/* Copyright 2013 The Chromium Authors
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file. */
/* XRay -- a simple profiler for Native Client */
#include <assert.h>
#include <errno.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <unistd.h>
#include "xray/xray_priv.h"
#if defined(XRAY)
/* GTSC - Get Time Stamp Counter */
#if defined(__amd64__) && !defined(XRAY_NO_RDTSC)
XRAY_INLINE uint64_t RDTSC64();
uint64_t RDTSC64() {
uint64_t a, d;
__asm__ __volatile__("rdtsc" : "=a" (a), "=d" (d));
return ((uint64_t)a) | (((uint64_t)d) << 32);
}
#define GTSC(_x) _x = RDTSC64()
#elif defined(__i386__) && !defined(XRAY_NO_RDTSC)
#define GTSC(_x) __asm__ __volatile__ ("rdtsc" : "=A" (_x));
#else
XRAY_INLINE uint64_t GTOD();
uint64_t GTOD() {
struct timeval tv;
gettimeofday(&tv, NULL);
return (uint64_t)tv.tv_sec * 1000000 + (uint64_t)tv.tv_usec;
}
#define GTSC(_x) _x = GTOD();
#endif
/* Use a TLS variable for cheap thread uid. */
__thread struct XRayTraceCapture* g_xray_capture = NULL;
__thread int g_xray_thread_id_placeholder = 0;
struct XRayTraceStackEntry {
uint32_t depth_addr;
uint64_t tsc;
uint32_t dest;
uint32_t annotation_index;
};
struct XRayTraceFrameEntry {
/* Indices into global tracebuffer */
int start;
int end;
uint64_t start_tsc;
uint64_t end_tsc;
uint64_t total_ticks;
int annotation_count;
bool valid;
#ifndef XRAY_DISABLE_BROWSER_INTEGRATION
struct XRayTimestampPair start_time;
struct XRayTimestampPair end_time;
#endif
};
struct XRayTraceFrame {
struct XRayTraceFrameEntry* entry;
int head;
int tail;
int count;
};
struct XRayTraceCapture {
/* Common variables share cache line */
bool recording;
uint32_t stack_depth;
uint32_t max_stack_depth;
int buffer_index;
int buffer_size;
int disabled;
int annotation_count;
struct XRaySymbolTable* symbols;
bool initialized;
uint32_t annotation_filter;
uint32_t guard0;
struct XRayTraceStackEntry stack[XRAY_TRACE_STACK_SIZE] XRAY_ALIGN64;
uint32_t guard1;
uint32_t guard2;
char annotation[XRAY_ANNOTATION_STACK_SIZE] XRAY_ALIGN64;
uint32_t guard3;
struct XRayTraceBufferEntry* buffer;
struct XRayTraceFrame frame;
#ifndef XRAY_DISABLE_BROWSER_INTEGRATION
int32_t thread_id;
#endif
} XRAY_ALIGN64;
#ifdef __cplusplus
extern "C" {
#endif
#if defined(__pnacl__)
XRAY_NO_INSTRUMENT void __pnacl_profile_func_enter(const char* fname);
XRAY_NO_INSTRUMENT void __pnacl_profile_func_exit(const char* fname);
#else
XRAY_NO_INSTRUMENT void __cyg_profile_func_enter(void* this_fn,
void* call_site);
XRAY_NO_INSTRUMENT void __cyg_profile_func_exit(void* this_fn,
void* call_site);
#endif
XRAY_INLINE int XRayTraceDecrementIndexInline(
struct XRayTraceCapture* capture, int index);
XRAY_INLINE int XRayTraceIncrementIndexInline(
struct XRayTraceCapture* capture, int index);
XRAY_NO_INSTRUMENT void __xray_profile_append_annotation(
struct XRayTraceCapture* capture,
struct XRayTraceStackEntry* se,
struct XRayTraceBufferEntry* be);
#ifdef __cplusplus
}
#endif
/* Asserts that the guard values haven't changed. */
void XRayCheckGuards(struct XRayTraceCapture* capture) {
assert(capture->guard0 == XRAY_GUARD_VALUE_0x12345678);
assert(capture->guard1 == XRAY_GUARD_VALUE_0x12345678);
assert(capture->guard2 == XRAY_GUARD_VALUE_0x87654321);
assert(capture->guard3 == XRAY_GUARD_VALUE_0x12345678);
}
/* Decrements the trace index, wrapping around if needed. */
int XRayTraceDecrementIndexInline(
struct XRayTraceCapture* capture, int index) {
--index;
if (index < 0)
index = capture->buffer_size - 1;
return index;
}
/* Increments the trace index, wrapping around if needed. */
int XRayTraceIncrementIndexInline(
struct XRayTraceCapture* capture, int index) {
++index;
if (index >= capture->buffer_size)
index = 0;
return index;
}
/* Returns true if the trace entry is an annotation string. */
bool XRayTraceIsAnnotation(
struct XRayTraceCapture* capture, int index) {
struct XRayTraceBufferEntry* be = &capture->buffer[index];
char* dst = (char*)be;
return 0 == *dst;
}
int XRayTraceIncrementIndex(struct XRayTraceCapture* capture, int index) {
return XRayTraceIncrementIndexInline(capture, index);
}
int XRayTraceDecrementIndex(struct XRayTraceCapture* capture, int index) {
return XRayTraceDecrementIndexInline(capture, index);
}
/* The entry in the tracebuffer at index is an annotation string. */
/* Calculate the next index value representing the next trace entry. */
int XRayTraceSkipAnnotation(struct XRayTraceCapture* capture, int index) {
/* Annotations are strings embedded in the trace buffer. */
/* An annotation string can span multiple trace entries. */
/* Skip over the string by looking for zero termination. */
assert(capture);
assert(XRayTraceIsAnnotation(capture, index));
bool done = false;
int start_index = 1;
int i;
while (!done) {
char* str = (char*) &capture->buffer[index];
const int num = sizeof(capture->buffer[index]);
for (i = start_index; i < num; ++i) {
if (0 == str[i]) {
done = true;
break;
}
}
index = XRayTraceIncrementIndexInline(capture, index);
start_index = 0;
}
return index;
}
struct XRayTraceBufferEntry* XRayTraceGetEntry(
struct XRayTraceCapture* capture, int index) {
return &capture->buffer[index];
}
/* Starting at index, return the index into the trace buffer */
/* for the next trace entry. Index can wrap (ringbuffer) */
int XRayTraceNextEntry(struct XRayTraceCapture* capture, int index) {
if (XRayTraceIsAnnotation(capture, index))
index = XRayTraceSkipAnnotation(capture, index);
else
index = XRayTraceIncrementIndexInline(capture, index);
return index;
}
int XRayFrameGetTraceStartIndex(struct XRayTraceCapture* capture, int frame) {
assert(capture);
assert(capture->initialized);
assert(!capture->recording);
return capture->frame.entry[frame].start;
}
int XRayFrameGetTraceEndIndex(struct XRayTraceCapture* capture, int frame) {
assert(capture);
assert(capture->initialized);
assert(!capture->recording);
return capture->frame.entry[frame].end;
}
/* Not very accurate, annotation strings will also be counted as "entries" */
int XRayFrameGetTraceCount(
struct XRayTraceCapture* capture, int frame) {
assert(true == capture->initialized);
assert(frame >= 0);
assert(frame < capture->frame.count);
assert(!capture->recording);
int start = capture->frame.entry[frame].start;
int end = capture->frame.entry[frame].end;
int num;
if (start < end)
num = end - start;
else
num = capture->buffer_size - (start - end);
return num;
}
/* Append a string to trace buffer. */
void XRayTraceAppendString(struct XRayTraceCapture* capture, char* src) {
int index = capture->buffer_index;
bool done = false;
int start_index = 1;
int s = 0;
int i;
char* dst = (char*)&capture->buffer[index];
const int num = sizeof(capture->buffer[index]);
dst[0] = 0;
while (!done) {
for (i = start_index; i < num; ++i) {
dst[i] = src[s];
if (0 == src[s]) {
dst[i] = 0;
done = true;
break;
}
++s;
}
index = XRayTraceIncrementIndexInline(capture, index);
dst = (char*)&capture->buffer[index];
start_index = 0;
}
capture->buffer_index = index;
}
/* Copies annotation from trace buffer to output string. */
int XRayTraceCopyToString(
struct XRayTraceCapture* capture, int index, char* dst) {
assert(XRayTraceIsAnnotation(capture, index));
bool done = false;
int i;
int d = 0;
int start_index = 1;
while (!done) {
char* src = (char*) &capture->buffer[index];
const int num = sizeof(capture->buffer[index]);
for (i = start_index; i < num; ++i) {
dst[d] = src[i];
if (0 == src[i]) {
done = true;
break;
}
++d;
}
index = XRayTraceIncrementIndexInline(capture, index);
start_index = 0;
}
return index;
}
/* Generic memory malloc for XRay */
/* validates pointer returned by malloc */
/* memsets memory block to zero */
void* XRayMalloc(size_t t) {
void* data;
data = calloc(1, t);
if (NULL == data) {
printf("XRay: malloc(%d) failed, panic shutdown!\n", t);
exit(-1);
}
return data;
}
/* Generic memory free for XRay */
void XRayFree(void* data) {
assert(NULL != data);
free(data);
}
/* Main profile capture function that is called at the start */
/* of every instrumented function. This function is implicitly */
/* called when code is compilied with the -finstrument-functions option */
#if defined(__pnacl__)
void __pnacl_profile_func_enter(const char* this_fn) {
#else
void __cyg_profile_func_enter(void* this_fn, void* call_site) {
#endif
struct XRayTraceCapture* capture = g_xray_capture;
if (capture && capture->recording) {
uint32_t depth = capture->stack_depth;
if (depth < capture->max_stack_depth) {
struct XRayTraceStackEntry* se = &capture->stack[depth];
uint32_t addr = (uint32_t)(uintptr_t)this_fn;
se->depth_addr = XRAY_PACK_DEPTH_ADDR(depth, addr);
se->dest = capture->buffer_index;
se->annotation_index = 0;
GTSC(se->tsc);
capture->buffer_index =
XRayTraceIncrementIndexInline(capture, capture->buffer_index);
}
++capture->stack_depth;
}
}
/* Main profile capture function that is called at the exit of */
/* every instrumented function. This function is implicity called */
/* when the code is compiled with the -finstrument-functions option */
#if defined(__pnacl__)
void __pnacl_profile_func_exit(const char* this_fn) {
#else
void __cyg_profile_func_exit(void* this_fn, void* call_site) {
#endif
struct XRayTraceCapture* capture = g_xray_capture;
if (capture && capture->recording) {
--capture->stack_depth;
if (capture->stack_depth < capture->max_stack_depth) {
uint32_t depth = capture->stack_depth;
struct XRayTraceStackEntry* se = &capture->stack[depth];
uint32_t buffer_index = se->dest;
uint64_t tsc;
struct XRayTraceBufferEntry* be = &capture->buffer[buffer_index];
GTSC(tsc);
be->depth_addr = se->depth_addr;
be->start_tick = se->tsc;
be->end_tick = tsc;
be->annotation_index = 0;
if (0 != se->annotation_index)
__xray_profile_append_annotation(capture, se, be);
}
}
}
#ifndef XRAY_DISABLE_BROWSER_INTEGRATION
void XRayGetTSC(uint64_t* tsc) {
GTSC(*tsc);
}
int32_t XRayGetSavedThreadID(struct XRayTraceCapture* capture) {
return capture->thread_id;
}
struct XRayTimestampPair XRayFrameGetStartTimestampPair(
struct XRayTraceCapture* capture, int frame) {
return capture->frame.entry[frame].start_time;
}
struct XRayTimestampPair XRayFrameGetEndTimestampPair(
struct XRayTraceCapture* capture, int frame) {
return capture->frame.entry[frame].end_time;
}
#endif
/* Special case appending annotation string to trace buffer */
/* this function should only ever be called from __cyg_profile_func_exit() */
void __xray_profile_append_annotation(struct XRayTraceCapture* capture,
struct XRayTraceStackEntry* se,
struct XRayTraceBufferEntry* be) {
struct XRayTraceStackEntry* parent = se - 1;
int start = parent->annotation_index;
be->annotation_index = capture->buffer_index;
char* str = &capture->annotation[start];
XRayTraceAppendString(capture, str);
*str = 0;
++capture->annotation_count;
}
/* Annotates the trace buffer. no filtering. */
void __XRayAnnotate(const char* fmt, ...) {
va_list args;
struct XRayTraceCapture* capture = g_xray_capture;
/* Only annotate functions recorded in the trace buffer. */
if (capture && capture->initialized) {
if (0 == capture->disabled) {
if (capture->recording) {
char buffer[1024];
int r;
va_start(args, fmt);
r = vsnprintf(buffer, sizeof(buffer), fmt, args);
va_end(args);
{
/* Get current string ptr */
int depth = capture->stack_depth - 1;
struct XRayTraceStackEntry* se = &capture->stack[depth];
if (0 == se->annotation_index) {
struct XRayTraceStackEntry* parent = se - 1;
se->annotation_index = parent->annotation_index;
}
char* dst = &capture->annotation[se->annotation_index];
strcpy(dst, buffer);
int len = strlen(dst);
se->annotation_index += len;
}
}
}
}
}
/* Annotates the trace buffer with user strings. Can be filtered. */
void __XRayAnnotateFiltered(const uint32_t filter, const char* fmt, ...) {
va_list args;
struct XRayTraceCapture* capture = g_xray_capture;
if (capture && capture->initialized) {
if (0 != (filter & capture->annotation_filter)) {
if (0 == capture->disabled) {
if (capture->recording) {
char buffer[XRAY_TRACE_ANNOTATION_LENGTH];
int r;
va_start(args, fmt);
r = vsnprintf(buffer, sizeof(buffer), fmt, args);
va_end(args);
{
/* get current string ptr */
int depth = capture->stack_depth - 1;
struct XRayTraceStackEntry* se = &capture->stack[depth];
if (0 == se->annotation_index) {
struct XRayTraceStackEntry* parent = se - 1;
se->annotation_index = parent->annotation_index;
}
char* dst = &capture->annotation[se->annotation_index];
strcpy(dst, buffer);
int len = strlen(dst);
se->annotation_index += len;
}
}
}
}
}
}
/* Allows user to specify annotation filter value, a 32 bit mask. */
void XRaySetAnnotationFilter(struct XRayTraceCapture* capture,
uint32_t filter) {
capture->annotation_filter = filter;
}
/* Reset xray profiler. */
void XRayReset(struct XRayTraceCapture* capture) {
assert(capture);
assert(capture->initialized);
assert(!capture->recording);
capture->buffer_index = 0;
capture->stack_depth = 0;
capture->disabled = 0;
capture->frame.head = 0;
capture->frame.tail = 0;
memset(capture->frame.entry, 0,
sizeof(capture->frame.entry[0]) * capture->frame.count);
memset(&capture->stack, 0,
sizeof(capture->stack[0]) * XRAY_TRACE_STACK_SIZE);
XRayCheckGuards(capture);
}
/* Change the maximum stack depth captures are made. */
void XRaySetMaxStackDepth(struct XRayTraceCapture* capture, int stack_depth) {
assert(capture);
assert(capture->initialized);
assert(!capture->recording);
if (stack_depth < 1)
stack_depth = 1;
if (stack_depth >= XRAY_TRACE_STACK_SIZE)
stack_depth = (XRAY_TRACE_STACK_SIZE - 1);
capture->max_stack_depth = stack_depth;
}
int XRayFrameGetCount(struct XRayTraceCapture* capture) {
return capture->frame.count;
}
int XRayFrameGetTail(struct XRayTraceCapture* capture) {
return capture->frame.tail;
}
int XRayFrameGetHead(struct XRayTraceCapture* capture) {
return capture->frame.head;
}
int XRayFrameGetPrev(struct XRayTraceCapture* capture, int i) {
i = i - 1;
if (i < 0)
i = capture->frame.count - 1;
return i;
}
int XRayFrameGetNext(struct XRayTraceCapture* capture, int i) {
i = i + 1;
if (i >= capture->frame.count)
i = 0;
return i;
}
bool XRayFrameIsValid(struct XRayTraceCapture* capture, int i) {
return capture->frame.entry[i].valid;
}
uint64_t XRayFrameGetTotalTicks(struct XRayTraceCapture* capture, int i) {
return capture->frame.entry[i].total_ticks;
}
int XRayFrameGetAnnotationCount(struct XRayTraceCapture* capture, int i) {
return capture->frame.entry[i].annotation_count;
}
void XRayFrameMakeLabel(struct XRayTraceCapture* capture,
int counter,
char* label) {
snprintf(label, XRAY_MAX_LABEL, "@@@frame%d@@@", counter);
}
/* Scans the ring buffer going backwards to find last valid complete frame. */
/* Will mark whether frames are valid or invalid during the traversal. */
int XRayFrameFindTail(struct XRayTraceCapture* capture) {
int head = capture->frame.head;
int index = XRayFrameGetPrev(capture, head);
int total_capture = 0;
int last_valid_frame = index;
/* Check for no captures */
if (capture->frame.head == capture->frame.tail)
return capture->frame.head;
/* Go back and invalidate all captures that have been stomped. */
while (index != head) {
bool valid = capture->frame.entry[index].valid;
if (valid) {
total_capture += XRayFrameGetTraceCount(capture, index) + 1;
if (total_capture < capture->buffer_size) {
last_valid_frame = index;
capture->frame.entry[index].valid = true;
} else {
capture->frame.entry[index].valid = false;
}
}
index = XRayFrameGetPrev(capture, index);
}
return last_valid_frame;
}
/* Starts a new frame and enables capturing, and must be paired with */
/* XRayEndFrame() Trace capturing only occurs on the thread which called */
/* XRayBeginFrame() and each instance of capture can only trace one thread */
/* at a time. */
void XRayStartFrame(struct XRayTraceCapture* capture) {
int i;
assert(NULL == g_xray_capture);
assert(capture->initialized);
assert(!capture->recording);
i = capture->frame.head;
XRayCheckGuards(capture);
/* Add a trace entry marker so we can detect wrap around stomping */
struct XRayTraceBufferEntry* be = &capture->buffer[capture->buffer_index];
be->depth_addr = XRAY_FRAME_MARKER;
capture->buffer_index =
XRayTraceIncrementIndex(capture, capture->buffer_index);
/* Set start of the frame we're about to trace */
capture->frame.entry[i].start = capture->buffer_index;
capture->disabled = 0;
capture->stack_depth = 1;
/* The trace stack[0] is reserved */
memset(&capture->stack[0], 0, sizeof(capture->stack[0]));
/* Annotation index 0 is reserved to indicate no annotation */
capture->stack[0].annotation_index = 1;
capture->annotation[0] = 0;
capture->annotation[1] = 0;
capture->annotation_count = 0;
capture->recording = true;
GTSC(capture->frame.entry[i].start_tsc);
g_xray_capture = capture;
#ifndef XRAY_DISABLE_BROWSER_INTEGRATION
capture->frame.entry[i].start_time = XRayGenerateTimestampsNow();
#endif
}
/* Ends a frame and disables capturing. Advances to the next frame. */
/* Must be paired with XRayStartFrame(), and called from the same thread. */
void XRayEndFrame(struct XRayTraceCapture* capture) {
int i;
assert(capture);
assert(capture->initialized);
assert(capture->recording);
assert(g_xray_capture == capture);
assert(0 == capture->disabled);
assert(1 == capture->stack_depth);
i = capture->frame.head;
GTSC(capture->frame.entry[i].end_tsc);
capture->frame.entry[i].total_ticks =
capture->frame.entry[i].end_tsc - capture->frame.entry[i].start_tsc;
capture->recording = NULL;
capture->frame.entry[i].end = capture->buffer_index;
capture->frame.entry[i].valid = true;
capture->frame.entry[i].annotation_count = capture->annotation_count;
capture->frame.head = XRayFrameGetNext(capture, capture->frame.head);
/* If the table is filled, bump the tail. */
if (capture->frame.head == capture->frame.tail)
capture->frame.tail = XRayFrameGetNext(capture, capture->frame.tail);
capture->frame.tail = XRayFrameFindTail(capture);
/* Check that we didn't stomp over trace entry marker. */
int marker = XRayTraceDecrementIndex(capture, capture->frame.entry[i].start);
struct XRayTraceBufferEntry* be = &capture->buffer[marker];
if (be->depth_addr != XRAY_FRAME_MARKER) {
fprintf(stderr,
"XRay: XRayStopFrame() detects insufficient trace buffer size!\n");
XRayReset(capture);
} else {
/* Replace marker with an empty annotation string. */
be->depth_addr = XRAY_NULL_ANNOTATION;
XRayCheckGuards(capture);
}
g_xray_capture = NULL;
#ifndef XRAY_DISABLE_BROWSER_INTEGRATION
capture->frame.entry[i].end_time = XRayGenerateTimestampsNow();
#endif
}
/* Get the last frame captured. Do not call while capturing. */
/* (ie call outside of XRayStartFrame() / XRayStopFrame() pair) */
int XRayGetLastFrame(struct XRayTraceCapture* capture) {
assert(capture);
assert(capture->initialized);
assert(!capture->recording);
assert(0 == capture->disabled);
assert(1 == capture->stack_depth);
int last_frame = XRayFrameGetPrev(capture, capture->frame.head);
return last_frame;
}
/* Disables capturing until a paired XRayEnableCapture() is called */
/* This call can be nested, but must be paired with an enable */
/* (If you need to just exclude a specific function and not its */
/* children, the XRAY_NO_INSTRUMENT modifier might be better) */
/* Must be called from same thread as XRayBeginFrame() / XRayEndFrame() */
void XRayDisableCapture(struct XRayTraceCapture* capture) {
assert(capture);
assert(capture == g_xray_capture);
assert(capture->initialized);
++capture->disabled;
capture->recording = false;
}
/* Re-enables capture. Must be paired with XRayDisableCapture() */
void XRayEnableCapture(struct XRayTraceCapture* capture) {
assert(capture);
assert(capture == g_xray_capture);
assert(capture->initialized);
assert(0 < capture->disabled);
--capture->disabled;
if (0 == capture->disabled) {
capture->recording = true;
}
}
struct XRaySymbolTable* XRayGetSymbolTable(struct XRayTraceCapture* capture) {
return capture->symbols;
}
/* Initialize XRay */
struct XRayTraceCapture* XRayInit(int stack_depth,
int buffer_size,
int frame_count,
const char* mapfilename) {
struct XRayTraceCapture* capture;
capture = (struct XRayTraceCapture*)XRayMalloc(
sizeof(struct XRayTraceCapture));
int adj_frame_count = frame_count + 1;
size_t buffer_size_in_bytes =
sizeof(capture->buffer[0]) * buffer_size;
size_t frame_size_in_bytes =
sizeof(capture->frame.entry[0]) * adj_frame_count;
capture->buffer =
(struct XRayTraceBufferEntry *)XRayMalloc(buffer_size_in_bytes);
capture->frame.entry =
(struct XRayTraceFrameEntry *)XRayMalloc(frame_size_in_bytes);
capture->buffer_size = buffer_size;
capture->frame.count = adj_frame_count;
capture->frame.head = 0;
capture->frame.tail = 0;
capture->disabled = 0;
capture->annotation_filter = 0xFFFFFFFF;
capture->guard0 = XRAY_GUARD_VALUE_0x12345678;
capture->guard1 = XRAY_GUARD_VALUE_0x12345678;
capture->guard2 = XRAY_GUARD_VALUE_0x87654321;
capture->guard3 = XRAY_GUARD_VALUE_0x12345678;
capture->initialized = true;
capture->recording = false;
XRaySetMaxStackDepth(capture, stack_depth);
XRayReset(capture);
/* Mapfile is optional; we don't need it for captures, only for reports. */
capture->symbols =
XRaySymbolTableCreate(XRAY_DEFAULT_SYMBOL_TABLE_SIZE);
if (NULL != mapfilename)
XRaySymbolTableParseMapfile(capture->symbols, mapfilename);
#ifndef XRAY_DISABLE_BROWSER_INTEGRATION
/* Use the address of a thread local variable as a fake thread id. */
capture->thread_id = (int32_t)(&g_xray_thread_id_placeholder);
#endif
return capture;
}
/* Shut down and free memory used by XRay. */
void XRayShutdown(struct XRayTraceCapture* capture) {
assert(capture);
assert(capture->initialized);
assert(!capture->recording);
XRayCheckGuards(capture);
if (NULL != capture->symbols) {
XRaySymbolTableFree(capture->symbols);
}
XRayFree(capture->frame.entry);
XRayFree(capture->buffer);
capture->initialized = false;
XRayFree(capture);
}
#endif /* XRAY */
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