diff options
| -rw-r--r-- | clang/docs/SourceBasedCodeCoverage.rst | 11 | ||||
| -rw-r--r-- | compiler-rt/lib/profile/InstrProfilingBuffer.c | 6 | ||||
| -rw-r--r-- | compiler-rt/lib/profile/InstrProfilingFile.c | 131 | ||||
| -rw-r--r-- | compiler-rt/lib/profile/InstrProfilingPort.h | 2 | ||||
| -rw-r--r-- | compiler-rt/test/profile/ContinuousSyncMode/online-merging.c | 138 |
5 files changed, 238 insertions, 50 deletions
diff --git a/clang/docs/SourceBasedCodeCoverage.rst b/clang/docs/SourceBasedCodeCoverage.rst index 0beb284e475..73197a57713 100644 --- a/clang/docs/SourceBasedCodeCoverage.rst +++ b/clang/docs/SourceBasedCodeCoverage.rst @@ -90,12 +90,11 @@ directory structure will be created. Additionally, the following special * "%c" expands out to nothing, but enables a mode in which profile counter updates are continuously synced to a file. This means that if the instrumented program crashes, or is killed by a signal, perfect coverage - information can still be recovered. Continuous mode is not yet compatible with - the "%Nm" merging mode described above, does not support value profiling for - PGO, and is only supported on Darwin. Support for Linux may be mostly - complete but requires testing, and support for Fuchsia/Windows may require - more extensive changes: please get involved if you are interested in porting - this feature. + information can still be recovered. Continuous mode does not support value + profiling for PGO, and is only supported on Darwin at the moment. Support for + Linux may be mostly complete but requires testing, and support for + Fuchsia/Windows may require more extensive changes: please get involved if + you are interested in porting this feature. .. code-block:: console diff --git a/compiler-rt/lib/profile/InstrProfilingBuffer.c b/compiler-rt/lib/profile/InstrProfilingBuffer.c index 089ff5a0153..174280fd4b5 100644 --- a/compiler-rt/lib/profile/InstrProfilingBuffer.c +++ b/compiler-rt/lib/profile/InstrProfilingBuffer.c @@ -10,11 +10,7 @@ #include "InstrProfilingInternal.h" #include "InstrProfilingPort.h" -/* When continuous mode is enabled (%c), this parameter is set to 1. This is - * incompatible with the in-process merging mode. Lifting this restriction - * may be complicated, as merging mode requires a lock on the profile, and - * mmap() mode would require that lock to be held for the entire process - * lifetime. +/* When continuous mode is enabled (%c), this parameter is set to 1. * * This parameter is defined here in InstrProfilingBuffer.o, instead of in * InstrProfilingFile.o, to sequester all libc-dependent code in diff --git a/compiler-rt/lib/profile/InstrProfilingFile.c b/compiler-rt/lib/profile/InstrProfilingFile.c index 6594fa991d5..208ae587bb3 100644 --- a/compiler-rt/lib/profile/InstrProfilingFile.c +++ b/compiler-rt/lib/profile/InstrProfilingFile.c @@ -380,11 +380,6 @@ static void truncateCurrentFile(void) { if (!Filename) return; - /* By pass file truncation to allow online raw profile - * merging. */ - if (lprofCurFilename.MergePoolSize) - return; - /* Only create the profile directory and truncate an existing profile once. * In continuous mode, this is necessary, as the profile is written-to by the * runtime initializer. */ @@ -397,8 +392,14 @@ static void truncateCurrentFile(void) { setenv(LPROF_INIT_ONCE_ENV, LPROF_INIT_ONCE_ENV, 1); #endif + /* Create the profile dir (even if online merging is enabled), so that + * the profile file can be set up if continuous mode is enabled. */ createProfileDir(Filename); + /* By pass file truncation to allow online raw profile merging. */ + if (lprofCurFilename.MergePoolSize) + return; + /* Truncate the file. Later we'll reopen and append. */ File = fopen(Filename, "w"); if (!File) @@ -406,6 +407,33 @@ static void truncateCurrentFile(void) { fclose(File); } +#ifndef _MSC_VER +static void assertIsZero(int *i) { + if (*i) + PROF_WARN("Expected flag to be 0, but got: %d\n", *i); +} +#endif + +/* Write a partial profile to \p Filename, which is required to be backed by + * the open file object \p File. */ +static int writeProfileWithFileObject(const char *Filename, FILE *File) { + setProfileFile(File); + int rc = writeFile(Filename); + if (rc) + PROF_ERR("Failed to write file \"%s\": %s\n", Filename, strerror(errno)); + setProfileFile(NULL); + return rc; +} + +/* Unlock the profile \p File and clear the unlock flag. */ +static void unlockProfile(int *ProfileRequiresUnlock, FILE *File) { + if (!*ProfileRequiresUnlock) { + PROF_WARN("%s", "Expected to require profile unlock\n"); + } + lprofUnlockFileHandle(File); + *ProfileRequiresUnlock = 0; +} + static void initializeProfileForContinuousMode(void) { #if defined(__Fuchsia__) || defined(_WIN32) PROF_ERR("%s\n", "Continuous mode not yet supported on Fuchsia or Windows."); @@ -438,28 +466,72 @@ static void initializeProfileForContinuousMode(void) { return; } - /* Open the raw profile in append mode. */ int Length = getCurFilenameLength(); char *FilenameBuf = (char *)COMPILER_RT_ALLOCA(Length + 1); const char *Filename = getCurFilename(FilenameBuf, 0); if (!Filename) return; - FILE *File = fopen(Filename, "a+b"); - if (!File) - return; - int Fileno = fileno(File); + FILE *File = NULL; + off_t CurrentFileOffset = 0; + off_t OffsetModPage = 0; + + /* Whether an exclusive lock on the profile must be dropped after init. + * Use a cleanup to warn if the unlock does not occur. */ + COMPILER_RT_CLEANUP(assertIsZero) int ProfileRequiresUnlock = 0; + + if (!doMerging()) { + /* We are not merging profiles, so open the raw profile in append mode. */ + File = fopen(Filename, "a+b"); + if (!File) + return; + + /* Check that the offset within the file is page-aligned. */ + CurrentFileOffset = ftello(File); + OffsetModPage = CurrentFileOffset % PageSize; + if (OffsetModPage != 0) { + PROF_ERR("Continuous counter sync mode is enabled, but raw profile is not" + "page-aligned. CurrentFileOffset = %" PRIu64 ", pagesz = %u.\n", + (uint64_t)CurrentFileOffset, PageSize); + return; + } - /* Check that the offset within the file is page-aligned. */ - off_t CurrentFileOffset = ftello(File); - off_t OffsetModPage = CurrentFileOffset % PageSize; - if (OffsetModPage != 0) { - PROF_ERR("Continuous counter sync mode is enabled, but raw profile is not" - "page-aligned. CurrentFileOffset = %" PRIu64 ", pagesz = %u.\n", - (uint64_t) CurrentFileOffset, PageSize); - return; + /* Grow the profile so that mmap() can succeed. Leak the file handle, as + * the file should stay open. */ + if (writeProfileWithFileObject(Filename, File) != 0) + return; + } else { + /* We are merging profiles. Map the counter section as shared memory into + * the profile, i.e. into each participating process. An increment in one + * process should be visible to every other process with the same counter + * section mapped. */ + File = lprofOpenFileEx(Filename); + if (!File) + return; + + ProfileRequiresUnlock = 1; + + uint64_t ProfileFileSize; + if (getProfileFileSizeForMerging(File, &ProfileFileSize) == -1) + return unlockProfile(&ProfileRequiresUnlock, File); + + if (ProfileFileSize == 0) { + /* Grow the profile so that mmap() can succeed. Leak the file handle, as + * the file should stay open. */ + if (writeProfileWithFileObject(Filename, File) != 0) + return unlockProfile(&ProfileRequiresUnlock, File); + } else { + /* The merged profile has a non-zero length. Check that it is compatible + * with the data in this process. */ + char *ProfileBuffer; + if (mmapProfileForMerging(File, ProfileFileSize, &ProfileBuffer) == -1 || + munmap(ProfileBuffer, ProfileFileSize) == -1) + return unlockProfile(&ProfileRequiresUnlock, File); + } } + int Fileno = fileno(File); + /* Determine how much padding is needed before/after the counters and after * the names. */ uint64_t PaddingBytesBeforeCounters, PaddingBytesAfterCounters, @@ -474,14 +546,6 @@ static void initializeProfileForContinuousMode(void) { CurrentFileOffset + sizeof(__llvm_profile_header) + (DataSize * sizeof(__llvm_profile_data)) + PaddingBytesBeforeCounters; - /* Write the partial profile. This grows the file to a point where the mmap() - * can succeed. Leak the file handle, as the file should stay open. */ - setProfileFile(File); - int rc = writeFile(Filename); - if (rc) - PROF_ERR("Failed to write file \"%s\": %s\n", Filename, strerror(errno)); - setProfileFile(NULL); - uint64_t *CounterMmap = (uint64_t *)mmap( (void *)CountersBegin, PageAlignedCountersLength, PROT_READ | PROT_WRITE, MAP_FIXED | MAP_SHARED, Fileno, FileOffsetToCounters); @@ -494,8 +558,9 @@ static void initializeProfileForContinuousMode(void) { " - FileOffsetToCounters: %" PRIu64 "\n", strerror(errno), CountersBegin, PageAlignedCountersLength, Fileno, FileOffsetToCounters); - return; } + + unlockProfile(&ProfileRequiresUnlock, File); #endif // defined(__Fuchsia__) || defined(_WIN32) } @@ -568,12 +633,6 @@ static int parseFilenamePattern(const char *FilenamePat, FilenamePat); return -1; } - if (MergingEnabled) { - PROF_WARN("%%c specifier can not be used with profile merging (%%m) " - "in %s.\n", - FilenamePat); - return -1; - } __llvm_profile_enable_continuous_mode(); I++; /* advance to 'c' */ @@ -583,12 +642,6 @@ static int parseFilenamePattern(const char *FilenamePat, FilenamePat); return -1; } - if (__llvm_profile_is_continuous_mode_enabled()) { - PROF_WARN("%%c specifier can not be used with profile merging (%%m) " - "in %s.\n", - FilenamePat); - return -1; - } MergingEnabled = 1; if (FilenamePat[I] == 'm') lprofCurFilename.MergePoolSize = 1; diff --git a/compiler-rt/lib/profile/InstrProfilingPort.h b/compiler-rt/lib/profile/InstrProfilingPort.h index d36539eb624..20cf5d660c6 100644 --- a/compiler-rt/lib/profile/InstrProfilingPort.h +++ b/compiler-rt/lib/profile/InstrProfilingPort.h @@ -22,6 +22,7 @@ /* Need to include <stdio.h> and <io.h> */ #define COMPILER_RT_FTRUNCATE(f,l) _chsize(_fileno(f),l) #define COMPILER_RT_ALWAYS_INLINE __forceinline +#define COMPILER_RT_CLEANUP(x) #elif __GNUC__ #define COMPILER_RT_ALIGNAS(x) __attribute__((aligned(x))) #define COMPILER_RT_VISIBILITY __attribute__((visibility("hidden"))) @@ -29,6 +30,7 @@ #define COMPILER_RT_ALLOCA __builtin_alloca #define COMPILER_RT_FTRUNCATE(f,l) ftruncate(fileno(f),l) #define COMPILER_RT_ALWAYS_INLINE inline __attribute((always_inline)) +#define COMPILER_RT_CLEANUP(x) __attribute__((cleanup(x))) #endif #if defined(__APPLE__) diff --git a/compiler-rt/test/profile/ContinuousSyncMode/online-merging.c b/compiler-rt/test/profile/ContinuousSyncMode/online-merging.c new file mode 100644 index 00000000000..d4298b4fe2b --- /dev/null +++ b/compiler-rt/test/profile/ContinuousSyncMode/online-merging.c @@ -0,0 +1,138 @@ +// Test the online merging mode (%m) along with continuous mode (%c). +// +// Create & cd into a temporary directory. +// RUN: rm -rf %t.dir && mkdir -p %t.dir && cd %t.dir +// +// Create two DSOs and a driver program that uses them. +// RUN: echo "void dso1(void) {}" > dso1.c +// RUN: echo "void dso2(void) {}" > dso2.c +// RUN: %clang_pgogen -dynamiclib -o %t.dir/dso1.dylib dso1.c +// RUN: %clang_pgogen -dynamiclib -o %t.dir/dso2.dylib dso2.c +// RUN: %clang_pgogen -o main.exe %s %t.dir/dso1.dylib %t.dir/dso2.dylib +// +// === Round 1 === +// Test merging+continuous mode without any file contention. +// +// RUN: env LLVM_PROFILE_FILE="%t.dir/profdir/%m%c.profraw" %run %t.dir/main.exe nospawn +// RUN: llvm-profdata merge -o %t.profdata %t.dir/profdir +// RUN: llvm-profdata show --counts --all-functions %t.profdata | FileCheck %s -check-prefix=ROUND1 + +// ROUND1-LABEL: Counters: +// ROUND1-DAG: dso1: +// ROUND1-DAG: Hash: 0x{{.*}} +// ROUND1-DAG: Counters: 1 +// ROUND1-DAG: Block counts: [1] +// ROUND1-DAG: dso2: +// ROUND1-DAG: Hash: 0x{{.*}} +// ROUND1-DAG: Counters: 1 +// ROUND1-DAG: Block counts: [1] +// ROUND1-DAG: main: +// ROUND1-DAG: Hash: 0x{{.*}} +// ROUND1-LABEL: Instrumentation level: IR +// ROUND1-NEXT: Functions shown: 3 +// ROUND1-NEXT: Total functions: 3 +// ROUND1-NEXT: Maximum function count: 1 +// ROUND1-NEXT: Maximum internal block count: 1 +// +// === Round 2 === +// Test merging+continuous mode with some file contention. +// +// RUN: env LLVM_PROFILE_FILE="%t.dir/profdir/%m%c.profraw" %run %t.dir/main.exe spawn 'LLVM_PROFILE_FILE=%t.dir/profdir/%m%c.profraw' +// RUN: llvm-profdata merge -o %t.profdata %t.dir/profdir +// RUN: llvm-profdata show --counts --all-functions %t.profdata | FileCheck %s -check-prefix=ROUND2 + +// ROUND2-LABEL: Counters: +// ROUND2-DAG: dso1: +// ROUND2-DAG: Hash: 0x{{.*}} +// ROUND2-DAG: Counters: 1 +// ROUND2-DAG: Block counts: [97] +// ROUND2-DAG: dso2: +// ROUND2-DAG: Hash: 0x{{.*}} +// ROUND2-DAG: Counters: 1 +// ROUND2-DAG: Block counts: [97] +// ROUND2-DAG: main: +// ROUND2-DAG: Hash: 0x{{.*}} +// ROUND2-LABEL: Instrumentation level: IR +// ROUND2-NEXT: Functions shown: 3 +// ROUND2-NEXT: Total functions: 3 +// ROUND2-NEXT: Maximum function count: 97 +// ROUND2-NEXT: Maximum internal block count: 33 + +#include <spawn.h> +#include <sys/wait.h> +#include <sys/errno.h> +#include <unistd.h> +#include <string.h> +#include <stdio.h> + +const int num_child_procs_to_spawn = 32; + +extern int __llvm_profile_is_continuous_mode_enabled(void); +extern char *__llvm_profile_get_filename(void); + +void dso1(void); +void dso2(void); + +// Change to "#define" for debug output. +#undef DEBUG_TEST + +#ifdef DEBUG_TEST +#define DEBUG(...) fprintf(stderr, __VA_ARGS__); +#else +#define DEBUG(...) +#endif + +int main(int argc, char *const argv[]) { + if (strcmp(argv[1], "nospawn") == 0) { + DEBUG("Hello from child (pid = %d, cont-mode-enabled = %d, profile = %s).\n", + getpid(), __llvm_profile_is_continuous_mode_enabled(), __llvm_profile_get_filename()); + + dso1(); + dso2(); + return 0; + } else if (strcmp(argv[1], "spawn") == 0) { + // This is the start of Round 2. + // Expect Counts[dsoX] = 1, as this was the state at the end of Round 1. + + int I; + pid_t child_pids[num_child_procs_to_spawn]; + char *const child_argv[] = {argv[0], "nospawn", NULL}; + char *const child_envp[] = {argv[2], NULL}; + for (I = 0; I < num_child_procs_to_spawn; ++I) { + dso1(); // Counts[dsoX] += 2 * num_child_procs_to_spawn + dso2(); + + DEBUG("Spawning child with argv = {%s, %s, NULL} and envp = {%s, NULL}\n", + child_argv[0], child_argv[1], child_envp[0]); + + int ret = posix_spawn(&child_pids[I], argv[0], NULL, NULL, child_argv, + child_envp); + if (ret != 0) { + fprintf(stderr, "Child %d could not be spawned: ret = %d, msg = %s\n", + I, ret, strerror(ret)); + return 1; + } + + DEBUG("Spawned child %d (pid = %d).\n", I, child_pids[I]); + } + for (I = 0; I < num_child_procs_to_spawn; ++I) { + dso1(); // Counts[dsoX] += num_child_procs_to_spawn + dso2(); + + int status; + waitpid(child_pids[I], &status, 0); + if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { + fprintf(stderr, "Child %d did not exit with code 0.\n", I); + return 1; + } + } + + // At the end of Round 2, we have: + // Counts[dsoX] = 1 + (2 * num_child_procs_to_spawn) + num_child_procs_to_spawn + // = 97 + + return 0; + } + + return 1; +} |
