIN(name, cookie) \
     atrace_async_begin(ATRACE_TAG, name, cookie)
 static inline void atrace_async_begin(uint64_t tag, const char* name,
         int32_t cookie)
 {
     if (CC_UNLIKELY(atrace_is_tag_enabled(tag))) {
         char buf[ATRACE_MESSAGE_LENGTH];
         size_t len;
         len = snprintf(buf, ATRACE_MESSAGE_LENGTH, "S|%d|%s|%d", getpid(),
                 name, cookie);
         write(atrace_marker_fd, buf, len);
     }
 }
 /**
  * Trace the end of an asynchronous event.
  * This should have a corresponding ATRACE_ASYNC_BEGIN.
  */
 #define ATRACE_ASYNC_END(name, cookie) atrace_async_end(ATRACE_TAG, name, cookie)
 static inline void atrace_async_end(uint64_t tag, const char* name,
         int32_t cookie)
 {
     if (CC_UNLIKELY(atrace_is_tag_enabled(tag))) {
         char buf[ATRACE_MESSAGE_LENGTH];
         size_t len;
         len = snprintf(buf, ATRACE_MESSAGE_LENGTH, "F|%d|%s|%d", getpid(),
                 name, cookie);
         write(atrace_marker_fd, buf, len);
     }
 }
 /**
  * Traces an integer counter value.  name is used to identify the counter.
  * This can be used to track how a value changes over time.
  */
 #define ATRACE_INT(name, value) atrace_int(ATRACE_TAG, name, value)
 static inline void atrace_int(uint64_t tag, const char* name, int32_t value)
 {
     if (CC_UNLIKELY(atrace_is_tag_enabled(tag))) {
         char buf[ATRACE_MESSAGE_LENGTH];
         size_t len;
         len = snprintf(buf, ATRACE_MESSAGE_LENGTH, "C|%d|%s|%d",
                 getpid(), name, value);
         write(atrace_marker_fd, buf, len);
     }
 }
 #else // not HAVE_ANDROID_OS
 #define ATRACE_INIT()
 #define ATRACE_GET_ENABLED_TAGS()
 #define ATRACE_ENABLED()
 #define ATRACE_BEGIN(name)
 #define ATRACE_END()
 #define ATRACE_ASYNC_BEGIN(name, cookie)
 #define ATRACE_ASYNC_END(name, cookie)
 #define ATRACE_INT(name, value)
 #endif // not HAVE_ANDROID_OS
 __END_DECLS
 #endif // _LIBS_CUTILS_TRACE_H

The Tor Browser / annotate

widget/gonk/libui/cutils_trace.h@ac0c01689b40 (annotated)

widget/gonk/libui/cutils_trace.h