pkmem: attempt to handle debug race conditions

1 files changed, 33 insertions, 12 deletions

diff --git a/pkmem.h b/pkmem.h
index e8e5714..a83aea5 100644
--- a/pkmem.h
+++ b/pkmem.h
@@ -163,13 +163,15 @@ static struct pk_membucket pk_buckets[PK_MAX_BUCKET_COUNT];
 static size_t pk_bucket_head = 0;
 
 #ifdef PK_MEMORY_DEBUGGER
+#include <stdatomic.h>
 struct pk_dbg_memblock {
 	struct pk_memblock blk;
 	struct pk_membucket *bkt;
 };
 static struct pk_dbg_memblock debug_all_allocs[1024 * 1024];
-static size_t debug_alloc_head = 0;
-static bool has_init_debug = false;
+static atomic_size_t debug_alloc_head = 0;
+static atomic_bool has_init_debug = false;
+static mtx_t debug_alloc_mtx;
 #endif
 
 bool
@@ -182,8 +184,13 @@ pk_memory_is_in_bucket(const void* ptr, const struct pk_membucket* bkt)
 void
 pk_memory_debug_print()
 {
+	size_t i, d;
+#ifdef PK_MEMORY_DEBUGGER
+	size_t count = 0;
+	size_t dah = debug_alloc_head;
+#endif
 	PK_LOGV_INF("Memory Manager printout:\nBucket count: %li\n", pk_bucket_head);
-	for (size_t i = 0; i < pk_bucket_head; ++i) {
+	for (i = 0; i < pk_bucket_head; ++i) {
 		PK_LOGV_INF("- bucket #%li\n", i);
 		PK_LOGV_INF("\tdescription:         %s\n", pk_buckets[i].description);
 		PK_LOGV_INF("\tsize:                %li\n", pk_buckets[i].size);
@@ -196,14 +203,13 @@ pk_memory_debug_print()
 		PK_LOGV_INF("\tptr:                 %p\n", (void *)pk_buckets[i].ptr);
 		PK_LOGV_INF("\ttransient:           %i\n", pk_buckets[i].transient);
 #ifdef PK_MEMORY_DEBUGGER
-		uint64_t count = 0;
-		for (size_t d = 0; d < debug_alloc_head; ++d) {
+		for (d = 0; d < dah; ++d) {
 			if (debug_all_allocs[d].bkt == &pk_buckets[d] && debug_all_allocs[d].blk.size > 0) {
 				count += 1;
 			}
 		}
 		PK_LOGV_INF("\tdebug alloc count:   %lu\n", count);
-		PK_LOGV_INF("\tdebug alloc last:    %lu\n", debug_alloc_head);
+		PK_LOGV_INF("\tdebug alloc last:    %lu\n", dah);
 #endif
 	}
 }
@@ -229,6 +235,11 @@ pk_memory_teardown_all()
 		pk_bucket_destroy(&pk_buckets[i - 1]);
 	}
 	pk_bucket_head = 0;
+#ifdef PK_MEMORY_DEBUGGER
+	debug_alloc_head = 0;
+	mtx_destroy(&debug_alloc_mtx);
+	has_init_debug = false;
+#endif
 }
 
 static int64_t
@@ -238,6 +249,7 @@ pk_bucket_create_inner(int64_t sz, bool transient, const char* description)
 #ifdef PK_MEMORY_DEBUGGER
 	if (has_init_debug == false) {
 		has_init_debug = true;
+		mtx_init(&debug_alloc_mtx, mtx_plain);
 		memset(debug_all_allocs, 0, sizeof(struct pk_dbg_memblock) * 1024 * 1024);
 	}
 #endif
@@ -283,6 +295,9 @@ void
 pk_bucket_destroy(struct pk_membucket* bkt)
 {
 	size_t i;
+#ifdef PK_MEMORY_DEBUGGER
+	size_t dah;
+#endif
 	for (i = 0; i < pk_bucket_head; ++i) {
 		if (&pk_buckets[i] == bkt) {
 			if (pk_bucket_head == i + 1)
@@ -302,9 +317,8 @@ pk_bucket_destroy(struct pk_membucket* bkt)
 	bkt->transient = false;
 	mtx_destroy(&bkt->mtx);
 #ifdef PK_MEMORY_DEBUGGER
-	size_t ii;
-	for (ii = debug_alloc_head+1; ii > 0; --ii) {
-		i = ii-1;
+	dah = debug_alloc_head;
+	for (i = dah; i > 0; --i) {
 		if (debug_all_allocs[i].bkt == bkt) {
 			debug_all_allocs[i].blk.data = NULL;
 			debug_all_allocs[i].blk.size = 0u;
@@ -317,7 +331,7 @@ void
 pk_bucket_reset(struct pk_membucket* bkt)
 {
 #ifdef PK_MEMORY_DEBUGGER
-	int64_t i;
+	size_t i;
 #endif
 	if (bkt->transient != true) {
 		PK_LOG_ERR("WARNING: pk_bucket_reset called on non-transient pk_membucket\n");
@@ -329,7 +343,7 @@ pk_bucket_reset(struct pk_membucket* bkt)
 	bkt->blocks->data = bkt->ptr;
 	bkt->blocks->size = bkt->size - (sizeof(struct pk_memblock) * bkt->maxBlockCount);
 #ifdef PK_MEMORY_DEBUGGER
-	for (i = debug_alloc_head; i > -1; --i) {
+	for (i = debug_alloc_head; i > 0; --i) {
 		if (debug_all_allocs[i].bkt == bkt) {
 			debug_all_allocs[i].blk.data = NULL;
 			debug_all_allocs[i].blk.size = 0u;
@@ -421,9 +435,10 @@ pk_new_bkt(size_t sz, size_t alignment, struct pk_membucket* bkt)
 	data = block->data + misalignment;
 #ifdef PK_MEMORY_DEBUGGER
 	bool handled = bkt->transient;
+	struct pk_dbg_memblock* mb = nullptr;
 	if (handled == false) {
 		for (i = 0; i < debug_alloc_head; ++i) {
-			struct pk_dbg_memblock* mb = &debug_all_allocs[i];
+			mb = &debug_all_allocs[i];
 			if (mb->bkt != NULL) continue;
 			assert((mb->blk.size == 0 || (void*)(mb->blk.data) != data) && "mem address alloc'd twice!");
 			if (mb->blk.size == 0) {
@@ -436,7 +451,9 @@ pk_new_bkt(size_t sz, size_t alignment, struct pk_membucket* bkt)
 		}
 	}
 	if (handled == false) {
+		mtx_lock(&debug_alloc_mtx);
 		i = debug_alloc_head++;
+		mtx_unlock(&debug_alloc_mtx);
 		debug_all_allocs[i].blk.data = (char*)data;
 		debug_all_allocs[i].blk.size = sz;
 		debug_all_allocs[i].bkt = bkt;
@@ -463,6 +480,8 @@ pk_new_bkt(size_t sz, size_t alignment, struct pk_membucket* bkt)
 		prevBlock->size += misalignment;
 		block->data += misalignment + sz;
 		block->size = 0; // if you make it here, afterSize has already been handled
+	} else {
+		assert(true == false && "this shouldn't happen");
 	}
 	bkt->allocs++;
 	assert(data >= bkt->raw && "allocated data is before bucket data");
@@ -529,6 +548,7 @@ pk_delete_bkt(const void* ptr, size_t sz, struct pk_membucket* bkt)
 #ifdef PK_MEMORY_DEBUGGER
 	size_t ii;
 	bool found = bkt->transient;
+	mtx_lock(&debug_alloc_mtx);
 	if (found == false) {
 		for (ii = debug_alloc_head; ii > 0; --ii) {
 			i = ii-1;
@@ -547,6 +567,7 @@ pk_delete_bkt(const void* ptr, size_t sz, struct pk_membucket* bkt)
 			}
 		}
 	}
+	mtx_unlock(&debug_alloc_mtx);
 	assert(found && "[pkmem.h] double free or invalid ptr");
 #endif
 	bkt->allocs--;