#include <time.h> #include <stdlib.h> #include <stdint.h> #include <assert.h> #include <string.h> #include <stdio.h> #include "../memcheck.h" // Test VALGRIND_CREATE_MEMPOOL_EXT features, the VALGRIND_MEMPOOL_METAPOOL and // VALGRIND_MEMPOOL_AUTO_FREE flags. // Also show that without these, having a custom allocator that: // - Allocates a MEMPOOL // - Uses ITSELF to get large blocks to populate the pool (so these are marked // as MALLOCLIKE blocks) // - Then passes out MALLOCLIKE blocks out of these pool blocks // Was not previously supported by the 'loose model' for mempools in memcheck // because it spotted these (correctly) as overlapping blocks (test case 3 // below). // The VALGRIND_MEMPOOL_METAPOOL says not to treat these as overlaps. // // Also, when one of these metapool blocks is freed, memcheck will not auto-free // the MALLOCLIKE blocks allocated from the meta-pool, and report them as leaks. // When VALGRIND_MEMPOOL_AUTO_FREE is passed, no such leaks are reported. // This is for custom allocators that destroy a pool without freeing the objects // allocated from it, because that is the defined behaviour of the allocator. struct pool { size_t allocated; size_t used; uint8_t *buf; }; struct cell { struct cell *next; char x[16 - sizeof(void*)]; }; static struct pool _PlainPool, *PlainPool = &_PlainPool; static struct pool _MetaPool, *MetaPool = &_MetaPool; #define N 10 #define POOL_BLOCK_SIZE 4096 #define NOISE_SIZE 256 // For easy testing, the plain mempool uses N allocations, the // metapool 2 * N (so 10 reported leaks are from the plain pool, 20 must be // from the metapool). static int MetaPoolFlags = 0; static int CleanupBeforeExit = 0; static int GenerateNoise = 0; static int NoiseCounter = 0; static struct cell *cells_plain[2 * N]; static struct cell *cells_meta[2 * N]; static unsigned char *noise[3 * N]; static char PlainBlock[POOL_BLOCK_SIZE]; static char MetaBlock[POOL_BLOCK_SIZE]; void create_meta_pool (void) { VALGRIND_CREATE_MEMPOOL_EXT(MetaPool, 0, 0, MetaPoolFlags); VALGRIND_MEMPOOL_ALLOC(MetaPool, MetaBlock, POOL_BLOCK_SIZE); MetaPool->buf = (uint8_t *) MetaBlock; MetaPool->allocated = POOL_BLOCK_SIZE; MetaPool->used = 0; /* A pool-block is expected to have metadata, and the core of valgrind sees a MALLOCLIKE_BLOCK that starts at the same address as a MEMPOOLBLOCK as a MEMPOOLBLOCK, hence never as a leak. Introduce such some simulated metadata. */ MetaPool->buf += sizeof(uint8_t); MetaPool->used += sizeof(uint8_t); } static void create_plain_pool (void) { VALGRIND_CREATE_MEMPOOL(PlainPool, 0, 0); PlainPool->buf = (uint8_t *) PlainBlock; PlainPool->allocated = POOL_BLOCK_SIZE; PlainPool->used = 0; /* Same overhead */ PlainPool->buf += sizeof(uint8_t); PlainPool->used += sizeof(uint8_t); } static void *allocate_meta_style (struct pool *p, size_t n) { void *a = p->buf + p->used; assert(p->used + n < p->allocated); // Simulate a custom allocator that allocates memory either directly for // the application or for a custom memory pool: All are marked as MALLOCLIKE. VALGRIND_MALLOCLIKE_BLOCK(a, n, 0, 0); p->used += n; return a; } static void *allocate_plain_style (struct pool *p, size_t n) { void *a = p->buf + p->used; assert(p->used + n < p->allocated); // And this is custom allocator that knows that it is allocating from a pool. VALGRIND_MEMPOOL_ALLOC(p, a, n); p->used += n; return a; } /* flags */ static void set_flags ( int n ) { switch (n) { // Case 0: No special flags. VALGRIND_CREATE_MEMPOOL_EXT is same as // VALGRIND_CREATE_MEMPOOL. // When mempools are destroyed, the METAPOOL leaks because auto-free is // missing. Must show 2*N (20) leaks. // The VALGRIND_MEMPOOL_ALLOC items from the plain pool are automatically // destroyed. CleanupBeforeExit means the metapool is freed and destroyed // (simulating an app that cleans up before it exits), and when false it // simply exits with the pool unaltered. case 0: MetaPoolFlags = 0; CleanupBeforeExit = 1; break; // Case 1: VALGRIND_MEMPOOL_METAPOOL, no auto-free. // Without explicit free, these MALLOCLIKE_BLOCK blocks are considered // leaks. So this case should show same as case 0: 20 leaks. case 1: MetaPoolFlags = VALGRIND_MEMPOOL_METAPOOL; CleanupBeforeExit = 1; break; // Same as before, but now the MALLOCLIKE blocks are auto-freed. // Must show 0 leaks. case 2: MetaPoolFlags = VALGRIND_MEMPOOL_METAPOOL | VALGRIND_MEMPOOL_AUTO_FREE; CleanupBeforeExit = 1; break; case 3: // Note: this is incorrect behaviour, and aborts valgrind. // (so it is not exercised during regression testing). // Just auto-free, not marked with meta pool flag. // This is an error, and will cause valgrind to abort when the pool // is created. MetaPoolFlags = VALGRIND_MEMPOOL_AUTO_FREE; CleanupBeforeExit = 1; break; case 4: // No auto-free, no cleanup. Leaves overlapping blocks detected // by valgrind, but those are ignored because of the METAPOOL. // So, no crash, no problems, but 20 leaks. MetaPoolFlags = VALGRIND_MEMPOOL_METAPOOL; CleanupBeforeExit = 0; break; case 5: // Main reason for the VALGRIND_MEMPOOL_METAPOOL flags: When not // specified, and the application has a memorypool that has MALLOC_LIKE // overlapping allocations, that leaves block(s) that overlap. // Causes a fatal error. // The METAPOOL allows the overlap. Test must show that without that // flag, a fatal error occurs. MetaPoolFlags = 0; CleanupBeforeExit = 0; break; case 6: // Test the VG_(HT_remove_at_Iter)() function, which removes a chunk // from a hashlist without the need to reset the iterator. The pool // is auto_freed, and the best test for the function (besides the ones // already done above) is by allocating lots of other chunks that are // NOT part of the pool so the MC_Alloc lists contain other stuff. // That will make the iterator find stuff AND skip stuff. MetaPoolFlags = VALGRIND_MEMPOOL_METAPOOL | VALGRIND_MEMPOOL_AUTO_FREE; CleanupBeforeExit = 1; GenerateNoise = 1; break; default: assert(0); } } static void GenerateNoisyBit (void) { // In case the HT_remove_at_Iter messes up the administration, the wrong // blocks may be deleted from the list, making access to these noise-blocks // invalid. So fill 256-byte blocks with easily tested contents. noise[NoiseCounter] = malloc(NOISE_SIZE); assert(noise[NoiseCounter] != NULL); memset(noise[NoiseCounter],(unsigned char) (NoiseCounter % 256), NOISE_SIZE); NoiseCounter++; } static void CheckNoiseContents (void) { int i; for (i = 0; i < NoiseCounter; i++) { unsigned char Check = (unsigned char) ( i % 256); int j; for (j = 0; j < NOISE_SIZE; j++) { assert(noise[i][j] == Check); } } } int main( int argc, char** argv ) { int arg; size_t i; assert(argc == 2 || argc == 3); assert(argv[1]); assert(strlen(argv[1]) == 1); assert(argv[1][0] >= '0' && argv[1][0] <= '9'); arg = atoi( argv[1] ); set_flags( arg ); create_plain_pool(); create_meta_pool(); // N plain allocs for (i = 0; i < N; ++i) { cells_plain[i] = allocate_plain_style(PlainPool,sizeof(struct cell)); if (GenerateNoise) GenerateNoisyBit(); } // 2*N meta allocs for (i = 0; i < 2 * N; ++i) { cells_meta[i] = allocate_meta_style(MetaPool,sizeof(struct cell)); if (GenerateNoise) GenerateNoisyBit(); } // Leak the memory from the pools by losing the pointers. for (i = 0; i < N; ++i) { cells_plain[i] = NULL; } for (i = 0; i < 2 * N; ++i) { cells_meta[i] = NULL; } if (GenerateNoise) CheckNoiseContents(); // This must free MALLOCLIKE allocations from the pool when // VALGRIND_MEMPOOL_AUTO_FREE // is set for the pool and report leaks when not. if (CleanupBeforeExit) { VALGRIND_MEMPOOL_FREE(MetaPool, MetaBlock); if (GenerateNoise) CheckNoiseContents(); VALGRIND_DESTROY_MEMPOOL(MetaPool); if (GenerateNoise) CheckNoiseContents(); } // Cleanup. VALGRIND_DESTROY_MEMPOOL(PlainPool); if (GenerateNoise) CheckNoiseContents(); // Try to trigger an error in the bookkeeping by freeing the noise bits. // Valgrind should report no leaks, and zero memory in use. If the // new HT_remove_at_Iter function would corrupt the bookkeeping in any // way, this should bring it out! if (GenerateNoise) { for (i = 0; i < NoiseCounter; i++) free(noise[i]); } // Perf test if (argc == 3) { struct pool perf_plain_pool; void *perf_plain_block; struct pool perf_meta_pool; void *perf_meta_block; size_t pool_block_size; int n; int nr_elts = atoi( argv[2] ); time_t dnow; #define tprintf(...) (dnow = time(NULL), \ printf(__VA_ARGS__), \ printf(" %s", ctime(&dnow))) pool_block_size = nr_elts * sizeof(struct cell) + sizeof(uint8_t) + 1; // Create perf meta pool VALGRIND_CREATE_MEMPOOL_EXT (&perf_meta_pool, 0, 0, VALGRIND_MEMPOOL_METAPOOL | VALGRIND_MEMPOOL_AUTO_FREE); perf_meta_block = malloc(pool_block_size); VALGRIND_MEMPOOL_ALLOC(&perf_meta_pool, perf_meta_block, pool_block_size); perf_meta_pool.buf = (uint8_t *) perf_meta_block; perf_meta_pool.allocated = pool_block_size; perf_meta_pool.used = 0; perf_meta_pool.buf += sizeof(uint8_t); perf_meta_pool.used += sizeof(uint8_t); // Create perf plain pool VALGRIND_CREATE_MEMPOOL(&perf_plain_pool, 0, 0); perf_plain_block = malloc(pool_block_size); perf_plain_pool.buf = (uint8_t *) perf_plain_block; perf_plain_pool.allocated = pool_block_size;; perf_plain_pool.used = 0; perf_plain_pool.buf += sizeof(uint8_t); perf_plain_pool.used += sizeof(uint8_t); tprintf("allocating %d elts", nr_elts); for (n = 0; n < nr_elts; n++) { (void) allocate_meta_style (&perf_meta_pool, sizeof(struct cell)); (void) allocate_plain_style (&perf_plain_pool, sizeof(struct cell)); } tprintf("freeing mempool"); VALGRIND_MEMPOOL_FREE(&perf_meta_pool, perf_meta_block); tprintf("destroying mempool"); VALGRIND_DESTROY_MEMPOOL(&perf_meta_pool); tprintf("done"); } return 0; }